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1
Silva, Marcos Erick Rodrigues da. "Post-Treatment for effluents of anaerobic reactors treating domestic effluent by natural and unnatural coagulants". Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=266.
Testo completoAbstract (sommario):
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoThe current investigation aimed to study post-treatments for effluents of anaerobic sludge blanket reactors by using both natural (Moringa oleifera, Lam) and unnatural coagulants. For that, many jar-tests were conducted either using sewage or effluent of a lab-scale UASB (upflow anaerobic sludge blanket) reactor. Many dosages of natural (Moringa oleifera) and unnatural (ferric chloride) coagulants were tested with sewage. Afterwards, the coagulants effect associated to a polymer (FO 4140) was assessed in the physical-chemical and microbiological parameters of the UASB reactor effluent. The results indicated that the natural coagulant moringa provided low turbidity removal in comparison with the unnatural coagulant ferric chloride, for both sewage and UASB effluent, questioning the real application of moringa in the physical-chemical treatment of sewage. Additionally, a negative effect of the moringa seeds was verified after the detection of a considerably increase of the Chemical Oxygen Demand (COD) and turbidity, while testing the UASB effluent. The results show that, in general, the moringa seeds were inefficient on the removal of physical-chemical and microbiological contaminants present in sewage and anaerobic effluents.
O presente trabalho teve como objetivo estudar pÃs-tratamentos de efluentes provenientes de reatores anaerÃbios de manta de lodo pelo uso de coagulantes naturais (Moringa oleifera, Lam) e nÃo naturais. Para tanto, foram realizados vÃrios ensaios de jar-test utilizando tanto esgoto sanitÃrio bruto quanto efluente de um reator UASB (upflow anaerobic sludge blanket) em escala de laboratÃrio. Foram testadas vÃrias dosagens dos coagulantes natural (Moringa oleifera) e nÃo-natural (cloreto fÃrrico) utilizando esgotos brutos domÃsticos. Em seguida foram estudados os efeitos dos coagulantes associados ao auxiliar de coagulaÃÃo (FO 4140), nos parÃmetros fÃsico-quÃmicos e microbiolÃgicos do efluente do reator UASB. A partir dos resultados, verificou-se que o coagulante natural moringa forneceu baixas remoÃÃes de turbidez na comparaÃÃo com o coagulante nÃo-natural cloreto fÃrrico, tanto para o esgoto bruto como para o efluente do reator UASB, questionando-se a real aplicaÃÃo da moringa no tratamento fÃsico-quÃmico de esgoto sanitÃrio. Adicionalmente, verificou-se um efeito negativo do uso das sementes de moringa, mediante a detecÃÃo de um aumento considerÃvel nas concentraÃÃes finais de DQO e turbidez, quando o efluente anaerÃbio era testado. Os resultados mostraram que, de uma forma geral, a semente de moringa se mostrou ineficiente na remoÃÃo de contaminantes fÃsico-quÃmicos e microbiolÃgicos presentes em esgotos sanitÃrios brutos e efluentes anaerÃbios.
2
Peterson, Mark. "Electrodisinfection of Municipal Wastewater Effluent". ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/294.
Testo completoAbstract (sommario):
To avoid the spread of disease from sewage treatment effluents, pathogenic microorganisms present must be destroyed by one or a combination of disinfection methods. Chlorine remains the predominant disinfectant used although it consumes considerable amounts of energy and has associated exposure risks from production, transportation and storage of this poisonous gas. In addition to bacteria and other objectionable microorganisms, color, suspended and colloidal solids also require removal from water for reuse. Aluminum and iron additions have been used to coagulate and remove non-settleable solids. By electrically dissolving aluminum to form solids-bridging aluminum hydroxide, the water itself can also be disinfected by the effects of electrical fields and its reactions to form disinfectant chemicals and direct destruction of microorganisms in the water. This research investigated the effects of electrical current, time, and chloride concentration on the electrochemical disinfection of sewage treatment plant effluent using aluminum electrodes to substitute for chlorine disinfection.
3
Santos, Bruno Alexandre Quistorp. "Continuous bioremediation of electroplating effluent". Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/865.
Testo completoAbstract (sommario):
Thesis submitted in fulfilment of the requirements for the degree
Magister Technologiae: Chemical Engineering
in the Faculty of
Engineering
at the
Cape Peninsula University of Technology
2013There are significant quantities of free cyanide (F-CN) and heavy metal contaminated effluent being discharged from electroplating operations globally. However, there is an overwhelming tendency in the industry to use physical and/or chemical treatment methods for cyanides (CNs) and heavy metals in effluent. Although these methods may be effective for certain CNs and heavy metals, they produce toxic by-products and also involve high operational and capital investment costs when compared to bioremediation methods. In this study, the design of a two-stage membrane bioreactor (MBR) system was conceptualised for the bioremediation of CNs and heavy metals in the effluent which was collected from an electroplating facility located in the Western Cape, South Africa. The design included a primary inactive bioremediation stage, to reduce the impact of contaminate concentration fluctuations, and a secondary active bioremediation stage, to remove the residual contaminants, in the effluent under alkaline pH conditions which typify most industrial effluent containing these contaminants. An analysis of the electroplating effluent revealed that the effluent contained an average of 149.11 (± 9.31) mg/L, 5.25 (± 0.64) mg/L, 8.12 (± 4.78) mg/L, 9.05 (± 5.26) mg/L and 45.19 (± 25.89) mg/L of total cyanide (T-CN), F-CN, weak acid dissociable cyanides (WAD-CNs), nickel (Ni), zinc (Zn) and copper (Cu), respectively. An Aspergillus sp., which displayed the characteristic black conidiophores of the Aspergillus section Nigri, was isolated from the electroplating facilities’ effluent discharge using a selective pectin agar (PA) and subcultured on 2% (v/v) antibiotic (10,000 units/L penicillin and 10 mg streptomycin/mL) potato dextrose agar (PDA). The isolate was tolerant to F-CN up to 430 mg F-CN/L on F-CN PDA plates which were incubated at 37 ˚C for 5 days. However, a significant decline in microbial growth was observed after 200 mg F-CN/L, thus indicating that the isolate was suitable for the bioremediation of the electroplating effluent. The identification of the isolate as Aspergillus awamori (A. awamori) was definitively determined using a multi-gene phylogenetic analysis, utilising ITS (internal transcribed spacer), -tubulin and calmodulin gene regions. Although an anomaly in the morphology of the conidia of the isolate was observed during the morphological analysis, indicating a possible morphological mutation in the isolate. A comparative study between “sweet orange” (Citrus sinensis (C. sinensis)) pomace, “apple” (Malus domestica (M. domestica)) pomace, “sweetcorn” (Zea mays (Z. mays)) cob and “potato” (Solanum tuberosum (S. tuberosum)) peel, i.e. waste materials considered to be agricultural residues, was conducted in order to assess their potential and as a sole carbon source supplement for A. awamori biomass development for the bioremediation of CNs and heavy metals. The suitability of these agricultural residues for these activities were as follows: C. sinensis pomace ˃ M. domestica pomace ˃ Z. mays cob ˃ S. tuberosum peel. For purpose of the sensitivity analysis, a temperature range of 20 to 50 ˚C and an alkaline pH range of 7 to 12 showed that: (1) optimal conditions for the uptake of Ni, Zn and Cu occurred at pH 12 and a temperature of 37.91 and 39.78 ˚C using active and inactive A. awamori biomass and unhydrolysed and hydrolysed C. sinensis pomace, respectively; (2) F-CN conversion increased linearly with an increase in pH and temperature using unhydrolysed and hydrolysed C. sinensis pomace; and (3) optimal conditions for the F-CN conversion and the respective by-products and sugar metabolism using active A. awamori biomass occurred at 37.02 ˚C and pH 8.75 and at conditions inversely proportional to F-CN conversion, respectively. The heavy metal affinity was Ni > Zn > Cu for all the biomaterials used and with the heavy metal uptake capacity being inactive A. awamori biomass > active A. awamori biomass > hydrolysed C. sinensis pomace > unhydrolysed C. sinensis pomace, respectively. Hydrolysed C. sinensis pomace had a 3.86 fold higher conversion of F-CN compared to the unhydrolysed C. sinensis pomace. The use of C. sinensis pomace extract as a nutrient media, derived from the acid hydrolysis of C. sinensis pomace, showed potential as a rich carbon-based supplement and also that low concentrations, < 0.1% (v/v), were required for the bioremediation of CNs and heavy metals. The two-stage MBR system was operated at 40 ˚C since this temperature was conducive to the bioremediation of CN and heavy metals. The primary bioremediation stage contained hydrolysed C. sinensis pomace while the secondary bioremediation stage contained active A. awamori biomass, supplemented by the C. sinensis pomace extract. After the primary and secondary bioremediation stages, 76.37%, 95.37%, 93.26% and 94.76% (primary bioremediation stage) and 99.55%, 99.91%, 99.92% and 99.92% (secondary bioremediation stage) average bioremediation efficiencies for T-CN, Ni, Zn and Cu were achieved. Furthermore, the secondary bioremediation stage metabolised the CN conversion by-products with an efficiency of 99.81% and 99.75% for formate (CHOO-) and ammonium (NH4+), respectively. After the first, second and third acid regeneration cycles of the hydrolysed C. sinensis pomace, 99.13%, 99.12% and 99.04% (first regeneration cycle), 98.94%, 98.92% and 98.41% (second regeneration cycle) and 98.46%, 98.44% and 97.91% (third regeneration cycle) recovery efficiencies for Ni, Zn and Cu were achieved. However, the design only managed to treat the effluent for safe discharge and the use of a post-treatment stage, such as reverse osmosis, is recommended to remove the remainder of the trace contaminants and colour from the effluent to ensure that the effluent met the potable water standards for reuse. There was a relatively insignificant standard deviation (≤ 3.22%) detected in all the parameters measured in the continuous operation and this indicates the reproducibility of the bioremediation efficiency in this continuous system.
