M-Tech: Chemistry (Vaal University of Technology) / ABSTRACT The research was aimed to study the causes of excessive foaming in a waste water treatment plant. Although the activated sludge process has been adopted to treat this industrial waste water , lots of problems were experienced by the inhibitory effects of toxic compounds that are found in industrial effluents and the foaming stability that was very high. Industrial waste water treatment using sludge processes was found to be more challenging than the normal municipal waste water treatment although the principle is the same; the foaming tendencies were found to be more in industrial waste water. In this study the composition of influents to the waste water treatment plant and operating parameter’s effects on foaming tendencies were examined. The foaming potential in the plant was found to be chemically related due to high contamination of compounds such as phenols, which played a major role in formation of stable foam. It was recommended that there must be pretreatment of the incoming influents to minimize their impact to waste water treatment.

This thesis presents details of investigations into the potential for co-disposal of the two rejects from Clarence Colliery and Kable's Transport Sand Mine. Column experiments were undertaken to simulate field conditions. The experiment consisted of: 1/. creating the required co-disposal arrangement and structure in containers 2/. infiltrating water through each container and measuring the rates of infiltration and overflow 3/. measuring the chemical properties of the leachate water. Geotechnical tests of co-disposal pile stability were undertaken using a specially constructed shear box. Results of this study suggest the co-disposal of course coal washery reject from Clarence Colliery with clay tailings from Kable's Transport Sand Mine is a feasible option for managing the generation of acetic drainage. It is recommended that field trials comprise layers of coal reject and clay tailings in a 9:1 ratio. Layering the coal reject with clay tailings creates a semi-permeable barrier which acts to restrict water percolation through the reject as well as reacting with the leachate to increase the leachate pH and adsorb metals / Master of Engineering (Hons)

Bibliography: leaves 166-180. Determines the effect of chromium on the soil microbial community and its activity, the biotic-abiotic mechanisms involved in chromium oxidation, and phytostabilization of chromium using plants and organic amendment in tannery-waste contaminated soil.

Bibliography: leaves 166-180. / 180, [4] leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Determines the effect of chromium on the soil microbial community and its activity, the biotic-abiotic mechanisms involved in chromium oxidation, and phytostabilization of chromium using plants and organic amendment in tannery-waste contaminated soil. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002

Corrigenda inside front cover. / Includes bibliographical references (leaves 205-232) / xii, 232, [27] leaves : ill., plates ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002

No description available.

Past operational practices at chemical manufacturing facilities and widespread use of synthetic chemicals in agriculture, industry, and military operations have introduced many anthropogenic compounds to the biosphere. Some of them are readily biodegradable as a likely consequence of bacterial evolution of efficient degradation pathways, whereas others are partially degraded or persistent in the environment. Insight about biodegradation mechanisms and distribution of bacteria responsible provide the basis to predict the fate of synthetic chemicals in the environment and to enable bioremediation. The main focus of the research described here encompasses basic science to discover pathways and evolutionary implications of aerobic biodegradation of two specific synthetic chemicals, cis-dichloroethene (cDCE) and diphenylamine (DPA). cDCE is a suspected carcinogen that frequently accumulates due to transformation of perchloroethene and trichloroethene at many contaminated sites. Polaromonas sp. strain JS666 is the only isolate able to use cDCE as the growth substrate, but the degradation mechanism was unknown. In this study, the degradation pathway of cDCE by strain JS666 and the genes involved were determined by using heterologous gene expression, inhibition studies, enzyme assays, and analysis of intermediates. The requirement of oxygen for cDCE degradation and inhibition of cDCE degradation by cytochrome P450 specific inhibitors suggested that cytochrome P450 monooxygenase catalyzes the initial steps of cDCE degradation. The finding was supported by the observation that an E. coli recombinant expressing cytochrome P450 monooxygenase catalyzes the transformation of cDCE to dichloroacetaldehyde and small amounts of the epoxide. Both the transient accumulation of dichloroacetaldehyde in cDCE degrading cultures and dichloroacetaldehyde dehydrogenase activities in cell extracts of JS666 further support a pathway involving the degradation of cDCE through dichloroacetaldehyde. Molecular phylogeny of the cytochrome P450 gene and organization of neighboring genes suggest that the cDCE degradation pathway evolved in a progenitor capable of degrading dichloroacetaldehyde by the recruitment of the cytochrome P450 monooxygenase gene from alkane assimilating bacteria. The discovery provides insight about the evolution of the aerobic cDCE biodegradation pathway and sets the stage for field applications. DPA has been widely used as a precursor of dyes, pesticides, pharmaceuticals, and photographic chemicals and as a stabilizer for explosives, but little was known about the biodegradation of the compound. Therefore, bacteria able to use DPA as the growth substrate were isolated by selective enrichment from DPA-contaminated sediment and the degradation pathway and the genes that encode the enzymes were elucidated. Transposon mutagenesis, the sequence similarity of putative open reading frames to those of well characterized dioxygenases, and 18O2 experiments support the conclusion that the initial reaction in DPA degradation is catalyzed by a multi-component ring-hydroxylating dioxygenase. Aniline and catechol produced from the initial reaction of DPA degradation are then completely degraded via the common aniline degradation pathway. Molecular phylogeny and organization of the genes involved were investigated to provide insight about the evolution of DPA biodegradation. The fate and transport of toxic chemicals are of a great concern at several historically contaminated sites where anoxic contaminant plumes emerge into water bodies. The release of toxic chemicals to overlying water poses a potential source of environmental exposure. Bench scale studies were conducted to evaluate the impact of biodegradation on the transport of toxic chemicals across the sediment/water interface. These studies demonstrated that substantial populations of bacteria associated with organic detritus at the interface rapidly biodegrade toxic chemicals as they migrate from contaminated sediment to overlying water, suggesting that the natural attenuation processes serve as a remedial strategy for contaminated sediments and protect the overlying water.

