This thesis investigated the final products from the current effluent treatment system for woolscouring (wool washing) plants, namely, (i) sludge produced from the chemical flocculation of solids in the wastewater from the wash bowls, and (ii) concentrated suint (sheep sweat) produced from evaporation of the liquid phase separated from the sludge. In addition, fibrous wastes from the woolscouring process were studied. The aims of the study were to (i) investigate whether suint could be applied in a sustainable way to arable land as a potassium fertiliser, and (ii) assess the conditions under which the sludge could be composted for use as a soil conditioner to return organic matter to soil. Experiments involving suint were performed at both laboratory and glasshouse scales, while experiments involving the solid woolscour wastes were based both in the laboratory and using a small-scale (4.5 m3 total capacity) in-vessel composting unit established at a New Zealand woolscour. Decomposition was measured using net-nitrogen mineralisation and weight loss methods. Suint, the water-soluble contaminants on the fleece, contained high levels of potassium (20% on a dry weight basis) and also appreciable quantities of sulphur, sodium, and chlorine. Biological treatment before evaporation stabilised the resulting suint and improved the consistency of its composition. Suint did not affect the soil processes examined, in that it partly decomposed in soil, did not inhibit the turnover of model organic compounds, did not affect soil properties such as pH and electrical conductivity, and did not lead to increased leaching of mineral nitrogen. Suint was either neutral or positive towards plant performance when applied to soil at a rate of 100 kg potassium per hectare. Suint was therefore judged to be suitable for application to land and could be targeted to soils known to be deficient in potassium or to areas where crops with a high potassium demand are grown. Sludge, composed of dirt (soil particles, faecal matter, and skin and fibre debris) and wool grease, was highly variable in terms of its rate of decomposition, ranging from 0.8 to 27.8% of the initial total nitrogen mineralised over 30 days at 37℃. Fibrous wastes, such as opener (fibre and contaminants removed from the wool by agitation prior to scouring) and scoured wool cleaner (wool fibre and dust removed from scoured and dried wool) wastes, also showed variability in decomposition rates. Sludge decomposition was improved by as much as threefold when co-incubated with fibrous wastes. Although it was shown that the polyacrylamide and pesticide content of sludge did not inhibit its decomposition, the effect of the grease content was not fully understood. Chemical properties of woolscour sludge, such as the carbon to nitrogen ratio, suggested that sludge was a substrate of good resource quality. From a biological perspective, however, the data suggested that woolscour sludge was limited in available nutrients; sludge nitrogen was derived principally from keratin, which decomposed at a low rate resulting in the slow release of mineral nitrogen and low levels of microbial activity. Thus, sludge appeared a poor substrate for composting. However, the results from composting trials indicated that the sludge could be successfully processed after blending with a bulking agent such as sawdust. The blended material showed a 90% reduction in wool grease over 21 days of composting when the moisture content of the composting mass was kept optimal. Compost temperature exceeded 55℃ when wool fibre was added to the blend. Initial results from a case study involving the commercial composting of the entire sludge production (16 tonnes per day) from a New Zealand woolscour indicated that a saleable compost could be produced from a material that would otherwise go to landfill, and served to illustrate the commercial significance of these research results.

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Typescript (photocopy). / Digitized by Kansas Correctional Industries

The entrainment of microbes from agricultural land into overland flow during rainfall events is recognised as an important source of pathogenic microbes to surface water bodies and yet this transport process is poorly understood. In this study, a method has been developed to separate bacteria into the forms in which they have been postulated to exist in overland flow. Then Escherichia coli was used as a model organism to investigate the transported state of bacteria eroded from cowpats and their subsequent transport in overland flow. Simulated rainfall experiments were used to generate runoff direct from cowpats. Concentrations of E. coli in the runoff direct from cowpats were found to be directly proportional to the concentration in the cowpat, regardless of the age of the cowpat. It was also observed that E. coli were predominantly eroded from cowpats as individual cells. The interactions between E. coli and soil particles in overland flow were then examined in a small laboratory scale model system and showed that E. coli attached to large (>45 [mu]m) soil particles were transported significantly less than unattached cells. However, in the runoff from the model system, E. coli were found to be attached mainly to clay particles that were similar in size to the bacterial cells. Furthermore, the transport of E. coli through the model system appeared to follow the transport of a conservative chemical tracer implying that (a) the cells were being transported as a solute with the bulk of the water flow, and (b) that E. coli attached to small clay particles were as mobile in the overland flow as unattached cells. These observations imply that E. coli predominantly interact with small clay particles that are also being carried along in the overland flow. The transport of E. coli at a larger scale was then investigated using 5-metre long, 1-metre wide buffer strips operated under saturation excess conditions. In buffer strips using intact soils and existing pasture cover, E. coli removal was very poor (26 % removal) at the low flow rate of 2 L min⁻� with no removal observed at the higher flow rates of 6 and 20 L min⁻�. E. coli removal rates were increased to 41 % removal at 2 L min⁻� by cultivating the soils, with the removal rate again decreasing with increasing flow rate. E. coli in the overland flow from the buffer strips did not form into large flocs or attach to large soil particles, but were transported in small neutrally buoyant particles that remain entrained in the overland flow. Under saturation excess runoff conditions, E. coli in overland flow were not effectively removed by buffer strips as the small particles are transported either over the soil surface or, through large pores in the soil. This Thesis has shown that E. coli is transported in overland flow in small particle sizes that are difficult to trap or remove from overland flow thereby explaining the high fluxes of faecal bacteria observed in overland flow from agricultural land.

