Due to the development of intensive livestock production methods -namely, high-density confinement feeding - animal wastes traditionally looked upon as "natural" or "background" wastes, are now being subject to the same restrictions, as regards disposal, as industrial wastes. As a result waste treatment of some nature has become necessary. Such treatment methods would reduce the amount of solids requiring disposal and make the liquid portion more acceptable for disposal to water courses or for re-use. Anaerobic lagooning is one such method of waste treatment of concentrated animal wastes. An investigation on a laboratory-scale of the effects of various parameters on the anaerobic decomposition of hog waste was undertaken. Included in this study was the effect of varied detention times and temperatures on such waste characteristics as oxygen demand, solids, nutrients and gas composition and production. The final outcome of this program was to add some degree of optimization to the anaerobic waste treatment method and to develop improved design guidelines related to this specific field. All recommendations presented are based on laboratory findings. Correlation between laboratory-scale results and field-scale results was not attempted in this portion of the study. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The siting of municipal solid waste disposal facilities is often unsuccessful or delayed because of host community opposition. Physical, economic, social and political impacts of landfill and an incinerator site are identified, assessed and combined in a rational model to explain the cause of opposition. Residents' beliefs about facility impacts correspond well with the assessed physical impacts at the landfill in identifying odor, birds, traffic, water emissions and explosion risks as negative impacts and convenient disposal as a benefit. At the incinerator, common resident beliefs comprise odors, noise, traffic and air emissions as negative impacts and energy recovery as a benefit. Underlying these obvious physical impacts, however is a group of non-physical beliefs about the harm to community image, loss of control, unfairness, and property value losses in the host community. These non-physical impacts influence the attitude about the facility as strongly as the physical impacts. Finally, exposure to obvious physical impacts is shown to negatively influence the beliefs about physical and non-physical (economic, social and political) impacts. Thus, by screening the host community from obvious physical impacts (nuisances), the beliefs about community image, control, fairness and property values can be enhanced. Since negative attitude and opposition action are strongest prior to facility construction, the siting efforts need to be focused on this period. After construction, the host community adapts to the new situation. The facility impacts are combined into a model to define a criterion for acceptance. The net value of facility impacts and benefits must reach or exceed in value the narrow tolerance range at the original host community reference point to avoid significant host community opposition. Impact reduction rather than compensation is theoretically shown to be the more effective approach to fulfilling the acceptance criterion. This approach is empirically tested at typical waste facility sites. Despite higher costs for prevention and emission control methods to reduce physical and non-physical impacts, these methods are shown to be superior to mitigation and compensation in gaining community acceptance. Based on the conclusions, the policy statement on waste facility sitings recommends first, defining entitlements and rules for the siting process, establishing increasing waste reduction and separation in a waste management plan, and using participative community planning as long-term, preventive facility siting measures. Short term siting measures comprise, the negotiation of siting agreements, the use of best available technical emission controls and continued monitoring by an overview committee. The focused use of prevention and control measures to address host community concerns can substantially enhance community acceptance of municipal solid waste facilities. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Until recently, the management of milking parlour effluent has received very little attention. The wastewater produced by milking operations comprises mainly milk solids and manure and can impose environmental threats to nearby water bodies if not properly treated before disposal. In this study, three bench-scale Sequencing Batch Biological Reactors were used to treat the UBC dairy barn milking centre wastewater. The experiment was designed to investigate the treatment efficiency of the reactors under different operating temperatures and different numbers of cycles employed per unit daily flow (for the same hydraulic retention time). Parameters studied included BOD₅, COD, Total Suspended Solids, NH₃-N, N0₂-NO₃-N and dissolved oxygen uptake. It was concluded that very high and consistent treatment efficiency can be achieved by using a Sequencing Batch Biological Reactor to treat milking centre wastes. Over 90% BOD₅ removal was observed in the room temperature and 30°C reactors. Even in low operating temperatures of 3.7 and 10.5°C, over 70% BOD₅ removal was attained. Removal of the other pollutional parameters studied was similarly excellent. Uncontrolled denitrification also occured to various degrees in all three reactors. It was also concluded that within the range studied in this experiment (4 to 8 cycles per day), changing the number of cycles employed per unit daily flow did not have any significant effect on the treatment efficiency of the reactors. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Turf growers have been farming the Ladner soil in the Boundary Bay area for the last decade. At each harvest, approximately a 2cm layer from the A horizon is taken out with grass. Consequently, the cultivation layer is becoming thinner year after year and the growers are already cultivating the B horizon. The possible improvement of the B horizon structure through sewage sludge application will benefit the fanners in the area. A greenhouse experiment was conducted using a Ladner subsoil. Treatments included application rates of 0, 33, and 100 t/ha of composted sewage sludge. The effect of sludge application on the soil structural stability in relation to the destructive action of water was evaluated. Soil columns were subjected to periodic 24-hour simulated ponding events. Adding sewage sludge increased the ponding tolerance of the soil. This was reflected by statistically significant differences in satiated hydraulic conductivity ('Ks') between the sludge-amended columns and the control columns. The significant decrease of 'Ks' of the control treatment as a result of ponding was responsible for widening the gap between 'Ks' of the control columns and 'Ks' of the sludge-treated columns. The incorporation of sewage sludge slowed down the decrease of 'Ks' but could not stop it. The most plausible explanation is that the addition of sewage sludge was effective in increasing the resistance of aggregates to breakdown when subjected to ponding. Fifty days after the last ponding event, the percent stable aggregates averaged 13.7, 26.9, and 48.1% for the 0, 33, and 100 t/ha treatments respectively. In no case was a significant difference in bulk density observed between the treatments. The soil structure deterioration as a result of ponding was not reflected by the bulk density measurements. Thus, it was concluded that hydraulic conductivity and aggregate stability are better idices of soil structural deterioration than bulk density. A side investigation was carried out to illustrate trends of essential nutrient and heavy metal uptake by bermuda grass. Sludge incorporation at 33 t/ha did not seem to increase nutrient and metal uptake by bermuda grass. However N, Cd, and Zn uptake appeared to increase at 100 t/ha. / Land and Food Systems, Faculty of / Graduate

One of the problems associated with the disposal of solid wastes in landfills, particularly in high precipitation areas, is the pollution caused by the production of the often highly contaminated leachate. This study was initiated to investigate the treatability of a low-strength municipal landfill leachate using aerobic digestion followed by activated carbon polishing, so that the most cost effective treatment system could be determined. Sludge desorption and leachate toxicity assessment were also included in the study. The aerated lagoon process alone was very effective in treating the leachate to a quality that is nearly acceptable for discharge to a receiving water. Only SO₄ and Fe in the settled effluent significantly exceeded the local requlatory standards for specific discharges. Carbon adsorption greatly improved the settled effluent quality in terms of color, Fe and COD. However, the addition of this polishing process for combined treatment may not be cost effective. For an influent COD of 1,600 mg/1 and with MLVSS concentrations ranging between 360 and 560 mg/1, the settled effluent COD removal increased from 82.6% to as high as 90.1% when 9C was increased from 2 to 10 days. For the corresponding influent BOD5 of about 1,000 mg/1 and with θ[sub c] greater than 3 days, the BOD5 removal efficiencies averaged 99.1% and the settled effluent BOD5's were no greater than 10 mg/1. This indicates that the raw leachate can be almost completely biodegraded by aerobic digestion. The metal removal efficiency in aerobic treatment was greater than 95% for Fe and Mn, better than 90% for Zn and Pb, and about 80% for Al. Metals expected to be mainly or significantly removed by chemical precipitation due to pH change during treatment included Ca, Fe, Mn, Zn and Pb. Analysis of the kinetic parameters associated with the biological treatment indicated that the concentrations of pollutants, such as heavy metals, in the leachate were not great enough to cause significant inhibition of biological growth. It also showed that this leachate could very likely be added to a domestic sewage, in a high percentage, for aerobic treatment without producing adverse effects. From a treatment efficiency point of view, the optimum solids detention time was found to be 7 to 10 days for leachate BOD₅ ranging from 1,000 to 3,000 mg/1. However, since the predicted θ[sub c] for failure was 0.42 day at 22°C for a 1,000 mg/1 BOD₅ leachate, a θ[sub c] of 2 to 4 days seems possible in the field. On the other hand, the effects of winter temperature on BOD₅ removal and sludge settleability, as well as many other unknown factors on the overall biological treatment efficiency must be considered. It was, therefore, felt that a solids detention time of 5 days or more would be the more realistic approach for a full-scale treatment system, despite the fact that an economic analysis favored a shorter θ[sub c]. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown

Foam separation has been successfully developed on a 4-1 laboratory column, an 80-1 field column installation and a 6000 gal pilot plant trough type system as a novel process for detoxifying bleached kraft mill effluents. Toxic surface active materials such as resin and unsaturated fatty acids collect at the gas-liquid interface of rising air bubbles and concentrate in the foam. The highly toxic collapsed foam represents 1-2% by volume of the influent and is subsequently detoxified by biological treatment. Process parameters controlling detoxification efficiency are pH, gas-liquid interfacial area, initial toxicity level and mode of operation. The gas-liquid interfacial area and pH are of utmost importance. For a typical effluent with MST of 3-4 hr, approximately 20-2 30 m²/l of interfacial area given to an effluent at pH > 7.0 are required for detoxification. Foam separation is universally applicable and reliable for detoxifying kraft whole mill effluent. Over 80% of 205 samples from 10 Canadian mills were detoxified. A 1 gal/min, one and two stage continuous flow systems detoxified over 90% of samples at pH 8 and 1-2 hr retention time over 80 days of operation period. Study of detoxification mechanism indicated that foam fractionation accounts for 77.5% of detoxification, volatization for 5.4% and unidentified mechanisms for 17.1%. Depending on the mode of operation, up to 5% of effluent volume was discharged as foam. The foam volume could be reduced to < 2% by increasing foam retention time and enhancing internal reflux. Collapsed foam was readily detoxified by a biodisc or aerated lagoon process. In addition to detoxification, foam separation removed 20-60% of suspended solids, 66% resin acids, 12% B0D5 (10% TOC), 8% color and 80% foaming tendency. Suspended solids removal could be increased to 88% if an expensive dissolved air system were used for bubble generation. Commercially available equipment for foam generation and foam breaking was reviewed. Jet aerators and turbine systems were assessed as most suitable for commercial application. Pilot plant evaluation of this equipment indicated that reliable and consistent operation could be obtained. The results were used to establish empirical formulae for use in process scale up. During a 4 month continuous flow study, approximately 5-7 m²/l of gas-liquid interfacial area was provided to detoxify 80-100 gal/min of mill A effluent with MST of 6-10 hr. The detoxification success rate of a large number of samples increased from 50 to 86 and to 100% as the operation changed from 1 to 2 to 3 stages. The foam produced by the pilot plant was collapsed by a 12" diameter turbine at 100% efficiency all the time. Costs of foam separation were examined for a projected 3 stage foam separation process, treating 25 M gal/day of bleached kraft whole mill effluent. Capital costs for pH control, foam generation, foam breaking and foam treatment were estimated at $2.26 M. Operating costs were estimated at $2.35/ton of pulp. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. / The design of a waste handling system is closely related to the functioning of the manufacturing system that it serves. The study considered the design of a waste handling system at the factory Printpak Gravure in Industria. The system in use was considered cost inefficient, The system was examlned, operating variables were determined, A model of the system was constructed so that the effectiveness of alternative systems could be compared. The replacement system selected reduced machine downtime and resulted in a lower yearly operating cost. / Andrew Chakane 2019

<p>A computer technique for the optimization of thermal waste destruction systems for various design modes, with emphasis on satisfying the air pollution limitations is discussed. The approach considers the incineration of wastes by addition of fuels to permit the thermal destruction of waste materials which are potential pollutants. The computer optimizing package developed utilizes a modified form of a NASA chemical equilibrium program, the Pasquill-Gifford gas diffusion equation and an optimization routine. </p><p>The method employed incorporates the mathematical modeling of elementary incineration systems, with consideration of the practical aspects of the problem. The final computer design and assessment package is flexible and is developed in a way that permits upgrading and modification for realistic systems. </p> / Thesis / Master of Engineering (ME)

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