The aim of process industries is to produce products and intermediates from raw materials and other intermediates. Inevitably, there are waste products to be disposed of and if these are of no use, they must be returned to the air, water or land environments. Such returns should be carried out in such a way as to minimise any adverse effects on the environment, otherwise the waste is bound to cause pollution to the environIDent. Wastewater is one such product that has to be returned to the environment. A weakness in the current practice of wastewater treatment is that the potential toxicity of the effluent is only addressed through the prevention of specific types of waste being discharged to the sewer. The discharge of effluents containing toxic or inhibitory substances is currently not directly addressed or controlled by many industries and local authorities. While cost recovery is important, due consideration must be given to the possible effect on the receiving environment. The magnitude of the problem of toxic components in the inflow to wastewater treatment plants in South Africa is largely unknown. However, it is thought by some treatment authorities to be relatively serious. In addition, there has been no attempt to quantify the effect of individual toxicants on the performance of the treatment processes and thus put a monetary value to individual discharges. Nitrification is one of the important biological processes that takes place in wastewater treatment plants, which may be affected by toxicants from wastewater. The toxicants may inhibit the nitrification process and create problems in the treatment plant. The aim of this study was to determine if the Amanzimtoti Wastewater Treatment Plant is experiencing inhibition of nitrification, and if so, determine whether large industries discharging into the plant contribute to this problem. The study site used in this research was the Amanzimtoti Wastewater Treatment Plant, located at Isipingo, in Durban, together with some selected industries that discharge their effluents into this treatment plant. In this study, the Amanzimtoti Wastewater Treatment Plant together with lO industries that discharge effluent into it, were surveyed for inhibition of nitrification. A screening method for estimation of inhibition of nitrification at municipal wastewater treatment plants described by Jonsson (2001) was used in the investigations. This involved testing inhibition of nitrification at various dilutions of wastewater effluent from 20% to 80% dilution. An investigation was conducted of inhibitory substances within influent wastewaters to the Amanzimtoti Wastewater Treatment Plant, and inhibitory substances were detected in all four sampling weeks. The level of inhibition was in general up to 29%, with the greatest inhibition being observed at 20% and the least at 80% dilution. In order to investigate the source of inhibition, inhibition of nitrification was measured in the sewage influent during times when industries are open and when they are closed. Inhibition was significantly lower during December when industries close, supporting the hypothesis that industrial effluent contributes to inhibition of nitrification. Comparison of wastewater from different industries showed that of 10 surveyed industries, 9 generated wastewaters that were found to be inhibitory, with Industry D showing the highest inhibition of approximately 30% over the 4 dilutions. The least inhibitory effluent was from Industry C with an average of 10%. Industry A was found to stimulate nitrification. There was no correlation found between the daily volume contribution of the industries to the treatment plant, and the inhibition of nitrification. There was also no correlation found between the inhibition of nitrification and the chemical oxygen demand and settleable solids concentration of wastewater from each of the industries.. At 80% dilution, the nitrification inhibition results obtained for all nine industries were similar and it was difficult to distinguish between them, whereas at 20% dilution, the differences among the industrial effluents on nitrification could be clearly evaluated. Industries B, D, E, G and J were found to have higher inhibition than the other four surveyed industries. Results obtained at the 20% dilution could therefore be used as a decision making tool by wastewater pollution officers to identify industries requiring close monitoring. From the study, it was clear that the inhibition of nitrification that resulted from mixtures of industrial wastewaters cannot be readily predicted from nitrification inhibition by the individual wastewaters. New compounds may be formed during mixing in the sewer network that are more or less inhibitory than if the wastewaters are not mixed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.