Laboratory scale microcosm studies were conducted using site specific groundwater and aquifer solids to assess the feasibility of stimulating indigenous microorganisms in-situ to biologically transform Trichloroethylene (TCE) and its lesser chlorinated daughter products dichloroethylene (DCE) and vinyl chloride (VC). Three different treatments were conducted to determine the best approach for biologically remediating TCE under site specific conditions: anaerobic reductive dechlorination, aerobic cometabolism and sequential anaerobic/aerobic stimulation. Studies were conducted in batch serum bottles containing aquifer solids, groundwater and a gas headspace. Long-term (302 days) TCE anaerobic reductive dechlorination studies compared lactate, benzoate and methanol as potential anaerobic substrates. Site characteristic sulfate concentrations in the microcosms averaged 1,297 mg/L and TCE was added to levels of 2.3 mg/L. Substrates were added at one and a half times the stoichiometric electron equivalent of sulfate. Nutrient addition and bioaugmentation were also studied. Both benzoate and lactate stimulated systems achieved complete sulfate-reduction and prolonged dechlorination of TCE to VC and ethylene. Dechlorination was initiated between 15 to 20 days following lactate utilization and sulfate-reduction in the presence of approximately 300 mg/L sulfate. Benzoate amended microcosms did not initiate dechlorination until 120 to 160 days following the complete removal of available sulfate. After 302 days of incubation lactate and benzoate amended microcosms completely transformed TCE to VC with 7 to 15% converted to ethylene. Re-additions of TCE into both systems resulted in its rapid transformation to VC. The dechlorination of VC to ethylene was very slow and appeared to be dependent on VC concentration. Hydrogen addition at 10����� and 10������ atmospheres had no effect on the transformation of VC. Rapid methanol utilization resulted in its nearly stoichiometric conversion to methane and carbon dioxide without significant sulfate-reduction or dechlorination occurring. Nutrient addition slightly enhanced dehalogenation with lactate but inhibited it with benzoate. Bioaugmentation with a TCE dechlorinating culture from a previous benzoate amended Point Mugu microcosm effectively decreased lag-times and increased overall dechlorination. Aerobic cometabolism studies evaluated methane, phenol and propane as cometabolic growth substrates. Methane and phenol amended microcosms were able to remove only 50 to 60% of the added TCE after four stimulations, while propane utilizers were unable to cometabolize any TCE. Primary substrate utilization lag-times of 4 to 5 days, 0 to 0.5 days and 40 to 45 days were observed for methane, phenol and propane, respectively. Cometabolism of VC was possible in the presence of methane. Complete removal of 210 ��g/L VC was achieved after 2 stimulations with methane under strictly aerobic conditions. Methane utilization and VC oxidation required nitrate addition, indicating that the system was nitrate limited. A sequential anaerobic/aerobic microcosm study failed to achieve methane utilization and VC transformation likely due to oxygen being utilized to re-oxidize reduced sulfate in the system. / Graduation date: 1999

More and more, modern society is incorporating the use of radioactive materials into everyday uses. And with society using more radioactive materials, the odds of it being accidentally disposed of into the solid waste stream increases. There are several radiation systems available which market themselves as being complete and "ready to go". While it is true that a person could purchase one of these systems and would have coverage of the landfill, such a system does not provide the necessary education, response and liability protection programs. Indeed, it would be feasible to foresee a scenario where installing a systems could lead to an increase in liability and employee problems. As a result, Coffin Butte Landfill worked with the author to establish a complete radiation monitoring program. This program encompasses everything from installment of the system to employee education and training. It also examined the myriad and murky depths of federal and state regulation dealing with solid and radioactive waste to help the landfill set an acceptance policy and minimize liability. This led the author to the belief that the combination of federal and state regulations imply a requirement for landfills to have a working radiation monitoring program. Future government action remains uncertain as pertaining to a requirement for landfills to maintain a radiation monitoring system. Indeed, current state regulations are out of sync with federal regulations regarding acceptable public exposures. It is hoped that, with this study's help, Coffin Butte Landfill and Oregon State University will continue with the established relationship and be prepared to respond to regulation changes. / Graduation date: 1999

Graduation date: 1995

Graduation date: 1994

Graduation date: 1995