4
Uhlman, Kristine, Susanna Eden, Channah Rock, Erin Westfall e Terry Sprouse. "Effluent Dependent Streams of Arizona". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/225865.
Testo completo
5
Long, Xiaoping. "Minimum effluent process for pulp mill". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/11825.
Testo completo
6
Santoyo-Gutierrez, Socrates. "Absorption heat pump assisted effluent purification". Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245055.
Testo completo
7
McClure, P. J. "The biodegradation of pharmaceutical effluent constituents". Thesis, Bucks New University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233071.
Testo completo
8
Hariyadi, Hari Rom. "Microbiological treatment of prochloraz process effluent". Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366913.
Testo completo
9
Wrigley, Timothy John. "Water quality improvement of piggery effluent". Thesis, Wrigley, Timothy John (1999) Water quality improvement of piggery effluent. PhD thesis, Murdoch University, 1999. https://researchrepository.murdoch.edu.au/id/eprint/52406/.
Testo completoAbstract (sommario):
An experimental wetland system was constructed to upgrade the water quality of piggery wastewater. Transplanted aquatic macrophytes were successfully established within the wetland. The wetland experiment was concluded prematurely because of continual pipework blockages which prevented wastewater flow into the wetland.
The precipitate in the pipework was identified as Struvite, MgNH4PO4.6H2O, a precipitate widely associated with wastewaters and kidney stones.
The formation of struvite in the piggery wastewaters indicated that struvite may be an important process in the removal of nutrients.
X-ray diffraction of lagoon sludge confirmed that struvite precipitation occurred in the three wastewater lagoons at the piggery.
Magnesium, essential for the formation of struvite, entered the waste water system via groundwater used for wash down. Magnesium was also an important food supplement in the feed provided for the pigs. Magnesium coupled with ammonia and phosphorus at pH values greater than nine (9) can produce struvite. Up to 250 tonnes/annum of struvite could be removed from the final piggery effluent under correct pH and dosing conditions. Struvite is a valuable slow release fertilizer, and its formation and removal from wastewaters may be important in the reduction of eutrophication in receiving waters.
Laboratory-scale batch and continuous anaerobic digestion of piggery effluent was undertaken. The removal of struvite from solution by chemical dosing with MgSO4 after digestion was determined.
During anaerobic digestion of piggery wastewater, COD was reduced by 50%- 90%, as measured by biogas production. Concentrations of PO4-P in the supemate increased during batch digestion (21 to 33 mg/L) while a marked reduction in PO4-P concentration of the supemate from the continuous digestion (21 to 10 mg/L) occurred. The addition of MgSO4 to the supernate reduced PO4-P concentrations from 33 to 7 mg/L (batch) and from 10 to 0.1 mg/L (continuous). Struvite, aphthitalite (K3Na(SO4)2) and thermardite (Na2SO4) were precipitated from solution.
A computer model was developed to describe struvite solubility chemistry; this included the electro-neutrality equation which allowed for greater variability in the input components. Relationships between the major ions were retained without approximation. The model results fitted data from both our laboratory results and published values. Equilibrium constants which markedly affect the output were identified and solubility constants derived.
The computer model of the solution chemistry of struvite was then improved. Firstly, the algorithm was smaller and faster with ammonia as the prime calculation point in the liquid phase. Secondly, the incorporation of dissolved magnesium hydrogen phosphate (dMHP) in the model significantly increased concentrations in solution. Thirdly, estimates of activity coefficients were included.
These improvements made a 5-10% improvement in the fit. This flexible modeling procedure allowed for the ready inclusion of all possible species. The addition of associated ammonium phosphates improved the fit. Estimates of the association constants were included. Applications of the model include waste-water treatment and the formation of kidney stones.
10
Chan, Kwok Ho. "Potential Reuse of wastewater effluent in Macau". Thesis, University of Macau, 2009. http://umaclib3.umac.mo/record=b1944060.
Testo completo
11
Farr, Gary Derek. "Chlorination effluent recycle in kraft pulp bleaching". Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29938.
Testo completoAbstract (sommario):
When performed at an industrial scale, kraft pulp bleaching commonly utilizes recycled chlorination effluent for brown stock dilution. Much of the information regarding this practice pertains to pulp quality. Some of the previous research done in this field failed to separate its effect from the effect of countercurrent effluent recycle for pulp washing. In addition, there are some shortcomings of the batch techniques that have been used to simulate effluent recycle in the laboratory. Thus little is known about the effect of this practice on effluent quality.
Accordingly, the objective of this research project was to determine the effect of chlorination effluent recycle for brown stock dilution on the quality of kraft pulp bleaching effluent. Chlorination effluent recycle was investigated in conjunction with the variables of multiple, mode, and chlorine dioxide substitution. Effluent quality was characterized in terms of toxicity, total chlorinated organic compounds, and chlorate. Pulp quality was also measured. A full 2⁴ factorial design was carried out with 24 bleaching runs.
The experimentation was performed in the laboratory using a two-stage (CE) bleaching sequence. A specially designed continuous laboratory-scale pulp chlorination apparatus, which was operated with an unbleached pulp throughput of 6 odg/min, was used to execute the first stage. By producing sufficient quantities of
effluent at steady state in a short period of time, this apparatus enabled the efficacious use of trout bioassays. The second stage was performed on a batch basis. Results from the laboratory experiments were compared to those from an industrial-scale bleach plant.
The chlorination stage toxic emission factor for rainbow trout decreased by 314 m³/adt as the level of recycle was increased from 4.5 to 22.5 m³/adt. The effects of multiple, mode, and substitution were also significant. Effluents from the extraction stage were much less toxic than those from the chlorination stage. The first stage toxic emission factors for trout and luminescent marine bacteria were not correlated. In addition, the concentration of organochlorine compounds and the number of toxic units were not correlated. A novel method for determining the toxic emission factor from median lethal time data was also developed.
Recycle had no significant effect on the total production of chlorinated organic compounds, which were quantified together in terms of AOX. A regression equation, which includes the effects of multiple and mode as well as the interaction between multiple and substitution, was formulated for the AOX results.
Recycle had no significant effect on the production of chlorate. A regression equation, which includes the variables of substitution and mode, was formulated for the chlorate results. A hypothesis, which involves the reactions of chlorine and chlorine dioxide with the phenolic hydroxyl groups of lignin, was developed to explain several characteristics of this equation.
Recycle also had no effect on pulp quality, which was measured after the extraction stage with the kappa number and the viscosity. Mode and multiple were the only factors that significantly affected the kappa number. A hypothesis, which involves the reactions of chlorine and chlorine dioxide with dissolved organic material in the chlorination stage, was developed to explain the effect of mode on delignification. None of the variables had a significant effect on the viscosity.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
12
Faustine, Claire. "Environmental Review of Petroleum Industry Effluent Analysis". Thesis, KTH, Industriell ekologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32828.
Testo completoAbstract (sommario):
The present report deals with environmental issues in refineries and petrochemical processes.More precisely gaseous, liquid and solid effluents from processes are analysed qualitativelyand quantitatively when possible. Techniques to treat these effluents are reviewed or proposedwhen lacking and methods to do not produce these effluents are envisaged.In the part A of the report general effluents that are released from all types of processes arestudied. These effluents include fugitive emissions, flue gases from process heaters,blowdown systems emissions and wastewaters. Fugitive emissions, one of the greatestsources of VOCs can be qualified and quantified by the average emission factor approach andreduced thanks to the implementation of an LDAR program. Flue gases from process heaters,which are a major source of NOx, SOx and particulate matters can be characterized withemission factors and several techniques exist to treat or prevent these emissions. Concerningblowdown systems emissions, which are difficult to quantify, methods to minimize theseemissions are given. Finally, wastewaters treatment in petroleum industry is shortly describedbefore best management practices and pollution prevention methods are enounced.In the part B of the report four families of processes are studied: naphtha hydrotreatment,naphtha isomerization, catalytic reforming and hydrogenation in olefin plants. Each of theseprocesses is firstly described, the process flow diagram is explained and continuous andintermittent effluents are characterized. In addition to general effluents dealt with in part A, ithas been found that processes can produce other effluents such as dioxins in isomerization orcatalytic reforming units or green oils during catalyst regeneration operations.Division Industrial Ecologywww.kth.se/itm/indecowww.ima.kth.se
13
Melanson, Jason B. "Effluent recycling in a Kraft pulp mill". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0009/MQ60153.pdf.
Testo completo
14
Schrader, Guillo Alexander. "Direct nanofiltration of wastewater treatment plant effluent". Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/55981.
Testo completo
15
Al-Wohoush, Mohammad. "Combustion of effluent concentrates from pulp mills". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84459.
Testo completoAbstract (sommario):
Recycling of bleaching effluents into the black liquor recovery system has become an important step of a closed cycle technology that, in a kraft pulp mill, will result in a reduction in pollutants discharge into receiving waters and also a decrease of fresh water consumption.In the current work, the combustion of pre-dried solid samples of black liquor (BL), chlorination effluent (C/D), and extraction effluent (E 1) as well as two-component and three-component mixtures was investigated experimentally in a Thermogravimetric Analyzer (TGA) and in a Constant-Temperature Tube Furnace.
Results of the thermogravimetric analyses showed that solids from the C/D stage were similar to those of the black liquor solids in the volatile matter, char, and ash contents, while the solids from the E1 stage contained less volatiles and were richer in their ash content. Results also revealed that both effluents were devolatilized and gasified at lower rates than that of black liquor. The addition of up to 20% of either effluent did not have a significant impact of the TGA behaviour of black liquor. In addition, mixtures containing solids from the three liquors were very close to black liquor in terms of their devolatilization and gasification rates and followed a weight-loss trend similar to that of black liquor.
Effect of temperature, O2, mixing ratio on the chemical compositions of combustion products was investigated in a constant-temperature tube furnace. Chemical analyses of the gaseous and solid phases were performed using a Mass Spectrometer (MS) and an Ion Chromatograph (IC), respectively. Results showed the combustion products of two-component mixtures containing up to 20% of C/D or E1 in black liquor solids would not be significantly different from those of typical black liquor, except that they contained more HCl in the gas phase and larger amounts of chloride in the solid phase, especially when C/D was added. Their amounts were greatly influenced by temperature and oxygen. Combustion of three-component mixtures (BL-C/D-E1) resulted in products very similar to those obtained during the combustion of black liquor alone. The HCl yield was increased with temperature and BL content in the mixture.
16
Smart, Gillian. "Bioremoval of recalcitrant colour from effluent wastestreams". Thesis, University of Bolton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494270.
Testo completo
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Miqdadi, Issam Mahmoud Ahmad. "Removal of algae from facultative pond effluent". Thesis, University of Newcastle Upon Tyne, 1992. http://hdl.handle.net/10443/475.
Testo completoAbstract (sommario):
Wastewater stabilization ponds have gained popularity as a means of secondary wastewater treatment because of their low cost and simplicity of operation and maintenance, in addition to several other advantages. However, the presence of algae in the effluent from facultative ponds may cause undesirable environmental impacts, such as DO depletion or eutrophication, in water bodies to which this effluent is discharged. Thus, regulations and/or the adverse environmental impacts of effluents containing algae sometimes necessitate reduction or removal of algae from pond effluents. Many methods have been used for the purpose of removal of algae from wastewater stabilization pond effluent. Upflow rock filtration and coagulationsedimentation have been investigated in this research. In the past, mechanisms of removal of algae in rock filters and factors that affect the removal process have not been well explained. Design of these filters has not been related mathematically to the operating variables. Three pilot rock filters were built for the purpose of this research. The first filter was filled with rock of 1 cm average diameter, the second and third filters were filled with 5 cm and 10 cm average diameter rock, respectively. Five different hydraulic loadings were applied to these filters, with variable influent characteristics and under different environmental conditions. The results of this research have shown that gravitational settling and hydrodynamic forces are the most important mechanisms affecting removal of algae in upflow rock filters. Also, a method of design of unisize-media upflow rock filters for removal of algae from facultative pond effluent has been established. The cost of coagulant has been the main disadvantage of the process of coagulation-sedimentation for algae removal from wastewater stabilization pond effluent. In this research, jar tests were carried out to determine the effect of settling time and/or addition of kaolinite or bentonite with the primary coagulant, alum, on the optimum dose of this primary coagulant required for removal of algae from facultative pond effluent. Both increase in settling time and coagulant aids, namely kaolinite and bentonite, have reduced optimum alum dose. Kaolinite and bentonite, applied as low-cost primary coagulants, were also effective in removing algae from facultative pond effluent. From the very limited experiments carried out at the end of this research, it was shown that crossflow microfiltration has some potential as a process for algae removal from facultative pond effluent. A mathematical model has been developed in this work to describe the eutrophic state of King Talal Reservoir in Jordan. The model predicts that even elimination of phosphorus from the effluent of Al-Samra Wastewater Stabilization Ponds will not bring the reservoir into an oligotrophic state.
18
White, Simon James George. "Monitoring of chemical toxicants in effluent streams". Thesis, University of Salford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427040.
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19
Brooks, Bryan W. "Ecotoxicological Investigations in Effluent-Dominated Stream Mesocosms". Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3359/.
Testo completoAbstract (sommario):
The University of North Texas Stream Research Facility (UNTSRF) was designed to examine contaminant impacts on effluent-dominated stream ecosystems. Stream mesocosms, fed municipal effluent from the City of Denton, TX, Pecan Creek Water Reclamation Plant (PCWRP), were treated with 0, 15 or 140 µg/L cadmium for a 10-day study in August 2000. Laboratory toxicity test and stream macroinvertebrate responses indicated that cadmium bioavailability was reduced by constituents of effluent-dominated streams. The Biotic Ligand Model (BLM) for Cd was used to predict a 48 hour Cd EC50 for Ceriodaphnia dubia of 280 µg/L in these effluent-dominated streams. This value is higher that an EC50 of 38.3 µg/L Cd and a 7-day reproduction effect level of 3.3 µg/L Cd generated for C. dubia in reconstituted laboratory hard water. These results support use of a cadmium BLM for establishing site-specific acute water quality criteria in effluent-dominated streams. Although not affected by 15 µg/L treatments, organisms accumulated Cd in 15 µg/L treated streams. Hence, over longer exposure periods, Cd accumulation may increase and a no effect level may be lower than the observed 10-day no effect level of 15 µg/L.
A toxicity identification evaluation procedure was utilized with in vitro and in vivo bioassays to identify estrogenic compounds in PCWRP effluent, previously identified to seasonally induce vitellogenin (VTG) in male fathead minnows. Steroids, nonylphenol ethoxylate metabolites, and other unidentified compounds were identified as causative effluent estrogens. These findings suggest that in vivo VTG bioassays should be used to confirm in vitro Yeast Estrogen Screening assay activity when effluents are fractionated or screened for estrogenicity. A subsequent 90-day cadmium study was initiated to assess long-term effluent and cadmium effects on fish endocrine function. Juvenile fathead minnows were placed in UNTSRF pool sections of replicate streams treated with 0, 5, 20 or 80 µg/L Cd. Male VTG was induced at each treatment level, indicating that PCWRP effluent was estrogenic during fall 2001. 20 and 80 µg/L Cd treatments reduced male circulating estradiol levels and critical swimming performance. Future studies are needed to assess impacts of environmental estrogen exposure on fish calcium metabolism and vertebral integrity.
20
Russo, Stephen Leonard. "Anaerobic treatment of a paper plant effluent". Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21988.
Testo completoAbstract (sommario):
The objective of this study was to investigate the anaerobic biological treatment of an organic-bearing wastewater from a particular paper manufacturing process at laboratory scale. The process produces paper by re-pulping waste paper. Effluent from the process has a Chemical Oxygen Demand (COD) concentration of approximately 4500 mg/l with a sulphate content of approximately 300 mg SO₄²⁻/l. The upflow anaerobic sludge bed (UASB) reactor was selected for the study. Important information derived from the laboratory treatability study was: (l) the extent of COD removal possible; (2) the effluent quality; (3) the maximum COD leading rate (kgCOD/m³ reactor/day) which can be achieved while maintaining reasonable COD removal, and the influence on loading rate of temperature: (4) the nature of the sludge produced in the reactor with particular reference to the extent of pelletisation: and (5) the effect of reactor effluent recycling on alkalinity requirements.
21
Brooks, George Benjamin Jr. "Dissolved Nitrogen Compounds in Integrated Aquaculture Effluent". College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208657.
Testo completoAbstract (sommario):
Integrated aquaculture utilizing pre- irrigation water will hypothetically increase the levels of dissolved nitrogen products in the resulting effluent. Research was performed to assess the levels of additional nutrients added. The results suggest however, that integrated aquaculture may reduce the amount of nitrogen as nitrate applied to the fields.
22
Santín, López Ignacio. "Application of control strategies in wastewater treatment plants for effluent quality improvement, costs reduction and effluent limits violations removal". Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/305238.
Testo completoAbstract (sommario):
En este trabajo se aplican diferentes estrategias de control en las plantas de tratamiento de aguas residuales. El primer objetivo es la mejora del rendimiento de control. Básicamente, esto sirve como una prueba de que la estrategia de control propuesta se ha aplicado correctamente. El objetivo final es el efecto de la estrategia de control aplicada sobre el rendimiento de la planta. En concreto, mejorar la calidad del efluente, reducir costes de operación y evitar violaciones de los límites establecidos en el efluente.
La evaluación de las diferentes estrategias de control se lleva a cabo en primer lugar con el Benchmark Simulation Model No. 1 (BSM1), y en segundo lugar con Benchmark Simulation Model No. 2 (BSM2). BSM1 se centra en el tratamiento biológico mediante reactores de lodos activos, y la evaluación se basa en una semana de simulación. BSM2 es una versión extendida del BSM1, agregando el tratamiento de lodos y proporciona un afluente más elaborado y variable, con un año de evaluación.
Los enfoques de control se basan en Control Predictivo basado en Modelo, control difuso, funciones que relacionan las variables de entrada y las manipuladas, y Redes Neuronales Artificiales. El Control Predictivo basado en Modelo se propone para una mejora del tracking. El control difuso y las funciones se implementan para mejorar los procesos de desnitrificación o de nitrificación en base a los objetivos propuestos. Sus parámetros de sintonía se seleccionan mediante análisis trade-off. Las Redes Neuronales Artificiales se aplican para detectar riesgo de violaciones y obtener una selección automática de la estrategia de control adecuada.
Se muestran los resultados y se comparan con las estrategias de control por defecto y con la literatura. Para el rendimiento de control, se obtiene una mejora satisfactoria. En cuanto al rendimiento de la planta, en la mayoría de los casos se evitan violaciones de los límites establecidos de nitrógeno total y de amonio y nitrógeno amoniacal, mientras que también se consigue una mejora de la calidad del efluente y una reducción de costes de operación.In this work different control strategies are applied in wastewater treatment plants. The first objective is the control performance improvement. Basically, this serves as a proof that the proposed control strategy has been applied properly. The final objective is the effect of the applied control strategy on the plant performance. Specifically, the effluent quality improvement, costs reduction and avoiding violations of the established effluent limits. The evaluation of the different control strategies is carried out first with Benchmark Simulation Model No. 1 (BSM1), and secondly with Benchmark Simulation Model No. 2 (BSM2). BSM1 is focused on the biological wastewater treatment by activated sludge reactors, and the evaluation is based on a week of simulation. BSM2 is extended adding the sludge treatment and provides a more elaborated and variable influent with an assessment of one year. The control approaches are based on Model Predictive Control, Fuzzy Control, functions that relate the input and manipulated variables and Artificial Neural Networks. Model Predictive Control is proposed for tracking improvement, Fuzzy Controllers and functions are implemented to improve the denitrification or nitrification processes based on the proposed objectives. Their tuning parameters are selected by trade-off analyses. Artificial Neural Networks are applied to detect risk of violations for an automatic selection of the suitable control strategy. The results are presented and compared with the default control strategy and with the literature. For the control performance, a satisfactory improvement is obtained. Regarding the plant performance, in most of the cases, violations of the established limits of total nitrogen and ammonium and ammonia nitrogen are avoided, as well as an effluent quality improvement and cost reduction are achieved.
23
Rui, Li. "The use of treated effluent for agricultural irrigation in the Bottelary River area: Effluent quality, farmers perception and potential extent". Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=init_1918_1177917293.
Testo completoAbstract (sommario):
The Bottelary River area is located in a Mediterranean climate region, where the agricultural sector plays an important role. During the dry summer season, there is not enough precipitation to meet the agricultural irrigation requirements. Some farmers extract river water which is practically the final treated effluent from the Scottsdene Wastewater Treatment Works to irrigate crops. This research investigated the use of treated effluent for agricultural irrigation in this area, particularly focused on the effluent quality, farmers perception, and the potential extent.
24
Domnik, Corinna S. "Activated sludge treatment of chemi-thermo-mechanical pulping effluent : a theoretical and experimental investigation of the response to effluent variation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29591.pdf.
Testo completo
25
Miller, Paul Thomas. "Seasonal Nutrient Dynamics in a Small-Scale Constructed Wetland Treating Primary Effluent with Applications of Effluent Reuse in Biomass Production". The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-05272008-135409/.
Testo completoAbstract (sommario):
Constructed wetlands have been investigated for use in the treatment of municipal wastewater. Species of nitrogen and phosphorus are the nutrients of focus and biochemical oxygen demand (BOD), total suspended solids (TSS) and fecal coliform are the pollutants. Prior work has focused on design concepts, plant effects on nutrient and pollutant treatment, and annualized treatment performance characteristics. This work builds upon published design concepts and wetland plant community and its function and investigates seasonal treatment performance and the kinetics of treatment performance for certain nutrients and pollutants during each season. Previous engineering based work has broadly suggested that first order kinetics govern the treatment chemistry of constructed wetlands. This work further investigates wetland chemistry by evaluating zero, first and second order kinetics for each season for certain nutrients and pollutants and compares regression analysis results between the orders. The results suggest that second order kinetics more closely describe the treatment kinetics realized. In addition, this work investigates an alternate function for constructed wetlands as a nutrient and pollutant buffer with the wetland effluent providing irrigation water for industrial crops. The industrial crops are then proposed to be utilized for energy production. Furthermore, a simple design model attempts to provide a rapid assessment of feasibility of constructed wetlands as a nutrient and pollutant buffer. The design model may be used by a municipality to quickly determine the feasibility of installing a wetland irrigation system as part of their overall wastewater treatment system. Finally, a simple mathematical correlation between a municipality's diesel fuel use and the projected size of a constructed wetland is presented.
26
Peters, Derek A. "Bleach plant effluent reduction at Fraser Papers Inc". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0023/MQ62143.pdf.
Testo completo
27
Hanna, Kalim Nabil. "Electrophoretic removal of fine particulates from aquacultural effluent". College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1663.
Testo completoAbstract (sommario):
Thesis (M.S.) -- University of Maryland, College Park, 2004.Thesis research directed by: Dept. of Biological Resources Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
28
Tam, Kawai 1969. "Neutralization of an acidic effluent using magnesium hydroxide". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26426.
Testo completoAbstract (sommario):
Metal and acid containing effluents generated by industry are most commonly treated with lime which neutralizes the acid and precipitates the dissolved metals. The resulting sludge contains gypsum which has a high water content and requires large landfill volumes. It is therefore desirable to find a neutralizing agent which has a good neutralizing capacity and a dense precipitate which can be easily dewatered at low cost. A dense, fast settling sludge would also reduce the cost of the process and the volume to be landfilled. Magnesium hydroxide has been examined in this research as a neutralizing agent for a simulated iron-containing acidic solution. The effects of reaction temperature, dosage, rate of Mg(OH)$ sb2$ addition, and recycle on the neutralization of acidic iron solutions with magnesium hydroxide were studied. Magnesium hydroxide was found to be an effective precipitating agent removing over 98.3% of the iron from solution and an effective neutralizing agent exhibiting a buffering effect which stabilized the pH between 8.8 to 9.7 even with overtreatment. Observation of precipitate colour suggested that at lower pH values (2.2 to 4.3) ferric hydroxide was formed in the sludge whereas at higher pH values (9.3 to 9.7) the sludge consisted primarily of ferrous hydroxide. Increasing reaction temperatures from 10$ sp circ$C to 25$ sp circ$C did decrease reaction time but had insignificant effects on sludge production or characteristics. However, slow Mg(OH)$ sb2$ addition to the acidic iron solution as well as the use of a recycle both resulted in the production of larger sludge particles which resulted in a denser, fast-settling sludge.
29
Andrews, Lisa Clare. "Electrolytic treatment of effluent streams using novel technologies". Thesis, Brunel University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270935.
Testo completo
30
Munn, Nigel Duoglas Kenneth. "Effluent Dispersal to the Chalk Aquifer in Hampshire". Thesis, University of Brighton, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506513.
Testo completo
31
Savage, Matthew John. "Integrated Treatment Processes For Primary Wool Scouring Effluent". Thesis, University of Canterbury. Chemical and Process Engineering, 2003. http://hdl.handle.net/10092/1125.
Testo completoAbstract (sommario):
The increasing cost of effluent treatment in the wool scouring industry is rapidly becoming a determining factor in the viability of existing scouring operations and new installations alike. This thesis details the development of an integrated effluent treatment process capable of treating the worst polluted effluent from a wool scour "heavy flow-down", to the point where it can either be economically discharged to local trade waste sewer, or directly discharged to river or ocean outfall with minimal environmental impact. The existing proprietary chemical flocculation process, Sirolan CF™, was improved by the addition of a bio-flocculation stage and turbidity monitoring and control, and the product from this process fed to an aerobic biological treatment system based upon the traditional activated sludge process. The biological treatment process was found to remove up to 98% of the BOD5 loading from the pre-treated liquor with a hydraulic residence time of at least 50 hours being required in the aerobic digestion vessels. A residual biorefractory COD of approximately 3,600mg/L was identified which could not be removed by biological treatment. When operating continuously, the biological process was observed to metabolically neutralise the pH 3.0 - 4.5 feed from the chemical flocculation system to pH > 7.0 without the need for supplemental addition of neutralising agents such as sodium hydroxide. This in itself provides a significant economic incentive for implementation of the process. Kinetic analysis of the biological process carried out under controlled laboratory conditions using a Bioflo 3000 continuous fermentor showed that the bio-chemical process followed substrate inhibition kinetics. An appropriate kinetic model was identified to represent the behaviour of the substrate degradation system, and modified by inclusion of a pseudo toxic concentration to account for the effect of pH inhibition upon the biological growth rate. The process was verified both at pilot plant scale and at demonstration plant scale at an operational wool scour. The demonstration plant was of sufficient size to handle the full heavy effluent flow-down from a small wool scour. At the time of publishing three full-scale effluent treatment systems based on this research had been sold to both domestic and international clients of ADM Group Ltd. who funded the research.
32
Diaper, Clare. "Low pressure nanofiltration membranes for dyehouse effluent treatment". Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284922.
Testo completo
33
Clark, Ian Paul. "Treatment studies on a xenobiotic containing industrial effluent". Thesis, University of Birmingham, 1990. http://etheses.bham.ac.uk//id/eprint/1397/.
Testo completo
34
Lopes, Celine de Oliveira Marques. "Evaluation of anaerobic acidification potential for winery effluent". Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10253.
Testo completoAbstract (sommario):
Mestrado em Estudos AmbientaisGiven that the industrial wastewater represent a negative contribution of great significance to environmental, developed this work with a practical study on the behavior of a particular industrial effluent, in this case the wine, when subjected to tests of anaerobic acidification in batch reactors, in order to obtain value-added products from this waste. In this sense we studied the effects of this treatment in three operating parameters: organic load, alkalinity and using a thermal pre-treatment for biomass, in order to inhibit methanogenic activity. In all there were three sets of reactors, with three reactors each, totaling nine reactors were analyzed with varying concentrations of four different organic load, three different concentrations of alkalinity solution of calcium bicarbonate, NaHCO3. It was observed a good acidogenic potential for the wine effluent where it was achieved, for reactors higher organic load, a degree of acidification of 85%, it was found that the alkalinity is related to the organic load used and shows great significance in the formation of the peaks of maximum acidogenic production and diversity of VFAs, higher alkalinities favor acids of longer carbon chain, and the peak is produced earlier. The thermal pre-treatment was not beneficial despite achieved good results in terms of degree of acidification it has not exceeded the values obtained in the reactors were the thermal pre-treatment was not applied to the sludge.
Tendo em conta que as águas residuárias industriais representam um contributo negativo de grande significância a nível ambiental, desenvolveu-se com este trabalho de um estudo prático sobre o comportamento de um determinado efluente industrial, neste caso o vínico, quando submetido a ensaios anaeróbios de acidificação em reatores descontínuos, com vista a obtenção de produtos de valor acrescentado a partir deste resíduo. Neste sentido foram estudados os efeitos deste tratamento sob três parâmetros de operação: carga orgânica, alcalinidade e a utilização de um pré-tratamento térmico para a biomassa, a fim de se inibir atividades metanogénica. Ao todo foram realizadas três baterias de ensaios, com três reatores cada, no total foram analisados nove reatores, variando quatro diferentes concentrações de carga orgânica, três diferentes concentrações de solução alcalina de Bicarbonato de Cálcio, NaHCO3. Observou-se um bom potencial acidogénico do efluente vinícola chegando a alcançar para os reatores de carga orgânica mais elevadas graus de acidificação de 85%.Constatou-se que a alcalinidade está relacionada com a carga orgânica utilizada e demonstra grande significância na formação dos picos máximos de produção acidegénica, e na diversidade dos VFAs obtidos. Desse modo, alcalinidades mais elevadas, favorecem ácidos de cadeia carbónica mais longa, e o pico máximo de produção forma-se mais cedo. O pré-tratamento térmico, não se mostrou vantajosos apesar de ter alcançado bons resultados em termos de grau de acidificação, não superou os valores obtidos em reatores que não tiveram as lamas submetidas a este pré-tratamento.
35
Santerior, Paula Denise 1966. "Nitrogen transformation in the subsurface during effluent recharge". Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/192068.
Testo completoAbstract (sommario):
The transformation of nitrogen in treated effluent during recharge at the Sweetwater Underground Storage and Recovery Facility was examined. The procedure consisted of obtaining samples of percolating water and groundwater below a 3.3 acre infiltration basin, carried out over the recharge season October 29, 1991 - May 23, 1992 and during an entire 4 day wetting/6 day drying cycle. Nitrate concentrations decreased in the profile and in groundwater throughout the season. During the wetting/drying cycle the nitrate level decreased from a maximum of over 20 mg/L NO₃⁻-N at a depth of 5 feet to about 10 mg/L NO₃⁻-N at 17 feet. Below 17 feet, the nitrate level remained approximately constant. A 36% reduction in total nitrogen concentration was observed between source water and groundwater. Results suggest that soil aquifer treatment (SAT) may be useful in reducing the total nitrogen concentration of effluent.
36
Littlehat, Jr Peter. "Thyromimetic and Proteomic Analysis of Secondary Wastewater Effluent". Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/193857.
Testo completoAbstract (sommario):
Wastewater reclamation and reuse is imperative in water-starved areas such as the southwestern United States. In the Tucson Active Management Area, a geographic region defined for the purpose of groundwater management, the total demand for water already exceeds the available water supply, which consists of renewable ground water and the regional entitlement to Central Arizona Project water. Thus, the regional demand cannot be satisfied without resorting to groundwater mining unless water is reclaimed for local beneficial use. Less certain are the acceptable uses for reclaimed water and the nature of use-dependent treatments or water quality requirements that will protect human and ecological health. Disruption of thyroid-mediated actions is among the possible risks from chronic exposure to environmental contaminants. Endocrine disrupting compounds are generally of greater concern in this context than other trace contaminants because of the very low concentrations at which hormones induce physiological responses. Accordingly, a sensitive nuclear-based bioassay system was developed in order to evaluate environmental samples. A luciferase-reporter construct and the human thyroid receptor β (TR-β) construct in the human hepatoma cell line (HepG2) and human medulloblastoma cells (TE671) was evaluated for sensitivity. The transfected cells were exposed to the thyroid hormone, T3, in order to establish a lower thyroid hormone detection limit for the new bioassay procedure. The assay was then applied to environmental samples containing organics concentrated from final effluent derived from a conventional secondary wastewater treatment plant. The effluent samples activated thyroid receptor-mediated transcription. Also in this study, a two-dimensional gel electrophoresis (2D-DIGE) was used as an in vitro bioassay to look for wastewater related alteration of cellular protein expression in the human breast cancer cell T47D. Steps in this bioassay include the one-dimensional separation of proteins by isoelectric focusing followed by orthogonal electrophoresis to isolate the proteins. The consistency of test response was examined for wastewater-dependent up- or down-regulation of protein expression. Some proteins that were upregulated were preliminarily identified via mass spectrometry. Here, the procedure is used to provide direct information regarding the probable effects of residual hormones in treated wastewater on the activities of human, estrogen-responsive cells in cell culture.
37
Brown, Jonathan Jed 1964. "Halophytes for the treatment of saline aquaculture effluent". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282715.
Testo completoAbstract (sommario):
The discharge of untreated aquaculture effluent can pollute receiving water bodies. I tested the feasibility of using salt-tolerant plants (halophytes) with potential as forage and oilseed crops, as biofilters to treat saline aquaculture effluent. Plants were grown in draining lysimeters in greenhouses and irrigated with effluent salinized with NaCl. Irrigation water came from a recirculating tilapia culture system. I measured yield potential, water use and capacity for nitrogen and phosphorus uptake. In Experiment 1, Suaeda esteroa, Salicornia bigelovii and Atriplex barclayana (Chenopodiaceae) were grown in sand in 0.02 m³ lysimeters. Plants were irrigated with effluent of 0.5 ppt, 10 ppt and 35 ppt salinity, to meet evapotranspiration demand and to allow 30% of the applied water to leach past the plant root zone. Despite the high leaching fraction and short residence time of water in the pots, the plant-soil system removed 98% and 94% of the applied total and inorganic nitrogen, respectively, and 99% and 97% of the applied total and soluble reactive phosphorus respectively. For all species, salt inhibited (P ≤ 0.05) the growth rate, nutrient removal, and volume of water the plants could process. The salt marsh species S. esteroa and S. bigelovii performed better than the desert saltbush, A. barclayana, at 35 ppt. In Experiment 2, Suaeda esteroa, was grown in lysimeters containing approximately 0.8 m³ sandy loam soil and irrigated three times per week with 31 ppt NaCl effluent. I used five irrigation treatments, ranging in volume from 50 to 250% of the potential evaporation rate. Plant biomass and water consumption increased significantly (P ≤ 0.05) with increasing irrigation volume. Nitrate concentrations in water draining from the lysimeters decreased during the experiment, and were significantly lower in the high-volume treatments than in the low-volume treatments. Phosphorus concentrations in the leachate water increased during the experiment as a function of increasing irrigation volume. Irrigating halophyte crops with aquaculture wastewater of seawater-salinity may be a viable strategy for disposal of effluent.
38
Zongo, Inoussa. "Étude expérimentale et théorique du procédé d'électrocoagulation : application au traitement de deux effluents textiles et d'un effluent simulé de tannerie". Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL066N/document.
Testo completoAbstract (sommario):
L’électrocoagulation est une technique de traitement des eaux usées basée sur la dissolution d’anode sacrificielle de fer ou d’aluminium. Ces métaux se dissolvent sous formes de cations Fe2+ puis Fe3+ et Al3+ qui vont former des hydroxydes de métal qui entraînent par adsorption les impuretés de l’effluent en diminuant le potentiel Zêta de ces impuretés. Le réacteur électrochimique utilisé est constitué de deux électrodes métalliques (Fe ou Al) planes et parallèles qui laissent passer entre elles l’effluent à traiter. Des densités de courant de 50 à 200 A/m2 ont été appliquées pour traiter les trois effluents. L’un est un effluent directement issu d’une usine textile (effluent « usine »). Un second provient du flux d’entrée de la station d’épuration du site qui collecte les effluents de plusieurs usines (effluent « station »). Le troisième est un effluent artificiel de tannerie, créé en ajoutant 200 ppm de chrome VI à l’effluent « station ». Pour chaque expérience, la densité de courant et le temps de traitement vont déterminer la charge électrique et la concentration en métal dissous atteinte. L’influence de ces quatre paramètres sur l’élimination de la DCO, de l’absorbance, de la turbidité, du COT et du chrome hexavalent a été étudiée. L’évolution au cours du temps d’autres paramètres de l’EC tels que le pH, la tension, le rendement faradique et la dissolution métallique ont été étudiés afin de comprendre leur rôle dans le procédé. Le traitement a permis d’avoir un abattement maximal de DCO de 82% et 80% pour l’effluent « station » traité respectivement avec les électrodes de fer et d’aluminium ; 75 et 67% pour l’effluent « usine » traité respectivement avec les électrodes de fer et d’aluminium. L’abattement du chrome est de 100% avec les électrodes de fer mais tombe à 70% avec celles en aluminium. Des modèles d’élimination de la DCO et de l’absorbance ont été établis pour chaque matériau d’électrode utilisé. Le modèle d’élimination du chrome VI a été établi à partir du traitement avec les électrodes de fer. Une étude de la spéciation des espèces a permis de déterminer les pH optimaux de coagulation-floculation pour chaque métal impliqué (Al, Fe, Cr). La compétitivité entre l’abattement de la pollution organique et du Chrome a aussi été étudiée pour chaque type d’électrodeElectrocoagulation (EC) is a water treatment technology that relies on the electrochemical sacrificial anodes (in Fe or Al) dissolution. This metal dissolve themselves in Al3+ and Fe2+ cations that later oxidise to Fe3+ ions. These cations form metal hydroxides that adsorb the impurities of the effluent while decreasing the zeta potential. The electrochemical reactor used consists on two plane parallel metal electrodes with recirculation of the effluent to be treated between them. Current densities from 50 to 200 A/m2 were imposed to treat each effluent. Three effluents were used in this study. The first one is an effluent sampled at the outlet of a textile plant (« plant »). The second one is a mixture of several effluents coming from different plant and collected at the inlet of the wastewater treatment (« treatment plant »). The last one is a wastewater tannery plant simulated by addition of 200 ppm Chromium VI in the treatment plant effluent. For each experience the current density and the time of treatment rule the electrical charge and the concentration in dissolved metal reached. The influence of these four parameters on the elimination of COD, absorbance, turbidity, COT and hexavalent chromium content has been studied. Parameters e.g. potential, faradic yield, metal dissolution and pH have also been continuously monitored to better understand their role on EC process. The results show that DCO abatement reached 80 and 82% for treatment plant effluent, respectively with iron and aluminium electrodes; and 75 and 67% for plant effluent, respectively with iron and aluminium electrodes. The chromium treatment yields 100 % abatement with Fe electrodes whereas it is only 70% using Al electrodes. Models have been developed for COD and absorbance removal for the two electrode materials. Model for chromium (VI) treatment has been established considering all reactions occurring for iron EC. Metal speciation study allowed us to determine the optimal pH of coagulation –flocculation for each metal involved in the treatment (Al, Fe, Cr). Competition between organic pollution removal and chromium elimination has been also investigated for each electrode material
39
Zodi, Salim. "Étude de l'épuration d'effluents de composition complexe par électrocoagulation et des couplages intervenants entre le traitement électrochimique et l'étape de séparation : application à l'industrie textile et papetière". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0097/document.
Testo completoAbstract (sommario):
L'électrocoagulation permet d'éliminer simultanément un large spectre de polluants organiques et minéraux, de colorants et de métaux lourds ; de ce fait, il a été beaucoup étudié. En revanche, peu de travaux ont été entrepris pour étudier de façon plus approfondie son fonctionnement. La complexité des effluents pour laquelle il est particulièrement intéressant d'utiliser ce procédé, fait aussi qu'il est difficile d'analyser les résultats. Cette thèse a pour objectif d'apporter une contribution à la compréhension du couplage électrocoagulation - décantation et des interactions liés à des effluents multi-polluants complexes. De plus l'aspect réacteur en continu a été abordé dans le cas d'un effluent synthétique simple pour mieux appréhender les différences par rapport au fonctionnement en discontinu. Cette étude est basée sur une approche systématique qui repose sur les processus élémentaires de l'électrocoagulation: Electrochimie, Coagulation et Séparation physique. Chaque processus fournit une base pour l'étude des interactions qui permettent ensuite la modélisation globale des processus. Afin d'étudier les couplages électrocoagulation-décantation, des effluents textiles industriels ont été traités par électrocoagulation suivie par une étape de décantation en éprouvette, sans agent floculant. L'effet des paramètres d'électrocoagulation sur la décantabilité des effluents traités et l'efficacité d'élimination de la pollution a été étudié en suivant en particulier la vitesse de décantation en éprouvette et en calculant le SVI. Le deuxième objectif de ce notre travail était d'étudier les couplages entre les différents types de pollution à éliminer et plus particulièrement un effluent de papeterie contenant des pollutions organiques et de l'arsenic. Enfin, nous avons réalisé une étude sur les performances du couplage EC-décantation pour le traitement d'un effluent synthétique textile en réacteur continu. Ce dernier est composé de deux éléments, la cellule électrochimique suivie d'une chambre de sédimentationElectrocoagulation eliminates simultaneously a large spectrum of organic pollutants, dyes and heavy metals; therefore, it has been studied extensively. However, little work has been undertaken to investigate more thoroughly its behaviors. The complexity of the effluent for which it is particularly interesting to use this method also makes it difficult to analyze the results. This thesis aims to contribute to understanding the coupling electrocoagulation - settling and interactions associated with complex effluent multi-pollutants. Also a continuous reactor has been addressed in the case of a simple synthetic sewage to better understand the differences from the batch operation. This study is based on a systematic approach based on the elementary processes of electrocoagulation: Electrochemistry, coagulation and physical separation. Each process provides a basis for studying the interactions that then the overall modeling process. To study the electro-decantation couplings, industrial textile effluents were treated by electrocoagulation followed by a settling step, without flocculent. The effect of parameters on electrocoagulation settleability of treated effluent and removal efficiency of pollution has been studied in particular by following the settling velocity in the test tube and calculating the SVI. The second objective of this our work was to study the coupling between the different types of pollution and to eliminate a particular paper mill effluent containing organic pollutants and arsenic. Finally, we conducted a study on the performance of EC-coupling settling for the treatment of a synthetic textile effluent flow reactor. The latter is composed of two elements, the electrochemical cell followed by a settling chamber
40
Bragg, Amanda Leann. "Phosphorus reduction in dairy effluent through flocculation and precipitation". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/1646.
Testo completoAbstract (sommario):
Phosphorus (P) is a pollutant in freshwater systems because it promotes eutrophication. The dairies in the North Bosque and its water body segments import more P than they export. Dairies accumulate P-rich effluent in lagoons and use the wastewater for irrigation. As more P is applied as irrigation than is removed by crops, P accumulates in the soil. During intense rainfall events, P enters the river with stormwater runoff and can become bio-available. Reducing the P applied to the land would limit P build up in the soil and reduce the potential for P pollution. Since wastewater P is associated with suspended solids (SS), the flocculants, poly-DADMAC and PAM, were used to reduce SS. To precipitate soluble P from the effluent, NH4OH was added to raise the pH. Raw effluent was collected from a dairy in Comanche County, TX, and stored in 190-L barrels in a laboratory at Texas A&M University. Flocculant additions reduced effluent P content by as much as 66%. Addition of NH4OH to the flocculated effluent raised the pH from near 8 to near 9, inducing P precipitation, further reducing the P content. The total P reduction for the best combination of treatments was 97%, a decrease from 76 to 2 mg L-1. If this level of reduction were achieved in dairy operations, P pollution from effluent application would gradually disappear.
41
Zapf-Gilje, Reidar. "Treatment and disposal of secondary sewage effluent through snowmaking". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/26034.
Testo completoAbstract (sommario):
When secondary sewage effluent is converted to snow, the nutrients and residual organics become concentrated in the early meltwater discharge through melt-freeze processes within the snow-pack. The early season melt comes off relatively slowly. Providing the soil can absorb the early melt, the bulk of the nutrients will be removed even if later season melt rates exceeds the soil's infil-trability. This could provide an inexpensive method for nutrient removal from secondary sewage effluents.
Laboratory experiments showed that the degree of impurity concentration was largely independent of the number of diurnal melt-freeze cycles, snow depth, snow temperature and initial concentration of impurity in the snow. As a result, the removal of impurities from a snowpack can be expressed in terms of the cumulative melt discharge. A simple exponential decay process was found to describe the impurity removal well for most cases. The first 20% of the melt removed, on the average, 65% of the phosphorus and 86% of the nitrogen from snow made from sewage effluent; and 92% of the potassium chloride from snow made from potassium chloride solution. Stripping of ammonia during snow production and melting increased the overall nitrogen removal to about 90%. A field investigation of salt movement through a natural snowpack confirmed the laboratory results.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Marquet, Richard. "Low-rate trickling filter effluent : characterisation and crossflow filtration". Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/27897.
Testo completoAbstract (sommario):
The low-rate trickling filter is the most common biological treatment process used in small and medium sized sewage works in the UK. It produces an inconsistent effluent quality, which has traditionally been related to seasonal changes in solids accumulation, grazing activity and sloughing of microbial film. The final effluent solids and, organic matter content is then too high for discharge or reuse. Given the increasingly stringent effluent standards, both in terms of quality and consistency, tertiary treatment is often required. This study was designed to investigate the key parameters affecting the performance of low-rate trickling filters and the characteristics of their effluents in terms of contaminant size, which might influence the efficiency of crossflow filtration as a tertiary treatment for the trickling filter.
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Frieberg, Kim. "Effects of effluent wastewater in developing zebrafish (Danio rerio)". Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-348556.
Testo completoAbstract (sommario):
Traditional wastewater treatment is known not to be specifically designed to eliminate the new generation of chemical residues that ends up in the sewage system. Polluted wastewatereffluent therefore reaches the aquatic environment possibly causing adverse effects in aquatic wildlife. The effects of effluent water from five Swedish sewage treatment plants sampled on 6 occasions 2017, were studied in developing zebrafish (Danio rerio). The study included morphological, physiological and behavioural endpoints. Overall there were few effectswhere deviations from control animals could be seen in the exposed zebrafish. The overall outcome of this assessment was that the wastewater effluent had no consistent effects on the early development of zebrafish. The consequences of continuous low-level exposure duringthe whole life-cycle of wild fish are presently unknown and further studies are needed to evaluate potential risks.
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KARNIK, POONAM PRAFULL. "USE OF CATIONIZED COTTON FOR TEXTILE EFFLUENT COLOR REDUCTION". NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-20020301-132054.
Testo completoAbstract (sommario):
ABSTRACTKARNIK, POONAM. Use of Cationized Cotton for Textile Effluent Color Reduction.(Under the direction of Dr. Brent Smith and Dr. Peter Hauser) The liquid effluents from the textile industry mainly consist waters colored by thedyes used in the coloring of textile yarns and fabrics. These dyes can be removed by adsorption onto adsorbing materials like cotton. Waste cotton fibers can be cationized using a quaternary ammonium compound like 3-chloro-2-hydroxypropyltrimethylammonium chloride to their cationic form. This cationic form can be used as the adsorption medium for anionic dyes like acid, direct and fiber reactive dyes.
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Vajda, Alan Milan. "Reproductive disruption of fishes by endocrine-active wastewater effluent". Diss., Connect to online resource, 2006. 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:3207688.
Testo completo
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Paraskeva, Panagiota. "The treatment of a secondary municipal effluent by ozone". Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298426.
Testo completo
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Alcalá, Borao Raquel. "Oxidation of pharmaceuticals by chlorine dioxide in wastewater effluent". Thesis, KTH, Mark- och vattenteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171862.
Testo completoAbstract (sommario):
The presence of pharmaceuticals in the environment has raised an emerging interest due to the fact that they pose negative environmental impact and health hazards related to long-term toxicity effects. As conventional treatments are not able to totally remove these substances it is necessary to seek for alternative advanced technologies such as oxidation with chlorine dioxide (ClO2). The objective of this master thesis is thus to find the most optimal dose – reaction time of ClO2 for the oxidation and maximum removal of selected environmentally relevant pharmaceuticals. Factorial design and subsequent optimization with MODDE was selected as the best approach to find the optimal dose – time. Batch oxidation tests were conducted on 100mL aliquots treated with ClO2 using wastewater effluent from Henriksdal WWTP. Thereafter solid phase extraction and final determination of pharmaceuticals was carried out on a high performance liquid chromatography- triple quadrupole mass spectrometry (HPLC-MS/MS). Results showed that applying a dose of 5 mg ClO2/L and a reaction time of 10 minutes, it is possible to remove more than a half of the 17 analyzed substances. Besides most of the pharmaceuticals with high and moderate environmental risk, would pose a low risk for the environment after treatment with the optimal ClO2 dose – reaction time. Despite the fact that ClO2 could successfully degrade most environmentally relevant pharmaceuticals, deeper research concerning the formation of toxic by-products after oxidative treatment needs to be done before upscaling this technology to pilot or full scale as a suitable end of pipe technology for pharmaceuticals removal.
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Visser, Hendrik Petrus. "Biodiesel production from a butter factory effluent / H.P. Visser". Thesis, North-West University, 2012. http://hdl.handle.net/10394/9250.
Testo completoAbstract (sommario):
The production of biodiesel from a butter factory effluent was the main focus of the study. The alkali transesterification reaction was used to produce the biodiesel.
The effect of the temperature, alcohol to oil molar ratio, catalyst concentration and the reaction time was investigated to determine the optimal reaction conditions. The reaction temperature varied from 45 °C to 65 °C with a 5 °C increment. The alcohol to oil molar ratio varied from 3:1 to 8:1 with an increment of 1:1. The experiments with varying catalyst load were carried out at 0.8 wt%, 1.0 wt% and 1.2wt%. The reaction time was kept constant at 120 minutes, but samples of the reaction mixture were taken at 10 minute intervals.
The optimal reaction conditions according to the results were 50 °C, 6:1 alcohol to oil molar ratio, 1.0 to 1.2 wt% catalyst loads and a reaction time of 60 to 90 minutes. The optimal temperature was also the maximum temperature since a further increase in temperature lowered the ester content. Increasing the alcohol to oil molar ratio above 6:1 had no effect on the ester content. The increase in catalyst load decreased the time needed for the reaction to reach equilibrium.
The purification process was also investigated. The biodiesel was washed with water, Magnesol® DSOLTM and Purolite® PD-206. The Magnesol® D-SOLTM was the best method for lowering the water content and the acid value of the fuel. A Magnesol® D-SOLTM content of 1.0 wt% was mixed with the biodiesel for 30 minutes in order to lower the water content and the acid value to below the maximum limit.
A kinetic model for the biodiesel reaction was developed. The model was based on the second order reversible reaction. The temperature range for the model is from 45 °C to 55 °C. The forward reaction was found to be exothermic with an endothermic reverse reaction. The activation energy for the exothermic forward reaction varied between 9.478 and 26.937 kJ/mol while the activation energy for the endothermic reverse reaction varied between 74.161 and 136.433 kJ/mol for the reactions with a catalyst load of 1.2 wt%.
The biodiesel was tested according to the SANS 1935:2011 standard. The biodiesel did not meet all the requirements of the standard. The flash point, sulphur content, carbon residue, oxidation stability, free glycerol, total glycerol and cold filter plugging point did not meet the specification of SANS 1935:2011. The biodiesel should be blended with mineral diesel if it is to be used commercially.
The butter factory effluent can be used as a feedstock for the production of biodiesel.Thesis (MIng (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.
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Newby, Philip Simon. "Biodegradation of recalcitrant organic chemicals in a coloured effluent". Thesis, University of Leeds, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392573.
Testo completo
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O'Neill, Cliona. "Combined anaerobic-aerobic treatment of a simulated textile effluent". Thesis, University of South Wales, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365088.
Testo completo