Every time a good is produced, waste occurs as an unwanted by-product. Waste has become a real environmental issue across the world, contributing to the degradation of the environment and human health. As part of a local and international effort to lessen industrial pollution, a concept to reduce waste production at source was introduced to companies in the early 1990s. Pioneered in the Netherlands and the United Kingdom (UK), this concept has been termed 'waste minimisation'. Waste minimisation is achieved by implementing changes to business practices and processes, such as improved housekeeping (e.g. prevention of spills), and changes to equipment that is less wasteful. It is often undertaken by a group of organisations, including for example service providers, manufacturing companies and regulators that join a waste minimisation club (WMC). This provides an opportunity in which training can be received by, waste minimisation assessments made on, and information and ideas about waste reduction at source exchanged by member companies. WMCs have been used successfully in Europe to achieve waste minimisation in industry and residential communities. This study aims to contribute to the development of a sustainable WMC model in South Africa. It analyses the WMC support structures in South Africa and compares them to support structures offered in the UK. This offers a point of reference from which the impact of South African support structures on WMCs in general, and the Pietermaritzburg Waste Minimisation Club (PWMC) in particular, can be established. The PWMC consists of small and medium companies across sectors, each with less than 200 employees and with an annual turnover less than 40 million rand. The club was initiated by the Pollution Research Group of the University of KwaZulu-Natal (UKZN). It was the first of its kind in South Africa, having been facilitated on a small budget by staff and students from the UKZN. The study found that the self-help approach adopted by the PWMC was only partially successful. The PWMC was successful in terms of raising awareness of its members to waste minimisation issues. The study also found that member companies, both from the PWMC and WMCs generally, need to be shown in practical terms that 2 waste minimisation can result in financial savings before management buy-in can be attained. If more University manpower had been allocated, in the form of students for instance, to identify and orchestrate implementation of sustainable waste minimisation solutions, the PWMC member adoption rate of waste minimisation may have been raised. The small PWMC budget may have made this impossible, however. Lack of funding may also have prevented facilitators putting together a large support team, as has been done for a similar and more successful project in England. This demonstrates that self-help WMCs need an initial funding boost to be successful. This funding should be invested in gaining buy-in from company personnel rather than to drive the waste minimisation process on behalf of member companies. Driving waste minimisation on behalf of companies or 'hand-holding' leads to a passive acceptance of waste minimisation as is currently the case in South Africa, as well as 'shirking' as has been observed in the UK. Such a facilitated self-help approach can then lay the basis for WMCs, which use the support infrastructure established by their predecessors. Studies of WMCs in England and Wales based on a self-help approach showed that they achieved financial savings that are comparable to those in demonstration clubs. The promotion of such sustainable WMCs in South Africa needs to be performed by a central support agency such as the British Envirowise. Envirowise was seen to successfully promote waste minimisation among those it reached. However, it reached only a small percentage of overall industry. A successful South African agency therefore needs to promote itself effectively and nation-wide. A successful South African Envirowise organisation should also facilitate the creation of WMCs by leading a forum of industry, service providers, higher education and waste minimisation champions of proven worth, to create an action plan for WMC development for each province. Each province would then allocate funds for a waste minimisation champion who, in conjunction with the local development agency, would create a provincial action plan for the development of facilitated self-help WMCs. The local support and expertise recruited to form and manage WMCs would decrease costs and leverage income. This kind of support agency needs to be upheld by waste management legislation based on the concept of sustainable development, recognising the need for environmental protection alongside that of economic growth. To date no such legislation is in place in South Africa. It is hoped that the White Paper on Integrated Pollution and Waste Management, which endorses the principle of sustainable development alongside with the necessity to reduce waste at source, will form the basis for a successful South African WMC culture. / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

