Spelling suggestions: "subject:"water:purification."" "subject:"afterpurification.""
281 |
An evaluation of wastewater reuse benefits a dissertation in partial fulfillment ... for the degree of Doctor of Public Health (Environmental Health Sciences and International Health) ... /Nkuchia, John. January 1994 (has links)
Thesis (D.P.H.)--University of Michigan, 1994.
|
282 |
Capacitive deionization tehnology TM development and evaluation of an industrial prototype systemWelgemoed, Thomas J. January 2005 (has links)
Thesis (M.Eng.)(Chemical)--University of Pretoria, 2005. / Title from opening screen (viewed March 14, 2005). Includes summary. Includes bibliographical references.
|
283 |
An evaluation of wastewater reuse benefits a dissertation in partial fulfillment ... for the degree of Doctor of Public Health (Environmental Health Sciences and International Health) ... /Nkuchia, John. January 1994 (has links)
Thesis (D.P.H.)--University of Michigan, 1994.
|
284 |
An evaluation process for optimizing activated-sludge floc-formation a dissertation submitted in partial fulfillment ... for the degree of Doctor of Public Health (Environmental Health Sicences) ... /Le Platte, Geoffrey Ewart. January 1994 (has links)
Thesis (D.P.H.)--University of Michigan, 1994.
|
285 |
Reuso de efluentes no processo industrial de siderurgiaSantos, Anderson Baptista dos [UNESP] 16 January 2014 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:45Z (GMT). No. of bitstreams: 0
Previous issue date: 2014-01-16Bitstream added on 2014-08-13T18:00:43Z : No. of bitstreams: 1
000755517_20160116.pdf: 165609 bytes, checksum: ab61e84e3da50b0a1ba379151fbf73fe (MD5) Bitstreams deleted on 2016-01-18T10:44:02Z: 000755517_20160116.pdf,. Added 1 bitstream(s) on 2016-01-18T10:44:39Z : No. of bitstreams: 1
000755517.pdf: 2280921 bytes, checksum: 48917e8b4317c8508e95a16c295a5cb2 (MD5) / O uso da água e consequentemente seu reúso são temas que tem ganhado destaque no mundo. Este trabalho analisou algumas possibilidades de reúso do efluente gerado em uma planta siderúrgica, especificamente em uma estação de tratamento de água de uma laminação que capta água do rio Paraíba do Sul e descarta os efluentes no ribeirão dos Surdos. Neste estudo analisou-se ainda a necessidade de adequação do efluente gerado para atender ao CONAMA 357/2005, CONAMA 430/2011 e Decreto 8.468/1976 visto que o ribeirão que recebe o efluente possui baixa vazão. Este fato exige o tratamento do efluente para atender aos parâmetros de qualidade de lançamento e faz com que eles sejam menores que os previstos nas resoluções e decretos. Ao tratar o efluente identificou-se que é possível aplicá-lo como reúso em vez de simplesmente descartá-lo. O trabalho apresentou os desafios para a aplicação do reúso em indústrias que produzem a própria água potável. Ao comparar as tarifas cobradas pela SABESP, na região do Vale do Paraíba, e o custo de produção interno da água. Nota-se que a água produzida na própria indústria pode ter um custo 8 vezes menor que a fornecida por terceiros. Então somente os trabalhos com pequenos investimentos conseguem tornar-se viáveis. Como é o caso do reúso em lavagem de pisos, resfriamento de escória, reúso em vasos sanitários e mictórios, que apresentaram retorno perto de cinco anos / The use of water and consequently its reuse are receiving a lot of attention around the World. This report has analyzed some possibilities for reusing the flowing out of a metallurgical company, specifically in a water treatment station from a rolling mill which receives the water from the Paraiba do Sul river and the effluents is discharged in the Surdos river. This report has also analyzed the need of adjustment to attend CONAMA 357/2005, CONAMA 430/2011 and Decree 8.468/1976 once the stream which receives this effluent has a low flow. Because of this, the treatment for this effluent has to obey strict parameter of quality, and the disposal has to be lower than the values fixed in the resolutions and decrees. While treating the effluent we have identified the possibility for reuse instead of just dismiss. The task has presented some challenges to the reuse application in industries that produce its own potable water. To compare the tax charged by SABESP, in Vale do Paraíba region, and the cost of internal water production has a 8 times difference in cost. Then only small work with low investment can became viable. As in the case of reusing water to wash the floor, scrap cooling, reuse in toilets and urinal, showing return only after five years
