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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Reduction of chloride in wastewater effluent with utilization of Six Sigma

Bodoh, Michael J.. January 2006 (has links) (PDF)
Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.
212

'n Evaluering van die drupfiltrerings- en die geaktiveerde slykproses van die Johannesburg-Noord rioolwerke deur middel van die biologiese groeipotensiaaltegniek

Brown, Leslie Robert 01 April 2014 (has links)
M.Sc. (Botany) / A comparison was made between the effectiveness of the biological filtering and activated sludge processes at the Johannesburg North Sewerage Works by making use of, inter alia, the physical-chemical and biological research methods. In addition to the standard physical and chemical analytical techniques, the biological growth potential technique, the lC method of determining primary productivity and biomass determination by way of the chlorophyll a method, were also used. The most important findings were: 1. that the activated sludge process purifies the water more effectively than the biological filtering process; 2. that no seasonal fluctuations affecting the effectiveness of the purifying systems were found, and 3. that the biological growth potential of the effluent in the Jukskei River was such that it could still cause algal growth. The primary recommendation is that tertiary purifying techniques will have to be employed in order to reduce The high phosphorous levels still prevailing in the effluent to comply with the requirements of the Water Act of 1984.
213

Monitoring of physico-chemical parameters and the behaviour of zinc oxide nanoparticles in a simulated wastewater treatment plant

Chauque, Eutilério Felizardo Crisino 26 June 2014 (has links)
M.Sc. (Chemistry) / In this study the stability as well as the fate and behavior of ZnO engineered nanoparticles (ENPs) in municipal wastewater systems were investigated. The first part of the study examined the influence of pH and ionic strength on the stability of ZnO ENPs in domestic wastewater to elucidate the dynamic changes on the ENPs physicochemical characteristics (e.g. aggregation or dissolution). The ZnO ENPs obtained commercially were characterized using transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), dynamic light scattering (DLS), BET surface area determination, and energy dispersive X-ray spectrometry (EDS). Results derived from inductively coupled plasma optical emission spectrometry (ICP-OES) for zinc analysis indicated a decrease on the released zinc concentration from wastewater as the pH and ionic strength increased. Conversely, an increase on zinc concentration from the sludge was observed. The findings suggest the removal of ZnO ENPs from the influent wastewater as the sludge settled out, and the removal efficiency was directly proportional to ionic strength and pH. In addition, the ZnO ENPs suspension in the wastewater was used to monitor the particle size distribution using the dynamic light scattering analysis (DLS). The formation of agglomerates was observed which the TEM and EDS analysis confirmed to be ZnO aggregates. The distribution of zinc in the sludge was investigated using XRD analysis and the findings indicated partial sedimentation of ZnO ENPs as the sludge settled out. The second part of the study assessed the fate and behavior of ZnO ENPs in wastewater treatment systems. This study was carried out in a simulated activated sludge wastewater treatment plant (AS WWTP), constructed in accordance to the Organization for Economic Co-operation and Development (OECD 303 A) guidelines. Results from the ICP-OES analysis for zinc indicated 50 – 200 μgL-1 and about 3 000 mgkg-1 were released into the effluent and sludge, respectively, after spiking the influent wastewater with 5 mgL-1 ZnO ENPs. Moreover, we noted that increasing the ZnO ENPs concentration up to 20 mgL-1 resulted in a linear increase in the zinc releases into effluent wastewater. However, the increase was insignificant in comparison to the zinc found in the control unit. Therefore, the findings indicated that ZnO ENPs had stronger affinity for the suspended bio-solids during wastewater treatment, and postulated that the ENPs removal from the influent wastewater was due to bio-sorption, and bio-solid settling mechanisms. These were confirmed by results from XRD and diffuse reflectance spectroscopy (DRS) analysis of the sludge as they showed the presence of ZnO in the sludge. The dissolved organic carbon (DOC) and chemical oxygen demand (COD) were concurrently monitored during the ENPs exposure studies to indirectly assess the ZnO ENPs impact to the bacterial degradation of the organic matter. An average of 43 and 91 % for DOC and COD removal efficiencies, respectively, were observed throughout the study. Overall, from results obtained indicated the suitability of the OECD 303 A method to assess the fate and behavior of ZnO ENPs in WWTPs. Secondly, in light of low concentrations of ZnO ENPs found in the treated effluent due to their removal with the waste activated sludge (WAS), suggest low likelihood of ZnO ENPs release and dispersion into the aquatic systems from WWTPs as point sources. Finally, the elevated concentrations of ZnO ENPs in the sludge therefore necessitates additional treatment steps to ensure mitigation of possible dispersion of ENPs from various disposal mechanisms such as landfilling, incineration, and agricultural applications.
214

