Дисертації: "Sewage Purification Heavy metal removal"

1

Shetty, Ameesha R. "Metal anion removal from wastewater using chitosan in a polymer enhanced diafiltration system." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-115241/.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Gu, Xiangyang. "Improving heavy metal bioleaching efficiency through microbiological control of inhibitory substances in anaerobically digested sludge." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/504.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Andersson, Eva Lotta. "Analysis of Various Bioreactor Configurations for Heavy Metal Removal Using the Fungus Penicillium ochro-chloron." Digital WPI, 2000. https://digitalcommons.wpi.edu/etd-theses/814.

Повний текст джерела

Анотація:

Penicillium ochro-chloron (ATCC strain # 36741), a filamentous fungus with the capability for removing copper ions from aqueous solutions, was studied as a possible biological trap (biotrap) for remediation of heavy metal contaminants in industrial wastewaters. This research demonstrated that in shake flasks the fungus removed copper from surrogate wastewater with 100mg/L copper contamination by as much as 99%. These results did not translate to the bioreactor configuration of a packed bed column, as channeling occurred through the bed, shown by conductivity tracer studies. A fluidized bed configuration was studied and resulted in copper removal of 97%, with a capacity of 149 mg[Cu]/g dry weight biomass, under the conditions of 50% dissolved oxygen. For dissolved oxygen concentrations below the critical oxygen concentration for the fungus (20% saturation) there was minimal copper removal. Mixing studies in the fluidized bed reactor showed that the system was diffusion limited. Mathematical modeling using first order kinetics associated with diffusion limited reactions resulted in rate constants for Cu 2+ uptake of approximately 0.031 h -1 , which were dependent on the dissolved oxygen concentration. Modeling of the reaction with a second order kinetic equation showed that there are possibly factors regulating copper uptake besides oxygen. Electron microscopy showed that in some instances the copper removed was retained as large porous spherical extracellular precipitates. Energy Dispersive X-ray (EDX) analysis has shown similar complexes to be copper phosphate precipitates (Crusberg, 1994). Removal of heavy metal contaminants from wastewater discharge is a necessity for many industries, due to environmental concerns and federal regulations. The use of a biological system for the removal and recycling of heavy metals could prove more economical than currently used physio-chemical processes.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Chan, Lau Chi. "Bioleaching of heavy metals from anaerobically digested sewage sludge using isolated indigenous iron- and sulphur-oxidizing bacteria." HKBU Institutional Repository, 2001. http://repository.hkbu.edu.hk/etd_ra/279.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Rappaport, Bruce D. "Availability and distribution of heavy metals from sewage sludge in the plant-soil continuum." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/71177.

Повний текст джерела

Анотація:

An investigation was conducted using in situ lysimeters (1.5 m x 2.3 m) to determine Cd, Cu, Ni, and Zn availabilities for barley (Hordeum vulgare L.) and corn (Zea mays L.) grown on four sludge-amended soils. These lysimeters were constructed in Acredale silt loam (Typic Ochraqualf), Bojac loamy sand (Typic Hapludult), Davidson clay loam (Rhodie Paleudult), and Groseclose silt loam (Typic Hapludult) soils. An aerobically digested sewage sludge from a sewage system with major industrial inputs was applied at rates of 0, 42, and 84 dry Mg ha-t to the lysimeters in the poorly-drained Acredale soil. Rates of 0, 42, 84, 126, 168, and 210 dry Mg ha-1 were applied to the lysimeters in the well-drained Bojac, Davidson, and Groseclose soils. Tissue metal concentrations were determined in 1984 and 1985 for a three crop rotation, which consisted of corn, barley, and corn on the Acredale soil. Increases in sludge-borne Ni and Zn led to increases in Ni and Zn concentrations in corn earleaf, corn grain, and barley silage. Copper concentration was increased in barley silage but not in corn grain and stover. On this poorly-drained soil, metal movement did not occur below the Ap horizon even when Cu was applied in excess of USEPA guidelines. Although there were increases in metal levels, all four metals were within the range considered normal for corn and barley growth. Soil, corn, and barley plants were sampled in 1984 and 1985 to determine Cd, Cr, Cu, Ni, and Zn availabilities for crops grown on the sludge-amended Bojac, Davidson, and Groseclose soils. Levels of DTPA-extractable Cd, Cu, Ni, and Zn in the Ap horizon of these soils increased linearly with sludge rate. Corn grain and stover yields were not decreased on the Bojac, Davidson, and Groseclose soils when 4.5, 5105, 760, 43.0, 135, and 620 kg ha-1 of Cd, Cr, Cu, Ni, Pb, and Zn were added as a sludge-amendment. Copper and Zn applied in excess of 480 and 60 kg ha- 1 of USEPA guidelines, respectively on the Bojac, Davidson, and Groseclose soils were not phytotoxic to corn plants in 1984. Corn and barley tissue sampled for three consecutive seasons had Cr concentrations <2.8 mg kg-1.
Ph. D.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Ginige, Pushpa. "Decontamination of biosolids for land application : metals bioleaching and process impacts on the nutrient value of biosolids." Thesis, Queensland University of Technology, 1998.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Wilhelmi, Brendan Shane. "The removal and recovery of toxic and valuable metals from aqueous solutions by the yeast Saccharomyces cerevisiae." Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1004062.

Повний текст джерела

Анотація:

This project considered the use of the yeast Saccharomyces cerevisiae as a biosorbent for the removal and recovery of a range of metals from contaminated waters. S. cerevisiae, as a biosorbent, has the potential to provide a cost effective, selective and highly efficient purification system. Initial studies focused on metal accumulation by an immobilized baker's S. cerevisiae biosorbent. The parameters affecting metal uptake were investigated, these included metal concentration, time and solution pH. Metal uptake was rapid. Gold and cobalt reached saturation within 5 min of contact with the biosorbent in batch reactors. Copper, zinc, nickel, cadmium and chromium reached saturation within 30 min of contact. Metal accumulation was pH dependent and was generally unaffected at a solution pH ≥ 4, and was substantially decreased at pH ≤ 2. The exception was gold which was preferentially accumulated at a solution pH of 2. The immobilized baker's yeast accumulated metals with maximum binding capacities in the order of gold > cadmium > cobalt > zinc > copper > chromium > nickel. A rapid method to assess metal recovery was developed. Bioaccumulated metal was efficiently recovered using dilute mineral acids. Copper recovery of ≥ 80 % was achieved by decreasing the solution pH of the reaction mixture to 2 with the addition of nominal quantities of HCl, H₂SO₄ or RNO₃. Adsorption-desorption over 8 cycles had no apparent adverse effect on metal uptake or recovery in batch reactors. Transmission electron microscopy showed no evidence of damage to cells used in copper adsorption-desorption investigations. Biosorption columns were investigated as bioreactors due to their application potential. The metals investigated were effectively removed from solution. At a saturation threshold, metal uptake declined rapidly. Most metals investigated were desorbed from the columns by eluting with 0.1 M HCl. Initially recoveries of copper, cobalt and cadmium were as high as 100%. Desorbed copper, zinc, cadmium, nickel and cobalt were concentrated in 10 to 15 ml of eluent, representing up to a 40 fold decrease in solution volume. Cadmium, nickel and zinc uptake increased with the second application to the columns. Initial accumulation of gold and chromium was 42.2 μmol/g and 28.6 μmol/g, however, due to the low recoveries of these two metals, a second application was not investigated. Copper was applied to a single column for 8 consecutive adsorption-desorption cycles. Uptake increased from an initial 31.3 μmol/g to 47.8 μmol/g at cycle 7. The potential for selective metal recovery was demonstrated using two biosorption columns in series. Copper was accumulated and recovered most efficiently. Zinc, cobalt and cadmium were displaced to the second column. Copper bound preferentially to zinc at a ratio of 6:1. Copper bound preferentially to cobalt at a ratio of 4:1. Cadmium was only displaced at a ratio of 2:1. The successful transfer of the bioremediation technology from the laboratory to an industrial application has yet to be realized. Bioremediation of a Plaatjiesvlei Black Mountain mine effluent, which contained copper, zinc, lead and iron, was investigated in this project. The removal of the metals was most effective at pH 4. A combined strategy of pH adjustment and bioremediation using immobilized S. cerevisiae decreased the copper concentration by 92.5%, lead was decreased by 90% and zinc was decreased by 60%. Iron was mostly precipitated from solution at pH ≥ 4. An ageing pond at the mine with conditions such as; pH, water volume and metal concentration, which were more conducive to biological treatment was subsequently identified. The investigation indicated a possible application of the biomass as a supplement to chemical remediation. The metal removal capability of a waste brewer's yeast was subsequently investigated. A yeast conditioning step increased metal uptake up to 100% and enhanced reproducibility. Metal removal from solution was rapid and pH dependent. The metals were efficiently removed from solution at pH ≥ 4. Uptake was substantially inhibited at pH ≤ 3. The waste brewer's yeast accumulated metals with maximum binding capacities in the order of copper (25.4 μmol/g) > lead (19.4 μmol/g) > iron (15.6 μmol/g) > zinc (12.5 μmol/g). No correlation between cell physiology and metal uptake was observed. Uptake of the four metals was confirmed by energy dispersive X-ray microanalysis. The interference of lead, zinc and iron on copper uptake by the waste brewer's yeast, and the interference of copper on the uptake of lead, zinc and iron was investigated. Maximum copper uptake was not decreased in the presence of lead. The Bmax remained constant at approximately 25 μmol/g. The dissociation constants increased with increasing lead concentrations. Lead bioaccumulation was significantly decreased in the presence of copper. The type of inhibition was dependent on the initial copper concentrations. Zinc had a slight synergistic effect on copper uptake. The copper Bmax increased from 30.8 μmol/g in a single-ion system to 34.5 μmol/g in the presence of 200 μmol/l of zinc. Zinc uptake was severely inhibited in the presence of copper. The maximum uptake and dissociation constant values were decreased in the presence of copper, which suggested an uncompetitive inhibition. The affinity of copper was substantially higher than zinc. The presence of higher levels of copper than zinc in the yeast cells was confirmed by energy dispersive microanalysis. Copper uptake was decreased in the presence of iron, with the copper Bmax being decreased from 25.4 μmol/g in a single-ion system to 20.1 μmol/g in the presence of 200 μmol/l iron. Iron Bmax values remained constant at 16.0 μmol/g. Combined biosorption and EDXA results suggested the iron bound at a higher affinity than copper to the cell wall. Total copper removal was higher as larger quantities of copper were deposited in the cell cytoplasm. Metal removal from the Plaatjiesvlei effluent by free cell suspensions of the waste brewer's yeast was satisfactory. Copper levels were decreased by 96%, iron by 42%, lead 25% and zinc 2%. Waste brewer's yeast is a cheap source of biomass in South Africa, and could potentially provide the basis for the development of an innovative purification system for metal-contaminated waters.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Yang, Die Daisy, and 楊蝶. "Development of polymers for electroplating waste water purification, polymer-supported reagents for organic synthesis and heterogeneouscatalysts for aerobic alcohol oxidation reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39848887.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Clements, William H. "Community responses of aquatic macroinvertebrates to heavy metals in laboratory and outdoor experimental streams." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53937.

Повний текст джерела

Анотація:

This research describes aquatic macroinvertebrate community responses to heavy metals (copper, zinc) in experimental streams and at metal-impacted sites in the field. Experiments employed substrate-filled trays which were colonized in the field and then transferred to laboratory or outdoor streams. Laboratory experiments conducted over three seasons showed that acute (96 h) exposure to copper (Cu) at 15-32 μg Cu/L significantly reduced macroinvertebrate abundance and number of taxa during each season. Owing to differences in sensitivity among taxa, the percent composition of dominant groups varied between control and dosed streams. Mayflies were quite sensitive to Cu, particularly during the summer when water temperatures were higher. Community responses to Cu and Zn in outdoor experimental streams were similar to those observed at metal-impacted sites in the field. Control streams and field reference Stations were dominated by mayflies and Tanytarsini chironomids. In contrast, treated Streams and impacted field sites were dominated by net-Spinning caddisflies (Hydropsychidae) and Orthocladiini chironomids. The similarity of these experimental results to those observed in the field suggest that macroinvertebrate community responses to heavy metals are highly predictable. Responses of these communities to Cu were greatly influenced by water quality. Effects were more severe in New River Streams, where water hardness and alkalinity were low, compared to Clinch River Streams, where hardness and alkalinity were higher. In soft water Streams, abundance was reduced by 84% after 10 d exposure to Cu (measured concentration = 13 μg/L). In contrast, abundance was reduced by only 45% in hard water Streams after 10 d at Similar Cu levels. These results demonstrate the importance of accounting for water quality characteristics of receiving systems when establishing site-specific criteria for metals. Chronic exposure (14 d) to sublethal levels of Cu (< 6 μg/L) increased Vulnerability of caddisflies (Hydropsyche morosa and Chimarra sp.) to predation by the Stonefly, Paragnetina fumosa. Caddisflies were also the major component of stonefly diets and were consumed Significantly more frequently in dosed Streams than controls. These results demonstrate that single Species bioassays were inadequate for predicting effects of toxicants on community level processes.
Ph. D.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Heudiard, Alban. "Surexpression de métallothionéines dans Nicotiana plumbaginifolia: impact sur l'homéostasie et la détoxication des métaux lourds." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210591.

Повний текст джерела

Анотація:

A des concentrations supra-optimales, les métaux lourds essentiels (comme le Cu, Zn ou Ni) ou les métaux lourds non essentiels (comme le Cd, Pb ou Hg) peuvent être toxiques. La contamination des sols et de l’eau par des métaux lourds toxiques est un problème mondial qui peut nuire à l’environnement et à la santé humaine. En particulier, le cadmium est l’un des métaux lourds les plus toxiques pour les organismes. L’utilisation de plantes pour extraire ou dégrader les polluants (dans le cas de polluants organiques) constitue une stratégie intéressante, à bas coût et respectueuse de l’environnement pour remédier au problème des sites pollués. Pour une phytoextraction des métaux lourds, les plantes doivent avoir une croissance rapide, développer des biomasses importantes et accumuler des niveaux élevés de métaux lourds dans leurs parties récoltables. En d’autres termes, elles doivent être très tolérantes et accumulatrices. Une alternative consiste à utiliser des plantes tolérantes de façon à contenir la pollution (pour réduire la biodisponibilité et limiter la dispersion dans l’environnement). Des gènes d’une banque d’ADNc synthétisée à partir d’un hyperaccumulateur Cd/Zn Thlaspi caerulescens, dont l’expression augmente la tolérance au Cd dans les cellules, ont été identifiés. Dans cette thèse de Doctorat, notre but est d’une part de contribuer à la caractérisation fonctionnelle de ces gènes et d’autre part de créer de nouveaux outils en vue d’améliorer les techniques de phytoremédiation. Nous avons sélectionné deux séquences codant pour des protéines riches en cystéines, capables de lier certains métaux lourds et d’augmenter la tolérance au cadmium :une métallothionéine de type 3 (Tc-MT3) et une métallothionéine potentielle (MRP) provenant d’un organisme contaminant de la banque d’ADNc. Nous avons générer des lignées de tabac exprimant TcMT3 ou MRP, sous le contrôle d’un promoteur fort et constitutif, CaMV35S. Les plantes MT3 et MRP ont présenté un retard de croissance par rapport aux plantes contrôles, en croissance sur milieu non contaminé. Différents tests de croissance ont été réalisés en présence d’excès de Zn, Ni ou Cu et dans des milieux modifié avec du Cd. Nous avons remarqué qu’en présence de plusieurs métaux lourds en particulier le Cu et le Cd, les plantes Tc-MT3 et MRP étaient plus tolérantes que les plantes contrôles. La tolérance au Cd était la plus augmentée dans les plantes MRP. Les plantes Tc-MT3 ou MRP semblaient avoir un besoin en métaux lourds plus grand. L’accumulation des métaux lourds dans les parties aériennes n’était pas augmentée mais la minéralomasse des plantes Tc-MT3 et MRP l’était sur sol contaminé de la Région Bruxelloise. Une analyse biochimique a confirmé un changement dans le statu rédox de ces plantes. Une tendance à un statut plus oxydant a été observée dans les milieux non contaminés. Enfin, l’induction d’une métallochaperonne (CCH) du Cu indique une diminution de la biodisponibilité de cet élément, alors que la concentration totale n’est pas altérée. Il semble donc que pour la première fois, des métallothionéines puissent entrer en compétition avec une métallochaperonne végétale. Cette compétition pour les métaux pourrait être à l’origine de l’altération du statut rédox, du retard de croissance ainsi que de la meilleure tolérance aux métaux lourds.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Hendricks, Nicolette Rebecca. "The application of high capacity ion exchange absorbent material, synthesized from fly ash and acid mine drainage, for the removal of heavy and trace metals from secondary co-disposed process waters." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&amp.

