Дисертації з теми "Dissolved heavy metal ion"
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1
Terdkiatburana, Thanet. "Simultaneous removal process for humic acids and metal ions by adsorption." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/1714.
Повний текст джерелаАнотація:
Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard.Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium.In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.
2
Terdkiatburana, Thanet. "Simultaneous removal process for humic acids and metal ions by adsorption." Curtin University of Technology, Dept. of Chemical Engineering, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18564.
Повний текст джерелаАнотація:
Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard.Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium.
In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.
3
Satofuka, Hiroyuki. "Studies on heavy metal ion-binding peptides : Application for heavy metal ion detection and detoxification." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149818.
Повний текст джерела
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Rozycki, Torsten von. "Computational investigations of divalent heavy metal ion homeostasis." kostenfrei, 2009. http://nbn-resolving.de/urn:nbn:de:gbv:3:4-359.
Повний текст джерела
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Lozenko, Sergii. "Heavy metal ion sensors based on organic microcavity lasers." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2011. http://tel.archives-ouvertes.fr/tel-00744846.
Повний текст джерелаАнотація:
Monitoring of environmental pollutants present at low concentrations requires creation of miniature, low-cost, and highly sensitive detectors that are capable to specifically identify target substances. In this thesis, a detection approach based on refractive index sensing with polymer micro-lasers is proposed and its application to the detection of heavy metal pollutants in water (mercury - Hg2+, cadmium - Cd2+ and lead - Pb2+) is studied. The resonance frequencies of the microcavity are highly sensitive to the refractive indices of the resonator surrounding: the resonances shift by a small amount when the surface refractive index changes, resulting from the interaction of the mode evanescent field with the surrounding medium. This permits label-free detection by coating the resonator with a suitable recognition species. The originality of this work lies in the utilization of active microcavities, or microlasers, created of the dye-doped polymers. Active microcavities offer an enhanced signal/noise ratio as compared to the passive ones and very narrow resonance peaks even at moderate quality factors (Q ≥- 6000). The choice of polymers as an active medium is connected with a number of advantages they offer: as opposite to semiconductors, polymers can be easily functionalized, integrated in microfluidic circuits and are cheaper in processing. Moreover, the use of porous polymer matrices may allow accumulation of analyte ions inside the microcavity and thus enhance the sensitivity. Two possible applications of microlasers are investigated in the thesis: refractive index variation sensing with non-functionalized cavities and heavy metal ion detection with functionalized cavities. In the first case, the sensitivity values have been obtained, comparable with the reported in literature for planar passive microresonators. In the second case, the experimental proofs of specific detection of mercury ions in liquid are presented. The ways of sensitivity improvement are discussed and verified and a foundation is layed for the creation of integrated Lab-on-Chip microfluidic biochemical detector.
6
Steinbaugh, Gregory E. "Heavy metal Ion transport utilizing natural and synthetic ionophores." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1189785736.
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Ma, Yiu Wa. "Fixed bed removal of heavy metal ions by chelating ion exchange." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491880.
Повний текст джерелаАнотація:
Column runs with varied operation conditions of flowrate, feed concentration and particle size have been conducted to observe the sorption of nickel, copper and zinc by the chelating resin. They all show a typical constant-pattern, steep curve in the first part of the breakthrough curve and the slope would dramatically reduce at a breakpoint such that it would take extremely long time to reach 100% breakthrough level. ~ The Modified Bed Depth Service Time (BDST) model incorporated with a timedependent bed capacity has been used together with the Empty Bed Residence Time (EBRT) model to analyze the fixed bed performance under different operating conditions. The Homogeneous Surface Diffusion Model (HSDM) and the Shrinking Core Diffusion . Model (SCDM) have been applied to- model the fixed bed performance. Due to the dramatic change in the slope, the first and second parts of the breakthrough curves need to be modeled separately. Comparing the two models, SCDM is more appropriate to explain the sorption of metal ions into the chelating resin. The research has suggested the existence of a Na-loaded outer shell and a H-loaded inner core in the chelating resin. When the moving boundary progresses from the outer shell into the inner core, there is a remarkable change in the ion exchange process, resulting in different kinetics. This explains the sharp change in the slope of the experimental breakthrough curves. A new version of SCDM has been developed to model the progression of the moving boundary inside the resin for the successive resin layers along the whole resin column so as to predict the column' s solid and liquid phase concentration profiles. The new SCDM has. the flexibility of varying the portion of the outer shell so that the behavior of resins with different resin Na contents can be predicted.
8
Jayasinghe, Manori. "Heavy-metal-ion transport in nanoporous selective-membranes theory and experiment /." Cincinnati, Ohio : University of Cincinnati, 2007. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1186764159.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Cincinnati, 2007.Title from electronic thesis title page (viewed Oct. 8, 2007). Includes abstract. Keywords: gamma alumina membranes, heavy-metal-ion transport, uranyl, membrane functionalization, nanoporous membranes, steering molecular dynamics, free energy study, liquid-liquid interface, water/hexane interface, tri-butyl phosphate. Includes bibliographical references.
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JAYASINGHE, MANORI I. "HEAVY-METAL-ION TRANSPORT IN NANOPOROUS SELECTIVE-MEMBRANES: THEORY AND EXPERIMENT." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1186764159.
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Sekhula, Koena Sinah. "Heavy metal ion resistance and bioremediation capacities of bacterial strains isolated from an Antimony Mine." Thesis, University of Limpopo, 2005. http://hdl.handle.net/10386/139.
Повний текст джерелаАнотація:
Thesis (M.Sc.) -- University of Limpopo, 2005Six aerobic bacterial strains [GM 10(1), GM 10 (2), GM 14, GM 15, GM 16 and GM 17] were isolated from an antimony mine in South Africa. Heavy-metal resistance and biosorptive capacities of the isolates were studied. Three of the isolates (GM 15, GM 16 and GM 17) showed different degrees of resistance to antimony and arsenic oxyanions in TYG media. The most resistant isolate GM 16 showed 90 % resistance, followed by GM 17 showing 60 % resistance and GM 15 was least resistant showing 58 % resistance to 80 mM arsenate (AsO4 3-). GM 15 also showed 90 % resistance whereas isolates GM 16 and GM 17 showed 80 % and 45 % resistance respectively to 20 mM antimonate (SbO4 3-). Arsenite (AsO2 -) was the most toxic oxyanion to all the isolates. Media composition influenced the degrees of resistance of the isolates to some divalent metal ions (Zn2+, Ni2+, Co2+, Cu2+ and Cd2+). Higher resistances were found in MH than in TYG media. All the isolates could tolerate up to 5 mM of the divalent metal ions in MH media, but in TYG media, they could only survive at concentrations below 1 mM. Also, from the toxicity studies, high MICs were observed in MH media than TRIS-buffered mineral salt media. Zn2+ was the most tolerated metal by all the isolates while Co2+ was toxic to the isolates. The biosorptive capacities of the isolates were studied in MH medium containing different concentrations of the metal ions, and the residual metal ions were determined using atomic absorption spectroscopy. GM 16 was effective in the removal of Cu2+ and Cd2+ from the contaminated medium. It was capable of removing 65 % of Cu2+ and 48 % of Cd2+ when the initial concentrations were 100 mg/l, whereas GM 15 was found to be effective in the biosorption of Ni2+ from the aqueous solutions. It was capable of removing 44 % of Ni2+ when the initial concentration was 50 mg/l. GM 17 could only remove 20 % of Cu2+ or Cd2+. These observations indicated that GM 16 could be used for bioremediation of xvi Cu2+ and Cd2+ ions from Cu2+ and Cd2+-contaminated aqueous environment, whereas GM 15 could be used for bioremediation of Ni2+.
National Research Foundation and the University of the North Research Unit
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Jia, Yong Feng. "Adsorption of heavy metal ion species from aqueous solution in activated carbon." Thesis, University of Newcastle Upon Tyne, 2000. http://hdl.handle.net/10443/519.
Повний текст джерелаАнотація:
Activated carbons are used widely for the adsorption of environmentally unfriendly species from both liquid and gas phases, the separation of gases and adsorption of species from aqueous solution. Examples of the processes are the adsorption of Au(CN)2 and Ag(CN)2 from aqueous solution for the recovery of precious metals, the treatment of waste water containing organic chemicals and toxic metal species and the preparation of metal catalysts supported on carbon. This investigation has involved the study of the influence of porous structure and surface functional groups on the adsorption of both anionic and cationic metal species in order to understand the mechanism of adsorption of these species on active carbon from aqueous solution. Various types of oxygen functional groups were introduced onto the surface of coconut shell derived activated carbon through oxidation using nitric acid. Fourier transform infrared spectroscopy (FTIR), temperature programmed desorption (TPD) and selective neutralisation were used to characterise the surface oxygen functional groups. The oxidised carbons were also heat treated to provide a suite of carbons where the oxygen functional groups of various thermal stability were varied progressively. It was found that acidic oxygen functional groups mainly as carboxylic acid groups were incorporated into activated carbon by HNO3 oxidation. The phenol and quinone groups were also introduced by the oxidation process while the lactone groups were formed during heat treatment. The oxygen functional groups had a range of thermal stabilities with carboxylic acid groups being the least stable. A coconut shell derived active carbon was treated with ammonia and nitric acid followed by ammonia to incorporate nitrogen functional groups into the carbon. Active carbon with high nitrogen content was also prepared from nitrogen-rich precursor polyacrylonitrile (PAN). X-ray absorption near edge structure spectroscopy (XANES) and FTIR were used to investigate the structures of the nitrogen functional groups in carbons. The possible nitrogen functional groups present on carbon surface were pyridinic, pyrrolic (or indolic), pyridonic and aromatic amine-like structures. The adsorption characteristics of gold and silver cyanide anionic species on a suite of active carbons derived from coconut shell, polyacrylonitrile and chemical modification of the coconut shell carbon were investigated. The gold and silver cyanide adsorption capacities for coconut shell derived carbons correlate with total pore volume. Nitric acid oxidation treatment of the carbon was detrimental to gold adsorption in spite of the incorporation of oxygen content of carbon. The influence of nitrogen functional groups in the carbon structure on gold and silver adsorption was investigated using carbons derived from polyacrylonitrile. The addition of ethanol and butanol to the solution had an adverse effect on gold adsorption. Adsorption of silver cyanide ionic species on the active carbon was suppressed in the presence of excess free cyanide ions in solution whereas gold cyanide adsorption was not greatly affected at room temperature. The adsorption of gold cyanide was suppressed by the excess free cyanide and sodium sulphide at 70 °C. The adsorption of cadmium ions was enhanced dramatically by oxidation of the carbon. The ratio of released proton to adsorbed cadmium on oxidised carbon was approximately 2 indicating cation exchange was involved in the adsorption process. Na+ exchange studies with the oxidised carbon gave a similar ratio. After heat treatment of the oxidised carbons to remove oxygen functional groups, the ratio of H+/Cd2+ decreased significantly as well as the adsorption capacity. Both reversible and irreversible adsorption were involved in the process of cadmium adsorption with reversible adsorption having higher enthalpy. The irreversible adsorption resulted from cation exchange with carboxylic acid groups whereas the reversible adsorption probably involved physisorption of the partially hydrated cadmium ion. The nitrogen functional groups may act as ligands which can coordinate with transition metal cations. The adsorption of transition metal cations such as Cd 2+, Ni2+ and Cu2+ on active carbon was appreciably increased by the nitrogen functional groups present on carbon surface whereas ammonia treatment of the carbon showed little effect on the adsorption of alkali earth metal cation Cat+. There is little difference in the adsorption capacities of cadmium ions on coconut shell derived carbon at pH 4.1 and pH 7 whereas the adsorption of cadmium ions was significantly enhanced with increasing pH for the carbons with high nitrogen content. The nitrogen rich carbons show selectivity towards various transition metal cations reflected by adsorbing more Cu 2+ than Cd2+. This is consistent with the fact that the coordination compound of Cu 2+ with pyridine has higher stability constant than that of cadmium.
