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A local company instituted a new chemical procedure in their spray phosphating system used in the pretreatment of large components for industrial racking systems. An inorganic conversion coating is deposited on the workpiece surface during phosphating and this prepares the surface to receive an organic top-coat. The organic coating is applied to the workpiece surface in the form of a powder and cured to form a continuous film about 80 u.m thick. The solution chemistry of the phosphating system was monitored by sampling and chemical analysis and taking direct reading instrumental measurements on the process and rinse solutions. The process was also evaluated using the results of a waste minimisation audit. This involved gathering data on composition, flow rates and costs of inputs and outputs of the process. Two types of information were collected and used during the audit, namely chemical monitoring (concentration levels of Na, Fe, Zn, Mo, Mn and Cr and measurements of conductivity, TDS, SS and pH) and water usage data on the Phosphating Line and existing data (raw materials, workpieces and utility inputs as well as domestic waste, factory waste and scrap metal outputs). The data were analysed using four established waste minimisation techniques. The Scoping Audit and the Water Economy Assessment results were determined using empirically derived models. The Mass Balance and the True Cost of Waste findings were obtained through more detailed calculations using the results of the chemical analysis. The results of the audit showed that the most important area for waste minimsation in the Phosphating Line was the (dragged-out phosphating chemicals present in) wastewater stream. According to the scoping audit, water usage had the third highest waste minimisation potential behind powder and steel consumption for the entire powder coating process. While the scoping audit and the specific water intake value showed that water consumption for the process was not excessive, it did not indicate that the pollution level in the rinse waters was high. Further, drag-out calculations showed that drag-out volumes were typical of those found in the metal finishing industry. However the presence of high levels of metal species in the rinse waters was highlighted through the chemical monitoring of the Phosphating Line. The True Cost of Waste Analysis estimated potential financial savings for the effluent stream at about R8000 for a period of 105 days. However this does not take into consideration the cost of the liability associated with this stream when exceeding effluent discharge limits (given in the Trade Effluent Bylaws) or of the chemical treatment necessary to render this stream suitable for discharge to sewer. Intervention using only "low-cost-no-cost" waste minimisation measures was recommended as a first step before contemplating further areas for technical or economic feasibility studies. However, a further study involving monitoring the sludge was recommended in order to establish the potential financial savings offered by this waste stream. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Theoretical waste minimisation opportunities and options for electroplating were sought from the literature. Their suitability under the specific site conditions of a chromium electroplating plant were evaluated using the results of a waste minimisation audit (audit). The audit showed that many waste minimisation practices were already in place. These included counter current flowing rinse systems, multiple use of rinses and recycling of the drag-out solution back into the plating solution. Two types of information were collected during the audit, namely new chemical monitoring (concentration levels of sodium, iron, zinc, copper, lead, chromium and nickel and conductivity, total dissolved solids and pH) and flow rate data and existing data (composition of the process solutions, products and waste outputs, and raw materials, workpieces and utility inputs). The data were analysed using four established waste minimisation techniques. The Scoping Audit and the Water Economy Assessment results were determined using empirically derived models while the Mass Balancing and the True Cost of Waste results were obtained through more detailed calculations. The results of the audit showed that the three most important areas for waste minimisation were water usage, effluent from rinse water waste streams and nickel consumption. Water usage has the highest waste minimisation potential followed by nickel. Dragged-out process chemicals and rinse water consumption contribute to ranking the effluent stream the most important waste minimisation opportunity identified by the True Cost of Waste Analysis. Potential financial savings were roughly estimated to be in the order of R 19949 and R 126603 for water and nickel respectively. Intervention using only "low cost-no-cost" waste minimisation measures was recommended as a first step before contemplating further focus areas or technical or economical feasibility. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

A chromium plating line used by a local company was monitored to identify any potential waste minimisation opportunities. Plating of the workpiece surface is carried out by immersing the workpiece in seven process (treatment) solutions including nickel and chromium plating baths. Between each process step the workpieces are rinsed. The chromium plating process was evaluated using the results of a waste minimisation audit. This involved gathering data on the composition, flow rates and costs of the inputs of the process. Two types of data were collected namely new and existing data. The new data included chemical monitoring (concentration levels of Ni, Cr, Na, S, B, P, Si, Fe, Cu, Zn, Pb as well as conductivity, TDS, SS and pH measurements) and water usage data. The existing data included raw materials, utility inputs, composition of process solutions and product outputs. The data were analysed using three established waste minimisation techniques. The Water Economy Assessment (a form of Monitoring and Targeting) results were determined using an empirically derived model. The Water Balance and True Cost of Waste results were obtained through more detailed calculations using the results of the chemical analysis. The results from the audit showed that the water usage on the chromium plating line has the highest waste minimisation potential. The True Cost of Waste analysis showed there is no significant chemical wastage in the effluent stream. The potential savings of the effluent stream was negligible (approximately R10 for 238 days). Drag-out calculations were also performed and showed that the drag-out volumes were in good agreement with the typical volumes found in the metal finishing industry. Intervention using simple lowcost and no-cost waste minimisation opportunities were recommended as a first step before contemplating further focus areas for technical or feasibility studies. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