Повний текст джерела

Анотація:

The objective of this study was to investigate the feasibility of the application of low cost high capacity inorganic ion exchange material, synthesized form collected fly ash and acid mine drainage solid residues, for the decontamination of secondary co-disposal process waters, with emphasis on investigating the processes governing the solid/solution interface.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Nordin, Andreas. "Heavy metal removal from sewage sludge by pyrolysis treatment." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-8807.

Повний текст джерела

Анотація:

Sewage sludge is the product from wastewater treatment that mostly is considered as a waste material. However, it contains several nutrients, especially phosphorus, potassium and nitrogen which are excellent fertilizers. The downside is the harmful content it also carries with pathogens, heavy metals and a variety of organic pollutants that in many cases have unknown effects on the ecosystem. A possible solution to this problem could be to pyrolyse the sewage sludge and by that decrease the levels of heavy metals and also render both pathogens and organic pollutants harmless. In this thesis project pyrolysis of dried sewage sludge has been evaluated at temperatures 650 750, 850 and 950 °C with addition of chlorine in the form of PVC and straw. An energy balance for pyrolysis and drying of dewatered sewage sludge has also been suggested. The results of the pyrolysis evaluation indicate that cadmium concentration can be reduced significantly with increasing temperature in the product char. But also other heavy metals like lead and zinc are affected at the higher temperatures evaluated. Mercury is completely removed from the char residue. The more latent volatile metals copper, chromium and nickel cannot be reduced to lower concentrations at these temperatures. They are instead enriched under these conditions. Chlorine addition to the sludge enhances the evaporation of all heavy metals but copper, nickel and chromium. The energy balance over the system indicates that the drying process requires more energy than is released from the sludge into the pyrolysis gases. The energy carried by the pyrolysis gases is however larger than what is required to drive the pyrolysis process.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Kulati, Thanduxolo Cullinan. "Evaluation of physiochemical qualities and heavy metal levels of the final effluents of some wastewater treatment facilities in the Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/1547.

Повний текст джерела

Анотація:

Water is the most abundant substance in nature and vital for life activities. The major water sources for use are surface water bodies such as rivers and lakes, and underground aquifers and pore spaces down the water table (Ring, 2003). Water derived from these sources is not necessarily pure since it contains dissolved inorganic and organic substances, living organisms (viruses, bacteria, etc). For these reasons, water intended for domestic uses should be free from toxic substances and microorganisms that are of health significance (WHO, 2005). The availability and quality of water always have played an important role in determining the quality of life. Water quality is closely linked to water use and to the state of economic development (Chennakrishnan et al., 2008). Ground and surface waters can be contaminated by several sources. In urban areas, the careless disposal of industrial effluents and other wastes may contribute greatly to the poor quality of water (Mathuthu et al., 1997). In most developing countries, most areas are located on the watersheds which are the end points of effluents discharged from various industries (Oberholster and Ashton, 2008). South Africa, as a developing country, is experiencing rapid demographic changes due to urbanization, industrialization and population growth. The country has also been identified as being water-scarce, which can lead to a challenge of meeting the increasing water demand due to industrialization and urbanization. Such population growth increase may result in an increase in wastewater output, especially around urban areas.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Mack, Cherie-Lynn. "Screening of technologies for the recovery of rhodium (III) metal ions from a precious metal refinery wastewater." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1004046.

Повний текст джерела

Анотація:

The selective recovery of rhodium from wastewaters, in which the metal would be otherwise lost, would be highly profitable if the process were suitably low-cost. Current recovery processes are generally high maintenance and high-cost, whereas biological processes can be engineered to run with little external input in terms of cost and maintenance. Three emerging technologies were chosen based on their reported efficiency when removing base metals from wastewaters. The first technology screened, the sulphide-extraction membrane bioreactor (SEMB), consists of a sulphate-reducing prokaryote (SRP) anaerobic digester, in which a silicone membrane is submerged. Wastewater is passed through the membrane and metal ions are precipitated as metal sulphides by the hydrogen sulphide gas, which is capable of permeating the membrane. The second technology screened was a fluidized sand bed reactor in which metal ions are removed from solution via induction of nucleated precipitation by sodium carbonate onto the sand grains. The third, and most well established removal technology screened was a biosorption system using immobilized Saccharomyces cerevisiae biomass as the biosorbent. Experimental trials with each technology highlighted drawbacks with each; the SEMB system proved to be largely ineffective when challenged with the removal of rhodium from the wastewater as the rhodium precipitate fouled the membrane within hours, the fluidized bed system seemed unable to overcome the acidity of the wastewater and thus could not precipitate out the rhodium metal, and the efficiency of the biosorption process was hampered by the diversity of rhodium species present in the wastewater, which reduced the amount recovered. The outcomes of the trials with each technology indicated that further optimization of the technology or pretreatment of the wastewater is necessary before any of these options can be implemented. It could be concluded, however, that despite further optimization, both the SEMB and the fluidized bed system were not applicable in this case as precipitation would be non-specific, resulting in the necessity for further steps in order to purify the rhodium ions. Hence, the biosorption system was shown to be most applicable, and further optimization of the system could yield a highly efficient rhodium recovery process.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Rusin, Patricia Anne. "Antibiotic resistance, heavy metal resistance, chlorine resistance and phage typing patterns of fecal coliforms isolated from secondary effluent." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184925.

Повний текст джерела

Анотація:

Antibiotic resistance profiles of fecal coliform isolated from unchlorinated and chlorinated secondary effluent were determined. Of 332 fecal coliforms isolated from chlorinated effluent a mean of 48% were multiply antibiotic resistant. In contrast, of 347 fecal coliforms isolated from unchlorinated effluent a mean of 29% were multiply antibiotic resistant. Resistance to ampicillin, cephalothin, and carbenicillin were significantly higher in the former than the latter. Randomly selected isolates survived and/or grew in sterile and unsterile effluent retaining resistance patterns for 40 days. Resistance factors were transferred in laboratory medium at frequencies from 0 to 1.2 x 10⁻² (number of recombinants/number of recipients) and in sterile neutralized tertiary effluent at frequencies from 0 to 1.0 x 10⁻⁴. Resuscitative techniques were necessary for optimal recovery of fecal coliforms from effluent using selective media. Antibiotic resistance patterns of fecal coliforms isolated from unchlorinated and chlorinated effluent was not associated with chlorine or heavy metal resistance. Multiply antibiotic resistant fecal coliforms from chlorinated effluent were significantly less sensitive to lytic phage than multiply antibiotic sensitive fecal coliforms from unchlorinated effluent (p < .05). Using group discriminate analysis of data, phage typing techniques were shown to be a potential tool for tracing fecal contamination of groundwater.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Agoro, Mojeed Adedoyin. "Evaluation of the physicochemical qualities and heavy metal regimes of the final effluents of some wastewater treatment facilties in Berlin, Alice and Bedford communities in the Eastern Cape, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/5003.

Повний текст джерела

Анотація:

Wastewater treatment facilities have been identified as potential source of surface water pollution worldwide. In this study, the physicochemical qualities and heavy metal (including Zinc, Cadmium, Iron, Lead and Copper) concentrations in the final effluents, as well as the reduction efficiencies of three municipal wastewater plants in the Eastern Cape, South Africa were evaluated from September 2015 to February 2016 using standard methods. Wastewater effluent and sludge samples were collected from the selected plants on monthly basis over a period of six months from September 2015 to February 2016. Standard analytical method (Atomic absorption spectroscopy [AAS]) was used to assess the concentration levels of heavy metals. The physicochemical parameters assessed include pH, Temperature, Total Dissolved Solid, Turbidity, Biochemical Oxygen Demand, Chemical Oxygen Demand, Alkalinity, Dissolved Oxygen, Free chlorine, Chloride, Sulphate, Phosphate, Ammonium and Electrical Conductivity. The results of the evaluation showed that temperature ranges from 19 to 36 °C, Electrical Conductivity from 60-1095 mS/m, Alkalinity from 2.6-20.9 mg/L, Nitrate from 0.24-26.5 mg/L, Nitrite from 0.01-90 mg/L, Phosphate from 0.02-5.12 mg/L, Ammonium from 0.06-112 mg/L, Sulphate from 3-72 mg/L, Chloride from 3.25-224 mg/L, Chemical Oxygen Demand from 17-394 mg/L and Turbidity from 1.96-715 NTU. Free chlorine concentrations and dissolved oxygen were within the recommended limits for most part of the sampling period and ranged between 0.17-0.48 mg/L and 0.19-21.9 mg/L respectively. The pH, Phosphate, Sulphate and Free chlorine were within acceptable limits while Electrical Conductivity, Temperature, Total Dissolved Solid, Turbidity, Chemical Oxygen Demand, Chloride, Ammonium, Nitrate and Nitrite were not within specified limits. The reduction efficiencies observed generally ranged between 43.9 and 100 percent at all sampling points while zinc and lead were not detected throughout the sampling period. Cadmium showed low reduction rate ranging from 0 to 11.7 percent, while the rate of Copper reduction ranged from 0 to25 percent in January and February 2016. Zinc, lead and cadmium were generally not detected in the sludge samples except in January and February which could be due to the prevailing atmospheric conditions during the sampling period. Cu and Fe were detected through the sampling months of the study. We conclude that these municipal sewage plants are sources of pollution to their receiving watersheds and threats to public and environmental health.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Islamoglu, Sezin. "Effect Of Ionic Strength On The Performance Of Polymer Enhanced Ultrafiltration In Heavy Metal Removal From Aqueous Solutions." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607832/index.pdf.

Повний текст джерела

Анотація:

Effect of ionic strength on the efficiency of heavy metal removal and recovery from aqueous solutions via continuous mode polymer enhanced ultrafiltration (PEUF) method was examined. Application of PEUF to divalent ions of cadmium, nickel and zinc after their prior linking with polyethylenimine (PEI) results in complete removal of metal ions from single component aqueous solutions at high pHs. Binding ability and hence the extent of metal retention in high ionic strength medium exhibits differences between solutions containing single and multicomponent metal mixtures. In single component metal solutions, extent of retention decreases but binding order of metals remains unaffected both in low and high ionic strength medium. But, in binary component metal mixtures, with increase in ionic strength the binding order of metals changes. Fractional separation of Cd, Ni and Zn ions from equimolar binary and ternary mixtures of these metals and effect of ionic strength on fractional separation efficiency were investigated. Depending on pH and salt concentration and metal pairs present in the solution fractional separation can be achieved.Dynamic and static light scattering experiments were performed in order to gain insight about the conformational changes in PEI structure due to the pH and ionic strength alternations in solution. It was found that, the increase in ionic strength reduces the size of the macromolecules. A chemical equilibrium model was developed in order to estimate the apparent binding constants of metal-PEI complexes. Based on the data obtained from continuous and batch mode PEUF experiments apparent binding constants were estimated and compared to reveal the performance differences between these operational modes.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Chinhoga, Nokuthula. "Defining a spectrum of metals biosorbed by Paenibacillus castaneae with respect to heavy metal contamination in Gauteng." Thesis, 2016. http://hdl.handle.net/10539/21732.

Повний текст джерела

Анотація:

A research project submitted to the Faculty of Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Sciences (Coursework and Research Report). Johannesburg, 2016.
Paenibacillus castaneae isolated from acid mine decant (Gauteng, South Africa) was previously shown to tolerate high concentrations of lead (Pb). The ability of the bacterium to tolerate/resist other heavy metals is probable and suggests a role for P. castaneae as a biosorbent for their removal from contaminated wastewaters. The current study aimed at determining whether the bacterium is also resistant to other common metal contaminants specifically, zinc (Zn) and nickel (Ni), found in South African wastewaters for biosorption by P. castaneae. Additionally, the influence of the external factors pH and competing cations on the uptake of these metals by the bacterium was evaluated. Specific rates of metal uptake (Q) were calculated indirectly from quantifying (by spectroscopy) the residual ion concentrations post exposure to 3 mM metal after various treatments. P. castaneae was found to tolerate Zn but showed vulnerability towards Ni. In a binary metal system, the bacterium showed a preferential metal uptake in the order Zn>>Co> Mn with a highest Q of 26 mg Zn/g biosorbent biomass recorded in the presence of Mn at pH 7. On the contrary, in a multimetal complex solution, the order of preference shifted to Co>>Zn with no absorption of Mn at the same pH. The results indicate that both pH and the presence of cations have an effect on the uptake of Zn by P. castaneae that could favour or inhibit its biosorption. The present study confirms the ability of P. castaneae to remove additional metals such as Zn, Mn and Co. These findings further suggest the potential of P. castaneae as a biosorbent for greener clean-up strategies of contaminated water facilities around Gauteng in the way of bioremediation. Keywords: P. castaneae, biosorption, specific metal uptake, zinc, lead, nickel
LG2017

Стилі APA, Harvard, Vancouver, ISO та ін.

19

"Enhancement of metal ion removal capacity of water hyacinth." 2001. http://library.cuhk.edu.hk/record=b5890617.

Повний текст джерела

Анотація:

by So Lai Man, Rachel.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 83-103).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstract --- p.ii
Table of Contents --- p.iv
List of Figures --- p.viii
List of Tables --- p.ix
Chapter 1. --- Literature Review --- p.1
Chapter 1.1 --- Introduction --- p.1
Chapter 1.2 --- Overview of metal ions pollution --- p.2
Chapter 1.3 --- Treatment of metal ions in wastewater --- p.4
Chapter 1.3.1 --- Conventional methods --- p.4
Chapter 1.3.2 --- Microbial methods --- p.5
Chapter 1.4 --- Phytoremediation --- p.6
Chapter 1.4.1 --- Rhizofiltration --- p.10
Chapter 1.4.2 --- Mechanisms of metal ion removal by plant root --- p.12
Chapter 1.5 --- Using water hyacinth for wastewater treatment --- p.15
Chapter 1.5.1 --- Biology of water hyacinth --- p.15
Chapter 1.5.2 --- Water hyacinth based systems for wastewater treatment --- p.21
Chapter 1.6 --- Biology of rhizosphere --- p.23
Chapter 2. --- Objectives --- p.26
Chapter 3 --- Materials and Methods --- p.28
Chapter 3.1 --- Metal ion stock solution --- p.28
Chapter 3.2 --- Plant material and growth conditions --- p.28
Chapter 3.2.1 --- Preparation of Hoagland solution --- p.28
Chapter 3.3 --- Metal ion resistance of water hyacinth --- p.31
Chapter 3.4 --- Effect of metal ion concentration on the bacteria population --- p.31
Chapter 3.4.1 --- Minimal medium (MM) --- p.31
Chapter 3.5 --- Isolation of rhizospheric metal ion-resistant bacteria --- p.34
Chapter 3.6 --- Metal ion removal capacity of isolated bacteria --- p.34
Chapter 3.7 --- Colonization efficiency of a metal ion-adsorbing bacterium onto the root --- p.35
Chapter 3.7.1 --- Suppression of the bacterial population in the rhizosphere by an antibiotic --- p.35
Chapter 3.7.2 --- Colonization efficiency --- p.36
Chapter 3.8 --- Effect of colonizing the metal ion-adsorbing bacteria on the metal ion removal capacity of roots --- p.37
Chapter 4. --- Results --- p.38
Chapter 4.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizo spheric bacteria --- p.38
Chapter 4.1.1 --- Metal ion resistance of water hyacinth --- p.38
Chapter 4.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria --- p.43
Chapter 4.1.3 --- Selection for optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.43
Chapter 4.2 --- Screening for bacterial strain with high metal ion resistance and removal capacity --- p.46
Chapter 4.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.46
Chapter 4.2.2 --- Isolation of the natural bacterial population in rhizosphere --- p.50
Chapter 4.2.3 --- Determination of the metal ion removal capacity of rhizospheric metal ion-resistant bacterial strains --- p.52
Chapter 4.2.4 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities of Cu2+-resistant bacterial strains" --- p.53
Chapter 4.3 --- Effect of inoculating Cu2+-resistant bacterial strain to the rhizosphere on the metal ion removal capacity of the root --- p.59
Chapter 4.3.1 --- Bactericidal efficiency of oxytetracycline --- p.59
Chapter 4.3.2 --- Effect of inoculating Cu2+-adsorbing bacterial cells into the rhizosphere --- p.62
Chapter 4.3.3 --- Effect of bacterial cell density of inoculum on colonizing efficiency --- p.63
Chapter 4.3.4 --- Colonizing efficiency and metal ion removal capacity of root by direct inoculation of metal ion-adsorbing bacterial cells into metal ion solution or pre-inoculation in Hoagland solution --- p.64
Chapter 4.3.5 --- Effect of inoculating Strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.64
Chapter 5. --- Discussion --- p.69
Chapter 5.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.69
Chapter 5.1.1 --- Metal resistance of water hyacinth --- p.69
Chapter 5.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria population --- p.70
Chapter 5.1.3 --- Selection for optimum concentration --- p.70
Chapter 5.2 --- Screening for high metal ion-resistant and -removal bacterial strains --- p.71
Chapter 5.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.71
Chapter 5.2.2 --- Select metal ion-resistant bacterial strain from the natural population in the rhizosphere --- p.72
Chapter 5.2.3 --- Determination of the metal ion removal capacity of respective metal ion-resistant bacterial strain --- p.72
Chapter 5.3 --- Effect of inoculating Cu2+-resistant bacterial strain in the rhizosphere on the metal ion removal capacity of the root --- p.74
Chapter 5.3.1 --- Bactericidal efficiency of oxytetracycline --- p.74
Chapter 5.3.2 --- Effect of inoculating Cu2十-adsorbing bacterial cells into the rhizosphere --- p.75
Chapter 5.3.3 --- Effect inoculum cell density on the colonizing efficiency --- p.76
Chapter 5.3.4 --- Comparison of colonizing efficiency and metal ion removal capacity of root by direct inoculation metal ion-adsorbing bacterial cells into metal solution or pre-inoculationin Hoagland solution --- p.77
Chapter 5.3.5 --- Effect of inoculating strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.78
Chapter 5.4 --- Limitation and future development --- p.79
Chapter 6. --- Conclusion --- p.81
Chapter 7. --- References --- p.83

Стилі APA, Harvard, Vancouver, ISO та ін.

20

"Improvement of removal and recovery of copper ion (Cu²⁺) from electroplating effluent by magnetite-immobilized bacterial cells with calcium hydroxide precipitation =: 利用綜合化學生物磁力系統去除及回收電鍍廢水中的銅離子". 2001. http://library.cuhk.edu.hk/record=b5890601.

Повний текст джерела

Анотація:

by Li Ka Ling.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 221-242).
Text in English; abstracts in English and Chinese.
by Li Ka Ling.
Acknowledgements --- p.i
Abstract --- p.ii
Contents --- p.vi
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Literature review --- p.1
Chapter 1.1.1 --- Heavy metals in our environment --- p.1
Chapter 1.1.2 --- Major source of metal pollution in Hong Kong --- p.2
Chapter 1.1.3 --- Chemistry and toxicity of copper ion --- p.9
Chapter 1.1.4 --- Removal of metal ions from effluents by precipitation --- p.12
Chapter 1.1.4.1 --- Metal ions in solution --- p.12
Chapter 1.1.4.2 --- Precipitation of metal ions --- p.13
Chapter 1.1.4.3 --- pH adjustment reagents --- p.15
Chapter 1.1.4.4 --- Precipitation of complexed metal ions --- p.19
Chapter 1.1.5 --- Other physico-chemical methods for the removal of metal ions --- p.21
Chapter 1.1.6 --- Removal of metal ions by microorganisms --- p.24
Chapter 1.1.6.1 --- Biosorption --- p.24
Chapter 1.1.6.2 --- Other mechanisms for the accumulation of metal ions --- p.28
Chapter 1.1.6.3 --- An attractive alternative for the removal and recovery of metal ions:biosorption --- p.30
Chapter 1.1.7 --- Factors affecting biosorption --- p.37
Chapter 1.1.7.1 --- Culture conditions --- p.38
Chapter 1.1.7.2 --- pH of solution --- p.39
Chapter 1.1.7.3 --- Concentration of biosorbent --- p.41
Chapter 1.1.7.4 --- Initial metal ion concentration --- p.42
Chapter 1.1.7.5 --- Presence of other cations --- p.43
Chapter 1.1.7.6 --- Presence of anions --- p.45
Chapter 1.1.8 --- Properties and uses of magnetite --- p.46
Chapter 1.1.8.1 --- Physical and chemical properties of magnetite --- p.46
Chapter 1.1.8.2 --- Use of magnetite for wastewater treatment --- p.48
Chapter 1.1.8.3 --- Immobilization of cells on magnetite for metal ion removal --- p.49
Chapter 1.2 --- Objectives of the present study --- p.54
Chapter 2. --- Materials and methods --- p.57
Chapter 2.1 --- Effects of physico-chemical factors on the precipitation of Cu2+ --- p.57
Chapter 2.1.1 --- Reagents and chemicals --- p.57
Chapter 2.1.2 --- Effects of equilibrium time --- p.59
Chapter 2.1.3 --- Effects of pH --- p.60
Chapter 2.1.4 --- Presence of anions and other cations --- p.61
Chapter 2.1.5 --- "Presence of chelating agent, EDTA" --- p.61
Chapter 2.2 --- Dissolution of metal sludge --- p.63
Chapter 2.2.1 --- Dewatering and drying of metal sludge --- p.63
Chapter 2.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.63
Chapter 2.3 --- Culture of biomass --- p.65
Chapter 2.3.1 --- Subculturing of the biomass --- p.65
Chapter 2.3.2 --- Culture media --- p.66
Chapter 2.3.3 --- Growth and preparation of the cell suspension --- p.66
Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.66
Chapter 2.5 --- Metal ion removal studies --- p.71
Chapter 2.5.1 --- Preparation of concentrated Cu2+ solutions --- p.71
Chapter 2.5.2 --- Removal of Cu2+ in the concentrated Cu2+ solutions by magnetite- immobilized cells --- p.74
Chapter 2.5.3 --- Effects of EDTA --- p.76
Chapter 2.5.4 --- Effects of anions --- p.77
Chapter 2.5.5 --- Effects of other cations --- p.78
Chapter 2.6 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.79
Chapter 2.7 --- Recovery of adsorbed Cu2+ from magnetite-immobilized cell --- p.79
Chapter 2.7.1 --- Desorption of Cu2+ from the immobilized cells using sulfuric acid --- p.79
Chapter 2.7.2 --- Multiple adsorption-desorption cycles --- p.80
Chapter 2.8 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.80
Chapter 2.8.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.80
Chapter 2.8.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.83
Chapter 2.9 --- Data analysis --- p.84
Chapter 3. --- Results --- p.86
Chapter 3.1 --- Effects of physical-chemical factors on the precipitation of Cu2+ --- p.86
Chapter 3.1.1 --- Effects of equilibrium time --- p.86
Chapter 3.1.2 --- Effects of pH --- p.86
Chapter 3.1.3 --- Presence of anions --- p.89
Chapter 3.1.3.1 --- Cu2+-S042- systems --- p.89
Chapter 3.1.3.2 --- Cu2+-Cl- systems --- p.89
Chapter 3.1.3.3 --- Cu2+-Cr2072- systems --- p.89
Chapter 3.1.3.4 --- Cu2+-mixed anions systems --- p.93
Chapter 3.1.4 --- Presence of other cations --- p.93
Chapter 3.1.4.1 --- Cu2+-Ni2+ systems --- p.93
Chapter 3.1.4.2 --- Cu2+-Zn2+ systems --- p.96
Chapter 3.1.4.3 --- Cu2+-Cr6+ systems --- p.96
Chapter 3.1.4.4 --- Cu2+-mixed cations systems --- p.99
Chapter 3.1.5 --- "Presence of chelating agent, EDTA" --- p.99
Chapter 3.1.5.1 --- Cu2+-EDTA4 -mixed anions systems --- p.102
Chapter 3.1.5.2 --- Cu2+-EDTA4--mixed cations systems --- p.102
Chapter 3.2 --- Dissolution of metal sludge --- p.105
Chapter 3.2.1 --- Dewatering and drying of metal sludge --- p.105
Chapter 3.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.105
Chapter 3.3 --- Removal of Cu2+ in the concentrated Cu2+ solution by magnetite- immobilized cells --- p.109
Chapter 3.4 --- Effects of EDTA on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.109
Chapter 3.4.1 --- Effects of EDTA --- p.109
Chapter 3.4.2 --- Effects of EDTA after precipitation --- p.112
Chapter 3.5 --- Effects of anions on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.120
Chapter 3.5.1 --- Effects of anions --- p.120
Chapter 3.5.2 --- Effects of anions after precipitation --- p.120
Chapter 3.5.3 --- Effects of anions in the presence of EDTA after precipitation --- p.124
Chapter 3.6 --- Effects of other cations on removal and recovery of Cu2+ by magnetite-immobilized cells --- p.129
Chapter 3.6.1 --- Effects of other cations --- p.129
Chapter 3.6.2 --- Effects of other cations after precipitation --- p.137
Chapter 3.6.3 --- Effects of other cations in the presence of EDTA after precipitation --- p.137
Chapter 3.7 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.142
Chapter 3.8 --- Multiple adsorption-desorption cycle --- p.148
Chapter 3.9 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.148
Chapter 3.9.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.148
Chapter 3.9.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.158
Chapter 4. --- Discussion --- p.167
Chapter 4.1 --- Effects of physical-chemical factors on the precipitation of Cu2+ --- p.167
Chapter 4.1.1 --- Effects of equilibrium time --- p.167
Chapter 4.1.2 --- Effects of pH --- p.168
Chapter 4.1.3 --- Presence of anions --- p.169
Chapter 4.1.4 --- Presence of other cations --- p.170
Chapter 4.1.5 --- "Presence of chelating agent, EDTA" --- p.171
Chapter 4.1.5.1 --- Presence of EDTA with anions --- p.174
Chapter 4.1.5.2 --- Presence of EDTA with other cations --- p.174
Chapter 4.2 --- Dissolution of metal sludge --- p.175
Chapter 4.2.1 --- Dewatering and drying of metal sludge --- p.175
Chapter 4.2.2 --- Dissolving of metal sludge by sulfuric acid --- p.175
Chapter 4.3 --- Metal ion removal studies --- p.176
Chapter 4.3.1 --- Selection of biomass --- p.176
Chapter 4.3.2 --- Removal of Cu2+ in the concentrated Cu2+ solution by magnetite- immobilized cells --- p.178
Chapter 4.4 --- Effects of EDTA on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.182
Chapter 4.4.1 --- Effects of EDTA --- p.182
Chapter 4.4.2 --- Effects of EDTA after precipitation --- p.184
Chapter 4.5 --- Effects of anions on removal and recovery of Cu2+ by magnetite- immobilized cells --- p.185
Chapter 4.5.1 --- Effects of anions --- p.185
Chapter 4.5.2 --- Effects of anions after precipitation --- p.188
Chapter 4.5.3 --- Effects of anions in the presence of EDTA after precipitation --- p.190
Chapter 4.6 --- Effects of other cations on removal and recovery of Cu2+ by magnetite-immobilized cells --- p.192
Chapter 4.6.1 --- Effects of other cations --- p.192
Chapter 4.6.2 --- Effects of other cations after precipitation --- p.195
Chapter 4.6.3 --- Effects of other cations in the presence of EDTA after precipitation --- p.197
Chapter 4.7 --- Maximum removal efficiency of Cu2+ by magnetite-immobilized cells --- p.198
Chapter 4.8 --- Multiple adsorption-desorption cycles --- p.199
Chapter 4.9 --- Treatment of electroplating effluent by magnetite-immobilized cells --- p.202
Chapter 4.9.1 --- Removal and recovery of Cu2+ from electroplating effluent collected from rinsing baths --- p.202
Chapter 4.9.2 --- Removal and recovery of Cu2+ from electroplating effluent collected from final collecting tank --- p.205
Chapter 5. --- Conclusion --- p.213
Chapter 6. --- Summary --- p.215
Chapter 7. --- Recommendations --- p.219
Chapter 8. --- References --- p.221

Стилі APA, Harvard, Vancouver, ISO та ін.

21

"Removal and recovery of metal ions by magnetite-immobilized chitin A." 2008. http://library.cuhk.edu.hk/record=b5893435.

Повний текст джерела

Анотація:

Wong, Kin Shing Kinson.
Thesis submitted in: November 2007.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.
Includes bibliographical references (leaves 145-158).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstract --- p.ii
摘要 --- p.v
Contents --- p.viii
List of figures --- p.xv
List of plates --- p.xx
List of tables --- p.xxi
Abbreviations --- p.xxiii
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Heavy metals --- p.1
Chapter 1.1.1 --- Characteristics of heavy metals --- p.1
Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.2
Chapter 1.1.3 --- Common usage of heavy metals --- p.4
Chapter 1.1.3.1 --- Copper --- p.4
Chapter 1.1.3.2 --- Nickel --- p.4
Chapter 1.1.3.3 --- Zinc --- p.5
Chapter 1.1.4 --- Toxicity of heavy metals --- p.5
Chapter 1.1.4.1 --- Copper --- p.6
Chapter 1.1.4.2 --- Nickel --- p.7
Chapter 1.1.4.3 --- Zinc --- p.7
Chapter 1.1.5 --- Treatment techniques for metal ions --- p.8
Chapter 1.1.5.1 --- Chemical precipitation --- p.9
Chapter 1.1.5.2 --- Ion exchange --- p.10
Chapter 1.1.5.3 --- Activated carbon adsorption --- p.10
Chapter 1.2 --- Biosorption --- p.11
Chapter 1.2.1 --- Definition of biosorption --- p.11
Chapter 1.2.2 --- Mechanism --- p.12
Chapter 1.2.3 --- Advantages of biosorption --- p.13
Chapter 1.2.4 --- Selection of biosorbents --- p.15
Chapter 1.3 --- Chitinous materials --- p.17
Chapter 1.3.1 --- Background of chitin --- p.17
Chapter 1.3.2 --- Structures of chitinous materials --- p.18
Chapter 1.3.3 --- Sources of chitinous materials --- p.18
Chapter 1.3.4 --- Application of chitinous materials --- p.20
Chapter 1.3.5 --- Mechanism of metal ion adsorption by chitin --- p.22
Chapter 1.4 --- Activated carbon --- p.25
Chapter 1.4.1 --- Characteristics of activated carbon --- p.25
Chapter 1.4.2 --- Applications of activated carbon --- p.26
Chapter 1.4.3 --- Factors affecting adsorption ability of activated carbon --- p.27
Chapter 1.4.4 --- Advantages and Disadvantages --- p.28
Chapter 1.4.4.1 --- Advantages (Adsorption) --- p.28
Chapter 1.4.4.2 --- Advantages (Regerneration) --- p.28
Chapter 1.4.4.3 --- Disadvantages (Adsorption) --- p.28
Chapter 1.4.4.4 --- Disadvantages (Regeneration) --- p.29
Chapter 1.5 --- Cation exchange resin --- p.29
Chapter 1.5.1 --- Usages of cation exchange resin --- p.29
Chapter 1.5.2 --- Characteristics of cation exchange resin --- p.30
Chapter 1.5.3 --- Disadvantages of using cation exchange resin --- p.30
Chapter 1.6 --- Magnetite --- p.31
Chapter 1.6.1 --- Reasons of using magnetite --- p.31
Chapter 1.6.2 --- Characteristics of magnetite --- p.31
Chapter 1.6.3 --- Immobilization by magnetite --- p.32
Chapter 1.6.4 --- Advantages of using magnetite --- p.33
Chapter 1.7 --- The biosorption experiment --- p.33
Chapter 1.7.1 --- The batch biosorption experiment --- p.33
Chapter 1.7.2 --- The adsorption isotherms --- p.34
Chapter 1.7.2.1 --- The Langmuir adsorption isotherm --- p.34
Chapter 1.7.2.2 --- The Freundlich adsorption isotherm --- p.36
Chapter 2. --- Objectives --- p.38
Chapter 3. --- Materials and methods --- p.39
Chapter 3.1 --- Adsorbents --- p.39
Chapter 3.1.1 --- Chitin A --- p.39
Chapter 3.1.2 --- Pretreatment of chitin A --- p.39
Chapter 3.1.3 --- Magnetite --- p.39
Chapter 3.1.4 --- Activated carbon --- p.41
Chapter 3.1.5 --- Cation exchange resin --- p.41
Chapter 3.1.6 --- Pretreatment of cation exchange resin --- p.41
Chapter 3.2 --- Chemicals --- p.43
Chapter 3.2.1 --- Metal ion solution --- p.43
Chapter 3.2.2 --- Buffer solution --- p.43
Chapter 3.2.3 --- Standard solution --- p.43
Chapter 3.3 --- Immobilization of chitin A by magnetite --- p.44
Chapter 3.3.1 --- Effect of chitin A to magnetite ratio --- p.44
Chapter 3.3.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.45
Chapter 3.3.3 --- Effect of pH --- p.45
Chapter 3.3.4 --- Effect of immobilization time --- p.46
Chapter 3.3.5 --- Effect of temperature --- p.46
Chapter 3.3.6 --- Effect of agitation rate --- p.46
Chapter 3.3.7 --- Effect of salinity --- p.46
Chapter 3.3.8 --- Mass production of magnetite-immobilized chitin A --- p.47
Chapter 3.4 --- Batch adsorption experiment --- p.47
Chapter 3.5 --- "Optimization of physicochemical condition on Cu2+，Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.48
Chapter 3.5.1 --- Effect of equilibrium pH --- p.48
Chapter 3.5.2 --- Effect of amount of adsorbent --- p.49
Chapter 3.5.3 --- Effect of retention time --- p.49
Chapter 3.5.4 --- Effect of agitation rate --- p.49
Chapter 3.5.5 --- Effect of temperature --- p.50
Chapter 3.5.6 --- Effect of initial metal ion concentration --- p.50
Chapter 3.5.7 --- Adsorption isotherms --- p.50
Chapter 3.5.8 --- Dimensionless separation factor --- p.52
Chapter 3.5.9 --- Kinetic parameters of adsorption --- p.52
Chapter 3.5.10 --- Thermodynamic parameters of adsorption --- p.53
Chapter 3.6 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.54
Chapter 3.6.1 --- Performances of various solutions on metal ion recovery --- p.54
Chapter 3.6.2 --- Multiple adsorption and desorption cycles of metal ions --- p.55
Chapter 3.7 --- Statistical analysis of data --- p.55
Chapter 4. --- Results --- p.56
Chapter 4.1 --- Immobilization of chitin A by magnetite --- p.56
Chapter 4.1.1 --- Effect of chitin A to magnetite ratio --- p.56
Chapter 4.1.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.59
Chapter 4.1.3 --- Effect of pH --- p.59
Chapter 4.1.4 --- Effect of immobilization time --- p.59
Chapter 4.1.5 --- Effect of temperature --- p.59
Chapter 4.1.6 --- Effect of agitation rate --- p.64
Chapter 4.1.7 --- Effect of salinity --- p.64
Chapter 4.1.8 --- Mass production of magnetite-immobilized chitin A --- p.64
Chapter 4.2 --- Batch adsorption experiment --- p.67
Chapter 4.2.1 --- Screening of adsorbents --- p.67
Chapter 4.3 --- "Optimization of physicochemical condition on Cu2+, Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.70
Chapter 4.3.1 --- Effect of equilibrium pH --- p.70
Chapter 4.3.2 --- Effect of amount of adsorbent --- p.74
Chapter 4.3.3 --- Effect of retention time --- p.78
Chapter 4.3.4 --- Effect of agitation rate --- p.82
Chapter 4.3.5 --- Effect of temperature --- p.82
Chapter 4.3.6 --- Effect of initial metal ion concentration --- p.86
Chapter 4.3.7 --- Summary of optimized conditions for three metal ions --- p.87
Chapter 4.3.8 --- Cost analysis of metal ion removal by three adsorbents --- p.87
Chapter 4.3.9 --- Performance of reference adsorbents (AC and CER) --- p.87
Chapter 4.3.10 --- Adsorption isotherms --- p.99
Chapter 4.3.11 --- Dimensionless separation factor --- p.103
Chapter 4.3.12 --- Kinetic parameters of adsorption --- p.106
Chapter 4.3.13 --- Thermodynamic parameters of adsorption --- p.113
Chapter 4.4 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.113
Chapter 4.4.1 --- Performances of various solutions on metal ion recovery --- p.113
Chapter 4.4.2 --- Multiple adsorption and desorption cycles of metal ions --- p.117
Chapter 5. --- Discussions --- p.121
Chapter 5.1 --- Immobilization of chitin A by magnetite --- p.121
Chapter 5.1.1 --- Effect of chitin A to magnetite ratio --- p.121
Chapter 5.1.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.121
Chapter 5.1.3 --- Effect of pH --- p.122
Chapter 5.1.4 --- Effect of immobilization time --- p.122
Chapter 5.1.5 --- Effect of temperature --- p.122
Chapter 5.1.6 --- Effect of agitation rate --- p.123
Chapter 5.1.7 --- Effect of salinity --- p.123
Chapter 5.2 --- Batch adsorption experiment --- p.123
Chapter 5.2.1 --- Screening of adsorbents --- p.123
Chapter 5.3 --- "Optimization of physicochemical condition on Cu2+, Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.124
Chapter 5.3.1 --- Effect of equilibrium pH --- p.125
Chapter 5.3.2 --- Effect of amount of adsorbent --- p.126
Chapter 5.3.3 --- Effect of retention time --- p.127
Chapter 5.3.4 --- Effect of agitation rate --- p.128
Chapter 5.3.5 --- Effect of temperature --- p.128
Chapter 5.3.6 --- Effect of initial metal ion concentration --- p.129
Chapter 5.3.7 --- Summary of optimized conditions for three metal ions --- p.130
Chapter 5.3.8 --- Cost analysis of metal ion removal by three adsorbents --- p.132
Chapter 5.3.9 --- Performance of reference adsorbents (AC and CER) --- p.133
Chapter 5.3.10 --- Adsorption isotherms --- p.133
Chapter 5.3.11 --- Dimensionless separation factor --- p.135
Chapter 5.3.12 --- Kinetic parameters of adsorption --- p.136
Chapter 5.3.13 --- Thermodynamic parameters of adsorption --- p.139
Chapter 5.4 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.140
Chapter 5.4.1 --- Performances of various solutions on metal ion recovery --- p.140
Chapter 5.4.2 --- Multiple adsorption and desorption cycles of metal ions --- p.141
Chapter 6. --- Conclusions --- p.143
Chapter 7. --- References --- p.145

Стилі APA, Harvard, Vancouver, ISO та ін.

22

"Heavy metal accumulation in free and immobilized pseudomonas picketti." Chinese University of Hong Kong, 1990. http://library.cuhk.edu.hk/record=b5886589.

Повний текст джерела

Анотація:

by Li Sze Kwan.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1990.
Bibliography: leaves 234-259.
ACKNOWLEDGEMENT --- p.i
ABSTRACT --- p.ii
CONTENTS :
Chapter CHAPTER 1: --- GENERAL INTRODUCTION --- p.1
Chapter 1.1 --- Our Environment Is Polluted --- p.1
Chapter 1.2 --- Heavy Metal Contamination --- p.3
Chapter 1.3 --- The Effect of Cadmium and Some Related Metals on Environment --- p.5
Chapter 1.4 --- The Uses of Microorganisms in Cleaning Up Environment --- p.9
Chapter 1.5 --- Mechanisms of Cadmium Uptake in Cadmium Accumulating Strains --- p.10
Chapter 1.6 --- Techniques for Cell Immobilization --- p.13
Chapter 1.7 --- Prospect --- p.20
Chapter CHAPTER 2: --- ISOLATION OF CADMUIM ACCUMULATNIG MICROORGANISMS --- p.22
Chapter 2.1 --- Introduction --- p.22
Chapter 2.2 --- Materials and Methods --- p.25
Chapter 2.2.1 --- Recipes Used for Growing Various Organisms --- p.25
Chapter 2.2.2 --- Methods Used for Collecting Organisms to be Tested --- p.27
Chapter 2.2.3 --- Observation of Samples by Microscope --- p.28
Chapter 2.2.4 --- Enrichment of Cadmium Resistant Microorganisms --- p.28
Chapter 2.2.5 --- Selection and Isolation of Cadmium Resistant Microorganisms --- p.29
Chapter 2.2.6 --- Purification of Microbial Colonies --- p.30
Chapter 2.2.7 --- Preliminary Classification of Selected Microorganisms --- p.30
Chapter 2.2.8 --- Screening of Cadmium Accumulating Strains --- p.30
Chapter 2.2.9 --- Cadmium Analysis --- p.31
Chapter 2.3 --- Result --- p.32
Chapter 2.3.1 --- Selection of Cadmium Resistant --- p.32
Chapter 2.3.2 --- Cadmium Resistance of Isolates --- p.36
Chapter 2.3.3 --- Screening of Cadmium Accumulating Microorganisms --- p.38
Chapter 2.4 --- Discussion --- p.39
Chapter CHAPTER 3: --- GENERAL CHARACTERIZATION OF STRAIN 1000A --- p.43
Chapter 3.1 --- Introduction --- p.43
Chapter 3.1.1 --- Various Factors Affecting the Accumulation of Cadmium of Strain 1000A --- p.43
Chapter 3.1.2 --- Identification --- p.44
Chapter 3.2 --- Materials and Methods --- p.45
Chapter 3.2.1 --- "Preparation of Solutions, Antibiotics and Reagents" --- p.45
Chapter 3.2.2 --- Culture Media Used --- p.47
Chapter 3.2.3 --- Growth Kenetics Determination --- p.48
Chapter 3.2.4 --- Determination of the Effect of Cadmium Concentration on Cd-uptake in Free Cells --- p.49
Chapter 3.2.5 --- Determination of the Effect of Phosphate Concentration on Cd-uptake in Free Cell --- p.49
Chapter 3.2.6 --- Determination of the Cd-uptake in Free Cells in Continuous Cultures --- p.50
Chapter 3.2.7 --- Determination of Antibiotic Resistance of Strain 1000A --- p.51
Chapter 3.2.8 --- Dstermination of Relationship between Chloramphenicol Resistance and Cd-uptake --- p.52
Chapter 3.2.9 --- Cadmium Analysis --- p.52
Chapter 3.2.10 --- Determination of Inorganic Precipitation of Cadmium --- p.53
Chapter 3.2.11 --- Assimilation Tests --- p.54
Chapter 3.2.12 --- Identification of Strain 1000A --- p.55
Chapter 3.3 --- Result --- p.55
Chapter 3.3.1 --- Growth Kinetics of Strain 1000A in Cadmium Supplemented Peptone Medium --- p.55
Chapter 3.3.2 --- Cd-uptake of Strain 1000A at Various Cadiuin Concentration --- p.65
Chapter 3.3.3 --- Effect of Phosphate concentration on Cd-uptake of Strain 1000A --- p.65
Chapter 3.3.4 --- Cd-uptake of Strain 1000A in Continuous Cultures --- p.70
Chapter 3.3.5 --- Inorganic Precipitation of Cadmium Phosphate --- p.75
Chapter 3.3.6 --- Determination of Antibiotic-Resistance of Strain 1000A --- p.78
Chapter 3.3.7 --- Effect of Chloramphenicol on Cd-uptake and Cadmium Resistance of Strain 1000A --- p.82
Chapter 3.3.8 --- Determination of the Effect of Tetracyclin --- p.85
Chapter 3.3.9 --- Assimilation Tests --- p.94
Chapter 3.3.10 --- Identification of Strain 1000A --- p.94
Chapter 3.4 --- Discussion --- p.97
Chapter CHAPTER 4: --- DETERMINATION OF CADMIUM UPTAKE MECHANISM IN P. PICKETTI 1000A --- p.102
Chapter 4.1 --- Introduction --- p.102
Chapter 4.2 --- Materials and Methods --- p.105
Chapter 4.2.1 --- Preparation of Solutions and Reagents --- p.105
Chapter 4.2.2 --- Preparation of Reagents for SDS-PAGE --- p.105
Chapter 4.2.3 --- Recipes for Growing Cells --- p.107
Chapter 4.2.4 --- Protein Determination --- p.108
Chapter 4.2.5 --- Examination of Cadmium Accommodation in P. picketti 1000A by Transmission Electron Microscope --- p.108
Chapter 4.2.6 --- SDS-polyacrylamide Gel Electrophoretic Determination of Protein Profiles --- p.109
Chapter 4.2.7 --- Phosphate Assay --- p.111
Chapter 4.2.8 --- Orthophosphate Estimation --- p.112
Chapter 4.2.9 --- Sulphide Analysis --- p.112
Chapter 4.2.10 --- Cadmium Analysis --- p.113
Chapter 4.2.11 --- Cd-binding Determination through Column Separation --- p.113
Chapter 4.2.12 --- Cd-binding Determinate ion through SDS Electrophoresis --- p.114
Chapter 4.2.13 --- Determination of Cadmium Distribution of Cells --- p.115
Chapter 4.3 --- Result --- p.116
Chapter 4.3.1 --- SDS-PAGE Determination of Protein Profiles of P. picketti 1000A --- p.116
Chapter 4.3.2 --- Determination of Cd-binding Protein of P. picketti 1000A --- p.121
Chapter 4.3.3 --- "Determination of the Relationship of Cellular Cadmium, Sulphide and Phosphate" --- p.131
Chapter 4.3.4 --- Examination of Cadmium Accumulation of P. picketti 1000A by Transmission Electron Microscope --- p.142
Chapter 4.3.5 --- Cadmium Distribution of Cadmium-Accommodated Cells --- p.148
Chapter 4.4 --- Discussion --- p.152
Chapter CHAPTER 5: --- CORRELATION AMONG METALS IN HEAVY METAL UPTAKE --- p.158
Chapter 5.1 --- Introduction --- p.158
Chapter 5.2 --- Materials and Methods --- p.158
Chapter 5.2.1 --- Preparation of Solutions --- p.159
Chapter 5.2.2 --- "Determination of Effect of Zn+2 ," --- p.160
Chapter 5.2.3 --- Determination of Effect of Cu+2 . --- p.161
Chapter 5.2.4 --- "Correlation among Cd+2, Cu+2 and Zn+2" --- p.161
Chapter 5.2.5 --- Growth Kenetics Determination --- p.162
Chapter 5.2.6 --- Cell Sample Preparation --- p.162
Chapter 5.2.7 --- Orthophosphate Estimation --- p.162
Chapter 5.2.8 --- Metal Analysis --- p.163
Chapter 5.3 --- Result --- p.163
Chapter 5.3.1 --- Effect of Zn+2 --- p.163
Chapter 5.3.2 --- Effect of Cu+2 --- p.173
Chapter 5.3.3 --- "Correlation among Cd+2, Cu+2 and Zn+2" --- p.178
Chapter 5.4 --- Discussion --- p.195
Chapter CHAPTER 6: --- HEAVY METAL UPTAKE OF IMMOBILIZED CELL --- p.197
Chapter 6.1 --- Introduction --- p.197
Chapter 6.2 --- Materials and Methods --- p.199
Chapter 6.2.1 --- Preparation of Solutions and Medium --- p.199
Chapter 6.2.2 --- Harvesting of Cells --- p.199
Chapter 6.2.3 --- Immobilization of Cells --- p.199
Chapter 6.2.4 --- Determination of the Effect of Temperature --- p.200
Chapter 6.2.5 --- Determination of Optimum Cell Concentration in Polyacrylamide Gel --- p.201
Chapter 6.2.6 --- Determination of pH Effect on Cd-uptake --- p.201
Chapter 6.2.7 --- Pretreatment with 70% Methanol --- p.202
Chapter 6.2.8 --- Combined Pretreatment with Methanol and NaOH --- p.202
Chapter 6.2.9 --- Effect of Phosphate on Cd-uptake of Immobilized Cell --- p.202
Chapter 6.2.10 --- Comparison of Cadmium- and Copper-uptakes in Cells Immobilized in K-carrageenan and in Polyacrylamide --- p.203
Chapter 6.3 --- Result --- p.204
Chapter 6.3.1 --- Effect of Temperature on Cd-uptake --- p.204
Chapter 6.3.2 --- Determination of Optimum Cell Concentration in Polyacrylamide Gel --- p.204
Chapter 6.3.3 --- Effect of pH on Cd-uptake of Immobilized Cells --- p.207
Chapter 6.3.4 --- Effect of Methanol on Cd-uptake --- p.210
Chapter 6.3.5 --- Combined Effect of pH and Methanol on Cd-uptake --- p.213
Chapter 6.3.6 --- Effect of Phosphate on Cd-uptake of Immobilized Cells --- p.213
Chapter 6.3.7 --- Comparison between Cadmium- and Copper-uptake of Cells Immobilized in K-carrageenan and in Polyacrylamide --- p.220
Chapter 6.4 --- Discussion --- p.228
Chapter CHAPTER 7: --- CONCLUSION --- p.232
REFERENCES --- p.234

Стилі APA, Harvard, Vancouver, ISO та ін.