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Pitcher, Sarah. "Investigation of heavy metal removal from motorway stormwater using inorganic ion exchange." Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/804873/.
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Sun, Xin. "Organofunctional silica mesostructures with improved accessibility and applications as heavy metal ion adsorbents." Diss., Connect to online resource - MSU authorized users, 2008.
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Baker, Alexander Roberts. "Proton and metal ion interactions of fulvic acid solution and of alumina and alumina/fulvic acid suspensions." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314936.
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Kothalawala, Kothalawalage Nuwan. "Nanoporous high surface area silicas with chelating groups for heavy metal ion adsorption from aqueous solution /." View online, 2010. http://repository.eiu.edu/theses/docs/32211131524422.pdf.
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Mahdi, Zainab A. "Single and Multicomponent Heavy Metal Ion Adsorption from Aqueous System Using Biochar Derived from Date Seed Biomass." Thesis, Griffith University, 2019. http://hdl.handle.net/10072/387300.
Повний текст джерелаАнотація:
Water contamination by heavy metal ions is a world-wide issue. Adsorption is an effective treatment method for heavy metal removal from contaminated aqueous solutions. Traditional adsorbents such as activated carbons are expensive and may prove un-economical. Therefore, it is important to develop effective low-cost adsorbents. The aims of this study are to prepare an effective low-cost adsorbent of biochar prepared from date seed biomass and to investigate the adsorption performance of the derived biochar for heavy metal removal from aqueous solutions. Single and multicomponent systems of lead, copper, and nickel were studied. The studies were conducted in two stages: the first was to investigate the preparation and operational conditions to identify the most promising biochar; the second was to investigate different methods to modify the biochar to enhance its adsorption characteristics.
In the first stage, nine sets of biochar were prepared using slow pyrolysis at different temperatures (350–550 oC) and heating times (1–3 h). The influences of pyrolysis temperature and heating time on the biochar physiochemical properties were studied. One–way ANOVA and Tukey Post-hoc tests showed that the biochars prepared at different pyrolysis conditions were significantly different. Initial evaluation of the nine biochars showed that the adsorption uptake was positively correlated with the pyrolysis temperature and heating time. Biochar prepared at 550 °C for 3 h (referred to as DSB550-3) with particle size range of 0.6-1.4 mm was the best adsorbent for Pb2+, Cu2+, and Ni2+ removal. Thus, it was selected in further investigations.
Batch experiments for single component systems indicated that the maximum adsorption capacities of DSB550-3 biochar were 0.718, 0.421 and 0.333 mmol g−1 for Pb2+, Cu2+, and Ni2+ respectively. These values were found to be higher than those of hickory wood biochar (0.016 for Pb2+, 0.041 for Cu2+, and 0.004 for Ni2+) mmol g-1 and Salisbury biochar (0.230
for Pb2+, 0.101 for Cu2+, 0.105 for Ni2+) mmol g-1. Fixed bed adsorption showed that DSB550-3 biochar effectively reduced the total amount of Pb2+, Cu2+ and Ni2+ by 97%, 70.3%, and 56%, respectively.
The adsorption performance of DSB550-3 biochar for heavy metal removal was evaluated under a variety of conditions including solution pH, particle size, temperature, and presence
of other cations. The removal efficiency increased with particle size until it reached a maximum in the particle size range (0.6-1.40 mm) after which removal efficiency declined. Solution pH strongly affects the adsorption uptake of biochar. The metal uptake increased as the pH increases and reached a plateau at around pH 6. The adsorption process was found to be thermodynamically favourable and spontaneous. Temperature also influenced the metal uptake and a change of 18-38% in uptake capacities within the temperature range of 25 and 45 oC on adsorption was observed.
When compared to single component systems, the adsorption capacities of Pb2+, Cu2+, and Ni2+ in multicomponent systems were reduced by 48-75% in both batch and fixed bed experiments. In fixed-bed experiments, both Ni2+ and Cu2+ broke through earlier than Pb2+ ion, indicating that the functional groups on the biochar had a relatively stronger affinity for Pb2+ ion than Cu2+ and Ni2+ ions. The overall adsorption capacities of the fixed bed for all three ions were reduced by approximately 55% (on mill equivalents basis) when compared to Pb2+ adsorption capacity in single component system but only marginally when compared to Ni2+ and Cu2+.
Post-adsorption characterization and chemical analysis indicated that the adsorption was mainly controlled by the mechanisms of ion exchange and metal complexation with carboxyl and hydroxyl groups of the biochar. The contribution of different adsorption mechanisms to the overall metal adsorption was different in the single and multicomponent systems. Ion exchange was the predominate mechanism for the adsorption of Pb2+, Cu2+, and Ni2+, which
accounted for 57%, 69%, and 72%, respectively, of the total adsorption in single component systems and accounted for 37-40% of the total adsorption in multicomponent system.
Equilibrium isotherms and adsorption kinetics were studied by using DSB550-3 biochar. The equilibrium isotherms of Pb2+, Cu2+, and Ni2+ adsorption in single component systems were well described by the Sips model. It was observed that for all three metals, equilibrium was reached within 3-6 h of contact. The kinetics for Pb2+ and Cu2+ and Ni2+ showed good agreement with the pseudo second order kinetic model suggesting that chemisorption might be one of the adsorption mechanisms. Quantitatively, the adsorption of Pb2+ and Cu2+ was faster than that of Ni2+ which might be either related to the binding strength of Pb2+ and Cu2+ with surface functional groups or due to the variance in ionic characteristics. Biochar re-usability for repeated applications was investigated in four consecutives regeneration cycles by using 0.5 M HCl as an elution agent. The adsorbent showed good re-use potential with only marginal reduction in its uptake capacity over the first 3 cycles. This has an important economic significance as the re-usability makes the material more comparable to the commercial adsorbents such as commercial activated carbon.
The biomass and/or biochar were modified to enhance the adsorption properties for the biochar. The modification methods included pre-treatment of biomass prior to pyrolysis using an alkali (DSB-PB) or an acid (DSB-PA) as well alkali and acid post–treatment of biochar pyrolyzed at 550 oC for 3 h (DSB-BW and DSB-AW, respectively). The modified biochar was compared to unmodified one in terms of their metal uptake capacities, kinetic behaviour, and surface chemistry and morphology based on FTIR and SEM analyses. Of the four modified biochars investigated, DSB-PA biochar showed the highest adsorption capacities for Pb2+, Cu2+, and Ni2+. When compared to those of DSB550-3 biochar, the adsorption capacity of DSB-PA biochar for Pb2+, Cu2+, and Ni2+ increased by 27%, 66% and 98%, respectively. The adsorption rates of metal ions onto DSB-PA biochar were higher
when compared to unmodified biochar, with almost 94% of the total amount of metals adsorbed within the first hour.
Electro-assisted adsorption was also investigated for Pb2+, Cu2+, and Ni2+ by using biochar (DSB-Electro). Comparing to DSB550-3, the results showed that DSB-Electro effectively increased the adsorption capacity of the biochar for Pb2+, Cu2+, and Ni2+ by 21%, 36% and 94%, respectively. Metal ion adsorption onto electrode occurred rapidly, for example; with around 88% of Pb2+ and Ni2+ ions adsorbed within the first 3 h, while 96% of total adsorption of Cu2+ ion occurred at the first hour of contact. From the reversing of the electrical potential, it was observed that the adsorbed ions were not completely desorbed, and a large fraction of the ions were retained in the biochar electrode. This indicated that the only a small fraction of the ions were held by the electrostatic charge introduced by the current. It was likely that the enhanced charged facilitated other adsorption mechanisms by bringing the ions in contact with the biochar initially via electrostatic force.
The results of this study indicated that date seed biochar is a suitable adsorbent which can effectively remove Pb2+, Cu2+, and Ni2+ from aqueous solutions. Findings of this study can provide a basis for preparing modified biochar in producing effective low-cost adsorbents.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
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Dietrich, Theo Henry. "The removal of heavy metals from dilute aqueous streams by the use of ion exchange resins." Thesis, Cape Technikon, 1998. http://hdl.handle.net/20.500.11838/887.
Повний текст джерелаАнотація:
Thesis (MTech (Chemical Engineering)--Cape Technikon, Cape Town, 1998Ion exchange resins are widely used to remove or concentrate heavy metals from aqueous solutions or slurries.This thesis attempts to properly evaluate the interaction between ion exchange resins and heavy metals at trace metal concentrations.The durability of the resins and their effectiveness in real slurries were also investigated. In this study, a chelating resin, as well as a cation, and anion exchange resin was contacted with aqueous solutions of heavy metals in both free and complexed form. Zinc, nickel and copper cyanide complexes were adsorbed onto the anion exchange resin, while the chelating and cation exchange resins were contacted with zinc and nickel nitrates, and cupric sulphate. All the tests were conducted in batch stirred tank reactors. All the metal cyanide complexes behaved in a similar manner when contacted with the anion exchange resins. These tests were p~rf0nned under variations in temperature, stirring speed, pH., ionic strength and . initial metal 90E~entrations. Fitting of a dual resistance model to the profiles for thetlptllk:e" of the complexes, show that both film diffusion and intraparticle diffusion rates were improved with an increase in temperature, and that film diffusion rates improved with an increase in stirring speed. A high ionic strength negatively affected equilibrium loading as well as diffusional rates.It was found that at these low concentrations, the diffusional rates improves with a decrease in the external metal concentration. A comparative study involving the chelating and cation·exchange resins were performed, during which the resins were contacted with the metals in free fonn. It was found that at high metal concentrations, the chelating resin induced a rate limiting effect, but at trace concentrations, this effect is virtually negated. Whereas the cation exchange resin exhibited little selectivity in adsorbing the metals, it was found that the chelating resin prefers the metals in the eu > Ni > Zn. The chelating resin proved to be no less durable then the cation exchange resin, and both slightly lost their ability to adsorb the metal cations as a result of the effects of an inert coarse sand slurry.Tests performed with a real ore leachate, showed the cation exchange resin to be efficient at a low pH , but also relatively non selective, since the adsorption of copper from the leachate was greatly reduced due to the presence of other heavy metals.