|
286 |
Exploration of Nahoon beach milieu for lignocellulose degrading bacteria and optimizing fermentation conditions for holocellulase production by selected strainsFatokun, Evelyn January 2016 (has links)
A significant trend in the modern day industrial biotechnology is the utilization and application of renewable resources, and ecofriendly approach to industrial processes and waste management. As a consequence thereof, the biotechnology of holocellulases: cellulase and xylanase and, enzymatic hydrolysis of renewable and abundant lignocellulosic biomass to energy and value added products are rapidly increasing; hence, cost effective enzyme system is imperative. In that context, exploration of microbiota for strains and enzymes with novel industrial properties is vital for efficient and commercially viable enzyme biotechnology. Consequent on the complex characteristics of high salinity, variable pressure, temperature and nutritional conditions, bacterial strains from the marine environment are equipped with enzyme machinery of industrial importance for adaptation and survival. In this study, bacterial strains were isolated form Nahoon beach and optimized for holocellulase production. Three isolates selected for lignocellulolytic potential were identified by 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis. Isolate FS1k had 98 percent similarity with Streptomyces albidoflavus strain AIH12, was designated as Streptomyces albidoflavus strain SAMRC-UFH5 and deposited in the GenBank with accession number KU171373. Similarly, isolates CS14b and CS22d with respective percentage similarity of 98 and 99 (percent) with Bacillus cereus strains and Streptomyces sp. strain WMMB251 were named Bacillus cereus strain SAMRC-UFH9 and Streptomyces sp. strain SAMRC-UFH6; and were deposited in the GenBank with accession number KX524510 and KU171374 respectively. Optimal pH, temperature and agitation speed for cellulase production by S. albidoflavus strain SAMRC-UFH5, and B. cereus strain SAMRC-UFH9 were 6 and 7; 40 and 30 (°C); and 100 and 150 (rpm) respectively; while xylanase production was optimal at pH, temperature and agitation speed of 8 and 7; 40 and 30 (°C); and 150 and 50 (rpm) respectively. Maximum cellulase activity of 0.26 and 0.061(U/mL) by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 were attained at 60 h respectively, while maximal xylanase activity of 18.54 and 16.6 (U/mL) was produced by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 at 48 h and 60 h respectively. Furthermore, xylanase production by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 was maximally induced by wheat straw and xylan respectively, while cellulase production was best induced by mannose and carboxymethyl cellulose respectively. On the other hand, cellulase and xylanase production by Streptomyces sp. strain SAMRC-UFH6 was optimal at pH, temperature and agitation speed of 7 and 8, 40 °C and 100 rpm, respectively. Highest production of cellulase and xylanase was attained at 84 and 60 h with respective activity of 0.065 and 6.34 (U/mL). In addition, cellulase and xylanase production by the strain was best induced by beechwood xylan. Moreover, xylanase produced by Streptomyces sp. strain SAMRC-UFH6 at optimal conditions was characterized by optimal pH and temperature of 8 and 80-90 °C respectively; retaining over 70 percent activity at pH 5-10 after 1 h and 60 percent of initial activity at 90 °C after 90 min of incubation. In all, optimization improved cellulase and xylanase production yields, being 40 and 95.5, 10.89 and 72.17, and 10 and 115- fold increase by S. albidoflavus strain SAMRC-UFH5, B. cereus strain SAMRC-UFH9 and Streptomyces sp. SAMRC-UFH6 respectively. The results of this study suggest that the marine bacterial strains are resource for holocellulase with industrial applications.
