The handling and disposal of hot tarry liquid residues can be problematic in industry, in this case, a phthalic anhydride plant using naphthalene as feed stock. The residue from the plant contains an appreciable amount of phthalic anhydride which desublimates from the residue during draining, resulting in an unsafe working environment. In addition, the residue is a hot liquid that solidifies upon cooling, causing additional risks to personnel during handling and various problems associated with disposal. Research was conducted into finding a treatment method to reduce or eliminate the desublimation of phthalic anhydride from the residue and addressing the hot liquid residue, making the residue safer to handle and easy to dispose of. Laboratory experiments showed that the addition of Dicalite 4151 (a filter aid) in a concentration of 0,3 kg Dicalite 4151 per kg phthalic anhydride residue, resulted in the formation of a powdered residue. This was confirmed during plant trials where using the same concentration proved that a powdered residue could be obtained, while at the same time desublimation of the phthalic anhydride from the residue was negated by distilling the product from the residue mixture. An opportunity exists to test the use of filter aid in other residue producing industries to determine if the same results can be achieved. / Dissertation (MEng (Environmental Engineering))--University of Pretoria, 2005. / Chemical Engineering / unrestricted

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Vegetation establishment on mine wastes is ultimately limited by the edaphic properties of the wastes. This thesis examines, characterizes and interprets the physical properties of some southern British Columbia mine wastes:- to elucidate the feasibility of various reclamation procedures. Vaste areas, including both mill tailings, rock dumps and adjacent natural soils are characterized. The project primarily addresses three areas in British Columbia affected by sulfide mining activities; the Princeton area, the Highland Valley area and the Kimberley area. Waste materials examined were derived from the Similkameen, Copper Mountain, Lornex, Bethlehem and Sullivan mines. Minor examination of the now revegetated Jersey Mine tailings located near Salmo, B.C. was also included. Field work involved mapping waste materials and natural soils and then systematically sampling the various units delineated. Laboratory methods were employed to define and compare the properties of samples collected. Limited water storage capacity was found to be a major problem in waste rock dump material. Mill tailings were found to have acceptable available water storage capacities. Some mill tailings may have aeration porosity deficiencies when wet. Cation exchange capacities, while usually adequate in waste rock dump materials, are sometimes very low in mill tailings; a factor that will present serious fertility problems in revegetation. Some adjacent coarse coniferous forest soils were found to have similar properties to waste rock dump material while some adjacent grass dominated soils were found to have similar properties to the mine tailings. Waste rock dump material appears best suited to eventual revegetation by aborescent species, while mill tailings appear best suited to eventual revegetation by grass or forb species. Soil processes were found to be both active and rapid in both types of waste material. / Land and Food Systems, Faculty of / Graduate

Published in: SAMJ November 2016, Vol. 106, 1096-1102, DOI:10.7196/SAMJ.2016.v106i11.10689 / Background. Healthcare professionals (HCPs) produce various types of waste in the course of rendering healthcare services. Each classification of waste must be disposed of according to the prescribed guidelines. Incorrect disposal of waste may pose a danger to employees, patients and the environment. HCPs must have adequate knowledge of the disposal of medical waste. Objectives. To determine the knowledge and practices of HCPs with regard to medical waste disposal at a hospital in Mpumalanga Province, South Africa. Methods. A quantitative cross-sectional research approach was used. The study respondents included nurses, medical doctors, dental health staff and allied health staff. Data were collected through self-administered questionnaires and analysed using IBM SPSS version 22.0. Results. A high proportion of HCPs did not have adequate knowledge regarding the disposal of medical waste, but nevertheless disposed of medical waste appropriately. While the knowledge and practices of HCPs with regard to medical waste disposal were not associated with age, gender or years of experience, there was an association between professional category and knowledge and practices. Conclusions. Disposal of medical waste is the responsibility of all HCPs. All categories of HCPs should receive regular training to improve their knowledge regarding disposal of medical waste and to minimise the risks associated with improper waste management. This will further increase compliance with the guidelines on disposal of medical waste.

Hazardous waste management practices at ten medical institutions in Cape Town were studied and tests undertaken to determine concentrations of specific chemicals and radioactivity in liquid effluent outflows, as well as emissions from incinerators. To investigate the sewage outflow for Chemical Oxygen Demand (COD), N, pH and heavy metals, a continuous sampler was installed at two hospitals and a Medical School. Samples were analysed by atomic absorption spectrometry for As, Hg, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and Fe. Mercury levels ranged from l-70μg l⁻¹, exceeding the Environmental Target Quality of 0.04μg l⁻¹, and the South African General Effluent Standard of 20μg l⁻¹ . All other heavy metals were below General Effluent Standard Limits. In addition, a sludge sample from the Athlone Wastewater Plant was tested for Hg, realising 6mg kg⁻¹ on a dry weight basis, which was within Department of Health (DOH) Guidelines of 10 mg kg⁻¹. Samples of incinerator bottom ash analysed for heavy metal content gave Hg concentrations of 1.1-4.0mg kg⁻¹, and Zn concentrations of 5.1-11.0g kg⁻¹. Incinerator ash was also analysed for radio-activity and substantial levels of ¹²⁵I (332-650 bq kg⁻¹ ), and Ga⁶⁷ (9186bq kg⁻¹) recorded, which exceeded the South African limits of 200bq kg⁻¹. In Cape Town, hospital incinerators are old, burn large amounts of plastics and produce toxic emissions. They are all situated in residential or inner-city areas, and even though there is legislation dealing with emissions and chemical waste, these laws are not being enforced. Based on the above results, an investigation was carried out to assess attitudes to and knowledge of hazardous waste in the ten institutions. One thousand questionnaires were administered to staff, and the data from the 80% response rate statistically analysed. Results suggest that there is an urgent need for an holistic approach to toxic waste management, encompassing enforceable legislation coupled with on-going educational programmes and strong support from top management and all levels of staff.

The objectives of this study were to investigate nutrient retention, intI1 prevalence, and compost maturity rates for poultry litter co-composted with 5, 10, and 20% southern yellow pine biochar and with or without 2% wood vinegar (WV). Samples were collected at 0, 57, and 112 days to measure nitrogen, phosphorus, and potassium (N, P, K) concentrations, microbial counts, pH, moisture content, carbon to nitrogen (C:N) ratio, and intI1 abundance. Composts were aerated once a week and the temperature was also recorded once a week. There was sufficient rainfall so no additional water was added. The results showed that N and P concentrations significantly increased over time in all treatments except 20% biochar and 20% biochar + wood vinegar, while K concentrations significantly decreased. In general, composting with wood vinegar significantly decreased nutrient concentrations; however, all nutrient concentrations were much higher than typical animal manure fertilizers. Increases in biochar level resulted in significantly lower bacteria counts and significantly higher fungi counts. Compost treatments containing wood vinegar had significantly lower bacteria and fungi counts, indicating that southern yellow pine wood vinegar had a biocide effect on microorganisms, and may be not suitable for composting at that application rate. intI1 prevalence was not significantly different among treatments, which may be due to insufficient thermophilic composting. Because thermophilic temperatures were not achieved, the compost was not mature by the end of the study; therefore, compost maturity rates could not be determined.

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