This study involved an assessment of the Pietermaritzburg Waste Minimisation Club (PWMC) during 2001, and a waste minimisation audit conducted at two coil coating lines. Waste minimisation is the reduction or elimination of waste at source4 • It is often achieved through waste minimisation clubs which comprise a small number of companies, generally in the same geographicaI area, that are interested in reducing waste 1"711 . The success of the PMWC was evaluated in terms of the degree to which members implemented waste minimisation principles. Two questionnaires were used to assess the success of the club. These indicated that although the training material gave the members a good understanding of the basic principles of waste minimisation, the material has not given the members enough practical information to implement a waste minimisation programme in their companies. The main barriers to waste minimisation identified include production pressure, operational constraints, lack of human resources and a lack of management time. The drivers for waste minimisation were financial savings, improved plant utilisation and improved environmental performance. Coil coating is a continuous process where a coiled sheet of aluminium is cleaned, pretreated and coated with paint. The flow rates, compositions and costs of all input and output streams to the cleaning and pretreatment sections were gathered from operators or measured. The data were collected over a three-month period to obtain a representative sample, and then analysed to determine waste minimisation opportunities using mass balances, monitoring and targeting, a scoping audit and a true cost of waste assessment. The scoping audit was found to be the most useful technique because it accurately prioritised the waste minimisation opportunities but required a relatively small amount of data for its application. However, the scoping audit underestimated the savings that could be achieved at the coil coating department and therefore the 'scope to save' percentages, which were developed for United Kingdom industries, need modification to better reflect South African industry. Opportunities for waste minimisation on Coil Coating Line 1 (CCL1) included reducing the water consumption, reducing the acid and chromium raw materials consumption, and finding a cheaper energy source for heating the process and rinse tanks. Potential fmancial savings of R116 000 and environmental savings of 18 200 kL of water or effluent per year were calculated for CCL1. The chromium and acid effluent treatment and solid waste disposal are the main areas for waste minimisation on Coil Coating Line 2 (CCL2). Savings could be achieved in these areas by using roller application ofthe chromium pretreatment rather than spray application, and by preventing a leak of chromium pretreatment into the acid process and rinse tanks. Other savings can also be achieved by operating the chromium process tank as a fed-batch process, and operating the alkali and acid process tanks as continuous processes at the specified chemical concentrations and with recycle of the rinse water (dragout). The total financial savings that can be achieved on CCL2 are R5.3 million, and potential environmental savings are 31 600 kL ofeffluent per year. / Thesis (M.Sc.)- University of Natal, Pietermaritzburg, 2002.

SAPPI SAICCOR is a pulp and paper mill situated in Umkomaas, 50 kms south of the port of Durban in South Africa. It was the first company to produce high grade dissolving pulp from the Eucalyptus tree and is currently the world's largest manufacturer of chemical cellulose. SAICCOR is one of the few pulp and paper mills that produces its dissolving pulp by the acid sulphite process using both calcium and magnesium as bases in the form of calcium bisulphite and magnesium bisulphite. Four streams of effluent are produced during their process, namely, the calcium spent liquor, the magnesium pulp condensate and two streams from the bleaching stages. An acid hydrolysis of the effluent streams yielded a range of organic compounds such as lignans and lignin - type precursors as well as a triterpenoid. Column chromatography and thin layer chromatography, using various ratios of hexane, dichloromethane, ethyl acetate and methanol, were carried out in isolating and purifying the compounds. The structures of these compounds were determined using NMR spectroscopic and mass spectrometric techniques. / Thesis (M.Sc.)-University of Natal, Durban, 2003.

Chemical and allied industries produce significant quantities of chlorinated wastes each year. Thermal treatnent of these chlorinated wastes has a long and controversial history. The most common and contentious method of waste destruction is incineration. Although waste incinerators are designed to provide greater control over the combustion process, toxic products are inevitably formed from incomplete combustion and released in stack gases and other residues. The most notable group belonging to the products of incomplete combustion (PICs) are dioxins and furans. The fact that oxygen is an integral part of the molecular structure of dioxins and furans suggests that the formation of these particular PICs may be reduced or avoided by minimizing or completely excluding oxygen from thermal waste treatment. Pyrolysis using induction heating is a relatively new technology that has shown much promise from the initial work performed by Pillay (2001). This research was an extension of that study, and investigated equipment and process optimization as well as macroscopic modeling of different systems. The objective of this study was to establish the technology of pyrolysis using induction heating as a competitive alternative to existing waste destruction systems. The novel approach of pyrolysing compounds using induction heating was demonstrated by destroying chlorinated aliphatic, aromatic and a mixture of these compounds. These experiments were conducted at atmospheric pressure in a tubular laminar flow reactor (5.2cm I.D) under a thermally transparent argon atmosphere. In this system heat was generated in an embedded graphite tube using induction heating. Thermal degradation occurred through the bombardment of the compounds by the photons emitted from the heated graphite tube. The compounds were pyrolysed at temperatures ranging from 330°C to 1000°C and at mean residence times from 0.47s to 2.47s. In addition to these process variables the effects of reactant concentration and additives were investigated The major species formed from this thermal treatment were solid carbon black and gaseous hydrogen chloride. Destruction efficiencies (DE) of the order of 99.9999% (six nines) and greater were obtained for the different feed mixtures at their respective operating conditions. A minimum DE of six nines adequately satisfies the regulation set by the Environmental Protection Agency (EPA) for successful waste destruction. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