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Rozycki, Torsten von [Verfasser], D. H. [Akademischer Betreuer] Nies, G. J. [Akademischer Betreuer] Krauss, and M. H. [Akademischer Betreuer] Saier. "Computational investigations of divalent heavy metal ion homeostasis / Torsten von Rozycki. Betreuer: D. H. Nies ; G. J. Krauss ; M. H. Saier." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2009. http://d-nb.info/1024859924/34.
Повний текст джерела
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Ogunleye, Adetoro O. "Bacterial poly-gamma-glutamic acid (γ-PGA) : a promising biosorbent of heavy metals". Thesis, University of Wolverhampton, 2015. http://hdl.handle.net/2436/579925.
Повний текст джерелаАнотація:
Poly-γ-glutamic acid (γ-PGA) is a biopolymer made up of repeating units of L-glutamic acid, D-glutamic acid or both. γ-PGA is water soluble, non-toxic and biodegradable, and can be used safely in a variety of applications that are increasing rapidly. This study investigated the production of HMW γ-PGA by five Bacillus species (B. licheniformis 1525, B. licheniformis NCTC 6816, B. licheniformis ATCC 9945a, B. licheniformis ATCC 9945a and B. subtilis (natto) ATCC 15245) in GS, C and E media for the removal of heavy metals in wastewaters. The highest γ-PGA yields of 11.69 g/l and 11.59 g/l were produced by Bacillus subtilis (natto) ATCC 15245 in GS medium and medium C respectively. Upon characterization, γ- PGAs with different properties (crystallinity, acid/salt form and molecular weights ranging from 2.56 × 105 Da to 1.65 × 106 Da) were produced. The water soluble, non-toxic, HMW (Mw 1.65 × 106 Da) γ-PGA produced by B. subtilis (natto) ATCC 15245 in medium C was investigated as a sorbent for the removal of heavy metal ions including Cu2+, Zn2+, Ni2+, Cd2+ and Ag+. The results showed that the removal of metals by γ-PGA was more dependent on the concentration of γ-PGA than the solution pH. The highest metal ions removal of 93.50%, 88.13%, 90.21%, 90.56% and 86.34% by HMW γ-PGA were obtained for Cu2+, Zn2+, Ni2+, Cd2+ and Ag+ respectively. The presence of interfering metal ions could hinder the adsorption of individual metal ions by γ-PGA. The affinities of heavy metal ions for γ-PGA followed the order: Cu2+ > Zn2+ > Ni2+ > Cd2+. The effect of molecular weight of γ-PGA on metal removal was also investigated, and it was found that metal ion adsorption capacity of γ-PGA strongly depended on its molecular weight. The maximum amount (93.50%) of Cu2+ sorbed by HMW γ-PGA was higher compared to that (59.48%) sorbed by LMW γ-PGA. Isotherm models showed that the Redlich-Peterson best described the metal adsorption capacity of γ-PGA. It was also found that a multisite adsorption mechanism occurred via the complexation of metal ions with the free α-carboxyl and possibly the amide functional groups in γ-PGA.
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Martí, Calatayud Manuel César. "STUDY OF THE TRANSPORT OF HEAVY METAL IONS THROUGH CATION-EXCHANGE MEMBRANES APPLIED TO THE TREATMENT OF INDUSTRIAL EFFLUENTS." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/46004.
Повний текст джерелаАнотація:
La presente Tesis Doctoral consiste en la determinación de las propiedades de transporte de diferentes especies catiónicas a través de membranas de intercambio catiónico. Las membranas de intercambio iónico son un componente clave de los reactores electroquímicos y de los sistemas de electrodiálisis, puesto que determinan el consumo energético y la eficiencia del proceso. La utilización de este tipo de membranas para el tratamiento de efluentes industriales no es muy extendida debido a los requisitos de elevada resistencia química y durabilidad que deben cumplir las membranas. Otro asunto importante radica en la eficiencia en el transporte de los iones que se quieren eliminar a través de la membrana. Normalmente, existe una competencia por el paso a través de las membranas entre diferentes especies debido al carácter multicomponente de los efluentes a tratar. Sin embargo, una mejora en las propiedades de las membranas de intercambio iónico permitiría la implantación del tratamiento mediante reactores electroquímicos de efluentes industriales con un contenido importante en compuestos metálicos, tales como los baños agotados de las industrias de cromado. La utilización de una tecnología limpia como la electrodiálisis conllevaría diferentes ventajas, entre las cuales destacan la recuperación de los efluentes para su reutilización en el proceso industrial, el ahorro en el consumo de agua y la disminución de la descarga de contaminantes al medio ambiente.
La determinación de las condiciones de operación óptimas así como la mejora de las propiedades de transporte de las membranas constituye el principal tema de la presente investigación. Para ello, se emplearán diferentes tipos de membrana. En primer lugar, se estudiará el comportamiento de las membranas poliméricas comerciales que poseen unas propiedades de resistencia química elevadas, las cuales se tomarán como referencia. De forma paralela, se producirán membranas conductoras de iones a partir de materiales cerámicos económicos, ya que la resistencia de los materiales cerámicos a sustancias oxidantes y muy ácidas es mayor que la de los materiales poliméricos. Este punto constituye la parte más innovadora de la investigación, puesto que la mayoría de las membranas de intercambio iónico comerciales están basadas en materiales poliméricos que no pueden resistir las condiciones específicas de los efluentes industriales. Una vez determinadas las condiciones de operación óptimas, se realizarán ensayos en plantas piloto con el fin de confirmar los resultados obtenidos mediante las técnicas de caracterización y determinar el grado de recuperación y coste energético asociado a los procesos electrodialíticos de tratamiento de efluentes industriales.Martí Calatayud, MC. (2014). STUDY OF THE TRANSPORT OF HEAVY METAL IONS THROUGH CATION-EXCHANGE MEMBRANES APPLIED TO THE TREATMENT OF INDUSTRIAL EFFLUENTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/46004
TESIS
Premiado
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Huang, Jing. "Functional Polymers Containing Semi-Rigid Alternating Sequences." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/89884.
Повний текст джерелаАнотація:
Alternating copolymers represent a special class of copolymers in which the two comonomers copolymerize in a regular alternating sequence along the polymer chain. Of particular interest in our group are the stilbene-maleic anhydride/maleimide alternating copolymers. These copolymers possess sterically congested backbones and precisely placed functional groups arising from the strictly alternating copolymerization. The research in this dissertation is focused on the synthesis, characterization, and potential application of functionalized copolymers that contain semi-rigid alternating copolymer sequences.
The fluorescence properties of a series of non-conjugated, tert-butyl carboxylate functionalized alternating copolymers were investigated. Extraordinarily high fluorescent intensity with excellent linearity was observed for the di-tert-butyl group-containing stilbene and maleic anhydride alternating copolymer in THF. We attributed the origin of the strong fluorescence to the “through space” π – π interactions between the phenyl rings from the stilbene and C=O groups from the anhydride. The fluorescence was maintained when the copolymer was deprotected and hydrolyzed and the resulting carboxylic acid-functionalized copolymer was dissolved in water at neutral pH.
The tert-butyl carboxylate functionalized alternating copolymer sequences were incorporated into highly crosslinked polymer networks using suspension polymerization. After removing the tert-butyl groups by acidic hydrolysis, the surface area of the networks increased significantly. Using this facile two-step strategy, we were able to achieve nanoporous polymers with BET surface area up to 817 m2/g and carboxylic acid-functionalized surfaces. The BET surface area of deprotected polymers increased with increasing crosslinking density, and the stilbene-containing polymers showed systematically higher BET surface area than the styrene-containing polymers due to the stiffness of the alternating sequences. The resulting nanoporous polymers have potential to be employed as solid sorbents for CO2.
The same tert-butyl carboxylate functionalized alternating copolymer sequences were also incorporated into microgels via miniemulsion polymerization. The miniemulsion technique ensured the successful synthesis of microgels with ~100 nm diameter using solid stilbene and maleimide monomers. The resulting tert-butyl carboxylate-containing microgels were converted into carboxylic acid-containing aqueous microgels by acid hydrolysis. These aqueous microgels showed good and reversible lead and copper ion adsorption capacities.
Amine-functionalized nanoporous polymers were synthesized by the post-modification of highly-crosslinked divinylbenzene-maleic anhydride polymers. High amine-contents were achieved by covalently attaching multiamines to the acid-chloride functionalized polymer surface. The resulting polymers showed medium to high BET surface areas (up to 500 m2/g) and high CO2 capture capacities.PHD
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Quattrini, Federico. "Emerging Techniques for Inorganic Metal Speciation and Bioavailability." Doctoral thesis, Universitat de Lleida, 2018. http://hdl.handle.net/10803/664422.
Повний текст джерелаАнотація:
El coneixement profund de la especiació dels metalls pesants és clau per a determinar la seva biodisponibilitat. Per això cal complementar la informació sobre les concentracions amb la informació sobre els fluxos d’internalització. Diverses tècniques analítiques han estat desenvolupades amb aquesta fi, i algunes d’elles aprofiten les propietats de les resines d’intercanvi iònic o quelants.
D’una banda, aquesta tesi investiga la velocitat d’acumulació d’ions metàl·lics a la resina Chelex 100, sigui experimentalment o a través d’un model teòric. Aquesta interpretació permet descriure els efectes dels lligands competidors i determinar les constants de dissociació dels complexes.