23

"Effects of heavy metals on microbial removal of inorganic nitrogen and phosphorus from secondarily treated sewage effluent." Chinese University of Hong Kong, 1989. http://library.cuhk.edu.hk/record=b5886191.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

24

"Development of seaweed biomass as a biosorbent for metal ions removal and recovery from industrial effluent." 2000. http://library.cuhk.edu.hk/record=b5890420.

Повний текст джерела

Анотація:

by Lau Tsz Chun.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 134-143).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstract --- p.ii
Contents --- p.vi
List of Figures --- p.xi
List of Tables --- p.xv
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Reviews --- p.1
Chapter 1.1.1 --- Heavy metals in the environment --- p.1
Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.3
Chapter 1.1.3 --- Electroplating industries in Hong Kong --- p.7
Chapter 1.1.4 --- "Chemistry, biochemistry and toxicity of selected metal ions: copper, nickel and zinc" --- p.8
Chapter a. --- Copper --- p.10
Chapter b. --- Nickel --- p.11
Chapter c. --- Zinc --- p.12
Chapter 1.1.5 --- Conventional physico-chemical methods of metal ions removal from industrial effluent --- p.13
Chapter a. --- Ion exchange --- p.14
Chapter b. --- Precipitation --- p.14
Chapter 1.1.6 --- Alternative for metal ions removal from industrial effluent: biosorption --- p.15
Chapter a. --- Definition of biosorption --- p.15
Chapter b. --- Mechanisms involved in biosorption of metal ions --- p.17
Chapter c. --- Criteria for a good metal sorption process and advantages of biosorption for removal of heavy metal ions --- p.19
Chapter d. --- Selection of potential biosorbent for metal ions removal --- p.20
Chapter 1.1.7 --- Procedures of biosorption --- p.23
Chapter a. --- Basic study --- p.23
Chapter b. --- Pilot-scale study --- p.25
Chapter c. --- Examples of commercial biosorbent --- p.27
Chapter 1.1.8 --- Seaweed as a potential biosorbent for heavy metal ions --- p.27
Chapter 1.2 --- Objectives of study --- p.30
Chapter 2. --- Materials and Methods --- p.33
Chapter 2.1 --- Collection of seaweed samples --- p.33
Chapter 2.2 --- Processing of seaweed biomass --- p.33
Chapter 2.3 --- Chemicals --- p.33
Chapter 2.4 --- Characterization of seaweed biomass --- p.39
Chapter 2.4.1 --- Moisture content of seaweed biomass --- p.39
Chapter 2.4.2 --- Metal ions content of seaweed biomass --- p.39
Chapter 2.5 --- Characterization of metal ions biosorption by seaweed --- p.39
Chapter 2.5.1 --- Effect of biomass weight and selection of biomass --- p.39
Chapter 2.5.2 --- Effect of pH --- p.40
Chapter 2.5.3 --- Effect of retention time --- p.41
Chapter 2.5.4 --- Effect of metal ions concentration --- p.41
Chapter 2.5.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.43
Chapter 2.5.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening for suitable desorbing agents --- p.44
Chapter 2.5.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.45
Chapter 2.5.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.45
Chapter 2.6 --- Statistical analysis of data --- p.46
Chapter 3. --- Results --- p.47
Chapter 3.1 --- Effect of biomass weight and selection of biomass --- p.47
Chapter 3.1.1 --- Effect of biomass weight --- p.47
Chapter 3.1.2 --- Selection of biomass --- p.58
Chapter 3.2 --- Effect of pH --- p.58
Chapter 3.2.1 --- Cu2+ --- p.58
Chapter 3.2.2 --- Ni2+ --- p.61
Chapter 3.2.3 --- Zn2+ --- p.61
Chapter 3.2.4 --- Determination of optimal condition for biosorption of Cu2+ ，Ni2+ and Zn2+ by Ulva lactuca --- p.67
Chapter 3.3 --- Effect of retention time --- p.67
Chapter 3.4 --- Effect of metal ions concentration --- p.73
Chapter 3.4.1 --- Relationship of removal capacity with initial concentration of metal ions --- p.73
Chapter 3.4.2 --- Langmuir adsorption isotherm --- p.73
Chapter 3.4.3 --- Freundlich adsorption isotherm --- p.77
Chapter 3.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.81
Chapter 3.5.1 --- Effect of mix-cations --- p.81
Chapter 3.5.2 --- Effect of mix-anions --- p.85
Chapter 3.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening of suitable desorbing agents --- p.91
Chapter 3.6.1 --- Cu2+ --- p.91
Chapter 3.6.2 --- Ni2+ --- p.91
Chapter 3.6.3 --- Zn2+ --- p.91
Chapter 3.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.94
Chapter 3.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.97
Chapter 4. --- Discussion --- p.106
Chapter 4.1 --- Effect of biomass weight and selection of biomass --- p.106
Chapter 4.1.1 --- Effect of biomass weight --- p.106
Chapter 4.1.2 --- Selection of biomass --- p.107
Chapter 4.2 --- Effect of pH --- p.109
Chapter 4.3 --- Effect of retention time --- p.112
Chapter 4.4 --- Effect of metal ions concentration --- p.114
Chapter 4.4.1 --- Relationship of removal capacity with initial concentration of metal ions --- p.114
Chapter 4.4.2 --- Langmuir adsorption isotherm --- p.114
Chapter 4.4.3 --- Freundlich adsorption isotherm --- p.115
Chapter 4.4.4 --- Insights from isotherm study --- p.117
Chapter 4.5 --- Effect of mix-cations and mix-anions on the removal capacity of selected metal ions by Ulva lactuca --- p.118
Chapter 4.5.1 --- Effect of mix-cations --- p.118
Chapter 4.5.2 --- Effect of mix-anions --- p.120
Chapter 4.6 --- Recovery of adsorbed metal ions from Ulva lactuca (I): screening of suitable desorbing agents --- p.122
Chapter 4.7 --- Recovery of adsorbed metal ions from Ulva lactuca (II): multiple adsorption-desorption cycles of selected metal ions --- p.124
Chapter 4.8 --- Removal and recovery of selected metal ions from electroplating effluent by Ulva lactuca --- p.126
Chapter 5. --- Conclusion --- p.131
Chapter 6. --- Summary --- p.134
Chapter 7. --- References --- p.134
Chapter 8. --- Appendixes --- p.144

Стилі APA, Harvard, Vancouver, ISO та ін.

25

"Removal and recovery of metal ions from electroplating effluent by chitin adsorption." 2000. http://library.cuhk.edu.hk/record=b5890286.

Повний текст джерела

Анотація:

by Tsui Wai-chu.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 161-171).
Abstracts in English and Chinese.
Acknowledgements --- p.i
Abstract --- p.ii
Abbreviations --- p.vii
Contents --- p.ix
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Literature review --- p.1
Chapter 1.1.1 --- Metal pollution in Hong Kong --- p.1
Chapter 1.1.2 --- Methods for removal of metal ions from industrial effluent --- p.4
Chapter A. --- Physico-chemical methods --- p.4
Chapter B. --- Biosorption --- p.7
Chapter 1.1.3 --- Chitin and chitosan --- p.11
Chapter A. --- History of chitin and chitosan --- p.11
Chapter B. --- Structures and sources of chitin and chitosan --- p.12
Chapter C. --- Characterization of chitin and chitosan --- p.17
Chapter D. --- Applications of chitin and chitosan --- p.19
Chapter 1.1.4 --- Factors affecting biosorption --- p.22
Chapter A. --- Solution pH --- p.22
Chapter B. --- Concentration of biosorbent --- p.24
Chapter C. --- Retention time --- p.25
Chapter D. --- Initial metal ion concentration --- p.26
Chapter E. --- Presence of other cations --- p.26
Chapter F. --- Presence of anions --- p.28
Chapter 1.1.5 --- Regeneration of metal ion-laden biosorbent --- p.28
Chapter 1.1.6 --- Modeling of biosorption --- p.29
Chapter A. --- Adsorption equilibria and adsorption isotherm --- p.29
Chapter B. --- Langmuir isotherm --- p.33
Chapter C. --- Freundlich isotherm --- p.34
Chapter 1.2 --- Objectives of the present study --- p.36
Chapter 2. --- Materials and methods --- p.37
Chapter 2.1 --- Biosorbents --- p.37
Chapter 2.1.1 --- Production of biosorbents --- p.37
Chapter 2.1.2 --- Pretreatment of biosorbents --- p.39
Chapter 2.2 --- Characterization of biosorbents --- p.39
Chapter 2.2.1 --- Chitin assay --- p.39
Chapter 2.2.2 --- Protein assay --- p.40
Chapter 2.2.3 --- Metal analysis --- p.41
Chapter 2.2.4 --- Degree of N-deacetylation analysis --- p.43
Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.43
Chapter B. --- Elemental analysis --- p.43
Chapter 2.3 --- Batch biosorption experiment --- p.44
Chapter 2.4 --- Selection of biosorbent for metal ion removal --- p.45
Chapter 2.4.1 --- Effects of pretreatments of biosorbents on adsorption of Cu --- p.45
Chapter A. --- Washing --- p.45
Chapter B. --- Pre-swelling --- p.46
Chapter 2.4.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.46
Chapter 2.4.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.46
Chapter 2.5 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.48
Chapter 2.5.1 --- Solution pH and concentration of biosorbent --- p.48
Chapter 2.5.2 --- Retention time --- p.48
Chapter 2.5.3 --- Initial metal ion concentration --- p.49
Chapter 2.5.4 --- Presence of other cations --- p.49
Chapter 2.5.5 --- Presence of anions --- p.51
Chapter 2.6 --- Optimization of Cu2+，Ni2+ and Zn2+ removal efficiencies --- p.53
Chapter 2.7 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden chitin A" --- p.53
Chapter 2.7.1 --- Performances of various eluents on metal ion recovery --- p.53
Chapter 2.7.2 --- Multiple adsorption and desorption cycle of metal ions --- p.54
Chapter 2.8 --- Treatment of electroplating effluent by chitin A --- p.54
Chapter 2.8.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.54
Chapter 2.8.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.55
Chapter 2.9 --- Data analysis --- p.56
Chapter 3. --- Results --- p.58
Chapter 3.1 --- Characterization of biosorbents --- p.58
Chapter 3.1.1 --- Chitin assay --- p.58
Chapter 3.1.2 --- Protein assay --- p.58
Chapter 3.1.3 --- Metal analysis --- p.58
Chapter 3.1.4 --- Degree of N-deacetylation analysis --- p.62
Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.62
Chapter B. --- Elemental analysis --- p.62
Chapter 3.2 --- Selection of biosorbent for metal ion removal --- p.67
Chapter 3.2.1 --- Effects of pretreatments of biosorbents on adsorption of Cu2+ --- p.67
Chapter A. --- Washing --- p.67
Chapter B. --- Pre-swelling --- p.67
Chapter 3.2.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.67
Chapter 3.2.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.70
Chapter 3.3 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.70
Chapter 3.3.1 --- Solution pH and concentration of biosorbent --- p.70
Chapter 3.3.2 --- Retention time --- p.78
Chapter 3.3.3 --- Initial metal ion concentration --- p.80
Chapter 3.3.4 --- Presence of other cations --- p.93
Chapter 3.3.5 --- Presence of anions --- p.93
Chapter 3.4 --- "Optimization of Cu2+, Ni2+ and Zn2+ removal efficiencies" --- p.104
Chapter 3.5 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden chitin A" --- p.104
Chapter 3.5.1 --- Performances of various eluents on metal ion recovery --- p.104
Chapter 3.5.2 --- Multiple adsorption and desorption cycle of metal ions --- p.109
Chapter 3.6 --- Treatment of electroplating effluent by chitin A --- p.117
Chapter 3.6.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.117
Chapter 3.6.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.121
Chapter 4. --- Discussion --- p.128
Chapter 4.1 --- Characterization of biosorbents --- p.128
Chapter 4.1.1 --- Chitin assay --- p.128
Chapter 4.1.2 --- Protein assay --- p.129
Chapter 4.1.3 --- Metal analysis --- p.129
Chapter 4.1.4 --- Degree of N-deacetylation analysis --- p.130
Chapter A. --- Diffuse reflectance Fourier transform infra-red spectroscopy --- p.130
Chapter B. --- Elemental analysis --- p.132
Chapter 4.2 --- Selection of biosorbent for metal ion removal --- p.133
Chapter 4.2.1 --- Effects of pretreatments of biosorbents on adsorption of Cu2+ --- p.133
Chapter A. --- Washing --- p.133
Chapter B. --- Pre-swelling --- p.133
Chapter 4.2.2 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities among three biosorbents" --- p.134
Chapter 4.2.3 --- Comparison of Cu2+ removal capacity of chitins with various degrees of N-deacetylation --- p.136
Chapter 4.3 --- "Effects of physico-chemical conditions on Cu2+, Ni2+ and Zn2+ adsorption by chitin A" --- p.137
Chapter 4.3.1 --- Solution pH and concentration of biosorbent --- p.137
Chapter 4.3.2 --- Retention time --- p.138
Chapter 4.3.3 --- Initial metal ion concentration --- p.139
Chapter 4.3.4 --- Presence of other cations --- p.141
Chapter 4.3.5 --- Presence of anions --- p.143
Chapter 4.4 --- "Optimization of Cu2+, Ni2+ and Zn2+ removal efficiencies" --- p.147
Chapter 4.5 --- "Recovery of Cu2+, Ni2+and Zn2+ from metal ion-laden chitin A" --- p.148
Chapter 4.5.1 --- Performances of various eluents on metal ion recovery --- p.148
Chapter 4.5.2 --- Multiple adsorption and desorption cycle of metal ions --- p.149
Chapter 4.6 --- Treatment of electroplating effluent by chitin A --- p.150
Chapter 4.6.1 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from rinsing baths" --- p.150
Chapter 4.6.2 --- "Removal and recovery of Cu2+, Ni2+ and Zn2+ from electroplating effluent collected from final collecting tank" --- p.152
Chapter 5. --- Conclusion --- p.154
Chapter 6. --- Further studies --- p.156
Chapter 7. --- Summary --- p.158
Chapter 8. --- References --- p.161

Стилі APA, Harvard, Vancouver, ISO та ін.

26

"Removal and recovery of copper ion (Cu²⁽) from electroplating effluent by pseudomonas putida 5-X immobilized on magnetites." Chinese University of Hong Kong, 1996. http://library.cuhk.edu.hk/record=b5888810.