SAPPI SAJCCOR, whose factory is situated south of Durban, South Africa, is one of the few paper and pulp mills that uses the acid sulphite process with calcium and magnesium bases to produce a high-grade cellulose pulp. Four streams of effluent, namely, the calcium - spent liquor stream, the magnesium condensate stream and two streams from the bleaching effluent are produced during this sulphite pulping process and they contain a variety of organic compounds extracted from the wood. Characterisation of the effluent was based on isolation using column chromatography and identification using NMR techniques. A range of constituents, such as lignans and lignin - type precursors, a trilerpenoid and fatty acids were isolated and identified. X-ray diffraction was used to identify an inorganic residue obtained from the calcium - spent liquor stream and gas chromatography/mass spectrometry was used to identify a wax residue. which builds up in the process. In addition to this, the carbohydrate content of the four streams of effluent was detennined using UV/visiblc spectroscopy. / Thesis (M.Sc.)-University of Natal, Durban, 2001.

Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Biotechnology, Durban Insititute of Technology, 2003. / Stimulated by the findings of international researchers, that the sulfate-reducing microorganism Desulfovibrio desulfuricans could be incriminated in the process of mercury bio-methylation, it was decided to test this hypothesis on sediments from selected areas of Durban Bay where elevated levels of the bio-hazardous heavy metal had previously been detected. The Environmentek Division of the Council for Scientific and Industrial Research (Durban) is involved in an ongoing chemical assessment of heavy metal contamination (including levels of mercury) in the sediments of this estuary, but nothing is currently understood about the form in which mercury exists or the biological processes that could be determining its fate. The purpose of this project was to attempt to answer some of these questions. The study involved attempting to isolate, identify and quantify microorganisms of the species Desulfovibrio desulfuricans, Escherichia coli and Clostridium perfringens in one hundred and eighty sediment samples taken from three designated sites in the bay. Each sample was additionally analysed for total and methyl mercury and sulfate content, as well as a number of physical parameters. Based on the outcome of the initial survey, it was envisaged that further laboratory experimentation would be conducted to determine whether or not isolates were responsible for the production of the highly toxic organic mercury and whether this process was occurring in situ in the sediments. The findings of this project were contrary to what had been expected. Total mercury concentrations (apart from one instance) did not appear to be appreciably elevated in the areas under study. Similarly, the levels of methyl mercury were fourrd to be either diminished or absent. Numbers of D. desulfuricans were low and not uniformly distributed throughout the sediments. Cl. perfringens was more in evidence, but counts were not perceptibly increased. Sulfate levels were consistently high, indicating significantly impaired rates of sulfate reduction. Difficulty experienced in sub-culturing / M

Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Biotechnology, Technikon Natal, 2001. / The vegetable oil industry produces effluent containing quantities of fat, oil, sodium, phosphates as well as other pollutants. Oils and greases tend to clog sewers and pumps, thus creating difficulties within the municipal wastewater treatment works. Physico-chemical treatment methods, such as (Dissolved Air Flotation) OAF, gravity separation and the use of coagulants have been attempted providing a considerable reduction in organic loading; however, discharge standards are still not met. Thus, biological treatment methods are being sought after. Aerobic treatment has been attempted however, shock loads cause problems while running such a process. The objective of this study was to assess the efficiency of anaerobic digestion to degrade Vegetable Oil Effluent (VOE) as well as the efficiency of the Anaerobic Baffled Reactor (ABR). Anaerobic digestion involves the breakdown of organic matter by the action of microorganisms in the absence of oxygen, producing methane-rich biogas. The VOE was characterized, providing significant information on its chemical composition. It was found that the effluent had high sulphate content as well as a high COD content. High sulpahte content of wastewaters have known to promote growth of Sulphate Reducing Bacteria (SRB), which utilize the same energy source as Methane Producing Bacteria (MPB) and therefore compete for the same energy source. Sulphate and lipid reduction pretreatment experiments were carried out, using barium chloride and gravitational separation respectively. The results obtained, showed that the use of barium chloride to reduce sulphate content in VOE was successful, with significant sulphate reduction. The lipid reduction experiments however, did not show any significant lipid reduction. Batch tests were conducted in serum bottles to assess the extent of biodegradation of the VOE in its raw state as well as with reduced sulpahte content. Methanogenic toxicity tests on the raw and pretreated VOE provided a range of toxicity results. These assays are relatively simple and inexpensive. Gas production was monitored to determine the rate and extent of biodegradation. The efficiency of digestion was assessed by COD reduction. Results indicated potential inhibition of the methanogenic bacteria responsible for methane production by the / M