D’altra banda, dues noves tècniques analítiques han estat desenvolupades. La primera deriva de la IET, una tècnica comunament utilitzada en equilibri, però n’extreu informació dinàmica. La segona és una modificació del popular DGT, que s’ha emprat un cop el sistema ha assolit l’equilibri.El conocimiento profundo de la especiación de los metales pesados es clave para determinar su biodisponibilidad. Por eso es necesario complementar la información sobre las concentraciones con la información sobre los flujos de internalización. Diversas técnicas analíticas han sido desarrolladas con este fin, y varias aprovechan propiedades de las resinas de intercambio iónico o quelantes. Por un lado esta tesis investiga la velocidad de acumulación de iones metálicos en la resina Chelex 100, tanto experimentalmente, como a través de un modelo teórico. Esta interpretación permite, asimismo, describir los efectos de los ligandos competidores y determinar las constantes de disociación de los complejos. Por otro lado, dos nuevas técnicas analíticas han sido desarrolladas. La primera deriva de la IET, una técnica comúnmente utilizada en equilibrio, pero extrae información dinámica de ella. La segunda es una modificación del popular DGT, que se ha empleado una vez el sistema ha alcanzado el equilibrio.
A deep knowledge of heavy metal ions speciation is key to assessing their bioavailability. In this regard, data about concentrations should be complemented with data about the internalization fluxes. Several analytical techniques have been developed to this purpose, and many of them exploit properties of ion-exchange or chelating resins. On the one hand, this thesis studies the rate of metal ions uptake on Chelex 100 resin, both experimentally and through a theoretical model. This interpretation also allows describing the effect of competing ligands and determining the dissociation constants of the complexes. On the other hand, two new analytical techniques are developed. The first one stems from IET, a technique commonly used at equilibrium, but aims at extracting dynamic information from it. The second one is a modification of the well-known DGT, devised to provide information once equilibrium has been attained.
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Diaz, Mendoza Alvaro. "Conception of a fibrous composite material for the retention of heavy metals." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI125.
Повний текст джерелаАнотація:
La contamination par les métaux lourds est un problème actuel qui affecte les écosystèmes et leurs organismes constitutifs. Ce problème a été reconnu dans le monde entier comme l'un des plus grands défis de notre époque. Depuis le milieu du siècle dernier, les innovations dans le domaine de la science des matériaux ont permis de mettre au point de nouvelles méthodes pour faire face à ce risque, avec des techniques telles que la précipitation chimique ou la flottation. Toutefois, il reste encore beaucoup à faire dans ce domaine. En outre, des recherches récentes ont exploré comment combiner des biomolécules telles que les protéines avec des matériaux tels que les polymères pour créer des solutions plus actives. Ce travail de thèse vise à créer un prototype de matériau adsorbant hybride capable de capturer spécifiquement les ions métalliques divalents Ni(II), Cd(II) et Pb(II) grâce à la présence d'une métalloprotéine synthétique dans sa structure. Pour atteindre cet objectif, le travail de thèse se concentre sur le développement d'une métalloprotéine synthétique capable de capturer spécifiquement les trois ions métalliques cibles, de la conception in silico à sa synthèse in vivo. D'autre part, le support de matériau est traité avec la technique d'électrofilage qui consiste en un matériau membranaire fibreux, étant optimisé pour accueillir la métalloprotéine synthétique dans sa structure. En outre, une méthode permettant d'intégrer la métalloprotéine dans le support polymère est recherchée. Ceci est réalisé au moyen d'une voie de greffage à travers des nanoparticules de silice modifiées en surface. À la fin, l'intégration des deux composants crée le prototype attendu de matériau biosorbant synthétique. Ce matériau a été caractérisé afin d'évaluer sa capacité à adsorber les trois ions métalliques d'intérêt, ce qui permet de dégager certaines tendances des perspectives futures de développement pour créer des matériaux plus efficaces pour l'industrieHeavy metal contamination is a current problem which affects the ecosystems and their constituent organisms. This problem has been worldwide recognized as one of the biggest challenges of our time. Since the middle of the last century, innovations in the material science field have developed new methods to confront this risk, with techniques such as chemical precipitation or flotation. However, there is still significant room for improvement in this line. Furthermore, recent research has explored how to combine biomolecules such as proteins with materials like polymers to create more active solutions. This thesis work seeks to create a prototype hybrid biosorbent material capable to capture specifically the divalent metal ions Ni(II), Cd(II) and Pb(II) thanks to the presence of a synthetic metalloprotein in its structure. To address this objective, the thesis work focuses on the development of a synthetic metalloprotein capable to specifically capture the three target metal ions, from the in silico conception to its in vivo synthesis. On the other hand, the biosorbent material support is processed with the electrospinning technique that consists of a fibrous membrane material, being optimized to host the synthetic metalloprotein in its structure. Additionally, a method to integrate the metalloprotein into the polymeric support is researched. This is achieved by means of a grafting route through surface modified silica nanoparticles. At the end, the integration of both components creates the expected prototype synthetic biosorbent material. This material has been characterized to evaluate its capacity to adsorb the three metal ions of interest, providing some trends of the future perspectives for further development to create more efficient materials for the industry
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Lappalainen, K. (Katja). "Modification of native and waste starch by depolymerization and cationization:utilization of modified starch in binding of heavy metal ions from an aqueous solution." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526209661.
Повний текст джерелаАнотація:
Abstract Starch is one of the most abundant polysaccharides found in nature and is widely utilized in various fields of industry. Due to the complex structure of native starch it is insoluble in most organic solvents and needs modification prior utilization. In this study, ionic liquids (ILs), modern green chemistry alternatives for common solvents were used as reaction media in starch modification. At first various starch species were depolymerized in 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) with p-TsOH as a catalyst. Microwave activation or conventional bath heating were used as heating methods while HPLC-ELSD was used as an analytical method. All studied starch species depolymerized similarly into water-soluble starch oligomers while microwave activation shortened the depolymerization time considerably compared to oil bath heating. Barley starch was chosen for further experiments, in which various ILs were studied as potential media for starch dissolution and depolymerization. Results suggested that both the anion and the cation part of the IL had an effect on the dissolution and depolymerization of barley starch. After the depolymerization reactions, the depolymerized barley starch was further modified by cationization. [AMIM]Cl was used as the reaction media, microwave activation as the heating method while HPLC-ELSD, 1H NMR and elemental analysis were used as analytical methods. The modified products had DS values from 0.2 to 0.5 depending on the reaction conditions. The products were studied as potential binding agents for heavy metal ions which showed that moderately substituted modified starch (DS 0.4) could be used to bind Cu(II), Fe(III) and Zn(II) ions from an aqueous solution. Finally, potato peel waste was studied as an alternative starch source to produce cationized starch for wastewater purification. Peel waste was pre-treated by alkaline depolymerization after which it was cationized in a water solution to produce cationized products with DS from 0 to 0.35. The cationized peel waste products were studied preliminary as binding agents for Cu(II) ions from a water solution using ICP-OES as an analytical method. The results suggested that when the molar ratio between cationized waste starch and copper was 3:1, cationized waste starch was an effective binding agent for copper ionsTiivistelmä Tärkkelys on yksi yleisimmistä luonnossa esiintyvistä polysakkarideista. Sitä hyödynnetään useilla eri teollisuuden aloilla. Monimutkaisen rakenteensa vuoksi tärkkelys on liukenematon useimpiin orgaanisiin liuottimiin ja veteen, minkä vuoksi sitä täytyy modifioida ennen käyttöä. Tässä väitöstutkimuksessa tärkkelyksen modifioinnissa käytettiin ionisia nesteitä reaktioväliaineena. Tutkimuksen alussa eri tärkkelyslajeja depolymeroitiin 1-allyyli-3-metyyli-imidatsoliumkloridissa ([AMIM]Cl) katalyyttinä p-TsOH. Mikroaaltoaktivointia ja haudekuumennusta käytettiin vaihtoehtoisina lämmitysmenetelminä. Reaktion edistymistä ja tuotteiden muodostumista tutkittiin HPLC-ELSD -menetelmällä. Eri tärkkelyslajit depolymeroituivat samankaltaisesti vesiliukoisiksi, lyhytketjuisiksi tärkkelysoligomeereiksi. Mikroaaltoaktivointi lyhensi reaktioaikaa haudekuumennukseen verrattuna. Tutkimuksen seuraavassa vaiheessa tutkittiin ohratärkkelyksen liukoisuutta ja depolymeroitumista eri ionisissa nesteissä. Tulosten perusteella ionisen nesteen sekä anioni- että kationiosa vaikuttivat tärkkelyksen liukenemiseen. Depolymeroidun ohratärkkelyksen modifiointitutkimuksia jatkettiin [AMIM]Cl:ssa kationisoinnilla. Lämmitysmenetelmänä käytettiin mikroaaltoaktivointia. Tuotteet tutkittiin käyttäen alkuaineanalyysiä sekä HPLC-ELSD- että 1H NMR-tekniikoita. Kationisoitujen tuotteiden substituutioaste (DS) vaihteli reaktio-olosuhteista riippuen välillä 0.2–0.5. Saatuja tuotteita tutkittiin raskasmetalli-ionien sitomisessa vesiliuoksesta. Havaittiin, että kohtalaisesti substituoitu (DS 0.4) modifioitu tärkkelys sitoi Cu(II)-, Fe(III)- ja Zn(II)-ioneja vesiliuoksesta. Tutkimuksen loppuosassa tutkittiin perunan kuorijätettä vaihtoehtoisena tärkkelyslähteenä kationisoidun tärkkelyksen valmistamisessa. Kuorijäte esikäsiteltiin kuumentamalla se emäksisessä etanoliliuoksessa, minkä jälkeen sille suoritettiin kationisointi vesiliuoksessa. Kationisten tuotteiden substituutioasteet vaihtelivat välillä 0–0.35. Tuotteiden soveltuvuutta Cu(II)-ionien sitomiseen vesiliuoksesta tutkittiin ICP-OES -menetelmän avulla. Alustavien tulosten mukaan kationisoitu jätetärkkelys sitoi kupari-ioneja vedestä, kun tärkkelyksen ja kuparin moolisuhde oli 3:1
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Hendricks, Nicolette Rebecca. "The application of high capacity ion exchange adsorbent material, synthesized from fly ash and acid mine drainage, for the removal of heavy and trace metal from secondary Co-disposal process waters." Thesis, University of the Western Cape, 2005. http://hdl.handle.net/11394/1455.
