Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 373-387). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 373-387). Also available on the Internet.

Thesis (MTech. degree inChemistry.)--Tshwane University of Technology, 2010. / Introduction: Since the establishment of relationships between BOD, COD and TOC in early 1980’s, total organic carbon (TOC) analysis has been the analytical backbone of many water treatment laboratories (Furlong et al. 1999). It is only a question of time before South Africa follows suite, if only to adhere to export legislation and requirements. The question is whether TOC is just another expensive analytical tool for policing effluent, or is TOC results valid criteria for monitoring pollution. Aim: The purpose of this project was to evaluate the determination of TOC as a management tool on a wastewater treatment plant (WWTP) and compare it to the chemical oxygen demand (COD) analysis traditionally applied. Experimental: Five sampling points throughout the wastewater treatment plant were evaluated. A possible comparison between TOC and COD was investigated. Sampling was done using an ISCO 3700 portable sampler at each individual sampling point. The samples were filtered and analysed for TOC in the laboratory using an ISCO EZ 3500 TOC analyser. COD analysis was done colorimetrically by using a Hach DR 2000 photometer. Both analyses were done according to standard methods for water and wastewater. Because the ISCO EZ 3500 TOC is an online instrument, it was evaluated at two of the wastewater treatment plant. Results: The analysis of TOC is a more rapid method than COD for the determination of organic load and thus has the potential for better early warning and pollution control management. The change in chemical composition of raw sewage made it difficult to find consistent correlation between COD and TOC results. However, it was found that an online TOC analyses was a practical alternative to COD for plant control, process management and monitoring of inflow and effluent flows in wastewater treatment plant. Conclusion: Limitations of TOC analysis must be considered and include practical problems due to the high content of suspended solids in raw sewage and activated sludge, as well as the partial oxidation of certain organic compounds by ultra-violet/persulphate digestion. Although COD analysis is chemically hazardous and time-consuming compared to TOC analysis, it is not likely that TOC will replace COD on the WWTP, due to historical data accumulation, practicality and people’s natural opposition to change. However, it is hoped that the results of this study will increase knowledge about TOC and be used for practical implementation where this technique has advantages over COD

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1926. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed September 15, 2009) Includes bibliographical references and index.

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaf 54).

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M.Ing. / The Rietvlei Water Treatment Plant was extended with a granular activated carbon (GAC) filtration system after an exhaustive series of tests, which were started in 1994. Upon commissioning towards the middle of 1999, a year of close monitoring followed to measure the GAC performance at full-scale. After verification that the GAC does indeed ensure a high quality product under all conditions, the emphasis shifted to the optimisation of the GAC handling and regeneration system. Frequently moving the entire GAC inventory from the filters to an off-site regeneration plant and back requires significant operational effort and contributes a major part of the total cost of the GAC system. A number of systematic investigations were carried out in response to a number of practical questions that arose at Rietvlei. The first part of the study was directed towards tracking and quantifying the GAC on and off site. The main findings were that 10.0% of the GAC is lost from the filter during backwashing (0.3%) and removal of GAC from the filter for regeneration (9.7%). The sump traps not all this GAC and 2.3% of the total inventory is lost to the river. Inserting a sieve at the outlet of the sump can eliminate this loss. A further 80.3% of the GAC in a filter is removed for regeneration, of which 18.7% is lost during the regeneration process. The minimising off this loss can only be achieved through the optimisation of the regeneration process, which falls within the domain of the regeneration contractor. The second part of the study was directed at the behaviour of the GAC whilst within the filter bed. The porosity and sphericity was determined by laboratory tests and calculations. The porosity was found to be 0.69 for the 12 x 40 size carbon and 0.66 for the 8 x 30 size carbon and the sphericity was found to be 0.67 for the 12 x 40 size carbon and 0.66 for the 8 x 30 size carbon. By using a calibrated bed expansion model, the bed expansion could be calculated at 9°C and 23°C for the two carbons gradings; the maximum temperature range experienced at Rietvlei. The main finding of this part of the study was that the average available freeboard is 650 mm for the 12 x 40 grading and 430 mm for the 8 x 30 grading, and therefore no GAC should wash over the weir at all during backwashing. The third part of the study measured the physical changes of the GAC found at different points in the GAC cycle. The main findings were that the small fraction of GAC washed out of the bed during backwashing and removal has a finer grading, higher apparent density and lower adsorption capacity than the GAC in the filter bed. There seems to be no marked attrition of the carbon or generation of fines during the removal and transport of the GAC to the regeneration plant. After regeneration, there was a 7% decrease in apparent density and a 30% increase in adsorption capacity. The final part of the study correlated the adsorption capacity of the GAC with its time in use as well as UV254 removal. After regeneration, UV254 removal begins at approximately 20% and declines to 14% after 400 days of operation, and to 10% after 600 days. After regeneration, the iodine number begins at approximately 800, declines to 600 after 400 days of operation, and to 500 after 600 days.

Nitrogen is an essential nutrient for plant and animal life; however, its presence in concentrations exceeding assimilative capacities of receiving water bodies is undesirable. Therefore, the form and concentration of total nitrogen released in wastewater effluents is of great concern. During the course of this study, the nitrogen analysis was performed on the various unit processes of the Florida Technological University wastewater treatment plant. The average percent removal of nitrogen between plant influent and clarifier effluent was 30.5% during the month of August 1975. It is believed that the nitrogen removal is attributed to luxury uptake by the biomass through the plant. The clarifier effluent was highly nitrified containing an average ammonia nitrogen concentration of 0.76 milligrams per liter and a nitrate nitrogen concentration of 16.47 milligrams per liter. The extent to which nitrification took place was 93 - 98% with an average of 96.5% for the month of August.

The dewatering characteristics of polyaluminum chloride (Hyper⁺Ion 1050A) sludges were investigated using lab-scale tests including specific resistance to filtration (r*), capillary suction time (CST), and sludge pH. The effects of chemical conditioning (lime and cationic polymer) and mixing intensity (Gt) upon the sludge dewatering characteristics in a pilot-scale plate and frame press were also studied. The dewatering characteristics of the Hyper⁺Ion sludges were found to be dependent upon the influent water turbidity conditions; specifically, the ratio of aluminum coagulant to total dry solids in the sludge. Lime was an effective conditioner for doses that produced a sludge pH value in the range of 11.5 to 11.8 which, again, was a direct function of the aluminum coagulant fraction in the sludge. Cationic polymer and a combination of lime and polymer were also effective conditioning schemes when the appropriate dose and mixing intensity were applied. / Master of Science