The dissertation analyses the economic and ecological aspects of Darvill Waste Water Works (WWW) through key indicators from Sustainable Development Records (SDR). The SDR study identifies disturbances caused by large concentrations of soap, oil and grease (SaG), therefore a framework of proposed solutions to dealing with these problems has also been investigated. The first component of the study highlights the importance of adequate indicators. Key indicators provide important information that is useful to management and policy makers. The SDR used to analyse the DarvillWWW in Pietermaritzburg provides relevant information for the management of Darvill WWW and Umgeni Water (UW), the City Council and the Department of Water Affairs and Forestry (DWAF). According to the SDR model the Works is identified as a service providing social institution. The operation of this institution affects the community of Pietermaritzburg as well as the surrounding natural environment. SDR uses the key indicators of effectiveness, Thrift and Margin to analyse the economic and ecological impacts of the service provided.The study incorporates relevant data for Darvill WWW during 1993- 1996. Effectiveness measures the degree of compliance with national water quality standards as set out by the DWAF. Compliance of the following variables, E.coli, Chlorine, Soluble Reactive Phosphate (SRP), Total Suspended Solids (TSS), Conductivity, Chemical Oxygen Demand (COD) and Ammonia were investigated. These variables produce varying trends. Increasing compliance is linked to improved plant efficiency while decreasing compliance is linked to the poor quality of industrial effluent. Industrial effluent containing large concentrations of SOG is a particular problem. Thrift measures the costs of operating the Works in terms of energy, chemicals, labour and capital. Overall financial, energy and labour thrift declined while chemical thrift increased. Increasing chemical thrift is due to the reduced consumption of chemicals as a result of a greater reliance on the process of biological phosphate removal. Decreasing thrift is related to increased costs of capital, energy and labour due to the deteriorating quality of vegetable oil effluent. Margin measures the deviation of non-complying samples from water quality standards. Analysis of the data produced varying trends. The following variables were analysed, E.coli, Chlorine, SRP, TSS, Conductivity, COD and Ammonia. Marginal difference is studied in an attempt to analyse those samples which do not comply with national standards. Deteriorating quality of industrial effiuent seems to be the reason for deviation from the standards. Chemical margin was also studied for the period between 1993-1996. Chemical margin is a comparison between the value of sludge produced and the cost of chemicals used to produce the sludge. The SDR study highlights deteriorating quality of industrial effluent as a cause for concern to Darvill WWW. Proposed management options are investigated to provide a workable solution. The second part of the study investigates alternate options for handling wet industrial effluent from the vegetable oil industries. These industries were identified as the source of large concentrations of SOG that were entering the Works which impacts negatively on the operational capacity, thereby increasing operating costs and decreasing the quality of the service provided. Vegetable oil industries were found guilty of discharging industrial effluent that did not meet the City standards into the sewers, they were also charged with illegal dumping into rivers. The study identified the interested and affected parties and alternate solutions were proposed to the problems. Interested and affected parties include UW, Pietermaritzburg City Council, DWAF. Some of the aspects that were investigated include the local industrial tariff, the drainage By-laws, national legislation, the "polluter pays" principle and the principle of pollution prevention. Economic incentives using economic instruments were reviewed. These include ecotaxes such as marketable/tradable permits and pollution charges. These instruments may allow for more equitable charges thereby promoting the "polluter pays" principle. The use of these instruments may be able to achieve a workable solution but further investigations are necessary. SDR analysis indicates that Darvill WWW seems to be effectively treating wastewater but operating costs are increasing in order to achieve compliance. These costs are being unfairly borne by the City ratepayers and UW and a more equitable situation is necessary. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 1997.