|
287 |
Spatial and seasonal distribution of selected persistent organic pollutants and phenolic derivatives along the course of the Buffalo River in the Eastern Cape Province of South AfricaYahaya, Abdulrazaq January 2017 (has links)
Persistent organic pollutants (POPs) fall under a group of synthetic chemicals known for their persistence in environmental matrices such as soil and water, and are used in industrial, domestic and agricultural applications. Because of their volatility and lipophilicity, POPs can be transported far away from their point sources and bio-accumulate in food and in fatty tissues of humans and animals. In view of their toxicity and carcinogenicity some organic pollutants such as polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs) and phenolic derivatives (chlorophenol and nitrophenol) have been classified by United State Environmental Protection Agency (USEPA) and World Health Organization (WHO) as priority pollutants. The present work evaluated the distribution patterns of 19 polychlorinated biphenyls congeners, 17 organochlorine pesticides and selected phenolic derivatives (USEPA 11-priority pollutants) in the Buffalo River, in the Eastern Cape Province, South Africa between December 2015 and May 2016. The Liquid-liquid extraction technique was used for PCBs, OCPs and phenolic derivatives in the river water samples. Silica gel and florisil clean up were carried out for PCBs and OCPs samples respectively and analyzed with gas chromatography electron capture detector (GC/ECD). Phenolic compounds were derivatized and analyzed by gas chromatography mass spectrometer (GC/MS). Limits of detection (LOD), limit of quantitation (LOQ) and relative standard deviation (RSD) for the PCBs were 10 to 330 ng/L, 20 to 1,060 ng/L and 1.18 to 14.1 percent respectively. The LOD, LOQ and RSD for the OCPs were from 20 - 60 ng/L, 110 - 530 ng/L and 0.02 - 0.06 percent, while the corresponding values for the phenolic derivatives were 10 to 70 ng/L, 33 to 222 ng/L and 1.99 - 10.86 percent. In summer, the concentrations of PCBs, OCPs and phenolic derivatives ranged from <LOD to 482 ng/L, <LOD to 4,403 ng/L and <LOD to 1,546 ng/L respectively, while in autumn they were from <LOD to 2,383 ng/L, <LOD to 858 ng/L and <LOD to 713 ng/L in that order. Also, in summer, the level of occurrence of total PCB congeners detected at the various sampling sites were Buffalo River Estuary (BRE) 11 percent, Mdantsane (MSN) 16 percent, Zwelitsha (ZW) 26 percent, King William’s Town (KWT) 47 percent, Izele (IZ) 32 percent, and Maden (MD) 21 percent. The level of occurrence of total OCPs at BRE was 65 percent, at MSN 65 percent, at ZW 82 percent, at KWT 47 percent, at IZ 29 percent, and at MD 18 percent. The level of occurrence of total phenolic derivatives at BRE was 63 percent, at MSN 63 percent, at ZW 54 percent, at KWT 63 percent, at IZ 63 percent, and at MD 54 percent. In autumn, the level of occurrence of total PCBs at BRE was 68 percent, at MSN 16 percent, at ZW 42 percent, at KWT 26 percent, at IZ 47 percent, and at MD 0 percent. The level of occurrence of total OCPs at BRE was 65 percent, at MSN 53 percent, at ZW 41 percent, at KWT 35 percent, at IZ 53 percent, and at MD 18 percent. The level of occurrence of total phenolic derivatives at BRE was 63 percent, at MSN 63 percent, at ZW 54 percent, at KWT 18 percent, at IZ 18 percent, and at MD 45 percent. In summer, the levels of PCBs in all sampling sites were below WHO recommended maximum permissible levels (500 ng/L) for humans but in autumn the levels were above the recommended values in all the sites except MD. The cancer risk assessment values were above permissible 10-6 while hazard quotients were above the USEPA maximum limits of unity. OCPs levels were above the USEPA limits (100 ng/L) in all sampling locations in both seasons. The cancer risk assessment values were below permissible 10-6 but hazard quotients were above the USEPA maximum limits. Phenolic derivatives were also above the USEPA maximum permissible limit (500 ng/L) in most of the sampling locations in summer whereas during autumn the values were notably below the permissible limit at ZW, KWT, IZ and MD. The cancer risk assessment values and hazard quotients were above USEPA maximum limits of 10-6 and unity respectively. Conclusively, the results of this study reveal that the pollutants were present in the river at concentrations higher than the tolerable limit for human and wildlife and thereby may constitute a serious risk to public health. Therefore, it is recommended that proper regulation of the use of the compounds and their safe disposal be ensured to protect aquatic resources and the well-being of humans.
|
288 |
Treatment of saline solutions using air gap membrane distillation (AGMD)Alkhudhiri, Abdullah Ibrahim January 2013 (has links)
No description available.