Повний текст джерела

Анотація:

by Sze Kwok Fung Calvin.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.
Includes bibliographical references (leaves 118-130).
Acknowledgement --- p.i
Abstract --- p.ii
Content --- p.iv
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Literature review --- p.1
Chapter 1.1.1 --- Heavy metals in the environment --- p.1
Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.2
Chapter 1.1.3 --- Electroplating industry in Hong Kong --- p.6
Chapter 1.1.4 --- Chemistry and toxicity of copper in the environment --- p.7
Chapter 1.1.5 --- Methods of removal of heavy metal from industrial effluent --- p.9
Chapter A. --- Physico-chemical methods --- p.9
Chapter B. --- Biological methods --- p.9
Chapter 1.1.6 --- Methods of recovery of heavy metal from metal-loaded biosorbent --- p.17
Chapter 1.1.7 --- The physico-chemical properties of magnetites --- p.18
Chapter 1.1.8 --- Magnetites for water and wastewater treatment --- p.19
Chapter 1.1.9 --- Immobilized cell technology --- p.24
Chapter 1.1.10 --- Stirrer-tank bioreactor --- p.26
Chapter 1.2 --- Objectives of the present study --- p.28
Chapter 2. --- Materials and Methods --- p.30
Chapter 2.1 --- Selection of copper-resistant bacteria --- p.30
Chapter 2.2 --- Culture media and chemicals --- p.30
Chapter 2.3 --- Growth of the bacterial cells --- p.32
Chapter 2.4 --- Immobilization of the bacterial cells on magnetites --- p.32
Chapter 2.4.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.34
Chapter 2.4.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.34
Chapter 2.5 --- Copper ion uptake experiments --- p.35
Chapter 2.6 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.35
Chapter 2.7 --- Transmission electron micrograph and scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.36
Chapter 2.7.1 --- Transmission electron micrograph --- p.36
Chapter 2.7.2 --- Scanning electron micrograph --- p.37
Chapter 2.8 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.37
Chapter 2.9 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.38
Chapter 2.9.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.38
Chapter 2.9.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.39
Chapter 2.10 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.39
Chapter 2.10.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.39
Chapter 2.10.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.40
Chapter 2.11 --- Statistical analysis of data --- p.43
Chapter 3. --- Results --- p.44
Chapter 3.1 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.44
Chapter 3.1.1 --- Effects of cells to magnetites ratio --- p.44
Chapter 3.1.2 --- Effects of pH --- p.44
Chapter 3.1.3 --- Effects of temperature --- p.44
Chapter 3.2 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.49
Chapter 3.3 --- Copper ion uptake experiments --- p.49
Chapter 3.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.49
Chapter 3.4.1 --- Effects of pH --- p.49
Chapter 3.4.2 --- Effects of temperature --- p.53
Chapter 3.4.3 --- Effects of retention time --- p.53
Chapter 3.4.4 --- Effects of cations --- p.53
Chapter 3.4.5 --- Effects of anions --- p.57
Chapter 3.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62
Chapter 3.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.62
Chapter 3.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68
Chapter 3.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.68
Chapter 3.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.68
Chapter 3.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.74
Chapter 3.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.74
Chapter 3.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.74
Chapter 3.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.81
Chapter 4. --- Discussion --- p.89
Chapter 4.1 --- Selection of copper-resistant bacteria --- p.89
Chapter 4.2 --- Effects of physical and chemical factors on the immobilization of the bacterial cells on magnetites --- p.89
Chapter 4.2.1 --- Effects of cells to magnetites ratio --- p.89
Chapter 4.2.2 --- Effects of pH --- p.90
Chapter 4.2.3 --- Effects of temperature --- p.91
Chapter 4.2.4 --- Effects of pH on the desorption of bacterial cells from magnetites --- p.92
Chapter 4.3 --- Copper ion uptake experiments --- p.93
Chapter 4.4 --- Effects of physico-chemical and operational factors on the Cu2+ removal capacity of the magnetite-immobilized bacterial cells --- p.94
Chapter 4.4.1 --- Effects of pH --- p.95
Chapter 4.4.2 --- Effects of temperature --- p.96
Chapter 4.4.3 --- Effects of retention time --- p.97
Chapter 4.4.4 --- Effects of cations --- p.98
Chapter 4.4.5 --- Effects of anions --- p.101
Chapter 4.5 --- Transmission electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.101
Chapter 4.6 --- Scanning electron micrograph of Pseudomonas putida 5-X loaded with Cu2+ --- p.102
Chapter 4.7 --- Copper ion adsorption isotherm of the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.103
Chapter 4.8 --- Recovery of adsorbed Cu2+ from the magnetite-immobilized cells of Pseudomonas putida 5-X --- p.104
Chapter 4.8.1 --- Effects of eluents on the Cu2+ removal and recovery capacity of the magnetite-immobilized cells --- p.104
Chapter 4.8.2 --- Batch type multiple adsorption-desorption cycles of Cu2+ using ethylenediaminetetra-acetic acid (EDTA) --- p.105
Chapter 4.9 --- Removal and recovery of Cu2+ from the electroplating effluent by a bioreactor --- p.107
Chapter 4.9.1 --- Batch type multiple adsorption-desorption cycles using the copper solution and electroplating effluent --- p.107
Chapter 4.9.2 --- Continuous type bioreactor to remove and recover Cu2+ from copper solution and electroplating effluent --- p.108
Chapter 5. --- Conclusion --- p.110
Chapter 6. --- Summary --- p.112
Chapter 7. --- References --- p.115

Стилі APA, Harvard, Vancouver, ISO та ін.

27

"Removal of copper ion (CU2+) from industrial effluent by immobilized microbial cells." Chinese University of Hong Kong, 1991. http://library.cuhk.edu.hk/record=b5886893.

Повний текст джерела

Анотація:

by So Chi Ming.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1991.
Includes bibliographical references.
Acknowledgement --- p.i
Abstract --- p.ii
Chapter 1. --- Objectives of the Study --- p.1
Chapter 2. --- Literature Review --- p.2
Chapter 2.1 --- Heavy Metals in the Environment --- p.2
Chapter 2.2 --- Heavy Metal Pollution in Hong Kong --- p.3
Chapter 2.3 --- Chemistry and Toxicity of Copper in the Environment --- p.6
Chapter 2.4 --- Conventional and Alternative Methods for Heavy Metal Removal --- p.10
Chapter 2.5 --- Heavy Metal Removal by Microorganisms --- p.14
Chapter 2.6 --- Factors Affecting Biosorption of Heavy Metals --- p.27
Chapter 2.7 --- Applicability of Biosorbent in Heavy Metal Removal --- p.31
Chapter 3. --- Materials and Methods --- p.36
Chapter 3.1 --- Screening of Bacteria for Copper Removal Capacity --- p.36
Chapter 3.1.1 --- Isolation of Bacteria from Activated Sludge --- p.36
Chapter 3.1.2 --- Selection of Copper Resistant Bacteria from Water Samples --- p.37
Chapter 3.1.3 --- Pre-screening of Bacteria for Copper Uptake --- p.37
Chapter 3.1.4 --- Determination of Copper Removal Capacity of Selected Bacteria --- p.37
Chapter 3.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.39
Chapter 3.2.1 --- Effect of Nutrient Limitation --- p.39
Chapter 3.2.2 --- Effect of Incubation Temperature and Culture Age --- p.41
Chapter 3.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.41
Chapter 3.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.41
Chapter 3.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.43
Chapter 3.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.43
Chapter 3.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.43
Chapter 3.5.1 --- Determination of Copper Uptake Kinetics --- p.43
Chapter 3.5.2 --- Determination of Freundlich Isotherm for Copper Uptake --- p.44
Chapter 3.5.3 --- Effect of pH on Copper Removal Capacity --- p.44
Chapter 3.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.44
Chapter 3.5.5 --- Effect of Anions on Copper Removal Capacity --- p.45
Chapter 3.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.45
Chapter 3.6.1 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.47
Chapter 3.6.2 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.47
Chapter 3.6.3 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles --- p.48
Chapter 3.6.4 --- Treatments of Effluent from an Electroplating Factory by Immobilized Cells --- p.48
Chapter 4. --- Results --- p.49
Chapter 4.1 --- Screening of Bacteria for Copper Removal Capacity --- p.49
Chapter 4.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.49
Chapter 4.2.1 --- Effect of Nutrient Limitation --- p.49
Chapter 4.2.2 --- Effect of Incubation Temperature and Culture Age --- p.52
Chapter 4.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.52
Chapter 4.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.52
Chapter 4.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.52
Chapter 4.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.56
Chapter 4.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.56
Chapter 4.5.1. --- Determination of Copper Uptake Kinetics --- p.56
Chapter 4.5.2 --- Determination of Freundlich Isotherm for Copper Uptake --- p.56
Chapter 4.5.3 --- Effect of pH on Copper Removal Capacity --- p.60
Chapter 4.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.60
Chapter 4.5.5 --- Effect of Anions on Copper Removal Capacity --- p.60
Chapter 4.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.60
Chapter 4.6.1 --- Copper Removal Capacity of Immobilized Cells and Breakthrough Curve for Copper Removal --- p.60
Chapter 4.6.2 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.65
Chapter 4.6.3 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.65
Chapter 4.6.4 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles --- p.65
Chapter 4.6.5 --- Treatment of Effluent from an Electroplating Factory by Immobilized Cells --- p.65
Chapter 5. --- Discussion --- p.72
Chapter 5.1 --- Screening of Bacteria for Copper Removal Capacity --- p.72
Chapter 5.2 --- Effect of Culture Conditions on Copper Removal Capacity of Pseudomonas putida 5-X --- p.73
Chapter 5.2.1 --- Effect of Nutrient Limitation --- p.73
Chapter 5.2.2 --- Effect of Incubation Temperature and Culture Age --- p.74
Chapter 5.3 --- Determination of Copper Uptake Mechanism of Pseudomonas putida 5-X --- p.75
Chapter 5.3.1 --- Effect of Glucose and Sodium Azide on Copper Removal Capacity --- p.75
Chapter 5.3.2 --- Transmission Electron Micrograph of Pseudomonas putida 5-X after Copper Uptake --- p.75
Chapter 5.4 --- Effect of Pretreatment of Cells on Copper Removal Capacity of Pseudomonas putida 5-X --- p.76
Chapter 5.5 --- Physico-chemical Characterization of Pseudomonas putida 5-X as Biosorbent for Copper Removal --- p.77
Chapter 5.5.1 --- Copper Uptake Kinetics --- p.77
Chapter 5.5.2 --- Freundlich Isotherm for Copper Uptake --- p.78
Chapter 5.5.3 --- Effect of pH on Copper Removal Capacity --- p.78
Chapter 5.5.4 --- Effect of Metal Ions on Copper Removal Capacity --- p.79
Chapter 5.5.5 --- Effect of Anions on Copper Removal Capacity --- p.80
Chapter 5.6 --- Copper Removal by Immobilized Cells of Pseudomonas putida 5-X --- p.80
Chapter 5.6.1 --- Copper Removal Capacity of Immobilized Cells and Breakthrough Curve for Copper Removal --- p.80
Chapter 5.6.2 --- Effect of Retention Time on Copper Removal Capacity of Immobilized Cells --- p.82
Chapter 5.6.3 --- Efficiency of Copper Recovery from Immobilized Cells by Various Eluants --- p.82
Chapter 5.6.4 --- Performance of Immobilized Cells on Multiple Copper Loading-elution Cycles 的 --- p.83
Chapter 5.6.5 --- Treatment of Effluent from an Electroplating Factory by Immobilized Cells --- p.84
Chapter 6. --- Conclusion --- p.85
Chapter 7. --- Summary --- p.87
Chapter 8. --- References --- p.89

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Phetla, Tebogo Pilgrene. "Removal and recovery of heavy metal from multi-component metal effluent by reduction crystallization." Thesis, 2012. http://hdl.handle.net/10210/4940.

Повний текст джерела

Анотація:

M.Tech.
The removal and recovery of heavy metals from effluents has been a subject of significant importance due the negative impact these toxic metals have on human health and the environment as a result of water and soil pollution. Precipitation is the mostly widely used wastewater treatment method because it is the most economical and easier to implement and operate on a large scale. However, traditional precipitation methods using lime, sulfides or hydroxides recover metals in the form of a sludge which is not reusable and has to be disposed in landfills creating a potential environmental hazard and resulting in loss of valuable minerals. The current focus in effluent treatment is now on the recovery and re-use of these heavy metals rather than removal and disposal. This study investigated the use of hydrazine as a reducing agent to remove and recover Ni2+, Cu2+, Co2+ and Fe2+ from effluent by reduction crystallization. In this process chemically reduced aqueous metal ions were plated on to a base substrate (nickel powder) with no electrical current required for deposition. A feasibility study was carried out to test the efficiency and find the optimum operating conditions for this method and generate an understanding of the chemical and particulate process occurring. The results obtained indicate that hydrazine is an effective reducing agent for removal and crystallization of Ni2+, Cu2+, Co2+ and Fe2+/ Fe3+ into their elemental states with nickel powder as a seeding material. Over 99 % of metals were removed from the effluent in all the systems (Ni-only, Ni-Cu, Ni-Fe and Ni-Fe). Breakage, aggregation and molecular growth were identified as the predominant mechanisms occurring during the reduction crystallization process in Ni-only, Ni-Cu, Ni- Co systems and there was evidence of nucleation in Ni-Fe solution. These finding were confirmed by analysing the scanning electron micrographs of the powder obtained. A nearly spherical structure powder with wide distribution in particle size and evidence of fragmentation was obtained in all the experimental runs. vii The residual concentrations obtained were far below the required limit for effluent discharge into sewer where 20 mg/L Ni, 20 mg/L Cu and 20 mg/L Fe and the total metal concentration of 50 mg/L for Fe, Cr, Cu, Ni, Zn and Cd is stipulated. Reduction crystallization using hydrazine as a reducing agent can be utilized for controlling environmental pollution and eliminating hazardous metals from the environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Kamika, Ilunga. "Tolerance limits of selected protozoan and bacterial isolates to vanadium and nickel in wastewater systems." 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000741.

Повний текст джерела

Анотація:

D. Tech. Environmental, Water and Earth Sciences
Pollution of water sources with heavy metals is currently a global concern due to the detrimental effect of these metals on both human and animal health. To address this issue, biological treatment methods have been seen as the most effective and eco-friendly option of the available treatment processes of wastewater. The aim of this study was to compare the ability of selected bacterial isolates and indigenous protozoan to tolerate nickel and vanadium in wastewater systems in order to determine which group of organisms might play a major role in the removal of nickel and vanadium, even at high concentrations, in wastewater treatment systems.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Mellem, John Jason. "Phytoremediation of heavy metals using Amaranthus dubius." Thesis, 2008. http://hdl.handle.net/10321/355.

Повний текст джерела

Анотація:

Thesis (M. Tech.: Biotechnology)-Dept. of Biotechnology and Food Technology, Durban University of Technology, 2008. xiv, 103 leaves : ill.
Phytoremediation is an emerging technology where specially selected and engineered metal-accumulating plants are used for bioremediation. Amaranthus dubius (marog or wild spinach) is a popular nutritious leafy vegetable crop which is widespread especially in the continents of Africa, Asia and South America. Their rapid growth and great biomass makes them some of the highest yielding leafy crops which may be beneficial for phytoremediation. This study was undertaken to evaluate the potential of A. dubius for the phytoremediation of Chromium (Cr), Mercury (Hg), Arsenic (As), Lead (Pb), Copper (Cu) and Nickel (Ni). Locally gathered soil and plants of A. dubius were investigated for the metals from a regularly cultivated area, a landfill site and a sewage site. Metals were extracted from the samples using microwave-digestion and analyzed using Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS). Further experiments were conducted with plants from locally collected seeds of A. dubius, in a tunnel house under controlled conditions. The mode of phytoremediation, the effect of the metals on the plants, the ability of the plant to extract metals from soil (Bioconcentration Factor - BCF), and the ability of the plants to move the metals to the aerial parts of the plants (Translocation Factor - TF) were evaluated for the different metals. Finally, A. dubius was micro-propagated in a tissue culture system with and without exposure to the metal, and the effect was studied by electron microscopy.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Setshedi, Katlego. "Bio compatible nano-structured hydrotalcite for the removal of heavy metals from wastewater." 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000293.