Down the Drain: A Story of Sewage

Ekman, Lisa 01 January 2010 (has links)
This creative nonfiction thesis tells a story of how water turns into waste. With Portland, Oregon as a base, the reader visits a wastewater treatment plant, several buried and lost streams, a high-tech sewage processor, stormwater education classes, a stormwater management conference, several "green" streets, sewage construction zones, and sewage-related parks. The thesis explores how Western sewage systems came to be, and how wastewater management might change in the future.
215

The efficiency and mechanisms for pollutant removal in biological wastewater treatment systems /

Cameron, Kimberley A. January 2001 (has links)
No description available.
216

Improving sanitation in coastal communities with special reference to Puerto Princesa, Palawan Province, Philippines

Navarro, Rachelle G. January 1994 (has links)
No description available.
217

Computer Driven Training Simulator of Wastewater Treatment Operations

Silkenson, G. Robert 01 April 1982 (has links) (PDF)
This research involves design and implementation of computer program for simulation of a wastewater treatment plant. The program has the capability to be interfaced with an existing analog wastewater plant process flow training board which is equipped with meter readouts of key process variables and adjustable control valves. It is planned that the total system simulator could be used to train wastewater treatment plant operators to afford them hands-on dynamic experience in plant operations. The wastewater treatment process modeled is the activated sludge process. Beginning with the known plant design stead-state equations for this particular process an algorithm was developed to simulate the treatment process through probable system dynamics. All assumptions are presented in a logical manner and used to develop the necessary transient equations. The success of this project demonstrates that a simulation program which emulates a waste treatment process is possible; however, it is suggested that further research is needed to provide deeper insight into variable changes during system transients.
218

Localized Wastewater Treatment Facilities

Garrett, Robert Russell 01 January 1972 (has links) (PDF)
The report describes an alternative to the use of septic tanks for invidual dwellings. The major problems confronting the larger wastewater treatment plants (0.012 to 10 million gallons per day) in central Florida are also discussed. Solutions in this report are for individual and multi-unit dwelling treatment systems (to 0.06 MGD). these units can provide 90% biochemical oxygen demand (BOD) and suspended solids (SS) removal in accord with new state and county regulations. A comparison of the large versus the small plants reveals that small innovative plants, though more expensive, are more environmentally sound than the poorly operated large facilities. Flexibility of modularized (using multiple small plant equipment) wastewater systems appear to be a major advantage in expanding areas. finally, proper control of individually owned and operated units is discussed with some practical solutions offered.
219

The sewage lagoon: its social, economic, and planning implications

Cherches, Charles William January 1961 (has links)
The basic objectives of this study were to determine: (1) the extent of water pollution contributed by our communities in the form of municipal and industrial wastes, (2) an investigation of the extent of use, performance characteristics, and costs or the sewage lagoon, (3) the planning aspects of the sewage lagoon, (4) the extent of anti-pollution law enforcement, and (5) the existing financial aid available to communities tor the construction of' sewage lagoons. The findings of this study indicate that: 1. The extensive contribution to the water pollution problem by municipalities and industry is serious. The projection of future water use based upon present standards of use and recovery indicates a very serious water problem in the near future. A need exists for an inexpensive method or sewage treatment. 2. Sewage lagoons are relatively new but are widely used. They have proved to be relatively inexpensive and are achieving a high standard of purification. 3. Possible secondary benefits resulting from the use of sewage lagoons may prove to be of substantial value to municipalities in terms of efficient land use and the preservation of open land for alternate future uses. 4. The enforcement of the existing anti-pollution laws have been ineffectively enforced; however, new emphasis is being placed upon legal proceedings I rather than the voluntary compliance that has been practiced in the past. 5. With proper planning, a community can conceivably use several governmental programs for financial assistance both in grants-in-aid and long term loans for the construction or a sewage lagoon. / Master of Science
220

Systems engineering analysis of urban region sludge disposal alternatives

Kozlowski, David Richard January 1986 (has links)
A microcomputer simulation model was developed to compare sludge disposal alternatives for an urban region. The model calculates both capital and operation costs for sludge treatment and disposal operations. For a study of an urban region with an equilibrium wastewater generation rate of 44.74 million m³/yr, the optimum sludge disposal alternative was dedicated land disposal for a baseline analysis of wastewater sludge treated by gravity thickening and anaerobic digestion. The capital cost at system equilibrium is $6.09 million and the total cumulative operation and maintenance cost over 100 years is $103.2 million. The operation and maintenance cost is 94% of the total capital and cumulative operation and maintenance cost. A description of the investigation and the criteria used for selection of this sludge disposal alternative ls included / Master of Science

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