Повний текст джерелаАнотація:
In South Africa, being the second largest global coal exporter, coal mining plays a pivotal role in the growth of our economy, as well as supplying our nation’s ever increasing electricity needs; while also accounting for more than 10% of the 20 x 109 m3 water used annually in the country. Coal mining may thus be classified as a large-scale water user; known to inevitably generate wastewater [acid mine drainage (AMD)] and other waste material, including fly ash (FA). Current and conventional AMD treatment technologies include precipitation–aggregation (coagulation/flocculation) – settling as hydroxides or insoluble salts. The process stream resulting from these precipitation processes is still highly saline, therefore has to undergo secondary treatment. The best available desalination techniques include reverse osmosis (RO), electro dialysis (ED), ion exchange and evaporation. All available treatment methods associated with raw AMD and its derived process stream fall prey to numerous drawbacks. The result is that treatment is just as costly as the actual coal extraction. In addition, remediation only slows the problem down, while also having a short lifespan. Research conducted into converting fly ash, an otherwise waste material, into a marketable commodity has shown that direct mixing of known ratios of FA with AMD to a pre-determined pH, erves a dual purpose: the two wastes (AMD and FA) could be neutralized and produced a much cleaner water (secondary co-disposal [FA/AMD]-process water), broadly comparable to the process water derived from precipitation-aggregation treated AMD. The collected post process solid residues on the other hand, could be used for production of high capacity ion exchange material (e.g. zeolite A, faujasite, zeolite P, etc.). The produced ion exchange material can subsequently be utilized for the attenuation of metal species in neutralized FA/AMDprocess waters.Magister Scientiae - MSc
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Olofsson, Emelie. "Lokal provtagning och analys på rökgaskondensat för driftövervakning av tungmetallrening med jonbytarmassor." Thesis, Uppsala universitet, Luft-, vatten- och landskapslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414340.
Повний текст джерелаАнотація:
I värme- och kraftvärmeverk förbränns olika typer av bränslen för produktion av el och fjärrvärme. Vid förbränningen bildas rökgaser som innehåller föroreningar, till exempel tungmetaller, från bränslet. Anläggningarna har ofta krav på utsläpp både via rökgaserna och avloppsvatten. Rökgaserna renas därmed genom olika tekniker var av en vanlig teknik är rökgaskondensering. Vid rökgaskondenseringen bildas en vätska, kallad rökgaskondensat, som delvis innehåller tungmetaller från bränslet. Rökgaskondensatet måste renas innan det kan lämna anläggningen och det görs bland annat med tungmetalljonbytare. Jonbytarmassan i tungmetalljonbytarkolonnerna behöver bytas ungefär två gånger per driftsäsong då den inte längre kan binda mer tungmetaller. Detta är en kostnad för värme- och kraftvärmeverken som de vill minimera. I denna studie undersöktes om lokal provtagning och analys på ett kraftvärmeverk av ett antal utvalda tungmetaller i rökgaskondensat är en bra metod för att optimering av reningssteget med tungmetalljonbytare. Samt om detta kan säkerställa att miljökraven för tungmetaller i det renade rökgaskondensatet uppfylls. Med optimering avses att jonbytarmassornas fulla kapacitet utnyttjas, d.v.s. att byten av jonbytarmassor kan reduceras utan att riskera otillåtna halter av tungmetaller i de renade rökgaskondensatet till följd av att jonbytarmassorna använts för länge. Även tiden som behöver avsättas för lokal provtagning och analys dokumenterades. I dagsläget sker analyser hos ackrediterade laboratorium där det tar drygt två veckor att få resultatet och under väntetiden kan mycket på anläggningen förändras. En verifiering av resultaten från studien gjordes mot resultat från ett sådant. I denna studie undersöktes lokal provtagning och analys med mätinstrumentet FREEDD som bygger på tekniken kvartskristall mikrobalans (QCM-teknik). Andra alternativ för lokal analys har inte undersökts här. Resultatet visade att det i dagsläget är svårt att med lokal provtagning optimera reningssteget med jonbytarmassor samt kontrollera utsläppen av tungmetaller via det renade rökgaskondensatet. Korrigeringar hos mätinstrumentet och provpunkterna behöver göras för att få pålitligt resultat. Tiden som behöver avsättas för provtagning och analys beror på vilken metall som ska analyseras då tiden för preparering av prov varierar. Men om det kan möjliggöra att anläggningarna kan använda jonbytarmassorna längre samt får kontroll på utsläppen via det renade rökgaskondensatet kan det vara lönsamt att avvara den tiden.In heating and combined heat and power plants, different types of fuels are burned to produce electricity and district heating. During the combustion flue gases containing pollutants, such as heavy metals, are formed from the flue. The plants have requirements for low emissions, both from the flue gases and the wastewater. The flue gases are purified by various techniques and a common technique is flue gas condensation. During the flue gas condensation, a liquid called flue gas condensate, is formed, which partly contains heavy metals from the flue. The flue gas condensate must be cleaned before it can leave the plant. A step in the purification of the flue gas condensate is usually heavy metal ion-exchanger. The ion-exchange mass in the heavy metal ion-exchange columns needs to be changed approximately twice per operating season as it no longer has room to bind more heavy metals. This is an expensive cost for the heating and combined heat and power plants that they want to minimize. This study investigated whether local sampling and analysis at a cogeneration plant of a number selected heavy metals in flue gas condensate is a good method for optimizing the purifications step with heavy metal ion-exchangers. And if this can ensure that the environmental requirements for the heavy metals in the purified flue gas condensate are met. Optimization means that the full capacity of the ion-exchange masses is utilized, i.e. that the exchange of ion-exchange masses can be reduced without risking unauthorized levels of heavy metals in the purified flue gas condensate as a result of the ion exchange masses being used for too long. The time needed for local sampling and analysis was also documented. At present, analyzes are done at accredited laboratories where it takes over two weeks to get the result and during that time much can be changes at the plant. A verification of the result of the study was also made against the result of an accredited laboratory. In this study, local analysis was made with the measuring instrument FREEDD which is based on quartz crystal microbalance (QCM-technology). Other options for local sampling and analysis have not been investigated. The result showed that, in the present, it is difficult to optimize the purification step with ion-exchange masses and check emissions of heavy metals with the purified flue gas condensate. To obtain reliable result, corrections to the measuring instrument and test points need to be made. The time that needs to be set aside for sampling and analysis depends on the metal, as the time for sample preparation varies. But if it can enable the plants to use the ion-exchange masses longer and gain control of the emissions of heavy metals with the purified flue gas condensate, it can be profitable to save that time.
27
Niehus, Christina. "Untersuchungen zur Selektivität unterschiedlich substituierter Iminodiessigsäure-Ionenaustauscher gegenüber zweiwertigen Metallionen." Phd thesis, Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2007/1319/.
Повний текст джерелаАнотація:
Zur selektiven Entfernung von Schwermetallen aus industriellen Abwässern und Prozesslösungen der metallverarbeitenden Industrie werden synthetische metallkomplexierende funktionelle Polymere – mit Iminodiessigsäure (IDE) als aktive Spezies – seit Jahren erfolgreich zur Eliminierung störender Kationen eingesetzt. Ständig steigende Anforderungen an die Qualität der aufzubereitenden Wässer verlangen nach leistungsfähigen Selektivaustauschern, die den Erhalt der Eigenschaften von Prozesslösungen (z. B. pH-Wert, Salzgehalt) ermöglichen. Ziel der Untersuchungen war es, die strukturellen Matrixeinflüsse auf Beladung, Kapazität, Selektivität und Kinetik durch Variation der Matrix und der experimentellen Bedingungen näher zu untersuchen. Auf Basis einer monodispersen Erstsubstitution eines Styren-Divinylbenzen-Copolymerisates wurde durch gezielten Einbau funktioneller Gruppen – Synthese mit differenziertem Substitutionsgrad (TK/N 1-2) – versucht, systematisch den Einfluss des Substitutionsgrades der Matrix auf die Eigenschaften der Ionenaustauscher zu analysieren. Methodisch geordnet wurden zunächst die Versuche nach dem Batch- und anschließend nach dem Säulenverfahren durchgeführt und parallel dazu die Matrix charakterisiert. Das Verhalten der funktionellen Ankergruppen in Abhängigkeit vom pH-Wert der Lösung (pH-Bereich 2 - 5) wurde untersucht, der optimale Anreicherungs-pH-Wert, die maximale Beladung (Kapazität) und Selektivität der unterschiedlich substituierten Proben für die Schwermetall-Ionen Cu, Zn, Ni, Cd, Pb und Co ermittelt. Den statischen Versuchen folgten dynamische Untersuchungen im Säulenverfahren. Ziel war die Ermittlung des Durchbruchverhaltens und der Durchbruchkapazität bei optimalem pH-Wert in Abhängigkeit vom Substitutionsgrad gegenüber den Einzelmetallionen (Cu, Ni, Zn) und ausgewählten Paaren (Cu/Ni, Cu/Zn, Ni/Zn). Alle Ionenaustauscher wurden ausschließlich in der Ca-Form eingesetzt.Selective ion exchange offers a good solution for cleaning many waste streams. The aim of this study was to develop selective ion exchange materials for effective and economical applications in waste water treatment. The investigation of chelate resins is based on iminodiacetate with different secondary substitution (degree of substitution TK/N 1 - 2, from aminoacetic acid to iminodiacetate as functional group). As comparison the weak acid resin Lewatit TP 207 was used. The research focused on the application of selective ion exchange resins for waste effluents to ascertain the feasibility of a selective ion exchange process employing chelating cation exchangers for heavy metal removal. The metals of interest were copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), lead (Pb) and cadmium (Cd) and the resins appointed in the Ca-form. The batch operation was conducted to determine the equilibrium data and the operating resin capacity, one of the most important properties. The main equilibrium parameter affecting the ion exchange was the pH value (array 2-5). The best accumulation pH value was obtained using pH 5 for all metals. The only exception was lead with pH 3. After determining the viability of the different resins with batch systems, this study has focused on the column mode experiments. They were generated for the selected resins in the continuous ion exchange process which are essentially reserved for industrial applications. A practical application of the breakthrough curves is the determination of the breakthrough time which helps to find the best operating conditions.
28
Bouillaud, Pascal. "Irradiation aux ions lourds de films minces nanocristallins d'alliages FeCo et FeAl." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37612171v.
Повний текст джерела
29
Kurdi, Mohamad. "Sur l'utilisation des sulfures en catalyse d'hydrotraitement le trisulfure du niobium /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376148133.
Повний текст джерела
30
Tsai, Cheng-Kuo, and 蔡正國. "A Study of Adsorption of Dissolved Heavy Metal Ions by Composite Carbon Nanotubes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/92212031270465937465.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
環境與安全工程系碩士班
93
The Study of Adsorption of Heavy Metals from aqueous Solution by Composite Carbon Nanotubes Student: Cheng-Kuo Tsai Advisor: Dr. Jao-Jia Horng Institute of safety Health and Environmental Engineering National Yunlin University of Science and Technology ABSTRACT Carbon Nanotubes (CNTs) were grown on alumina oxide (α- Al2O3 ) after deposited Fe-Ni nanoparticles by chemical vapor deposition method to form CNT/Fe-Ni/ Al2O3 composite particles. Composite particles would be fabricated at low price, easy handling and had higher adsorption capacities of Pb+2, Cu+2 and Cd+2 than these of active carbon powders (PAC) and merchant CNTs. The composite CNTs were at sizes of micrometer length and with tube diameters of 80-100 nm. The sinking tests showed that merchant CNTs would aggregate fast while composite particles could disperse in solution to enhance mixing efficiency. The experimental results revealed that the composite particles were good adsorbent with capacities of Pb2+ 67.11 mg/g 、Cu2+ 26.59 mg/g、Cd2+ 8.89 mg/g, respectively. In this study the adsorption capacities of Pb+2, Cu+2 and Cd+2 were regressed by three adsorption models and Langmuir isotherm model showed good fit. The multi-layers adsorption (BET) was not accepted. The kinetic mechanism of adsorption by composite particles was found to be second order. The adsorption efficiency of 40 mg/l Pb2+、Cu2+ could reach 80% at 0.2 g dosage. The affinity order of competitive adsorption of three metal ions onto active carbon powders, merchant CNTs and composite particles were the same of Pb+2> Cu+2> Cd+2. The recovery of composite particles could still reach 90 % by 0.5 N nitrite even after six adsorption/regenerate cycles.
31
Lee, I.-Hsien, and 李逸先. "Multi-component Heavy Metal Ion Exchange Process." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/29894495331980365060.
Повний текст джерелаАнотація:
碩士大同大學
化學工程研究所
90
Due to limited water resources, how to treat and reuse industrial wastewater has become a very important task to environmental protection. Ion-exchange process can not only remove heavy metals from wastewater efficiently but also recover them easily without generating the secondary pollution problems caused by heavy metal sludge. This study, based on the non-linear wave propagation theory, carries a series of batch and column experiments to predict the dynamics at different feed compositions. The batch experiments are performed to obtain the binary copper-hydrogen, zinc-hydrogen, and cadmium-hydrogen ion-exchange equilibria, expressed in terms of the separation factor and selectivity coefficient, at different total mobile-phase concentrations. The column experiments are conducted to measure the breakthrough and regeneration curves, effluent solution pH and conductivity of the binary, tertiary and four-component systems at various feed compositions. The predicted column dynamics of this study does not match the experimental results perfectly, but the trends are consistent.
32
Lee, I.-Hsien, and 李逸先. "HEAVY METAL SLUDGE TREATMENT BY ACID LEACHING AND ION EXCHANGE." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/pehh5n.
Повний текст джерелаАнотація:
博士大同大學
化學工程學系(所)
95
A huge quantity of sludge containing heavy metals was and is being generated from wastewater treatment processes in order to treat the industrial wastewaters in Taiwan. Heavy metal sludge is classified as hazardous solid waste and cannot be disposed off because of its toxicity. This study aims at developing a combined acid extraction and ion-exchange process by using ion exchange resin to facilitate remove heavy metals such as copper, zinc, cadmium, chromium, nickel and iron from the sludge generated by a PCB manufacturing plant in Taiwan. Factorial experimental design methodology was first used to study the feasibility of using the combined acid extraction and ion exchange process. The statistical analysis shows that leaching acid and reaction temperature plays an important role in the sludge extraction or metal recovery. The individual extraction kinetic results showed that the metal extraction rates increased with the acid concentration, temperature, but decreased with increasing particle size. Nitric acid was found to be more effective than citric acid to extract the heavy metals from the sludge. The ion-exchange equilibrium data were analyzed by the Langmuir isotherm, Freundlich isotherm, and thermodynamic equilibrium constant approaches. The Langmuir isotherm fits the ion-exchange equilibrium data better than the Freundlich approach. But for ions with different valences such as heavy metal and hydrogen ions the ion-exchange equilibrium was better described by the mass action law using thermodynamic equilibrium constant. The reversible reaction model was capable to predict the effects of resin to solution ratio, initial heavy metal concentration, and temperature on the ion-exchange kinetic curves. The ion-exchange column results showed that the total cation concentration in the mobile-phase played a key role on the breakthrough curves; a higher feed concentration resulted in an earlier breakthrough. The self-sharpening wave model assuming local ion-exchange equilibrium could provide a simple and quick estimation for the breakthrough volume, but the predicted breakthrough curves did not match the experimental data very well. On the contrary, the constant-pattern wave model using a constant driving force model for finite ion-exchange rate provided a better fit to the experimental data. The obtained liquid-phase mass transfer coefficient was correlated to the flow velocity and other operating parameters; the breakthrough curves under varying operating conditions could thus be predicted by the constant-pattern wave model using the correlation. Experiments carried out in a re-circulation system including a leaching reactor and an ion-exchange column supported the concept of enhanced heavy metal leaching from the sludge and heavy metal recovery by the ion exchange resin. A mathematical model for batch heavy metal extraction in the presence of ion-exchange resin was established for the purpose of process design for sludge treatment.
33
Chang, Fang-Ching, and 張芳菁. "SEPARATION AND RECOVERY OF HEAVY METAL BY ION EXCHANGE PROCESS." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/97637853110278378272.
Повний текст джерелаАнотація:
碩士大同工學院
化學工程學系
84
Due to limited water resources and increasing water demands of various kinds, especially of industries, how to treat and reuse industrial wastewatershas become not only a very important problem to environmental protection but also a crucial issue to industries seeking sustainable development. Wastewatercontaining heavy metals is one of the most difficult industrial wastewaters totreat. Although the conventional chemical precipitation method, which is the most popular one, is quite effective in removing heavy metals from wastewatersdeal with and usually causes a secondary pollution problem. On the contrary, ion exchange process are also very efficient but generate much less sludge. Moreover, different heavy metals could be separated and recovered and ideal state of the so-called zero discharge could be achieved via adequate ion exchange resin selection, process design, and column operation. In order to operate ion exchange columns adequately, the column dynamics which is governed by a set of coupled partial differential equations and associated equilibrium algebraic equations must be understood. Instead of solving the tedious equations, this research project modify the traditional wave propagation theory to predict the breakthrough and regeneration curves under various operating conditions. Batch experimental tests were conducted to obtain the exchange equilibria of H/Cu and H/Ni systems, and column tests were conducted to obtain the breakthrough and regeneration curves under various operating conditions. The experimental results showed that the wave theory indeed predicts the column dynamics well. Operating strategy for Cu and Ni separation by ion exchange was proposed based on this research project.
34
Chen, Chun-Hsing, and 陳俊興. "EFFECTS OF COMPLEXATION REACTIONS ON HEAVY METAL ION EXCHANGE PROCESSES." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/13029823721451937861.
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35
Ciou, Shin Fan, and 邱仕帆. "Development of Nanofibrous Chitosan Membranes for Heavy Metal Ion Removal." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/00228137319529150746.
Повний текст джерелаАнотація:
碩士長庚大學
機械工程學系
101
We developed biodegradable nanofibrous polylactide/chitosan membranes for the removal of heavy metal ions. Polylactide and chitosan were first separately dissolved intrifluoroacetic acid (TFA). The solutions were then mixed and electrospun into nanofibrous membranes via an electrospinning process. The morphology of as-spun nanofibers was examined by scanning electron microscopy. The average diameter of electrospun nanofibers ranged from 410 nm to 710 nm. The adsorption capability of nanofibrous polylactide/chitosan membranes was measured and compared with that of bulk chitosan. The influence of various process conditions on adsorption efficiency was also examined. The experimental results suggested that the electrospun nanofibrous polylactide/chitosan membranes exhibit good silver ion uptake capabilities. The metal uptake of nanofibrous membranes increased with the initial metal ion concentrations and decreased with the filtering rate of the solutions. Furthermore, the electrospun membrane could be reused after the recovery process. The empirical results in this study suggested that electrospun nanofibrous polylactide/chitosan membranes can be a good candidate for the removal of heavy metal ions.
36
Tseng, PoWei, and 曾柏維. "Ion Exchange of Heavy Metal Ion with Glycidyl Methacrylate Copolymer Containing Dithiocarbamate Chelating Group." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/88166578094091855946.
Повний текст джерелаАнотація:
碩士淡江大學
化學學系
91
A dithiocarbamate group containing compound is introduced into glycidyl methacrylate copolymer and the resulting copolymer serves as a metallic ion chelating functional polymer. Amino-terminated and dithiocarbamate group containing compounds are obtained from the reaction of carbon disulfide with p-phenylenediamine and ethylenediamine in an alkali solution, respectively. Amino group of these dithiocarbamate compounds react with the epoxide group of glycidyl methacrylate copolymer and dithiocarbamate becoming a pendent of these copolymers. The ion exchange of lead and cupric ions with these dithiocarbamate containing polymers under different pH values are investigated. The identification of dithiocarbamate group containing compounds are carried by FT-IR and FT-NMR; the metallic ion exchange capacity of a known solution before and after these chelating processes by these polymers are measured by atomic absorption spectra; The thermal stability of these copolymers before and after metallic ion exchange are evaluated by thermogravimetric analyzer.
37
Sukesan, Revathi, and 梅. 莉. "Rapid Heavy Metal Ion Screening using Extended Gate Ion Selective Field Effect Transistor Sensor." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/74ry67.
Повний текст джерелаАнотація:
碩士國立清華大學
奈米工程與微系統研究所
106
Heavy metals are a risk to humans if they get accumulated in your body. Mercury is an extremely dangerous one, if inhaled it directly targets the brain, whereas mercuric salts mainly affects the kidney. Monitoring concentration of mercury in drinking water, tap water and juices or food we intake are thus really important. There are several techniques in place in order to check the concentration of mercury but most of them are either laboratory based and expensive, some are inconvenient as well. Since there is an increasing case of mercury related poisoning it becomes necessary to monitor the mercury level. The extended gate ISMFET sensor enables easy and economical testing and provides a reliable output on the amount of mercury in that particular test material in a really short period of time. This sensor deciphers a sensing methodology which is highly selective to the target ion and offers a low affinity to other interfering ions. By combining ion-selective membrane with an extended gate device connected to a FET, and introducing the electric double layer structure with an extremely small gap distance enables us to attain sensitivity higher than the Nernst behaviour, and also improves the detection limit to 10-13 M which is much better than the benchtop instruments. We have also achieved a dynamic range from 10-13 M to 10-5 M. the sensor can also be used for real time testing in different water based systems such as tap water, drinking water, industrial waste water, medicines, food and beverages. Along with the advantages of small size, portable, less expensive and easy to fabricate this can be coined as a reliable and user friendly mercury sensor.
38
Kney, Arthur D. "Synthesis and characterization of a new heavy-metal-selective inorganic ion exchanger /." Diss., 1999. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9935165.
Повний текст джерела
39
Fang, Yun-Lung, and 方雲龍. "Amino acid-base hydrogel: A heavy metal ion scavenger in blood." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/m24drj.
Повний текст джерелаАнотація:
碩士國立中央大學
生醫科學與工程學系
106
Heavy metal pollution has been one of the most important environmental problems today. Copper-containing wastewater is extensively released from different industries. The release of metal ions into food chains results in serious healthcare issues such as overaccumulation in human body leading to Alzheimer's, Parkinson's and Wilson diseases. Pharmaceutical chelating agents are widely used in the treatment of copper-induced toxicity. However, it had been reported that the side effects of the treatment damage the immune system, kidneys and neurological symptoms of patients with pre-existing neurological problems. Zwitterionic amino acid-based polymers were developed for excellent biocompatibility and antifouling properties. In previous studies, amino acid group enables specifically catching copper ions from solution by formation of a chelating structure. Here, we developed an amino acid-based hydrogel adsorbent in order to rapid and effective removal of Cu2+ ions from blood by filtration in a gel-packed column. We performed the chelating ability of gel adsorbent to Cu2 + under different conditions and confirmed the hemocompatibility by hemolysis test and platelet adhesion test. Finally, we verified the capability of gel column to remove copper ions from the solution in an animal experiment. As result, it owns good adsorption and regeneration ability, and good hemocompatibility and it also can sorption copper in blood. We expect that the amino acid-based hydrogels hold a great potential as a Cu2+-removal hemodialysis system in the future.
40
Yang, Cheng-Yu, and 楊政育. "Adsorption of Heavy Metal Ions ( Cu, Zn, Ni, Pb, ) by crosslinked metal ion-templated chitosan." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/56640797127369507350.
Повний текст джерелаАнотація:
碩士國立高雄師範大學
化學系
94
Chitosan is capable of adsorbing metal ions due to its amine and hydroxy groups, but chitosan is soluble in organic acids and inorganic acids. Crosslinking is used to improve the acid-resisting of chitosan. Moreover, crosslinking will lower the adsorbability of chitosan. In this research, we made the crosslinked metal ion-templated chitosan with two crosslinker of Glutaraldehyde, Epichlorohydrin and four metal ion of Cu2+、Zn2+、Ni2＋、 Pb2+, and observe the situation of adsorbing heavy metal ions such as Cu2+、Zn2+、Ni2＋and Pb2+ ions with it. In this research, (1) the GLA-crosslinked metal ion-templated chitosan : The adsorption capacity of Cu2+ is 35.51 mg/g for Cu(II)-templated chitosan and increase 54.8% compared with the non-templated chitosan. The adsorption capacity of Zn2+ is 15.97 mg/g for Zn(II)-templated chitosan and increase 42.08% compared with the non-templated chitosan. The adsorption capacity of Ni2+ is 65.38 mg/g for Ni(II)-templated chitosan and increase 428.17% compared with the non-templated chitosan; The adsorption capacity of Pb2+ is 100.12 mg/g for Pb(II)-templated chitosan and increase 42.09% compared with the non-templated chitosan. (2)the ECH-crosslinked metal ion-tempalted chitosan: The adsorption capacity of Cu2+ is 26.97 mg/g for Cu(II)-templated chitosan and increase 198.34% compared with the non- templated chitosan. The adsorption capacity of Zn2+ is 14.59 mg/g for Zn(II)-templated chitosan and increase 46.34% compared with the non- templated chitosan. The adsorption capacity of Ni2+ is 17.05 mg/g for Ni(II)- templated chitosan and increase144.62% compared with the non- templated chitosan. The adsorption capacity of Pb2+ is 61.49 mg/g for Pb(II)-templated chitosan and increase 17.66% compared with the non- templated chitosan. We found that the crosslinked metal ion-templated chitosan has higher adsorbtion capacity and selectivity than the crosslinked non-templated chitosan and that the GLA-crosslinked metal ion-templated chitosan has higher adsorption capacity than ECH- crosslinked metal ion-templated chitosa
41
Lai, Jian Ren, and 賴建任. "Porous Silicon Based Photonic-Sensor for High Sensitive Heavy Metal Ion Detecrtion." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/put9b8.
Повний текст джерелаАнотація:
碩士國立清華大學
工程與系統科學系
103
Water is essential to human life material, settlement of people's lives as much dependent on the water area and growth. Human society continues to progress from the first agricultural society through the industrial revolution until now, people with the growth of industry and technology have had a relatively affluent life than ever before. But in the booming industry it has been accompanied by a number of environmental pollution produced, such as carbon dioxide cause global warming caused by industrial waste water in various forms of water pollution and so on. This will gradually hurting the environment we live. The heavy metal pollution in water pollution in 70 to 80 years is relevant agricultural, fishery and animal husbandry against Taiwan, such as arsenic, cadmium, mercury, lead and heavy metal pollution. In view of this, the aim of this study is related to the manufacture of heavy metals in water pollution detection mechanism. The current detection mechanism mostly use the more expensive equipment or the use of complex chemical titration step approach to the analysis of heavy metals in aqueous solution. In this experiment, the first generation of wafer-dimensional photonic crystal having a characteristic and by a simple chemical synthesis and surface modification of it in Fourier infrared spectroscopy (FTIR) for detecting signals of heavy metals, and to achieve qualitative and quantitative results. The second generation of photonic crystal wafer as visible light with a wavelength of electrochemical reduction of metal ions to be measured directly in the porous silicon precipitates hole caused large refractive index change, to enhance the signal strength and the detection limit of the effect. The first two chapters illustrate the application of this study motive and related experiments. Today introduced the relevant heavy metal detection equipment, introduces the basic principles of photonic crystals with porous silicon etching works. The third and fourth chapters compared with experimental design processes and related process steps. Fifth and sixth chapters, compared with results of the discussions and conclusions. Literature review is included in Chapter VII.
42
Wu, Ming Tsung, та 吳明宗. "Amino-grafted β-chitosan and its application on heavy metal ion adsorption". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/98585110763612174580.
Повний текст джерелаАнотація:
碩士萬能科技大學
材料科技研究所
99
Industrial effluent containing any heavy metals will cause seriously environmental pollutions and damages. Any attempts on removal of metal ions for contaminated water prior to discharging will win universal acceptance. Chitosan has a number of commercial and possible biomedical uses owing to its biocompatible, biodegradable and renewable properties, and was found to be one of excellent candidates for metal ion adsorbents. In order to enhance its adsorbing capability, β-chitosan was used as a precursor for further modification, by which the amino group on C2 of the chitosan can react with benzaldehyde under protection and thereby generates a Schiff base in the reaction system. It allows epichlorohydrin and triethylenetetramine to react with chitosan by means of grafting polymerization, and eventually, a crosslinked structure was formed. The structural changes, properties, and adsorbing capabilities of modified chitosans among these reaction sequences were systematically analyzed using FTIR, UV-VIS, XRD, EA, NMR, TGA, DSC, BET and SEM measurements. For the reaction of Schiff base formation, an ultimate reaction condition was obtained by using the orthogonal optimal method. It indicated that a feed composition containing chitosan of 1 g and benzaldehyde of 5ml can get optimal effect as performed a reaction under pH 7 at a reaction temperature of 60 oC for 3 h. It was found from the result that the capacity of modified chitosan for copper ion adsorption can be greatly promoted at pH 2 ~ pH 6, i.e., increased from 67.76mg/g to 117.60mg/g at a pH of 6. In addition to, the adsorptions on silver ions are higher than those of copper ions as compared under the same pH value, for instance, the silver adsorption at pH 6 is 151.20mg/g, and the copper adsorption 117.60mg/g. An important point to emphasize is the fact that the modified chitosan becomes more acid resistant as compare with the pristine one.
43
Lee, Cheng-Hsun, and 李政萱. "Monitoring Heavy Metal Ions in Water by Using Ion Exchange Resin Packs." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/72047911269205041813.
Повний текст джерелаАнотація:
碩士國立臺灣大學
生物環境系統工程學研究所
104
Unlawful manufacturers have often discharged their wastes secretly and caused severe damages to our environment. These kind of polluting events are usually done unpredictably in a short time without any sign, but the discharges could be highly concentrated and the locations are quite uncertain and dispersed. The goal of this study is to develop the ion exchange resin pack as an environmental fingerprinting method, which will enable the regulatory agencies to monitor and identify illegal polluters, in order to assure irrigation water and soil quality. In this study, inexpensive ion exchange resin packs are developed and deployed for a given period of time in the areas being monitored. After the packs are recovered, we can then determine the amount of heavy metal in ion exchange resin packs and identify the distribution of the hidden pollution sources. This study was divided into two parts, the laboratory experiments and the field testing respectively. The results of the laboratory experiments show that approximately 40% of the heavy metal ions were absorbed onto cation exchange resin from aqueous solution in 30 minutes. There were no significant differences in the percentage being absorbed at various concentrations tested as long as the resins did not reach exhaustion in the range we tested. In the field experiment, we chose Changhua as a study area. There were 151 point sites in two canals and each site was placed three packs for monitoring time for 7, 14, and 21 days. Metal ions in the recovered packs were determined with an Itrax X-Ray fluorescence mass spectroscopy. The principal component analysis (PCA) method was used to analyze the data which indicated that there were 4 principal components, the natural background (PC1), the background of the monitored area characteristics (PC2), the metal treatment and the electroplating industry (PC3 and PC4). It is expected that these results will provide a good foundation for further research and applications of this monitoring method.
44
Grosse, Andrew Clifton. "The synthesis of adsorbents for metal ions in soils and ores." Thesis, 1998. https://eprints.utas.edu.au/19688/1/whole_GrosseAndrewClifton1998_thesis.pdf.
Повний текст джерелаАнотація:
A series of porous copolymer resins with ionogenic or chelating
functional groups was prepared from commercial polystyrene or
polymethacrylate precursors. Samples of all resins were supplied to Geo2
laboratories for assessment of their efficacy in a proprietary heavy metal
remediation process. Two of these resins, DMA-1 and CMS-2, were
prepared in bulk to supply pilot scale testing.
The crosslinked resin-bead substrates used were: chloromethylated
polystyrene (CMS), diethylenetriamine poly(methacrylamide) (DMA),
glycidyl methacrylate (GMA), and three types of poly(methyl
methacrylate) (MMA, MMB & MMC) with varying degrees of porosity
and crosslinking.
The alkyl halide moiety of CMS was used to anchor 2° or 3°
alkylamines, diethylenetriamine, tris(2-aminoethylamine), or a
quaternary ammonium group. Alternatively, a primary amine group was
introduced via hydrolysis of hexamethylene tetramine.
Poly(ethylene glycol)s of various sizes were affixed to the
chloromethylated substrate via Williamson ether synthesis to form
"pseudocrown" ether chains. Benzocrown ether groups were produced by
anchoring catechol to the CMS resin and subsequent reaction with a,codichloropoly(ethylene
glycol).
Functional groups on poly(methyl methacrylate) resins were
introduced via hydrolysis of the backbone, or by aminolysis with tris(2-
aminoethyl)amine or 2-aminoethanol. The epoxide moiety of GMA was alkylated with either high-pressure ammonia, tris(2-aminoethyl)amine,
or various grades of poly(ethylene glycol)s. Hydrolysis of the epoxide in
aqueous acid was also investigated.
Resins with aminocarboxylate moieties were prepared via
carboxymethylation of resins with primary amine or diethylenetriamine
groups (including DMA), using excess chloroacetic acid in aqueous
carbonate solution. The moieties prepared were diethylenetriamine
triacetic- and tetraacetic- acids, and aminodiacetic acid. Several nonporous
pseudocrown ether materials were also produced via
copolymerisation, yielding urethane or methacrylate substrates.
The resins were characterised by elemental analysis, and by their
Infra-Red spectra. A subset of resins was also characterised by their affinity
and capacity to adsorb metal ions in aqueous solution. The sorption of
copper from a 75 ppm solution into these resins was measured over a 25
hour period. Adsorption isotherms for Cu 2+ in 0.010 M aqueous
hydrochloric acid were also obtained in the range 10-75 ppm. The highest
metal capacities were achieved with aminocarboxylate functionalities;
amine resins adsorbed very little.
45
Yang, Te-Chien, and 楊得謙. "Application of bacterial heavy metal ion binding proteins for silver resistance and adsorption." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/18326510462067964364.
Повний текст джерелаАнотація:
碩士國立中興大學
生命科學院碩士在職專班
97
Heavy metal pollution has posed one of the serious threat to human health, therefore, seeks an economy and effective method to clear the heavy metal pollution is the urgent matter.Bioremediation is the best method can clear heavy metal pollution completely and will not cause the second pollution. Because the bacterial heavy metal binding proteins can absorb the heavy metal ions, therefore we can use the biological characteristics to eliminate the heavy metal pollution in the soil or water. Take the SilE protein as the example, the SilE protein has played the key role in the resistant mechanism of silver resistant bacterium, therefore, the Ag+ adsorptive capacity of SilE protein will be closely linked to its silver resistance. Six strains were included in this project. E.coli strain J53 contains plasmid pMG101 which have silver resistance. There are nine open reading frames of the silver resistance determinant in the plasmid, including SilE protein. Two recombinant plasmids were constructed by cloning silE gene with or without signal sequence into pET21b vector, resulting SilE-SP and SilE-NSP respectively. For MerP protein, another two constructs were made by cloning MerP with signal sequence or B95P without signal sequence into pET21b vector. All recombinant plasmids were transformed to E.coli BL21 (DE3) strain. One control is with backbone pET21b in E.coli BL21 (DE3). Resistance tests in agar plate and in liquid medium were performed to detect the strength of resistance to Ag+. In disc assay, the strength was pMG101＞SilE-SP＞MerP＞pET21b＞SilE-NSP＞B95P and pMG101＞MerP＞SilE-SP＞pET21b＞SilE-NSP＞B95P for resistance test in liquid medium. Because both SilE and MerP protein can absorb heavy metal ions, adsobability experiment was also done to detect the Ag+ residue in the buffer. The results were 1.89 ± 0.026 mg/l for pMG101，1.92 ± 0.031 mg/l for MerP，1.93 ± 0.006 mg/l for pET21b，1.94 ± 0.021 mg/l for SilE-SP，1.94 ± 0.020 mg/l for SilE-NSP，and 2.10 ± 0.026 mg/l for B95P. In brief, the adsorbability to adsorb Ag+ is pMG101＞MerP＞pET21b＞SilE-SP≒SilE-NSP＞B95P. The results above showed that MerP protein can absorb Ag＋ and the efficiency is only less than pMG101（J53）, therefore, the next experiment was to observe the growth and detect the amount of the Ag＋ can be absorbed by the transgenic plant containing merP gene （P5 transgenic plant）. The host of bacterial merP gene is Arabidopsis. Furthermore, because MerP protein can absorb Hg+2, Ag+ and other heavy metals, the character of adsorption to heavy metal ions needs to be further investigated for the P5 transgenic plant. We found the differences for silver adsorption of P5 transgenic plant embedding in MS medium containing between Ag+ only and both Hg+2 and Ag+.The results indicated that the plant can absorb more Ag+ in the condition containing both Hg+2 and Ag+.
46
蔡承延. "Design of A Heavy Metal Ion Sensor Based on Brush-distributed Nanofiber Technology." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/82489483038939873926.
Повний текст джерела
47
Li, Chia-Lin, and 李佳霖. "Synthesis of Fluorescent Chemosensors and the Studies of Heavy Metal Ion-Sensing Properties." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/bjpva6.
Повний текст джерелаАнотація:
碩士國立彰化師範大學
化學系
106
Abstract We successful design and synthesized five fluorescent chemosensors and further explore their recognition ability toward metal ions. From the results, chemosensors 1 and 2 can selectivity recognize Hg2+ ions and Pb2+ ions among a series of metal ions, respectively. They show obvious fluorescence quenching and fluorescence enhancement, respectively. Interesting, chemosensors 3, 4 and 5 all can selectivity recognize Al3+ ions by different color change under U.V lamp detection. And all of them show obvious fluorescence enhancement. In addition, chemosensors 1, 4 and 5 were also applied in the fluorescent indicator paper. Keyword：Chemosensor、Fluorescent probe
48
"Enhancement of metal ion removal capacity of water hyacinth." 2001. http://library.cuhk.edu.hk/record=b5890617.
Повний текст джерелаАнотація:
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
49
Cheng, Chi-Wei, and 鄭基偉. "The feasibility of recycling sulfuric acid containing heavy metal with ion exchange membrane process." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/95164896007215293088.
Повний текст джерелаАнотація:
碩士國立高雄第一科技大學
環境與安全衛生工程研究所
101
Waste lead acid batteries in the battery case and the waste scrap lead to high-valued recycling, waste lead-acid battery recycling industry, for recycling, resource recycling, mainly recycling of lead metal and plastic casing waste lead acid batteries, the comcentration of sulfuric acid is lower, it’s not applicable to ordinary technology of recovery, so far it’s not to be considered and the recycling and reuse of resources; generally lead battery scrap recycling industry waste sulfuric acid process, the main practice is to waste sulfuric acid solution is added to neutralize alkaline chemical reaction and then transferred to water treatment plant in industrial zone. According to the reference , it indicate that foreign recyclers have developed several kinds of recyclable waste sulfuric acid lead battery fluid produced by the technology, so the study will be conducted the evaluation of these technologies, and try to estimate its cost. From waste sulfuric acid recovery techniques in the literature were screened out of eight kinds of recovery methods, such as ion exchange resins, diffusion dialysis, electrical dialysis and sodium recovery method, by sampling survey of waste sulfuric acid solution to the current situation and considering Taiwan recyclers the scale, preliminary assessment of diffusion dialysis method for the possible use of recycling technologies. Technical processing using the diffusion dialysis solution containing heavy metal waste sulfuric acid with the principles of the waste sulfuric acid solution of sulfuric acid as a solute, the use of waste sulfuric acid solution with heavy metal salts chargeability between differently to ion diffusion film itself has through sexual selection, acid and metal salts such separation and recovery of sulfuric acid. Affect diffusion dialysis recovery and removal of heavy metals are three main factors, (one) into the flow of traffic (two) into the flow and recycling of waste sulfuric acid solution of sulfuric acid liquid flow ratio (three) waste sulfuric acid solution of sulfuric acid concentration; in a variety of different operating conditions, to get into the flow when the flow of waste acid 10 mL / min and the feed stream and recycling of waste sulfuric acid solution of the flow rate ratio of 1:1.1 obtained when the best operating results, sulfuric acid recovery may more than 90%, lead and iron removal efficiency was 80% or more. In the waste sulfuric acid status survey results show that the detection of the recycling industry concentration of sulfuric acid and various metal concentration in iron concentration in the highest, followed by lead, in the original waste lead acid batteries of the sulfuric acid solution of iron concentrations are not particularly high, but after the dismantling of waste sulfuric acid solution, the concentration of iron obviously higher than other metal elements, presumably used in the process of dismantling dismantling machine mainly composed of iron and steel, disassembled waste lead acid batteries out of the waste sulfuric acid solution in contact with the dismantling of mechanical components, and thus after the dismantling of waste sulfuric acid solution measured higher iron concentrations, the concentrations of other metals were higher than in the original concentration of waste lead acid batteries. In this study, at the final stage, to two recycling plants take practical waste sulfuric acid solution, the use of waste taken back diffusion of acid in the laboratory assessment of the feasibility of the dialysis membrane. Experimental results show that the recovery of each batch of sulfuric acid concentration can reach more than 90%, and synthetic waste sulfuric acid solution similar to the experimental results, but the removal of lead and iron is about 20-40%, much lower than the synthetic waste the experimental results of sulfuric acid (which can be higher than 75%), presumably for the actual waste sulfuric acid solution has a high cation concentration and containing organic compounds (such as grease, etc.) which affect the diffusion of metal ions in the membrane selectivity. Above results, the use of ion diffusion membrane separation and recovery of waste lead acid storage battery has a considerable feasible, but further improve diffusion of the metal ion selective membrane to remove the metal ion recovery of sulfuric acid.
50
Wu, Yi-lin, and 吳易霖. "The study of heavy metal ion removal by citric acid modified cellulose filter paper." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/a7rc97.
Повний текст джерелаАнотація:
碩士國立清華大學
生醫工程與環境科學系
105
Membrane filtration is a promising water treatment technique, but its high energy consumption hinders its universal application. We herein introduce a low energy consumption filtration system, in which the cobalt rejection rate is greatly enhanced through Donnan exclusion from 10% to 95%. This is achieved by grafting citric acid onto the cellulose filter paper through esterification. The incorporated acid sites exhibits high cobalt affinity which enhances the Donnan exclusion effect. Most importantly, the filtration was conducted at atmospheric pressure yet still achieving permeate flux of 100 L/m2h. In conclusion, we demonstrate a new low energy consumption filtration system with high cobalt rejection through Donnan exclusion effect, which may have promising potential in various heavy metal contaminated waters.