Повний текст джерела

Анотація:

M. Tech. Chemical Engineering.
In this study, nano-structure hydrotalcite material was used as an adsorbent for the removal of heavy metals of lead (Pb), nickel (Ni), cadmium (Cd) and cobalt (Co) from wastewater. It was observed that, in comparison with single component system (Ni, Cd and Co only), the presence of co-ions reduced the Ni (II), Cd (II) and Co (II) adsorption suggesting suppression of the desired ion by the presence of co-existing ions. The kinetic data fitted well to pseudo-second order model while the equilibrium data were satisfactorily described by Langmuir isotherm. The adsorption capacities of Ni (II), Cd (II) and Co (II) at pH 6.0 were found to be 142.8, 200 and 142.8 mg/g at 25oC.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Nleya, Yvonne. "Removal of toxic metals and recovery of acid from acid mine drainage using acid retardation and adsorption processes." Thesis, 2016. http://hdl.handle.net/10539/21051.

Повний текст джерела

Анотація:

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2016
The remediation of acid mine drainage (AMD) has received much attention over the years due to the environmental challenges associated with its toxic constituents. Although, the current methods are able to remediate AMD, they also result in the loss of valuable products which could be recovered and the financial benefits used to offset the treatment costs. Therefore, this research focused on the removal of toxic heavy metals as well as the recovery of acid using a low cost adsorbent and acid retardation process, respectively. In the first aspect of the study, three low cost adsorbents namely zeolite, bentonite clay and cassava peel biomass were evaluated for metal uptake. The adsorption efficiencies of zeolite and bentonite, was found to be less than 50% for most metal ions, which was lower compared to the 90% efficiency obtained with cassava peel biomass. Subsequently, cassava peel biomass was chosen for further tests. The metal removal efficiency using the cassava biomass was in the order Co2+> Ni2+> Ca2+> Mn2+> Fe3+> Mg2+. The highest metal removal was attained at 2% adsorbent loading and 30 ˚C solution temperature. Amongst the equilibrium models tested, the experimental data was found to fit well with the Langmuir isotherm model. Column studies using the immobilized cassava waste biomass suggested that the breakthrough curves of most metal ions did not resemble the ideal breakthrough curve, due to the competitive nature of the ions present in the AMD used in this study. However, the experimental data from the column tests was found to correlate well with the Adam-Bohart model. Sulphuric acid recovery from the metal barren solution was evaluated using Dowex MSA-1 ion exchange resins. The results showed that sulphuric acid can be recovered by the resins via the acid retardation process, and could subsequently be upgraded to near market values of up to 70% sulphuric acid using an evaporator. Water of re-usable quality could also be obtained in the acid upgrade process. An economic evaluation of the proposed process also showed that it is possible to obtain revenue from sulphuric acid which could be used to offset some of the operational costs.
M T 2016

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Setshedi, Katlego. "Removal of heavy metals from industrial wastewater using polymer clay nanocomposites as novel adsorbents." 2014. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001683.

Повний текст джерела

Анотація:

D. Tech. Chemical Engineering.
This research aims to improve the current state of wastewater treatment technologies by exploiting the characteristics and capabilities of nanomaterials. Also, it aims at protecting the environment and human health by minimizing exposure of toxic contaminants found in waters sources by treatment with cheaply engineered materials. The nanocomposites that will be employed in this study have shown to be effective for removing a number of heavy metals from aqueous solutions during trial experiment. The study is therefore carried out to reduce the water scarcity in South Africa by minimizing the contamination of remaining water resources. With industrial effluents the main targets, the aim is to design systems that will enable industries to recycle their wastewater instead of discharging into the environment. This study will therefore benefit the communities who solely depend on surface and ground water and again it will safe industrial bodies high costs of treating their wastewater with ineffective conventional methods. The research focuses on the application of polypyrrole-clay nanocomposites for removing heavy metals from wastewater streams. The research conducted hereby highlights the application of polymer based nanocomposites as suitable adsorbents for the remediation of the toxic chromium(VI) [Cr(VI)] from water. The work describes the preparation and characterization of the nanocomposites, their application to wastewater laden with Cr(VI) in both batch and continuous adsorption and finally understanding the adsorbent-adsorbate interactions and sorption mechanisms under various physico-chemical conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Muthui, Muliwa Anthony. "Magnetic adsorption separation process for industrial wastewater treatment using polypyrrole-magnetite nanocomposite." 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001106.

Повний текст джерела

Анотація:

M.Tech. Engineering: Chemical.
Aims at demonstrating the application of semi-continuous and continuous magnetic adsorption separation (MAS) techniques to extract Cr (VI) ions from wastewater streams using PPy-Fe3O4 nanocomposite. Specifically, the research aims to achieve the following objectives: to design, synthesize and characterize new generation PPy-Fe3O4 nanocomposite with varied magnetite composition for hexavalent chromium removal ; to generate batch adsorption kinetic data in a continuously stirred tank reactor (CSTR) and apply existing kinetic models to aid in water treatment system design.; to design and construct magnetic adsorption separation (MAS) device that can operate in a semi-continuous and continuous mode and explore their performances and to optimize the systems' performance.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Van, Der Walt Hendrik Stephanus. "Die invloed van sekere swaarmetale op groeiverskynsels van Euglena gracilis." Thesis, 2014. http://hdl.handle.net/10210/9212.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Phaal, Clinton B. "Complex soil-microorganism-pollutant interactions underpinning bioremediation of hydrocarbon/heavy metal contaminated soil." Thesis, 1996. http://hdl.handle.net/10413/9147.

Повний текст джерела

Анотація:

This study evaluated the efficacy of bioremediation as a treatment option for a hydrocarbon and heavy metal contaminated soil. Microbial degradation of hydrocarbons under aerobic, nitrate-reducing and sulphate-reducing conditions was examined. Nutrient supplementation with nitrogen and phosphate as well as aeration seemed to be the most important factors for enhancing biodegradation. From initial batch studies, a carbon: nitrogen ratio of 50: 1 was found to be optimal for biodegradation. However, very low carbon to nitrogen ratios were undesirable since these inhibited microbial activity. Manipulation of the pH did not seem to be beneficial with regard to hydrocarbon biodegradation. However, low pH values induced elevated concentrations of leachate heavy metals. Aerobic conditions provided optimal conditions for hydrocarbon catabolism with up to 54% of the original contaminant degraded after 2 months of treatment. Further treatment for up to 20 months did not significantly increase hydrocarbon biodegradation. Under nitrate- and sulphatereducing conditions, 6% and 31 % respectively of the initial contaminant was degraded after 2 months while after a further 20 months, 50% and 42%, respectively were degraded. The addition of soil bulking agents and the use of sparging did not significantly increase biodegradation. Similarly, the addition of inoculum did not influence biodegradation rates to any great degree. The presence of heavy metals up to concentrations of 400 mgt1 Mn, 176 mgt1 Zn and 94 mgt1 Ni did not reduce microbial activity within the soil. During the treatment phase, heavy metal and hydrocarbon migration were limited even under water saturation and low pH conditions. A Biodegradation Index was developed and evaluated and may, potentially, find use as an in situ assessment technique for microbial hydrocarbon catabolism. The iodonitrophenyltetrazolium salt assay was also found to be an effective and rapid alternative assay for monitoring bioremediation progress.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Maharaj, Saroja. "The accumulation of heavy metals by aquatic plants." Thesis, 2003. http://hdl.handle.net/10321/2082.

Повний текст джерела

Анотація:

Submitted in partial fulfillment of the requirements for the degree in Masters of Technology: Chemistry, ML Sultan Technikon, Durban, 2003.
The pollution of water bodies by heavy metals is a serious threat to humanity. The technique known as phytoremediation is used to clean up these polluted water bodies. The accumulation of heavy metals by aquatic plants is a safer, . cheaper and friendlier manner of cleaning the environment. The aquatic plants -studied in this project are A.sessilis, P.stratiotes, R.steudelii and T.capensis. The accumulation of heavy metals in aquatic plants growing in waste water treatment ponds was investigated. The water, sludge and plants were collected from five maturation ponds at the Northern Waste Water Treatment Works, Sea Cow Lake, Durban. The samples were analysed for Zn, Mn, Cr, Ni, Pb and Cu using ICP-MS. In general it was found that the concentrations of the targeted metals were much lower in the water (0.002 to 0.109 mg/I) compared to sediment/sludge (44 to 1543mg/kg dry wt) and plants (0.4 to 2246 mg/kg dry wt). These results show that water released into the river from the final maturation pond has metal concentrations well below the maximum limits set by international environmental control bodies. It also shows that sediments act as good sinks for metals and that plants do uptake metals to a significant extent. Of the four plants investigated it was found that }t.sessi[ir (leaves, roots and stems) and }A.sessilis (roots and stems) are relatively good collectors of Mn and Cu respectively. These findings are described in the thesis. The concentration of heavy metals in the stems, leaves and roots of the three plants were compared to ascertain if there were differences in the ability of the plant at different parts of the plant to bioaccumulate the six heavy metals studied.
M

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Sekhula, Mahlatse Mapula. "The use of maize tassel as a solid phase extraction sorbent for the recovery of copper, gold and silver from aqueous solution." 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000465.

Повний текст джерела

Анотація:

M. Tech. Environmental Management
Investigates the possibility of using maize tassel powder as a solid phase extraction sorbent for the recovery of Ag, Au and Cu from aqueous solution. The surface characteristics of maize tassel and its ability to remove Ag, Au and Cu from aqueous solutions needed to be established before the preparation of maize tassel beads.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Songo, Morongwa Martha. "Wastewater treatment using magnetic metal doped iron oxide nano particles." 2014. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001512.

Повний текст джерела

Анотація:

M. Tech. Chemical Engineering
The lack of clean and fresh water has become a worldwide problem because of water pollution caused by industrialization. Contamination of natural water sources by heavy metal is a worldwide public health problem, leading to waterborne outbreaks of infectious hepatitis, viral gastroenteritis, and cancer. Therefore it very important to remove these toxic metal ions from municipal and industrial effluents in order to protect plants, animals and human beings from their adverse effect before discharging into natural water bodies. Although, several separation methods such as filtration, reverse osmosis and membrane technology have been developed to remove these toxic heavy metal ions from wastewater, however these conventional treatments technologies were found to be expensive on a sustainable basis. Adsorption process was identified as the most effective, and extensively used essential process in wastewater treatment, and in order for adsorption process to feasibly remove pollutants from wastewater, there should be a need for a suitable adsorbent which will have a large porous surface area, and a controllable porous structure. Through the application of nanotechnology, nano adsorbents can be developed as effective adsorbents to treat wastewater. The main objective of this project was to apply magnetic metal doped iron oxides as an efficient adsorption media for the removing of Cr(VI), Cd(II) and V(V) ions from wastewater.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Desta, Tsegazeab Goje. "Humic acid pretreatment for enhancing microbial removal of metals from a synthetic 'wastewater'." Thesis, 2004. http://hdl.handle.net/10413/3576.

Повний текст джерела

Анотація:

The presence of heavy metal ions in waste streams is one of the most pervasive environmental issues of present times. A rotating biological contactor (RBC) was used to investigate the potential capacity of microbial biofilms in remediation of the metal ion species from a mixed metal contaminated effluent solution containing Cr+3 , Pb+2 and Cu+2 , each at a concentration of 200 mg r1 • In the first part of this study the effectiveness of various support materials for the development of microbial biofilms capable of removing heavy metals from a synthetic effluent was investigated. EDX analysis showed that none of the support matrices investigated, viz. gravel, polyester batting and sand, adsorbed metal ions on their surfaces; hence, metal adsorption was due purely to microbial activities. The biofilms attached more firmly and uniformly to polyester batting than to gravel and sand. The characteristics of polyester batting which made it a superior support matrix were its surface roughness and porous hydrophilic nature, which provided a larger surface area for the adhesion of microorganisms and attraction of nutrients during the biofilm development process. The selective accumulation of metal ion specIes by various microbial populations grown as biofilm using polyester batting as support matrix in separate compartments of a single-stage RBC bioreactor was examined. Lead ions were readily accumulated by almost all the microbial biofilms tested. Fungus-dominated biofilms selectively accumulated chromium ions whereas biofilms comprising mainly bacteria more readily accumulated copper ions from the mixed metal contaminated effluent solution. However, where interactions between the bacterial and fungal components were encouraged the mechanical stability of the biofilms was enhanced so that large amounts of all three metal ion species were removed by this biofilm. The combined effect of a series of bench-scale columns containing liquid humic acid and a three stage RBC bioreactor on the removal of metal ion species from a mixed metal contaminated effluent was investigated. After seven days of treatment the combined system had removed approximately 99% of the Cr+3, 98% of the Pb+2 and 90% of the Cu+2 ions from the mixed metal contaminated synthetic effluent. Complexation of the metal ions with humic acid was the predominant factor accounting for approximately 68-86% Cr+3 , 70-86% Pb+2 and 53-73% Cu+2 removal levels within the columns. A large proportion of the remaining Cr+3 and Pb+2, but not of the Cu+2, was removed in compartment 1 of the RBC. This suggested that the presence of the former two metals in solution might have reduced the removal of the Cu+2 ions from the system. The removal of substantially large amounts of the competing ions chromium and lead during the initial stages of the treatment process meant that copper was successfully taken up in the second and third RBC compartments. Hence, the economy of the treatment process was improved as larger quantities of the metal ions were removed in a shorter period of time than was possible when using the individual treatments (humic acid-metal complexation and biofilm adsorption) separately. More than 75%,92% and 86% of the adsorbed Cr+3 , Pb+2 and Cu+2 ions, respectively, were recovered from the three RBC bioreactor compartments following repeated washing of the biofilms with 0.1 M HCI. This relatively easy desorption suggested that the metal ions were simply adsorbed onto the surfaces of the biofilm cells rather than being taken into the cytoplasm of the cells.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Zaal, Steven Michael. "Passive treatment of acid mine drainage through permeable concrete and organic filtration." Thesis, 2016. http://hdl.handle.net/10539/20998.

Повний текст джерела

Анотація:

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016
The aim of this research was to reduce heavy metal and sulfate content of acid mine drainage (AMD) through the methods of passive filtration by combining permeable concrete and organic materials. This was to achieve a low cost, yet effective temporary treatment method for rural/poor communities who are affected by AMD. The acids are filtered through layers of alternating pervious concrete and biological composting layers. The concrete layers target removal of heavy metals such as iron, manganese, potassium, and magnesium, etc. through precipitation as well as reduce sulfate content to a small degree along with total dissolved solids. The concrete layers also aid in raising the pH of the AMD to more acceptable levels. The biological layers achieve sulfate remediation through the metabolism of sulfatereducing- bacteria (SRB). This process however required time and the organic layers were thus thicker and less permeable than the concrete layers in order to allow seepage to take place at a reduced rate. A wide variation of composting layers were tested, including cow manure, chicken manure, sawdust, straw, zoo manure, and leaf compost to find an optimum mix of materials which allows for the greatest sulfate reduction through sulfate reducing bacteria in the shortest possible time. Short as well as Long-term testing of rigs was undertaken to establish effectiveness, limitations and lifespan of the filtration systems. AMD from a mine in the Mpumalanga coal fields with exceptionally high sulfate content was used to test effectiveness of the organic materials over a short period of time. With long term testing conducted with a synthetic AMD, due to limited supply from the mine. The short term testing yielded removal of sulfates in the order of 56% when using kraal manure as the biological reagent mixed with sawdust for added organic carbon. The mix percentages by volume were 80%Sawdust to 20%manure and this setup was able to achieve the 56% removal of sulfates within 14 days. The filter also successfully raised the pH to 8 while removing a significant portion of heavy metals. The long term tests showed complete (100%) remediation of sulfates after a period of approximately sixty days. The tests are continuing to determine their finite lifespan and limitations. The results show promise for using the technology as a low cost, temporary measure to protect locally impacted groundwater, especially for isolated and/or rural communities while a permanent long term solution is sought.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Iloms, Eunice Chizube. "Investigating industrial effluent impacts on municipal wastewater treatment plant." Diss., 2018. http://hdl.handle.net/10500/25877.