|
289 |
The investigation of microbial denitrification processes for the removal of nitrate from water using bio-electrochemical methods and carbon nano-materialsAlharbi, Njud Saleh F. January 2012 (has links)
With ever increasing regulation of the quality of drinking water and wastewater treatment, there is a need to develop methods to remove nitrogenous compounds from water. These processes are mediated by a variety of micro-organisms that can oxidise ammonia to nitrate, and then reduced to gaseous nitrogen by another set of organisms. This two stage process involves the relatively slow oxidation of ammonia to nitrate followed a relatively fast reduction of nitrate to nitrogen. Nitrate reduction normally requires anaerobic environments and the addition of organic matter to provide reducing power (electrons) for nitrate reduction. In practical situations the nitrate reduction can be problematic in those precise quantities of organic matter to ensure that the process occurs while not leaving residual organic matter. The aim of this study was to investigate microbial denitrification using electrochemical sources to replace organic matter as a redactant. The work also involved developing a system that could be optimised for nitrate removal in applied situations such as water processing in fish farming or drinking water, where high nitrate levels represent a potential health problem. Consequently, the study examined a range of developments for the removal of nitrate from water based on the development of electrochemical biotransformation systems for nitrate removal. This also offers considerable scope for the potential application of these systems in broader bio-nanotechnology based processes (particularly in bioremediation). The first stage of the study was to investigate the complex interactions between medium parameters and their effects on the bacterial growth rates. The results proved that acetate is a good carbon source for bacterial growth, and therefore it was used as an organic substrate for the biological process. High nitrate removal rate of almost 87% was successfully achieved by using a microbial fuel cell (MFC) enriched with soil inocula with the cathodes cells fed with nitrate and the anode fed with acetate. The maximum power density obtained was 1.26 mW/m2 at a current density of 10.23 mA/m2. The effects of acetate, nitrate and external resistance on current generation and denitrification activity were investigated, and the results demonstrated that nitrate removal was greatly dependent on the magnitude of current production within the MFC. Increase of acetate (anode) and nitrate (cathode) concentrations improved the process, while increasing external resistance reduced the activity. Furthermore, for a clear understanding of the nitrate reduction process, the analysis of the associated bacteria was performed through biochemical tests and examination of morphological characteristics. A diversity of nitrate reducing bacteria was observed; however a few were able to deliver complete denitrification. Pure cultures in MFC were examined and the voltage output achieved was about 36% of that obtained by mixed cultures. The nitrate removal gained was 56.2%, and this is almost 31% lower than that obtained by the mixed bacterial experiment. In an attempt to improve the MFC, modifications to the electrochemical properties of the electrode were investigated through the use of a cyclic voltammetry using carbon nanomaterials to coat the graphite felts electrodes. Among all the nanomaterials used in this study, graphitised carbon nanofibres (GCNFs) was selected for further investigation as it offered the best electrochemical performance and was thought to provide the largest active surface area. The performance of the MFC system coupled with the GCNFs modified electrodes was evaluated and significant improvements were observed. The highest voltage output achieved was about 41 mV with over 95% nitrate removal. The work is discussed in the context of improved MFC performance, potential analytic applications and further innovations using a bio-nanotechnology approach to analyse cell-electrode interactions.
|
290 |
Technical and social acceptance evaluation of an ultrafiltration membrane system for potable water supply to rural and remote communitiesSetlolela, Jobo January 2004 (has links)
Thesis (MTech (Civil Engineering))--Peninsula Technikon, 2004. / When considering water treatment in small rural and peri-urban communities,
sustainability is one of the most important factors to be considered. Sustainability needs
to be considered from financial, technological and socio-political perspectives. The major
problems with sustainability of conventional small water treatment systems are the
difficulty of controlling chemical treatment processes, especially when the raw water
quality changes, and the production of substandard quality water. Another very important
problem is lack of community involvement, especially over the longer term. The
acceptance of new technologies by the community is of crucial importance in ensuring
successful water supply projects.
The anticipation of more stringent drinking water quality regulations and decrease in
adequate water sources have brought membrane separation processes such as
microfiltration and ultrafiltration on the advantage for potable water supply to rural and
peri-urban areas. Membrane processes have the advantage of production of superior
quality water and addition of fewer chemicals in the treatment process.
The pUIpose of this study was to further investigate the potential of ultrafiltration
capillary membranes as a one-step membrane water treatment system for potable water
supply to developing communities. To successfully transfer a technology to a particular
community, the technology must be suitable and acceptable and a social study was
therefore also done to understand the social acceptance factors that govern the acceptance
of these new technologies.
|
Page generated in 0.1402 seconds