Повний текст джерела

Анотація:

Industrial effluents with high concentrations of heavy metals are widespread pollutants of great concerns as they are known to be persistent and non-degradable. Continuous monitoring and treatment of the effluents become pertinent because of their impacts on wastewater treatment plants. The aim of this study is to determine the correlation between heavy metal pollution in water and the location of industries in order to ascertain the effectiveness of the municipal waste water treatment plant. Heavy metal identification and physico-chemical analysis were done using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and multi-parameter probe respectively. Correlation coefficients of the measured values were done to investigate the effect of the industrial effluents on the treatment plants. Heavy metal resistant bacteria were identified and characterised by polymerase chain reaction and sequencing. Leeuwkuil wastewater treatment plants were effective in maintaining temperature, pH, and chemical oxygen demand within South Africa green drop and SAGG Standards whereas the purification plant was effective in maintaining the values of Cu, Zn, Al, temperature, BOD, COD, and TDS within the SANS and WHO standard for potable water. This findings indicated the need for the treatment plants to be reviewed.The industrial wastewater were identified as a point source of heavy metal pollution that influenced Leeuwkuil wastewater treatment plants and the purification plants in Vaal, Vereenining South Africa. Pseudomonas aeruginosa, Serratia marcescens, Bacillus sp. strain and Bacillus toyonensis that showed 100% similarity were found to be resistant to Al, Cu, Pb and Zn. These identified bacteria can be considered for further study in bioremediation.
Environmental Sciences
M. Sc. (Environmental Science)

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Meyer, Angela. "Bioremediation of heavy metal polluted waters." Thesis, 1995. http://hdl.handle.net/10413/9249.

Повний текст джерела

Анотація:

Microorganisms have the potential to remove heavy metals from polluted waters and effluents and may be used in clean-up processes. Microbial associations were enriched for and adapted to grow in nutrient solutions containing various concentrations of different metals. As immobilised cells are known to be more stable and more efficient in metal uptake than are corresponding planktonic or free-living cells the attachment of the microbial associations was investigated using a model stream and it was found that biofilm development was better on rough surfaces such as ground glass and polystyrene than on smooth surfaces such as unetched glass plates and glass beads. When comparing metal uptake by planktonic and attached microorganisms, attached populations were found to have a greater metal-uptake capacity. The uptake of individual metals from various metal combinations was tested with various proportions of pregrown metal-adapted microbial populations as inoculum and it was found that a particular metal was taken up more readily by microbial associations which had previously been exposed to that metal. Lead (Pb2+) appeared to be taken up more readily than copper (Cu2+) or cadmium (Cd2+) while Cd2+ was more actively removed than Cu2+ from solution. pH also affected metal uptake and the optimum range for Cu2+ uptake by the Cu2+ -adapted microbial association was found to be between 5.8 and 7.0. Dead microbial biomass was investigated and found to have efficient metal uptake capacity. Living mycelium from an isolated Aspergillus species showed poor uptake of Cu2+ initially, but when this fungus was pregrown and subsequently killed by moist heat treatment the non-living mycelium was efficient in removal of Pb2+ and Cu2+ ions. The optimum mycelial biomass concentration for metal uptake was also determined. The mechanism of metal uptake by this Aspergillus species was determined, using electron microscopy and EDX techniques, to be metabolism-independent biosorption onto the hyphal surface. Thus the microbial associations and fungal cultures used in this study were shown to have the potential for use in the removal of heavy metals from polluted waters.
Thesis (Ph.D.)-University of Natal, Pietermartizburg, 1995.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

De, Kock Luéta-Ann. "Hybrid ion exchanger supported metal hydroxides for the removal of phosphate from wastewater." Thesis, 2015. http://hdl.handle.net/10210/15093.

Повний текст джерела

Анотація:

Ph.D. (Chemistry)
Phosphorus in the form of phosphate needs to be removed from the aqueous environment as it is primarily responsible for eutrophication of water bodies. In an attempt to limit the discharged of phosphorus into the aqueous environment, the phosphate discharge limits for wastewater treatment plants have been decreased. These limits are not easily or economically met by current phosphorus removal technologies. In addition phosphorus is a non-renewable resource. To ensure the ongoing quality of water bodies and security of food production it is vital that phosphate in water be removed and recovered. In order to address these issues, novel hybrid metal oxide ion exchange resins based on Fe(III), Cu(II), Mn(IV and Ti(IV) oxides have been prepared and their phosphate adsorption characteristics determined.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Mthombo, Sydney Thabo. "Polymer-zeolite nanocomposites : preparation, characterization and application in heavy-metal removal." Thesis, 2013. http://hdl.handle.net/10210/8603.

Повний текст джерела

Анотація:

M.Sc. (Chemistry)
Polymer nanocomposites are a new class of composites in which at least one dimension of the particles dispersed in the polymer matrix is in the nanometer range. Recently, different types of zeolite minerals, either natural (Clinoptilolite, chabazite, modernite) or synthetic (A-type, X-type, Y-type) are being employed as particulate fillers into the polymer matrix. Owing to their unique ion exchange phenomenon, zeolites have been widely studied as heavy metal adsorbents, but very few researchers have focused on the sorption of heavy metal ions on zeolite-filled polymer nanocomposites...

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Leswifi, Taile Yvonne. "Removal of Lead, Fluoride and Chromium from water using Metal oxide nanostructured adsorption media." 2010. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001339.

Повний текст джерела

Анотація:

M. Tech. Chemical Engineering.
Discusses the application of nanotechnology process to offer wholesale benefits in water and wastewater treatment, extremely very few researches have been conducted in this field. Even with the few, studies have mainly focused on using single ion aqueous solution. Such approach is novel but the results may not give true picture of performance of nano-materials. It's known that water quality adversely affect sorption process. It's thus product to use real field water and wastewater to get valuable results. Presently, there is almost no information is open literature regarding the application of nano-scale adsorbents in treating real water and wastewater.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Akinsaya, Nurudeen Akinwale. "Analysis of Heavy Metals and Persistent Organic Pollutants in Sewage Sludge from Thohoyandou Wastewater Treatment Plant and transfer to Vegetables." Diss., 2018. http://hdl.handle.net/11602/1112.

Повний текст джерела

Анотація:

MENVSC
Department of Hydrology and Water Resources
Sewage sludge (biosolids) from wastewater treatment plants (WWTPs) has been widely used as a soil improver in Europe, United States of America and some developing countries including South Africa. It has its benefits for farmers as a good source of organic matter and minerals, however, sludge after treatment still contains pathogenic organisms, heavy metals and persistent organic pollutants (POPs). The POP and heavy metal contaminants that accumulate in sludge may transfer through the food chain and cause adverse effects on human beings. In this study, a field experiment was carried out on farmland fertilized with sewage sludge from a wastewater treatment plant (WWTP) that vasically receives domestic wastewater and storm water. Vegetable spinach (Spinacia oleracea) was used for this study and was planted on a farmland under controlled conditions. Ten ridges each of dimensions 20 m × 0.3 m was made and dry sludge weights of 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 kg were applied as manure on each of the ridges, respectively. Representative samples of sludge and soil were taken for analysis of heavy metals and POPs. At maturity, in twelve weeks, the root and leave samples of the vegetable were taken from all the ridges including the control. The soil, sludge, and vegetable samples were analyzed for total heavy metal content (Cd, Cr, Cu, Ni, Pb, Co, Zn, Al, Fe, Mn), speciated heavy metal content and POP (PAH, PCB). Soil and sludge samples were also analyzed for total organic content, pH, cation exchange capacity (CEC), conductivity and alkalinity. The analysis for total heavy metals and speciated heavy metal content was carried out using inductively coupled plasma optical emission spectrophotometer (ICP-OES), and CEC analysis was carried out using atomic absorption spectrophotometer (AAS). A two-dimensional gas chromatograph with time of flight mass spectrometry detector (GC X GC TOFMS) was used for POP measurements. pH measurement was made using a pH meter and conductivity measurement using a conductivity meter. Alkalinity and total organic content analysis was performed using titrimetric apparatus. The highest total heavy metal concentration of 378.9 mg / kg was recorded in Fe metal in soil and Leaf sample while the lowest total metal concentration of 0.0003 mg / kg was in Cu metal in root sample. The highest heavy metal concentration of 1002 mg / kg in speciated forms was in Mn metal in F1 fraction and the lowest of 0.0004 mg / kg was in Cd metal in F5 fraction. PAHs were only found in soil samples and their concentrations ranged from 2.53 mg / kg to 146.5 mg / kg. There were no PCB detected in all the samples analysed. The results indicated that the trace metals concentrations found in the exchangeable fraction were higher than those observed in any of the preceding extractions except in the case of Cd, Cr, Fe and Pb where Fe-Mn oxide and organic matter fractions predominated and were closely followed by exchangeable fraction.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Mukosha, Lloyd. "Enhanced adsorption of base metal, phenol and aldehyde from aqueous solutions on low-cost activated carbon." 2014. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001749.

Повний текст джерела

Анотація:

D. Tech. Chemical Engineering
Aims of this research project was to add value to largely wasted South African sawdust by development of low-cost AC of high efficiency for removal of toxic Cr (VI), phenol and glutaraldehyde from dilute aqueous media. The main objectives of the research project were: a) To develop low-cost AC based on South African P. patula sawdust using economical physical superheated steam activation.Characterization of carbon samples for selection of optimum preparation conditions for development of low-cost AC of effective microporosity mesoporosity and surface functionality for enhanced adsorption capacity of Cr (VI) and/or phenol and/or glutaraldehyde from dilute aqueous solution. Acid-amine surface groups modification of optimally developed AC for further enhancement of adsorption capacity for mixed polarized glutaraldehyde molecules from aqueous solution. b) To evaluate the aqueous phase batch adsorption properties of developed AC for Cr (VI) and phenol and, of acid-amine modified developed AC for glutaraldehyde. Determination of optimum pH for adsorption; accurate adsorption isotherm modelling for determination of maximum adsorption capacity, comparison of maximum adsorption capacities for Cr (VI) and phenol of developed AC with commercial AC and literature ACs, and attempt to establish average micropore size for enhanced capacity for Cr (VI) and phenol from dilute aqueous solution.Kinetics reaction and diffusion modelling for determination of adsorption rate constants and diffusion parameters; and determination of adsorption thermodynamic parameters.Evaluation of equilibrium selectivity of developed AC for Cr (VI) and/or phenol in binary aqueous solutions. c) To evaluate aqueous phase fixed-bed adsorption characteristics of developed AC for single Cr (VI) and mixed solution using Rapid Small Scale column Tests (RSSCTs). Generation of breakthrough curves at optimum adsorption conditions for evaluation of column performance indicators at different process conditions, bed regeneration-reusability potential, and dynamic adsorption selectivity of developed AC for Cr (VI) from solution of base metals. Determination of column diffusion parameters; accurate mass transfer and empirical modelling of breakthrough data; determination of applicable RSSCT scaling equation; and optimization of breakthrough data for accurate RSSCT scale-up.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Saad, Dalia. "Development and application of polymeric materials for heavy metal ions recovery from industrial and mining wastewaters." Thesis, 2012. http://hdl.handle.net/10539/11225.

Повний текст джерела

Анотація:

M.Sc., Faculty of Science, University of the Witwatersrand, 2011
Contamination of water bodies by heavy metals and metalloids is an established problem and several studies have been conducted to deal with it. South Africa is amongst those countries whose water systems are most affected as a result of intensive mining activities. This research was dedicated to the development of insoluble chelating polymers for use as adsorbents to abstract heavy metal ions from mining and industrial wastewater. Branched polyethylenimine (PEI), well known for its metal chelating potential, was cross linked by epichlorohydrin in order to convert it into a water-insoluble form. The water-insoluble property gives the advantage of being used in situ and a possibility of regeneration and re-use, making it a more feasible and cost-effective method. Its surface was also modified for selective removal of specifically-targeted heavy metal and metalloid ions. The binding affinity of the synthesized materials to heavy metal and metalloid ions has been determined as well as their ability to be regenerated for reuse. These processes demonstrated that cross-linked polyethylenimine (CPEI) exhibited good complexation ability with high affinity to Cr and some divalent metal ions such as Fe, Zn, and Ni. On the other hand, it showed very poor ability to bind oxo-anions such as SeO32- and AsO2- which has been attributed to the unavailability of suitable functional groups to interact with these ions. The observed order of complexation was: Cr > Zn> Fe >> Ni > Mn > Pb >> As > U > Se. The phosphonated polyethylenimine (PCPEI) showed high selectivity for As, Mn and uranyl ions. The observed order of removal was: U > Mn> Ni > Zn > As >> Cr > Pb > Fe >> Hg > Se; whereas the suffocated polyethylenimine (SCPEI) exhibited high affinity to Se, and Hg. The observed order of adsorption was: Hg > Se >> U > Zn >Pb > Ni >> As > Cr > Fe. v The adsorption behaviour of these polymeric materials involved more than one mechanism such as complexation, normal surface charge exchange, and anion replacement and all these mechanisms are governed by the functional groups. The nitrogen atom on the chelating group (-NH) in the cross-linked polyethylenimine; the phosphorus atom on the chelating group (-PO3H2) in phosphonated cross-linked polyethylenimine; and sulphur atom on the chelating group (-SO3H) in suffocated cross-linked polyethylenimine act as Lewis bases and donate electrons to metal cations which are considered Lewis acids. The existence of the chelating groups in SCPEI and PCPEI facilitate the removal of oxo-anions through anion replacement since they exist as bases in solution and hence cannot be electron acceptors. Thus, the expected mechanism is the normal anion replacement. This mechanism can explain the high removal of Se by SCPEI since Se has similar chemical behaviour as sulphur and are in the same group in the periodic table. As such they can easily replace each other. Sulphur is released from the polymer into the solution by replacing the selenium ions in the polymer. Similar behaviour occurs between phosphorus in PCPEI and arsenic ions as As and P belong to the same group in the periodic table and hence have similarities in their chemical behaviour. The Langmuir and Freundlich isotherm models were used to interpret the adsorption nature of the metal ions onto synthesized polymers. The Freundlich isotherm was found to best fit and describe the experimental data describing the adsorption process of metal and metalloid ions onto the synthesized polymeric materials The kinetic rates were modelled using the pseudo first-order equation and pseudo second-order equation. The pseudo second-order equation was found to explain the adsorption kinetics most effectively implying chemisorption. vi The thermodynamic study of the adsorption of metals and metalloids by the synthesized CPEI, PCPEI and SCPEI resulted in high activation energies > 41 KJ mol-1 which confirm chemisorption as a mechanism of interaction between adsorbate and adsorbent. So far, the developed polymeric materials showed good results and have potential to be applied successfully for remediation of heavy metal-polluted waters, and they have potential for use in filter systems for household use in communities that use borehole water impacted by mining and industrial waste waters. The desorbed metals can be of use to metal processing industries.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Dimpe, Mogolodi. "Sample preparation techniques for determination of total metal content in wastewater treatment plants in Gauteng Province." Thesis, 2015. http://hdl.handle.net/10210/13709.

Повний текст джерела

Анотація:

M.Sc. (Chemistry)
Prosperity for South Africa depends on the sound management and utilization of many resources, with water playing a crucial role. Located largely in a semi-arid part of the world, South Africa’s water resources are, in global terms, scarce and extremely limited. A key environmental problem facing South Africa is water pollution. This arises from many sources, including mining and industrial effluents, and runoff of biocides, nutrients and pathogens from agricultural lands, urban areas and informal settlements with poor sanitation. The consequences are often severe, including among other impacts, habitat destruction, reduced oxygen levels, fish kills and loss of human life. Inorganic and organic pollutants as well as microbes are the main constituents of the effluent from the domestic, mining, agriculture, metal electroplating, petrochemical and transport industries. The presence of pollutants in environmental systems is of concern because ultimately, they are incorporated into drinking water and various food chains. Therefore, the overall focus of this study was mainly metals analysis in wastewater systems before and after treatment processes so as to establish the efficiency of the treatment processes....

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Sewage Purification Heavy metal removal"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями