Dissertations / Theses on the topic 'Windrows'

South Africa produces an average of 154 million broilers (Gallus gallus domesticus) annually, arising to an estimated 886 million kg of broiler litter. The largest population of broilers are reared in the North West province. Various applications for this largely underexploited resource have been published, including forming part of ruminant diets and direct land application. This however has several disadvantages, as it could lead to eutrophication of fresh water sources and faecal contamination of produce. Windrow composting of broiler litter has previously been studied, and found to deliver a stabilized product free of pathogenic and phytotoxic effects, therefore making it an excellent soil conditioner. This study aimed to characterize the microbial community present during the windrow composting of broiler litter. Four different formulations of substrate were tested; these being broiler litter (Windrow 1), Windrow 1 with previously composted material (Windrow 2), Windrow 2 amended with woodchips (Windrow 3) and Windrow 3 with an additional 12.5% (w/w) zeolite (Windrow 4). Broiler litter used in this experiment had a C:N ration of 10.3:1, whilst the blue gum woodchips added as an amendment had a C:N ratio of 172:1. Windrow and environmental temperatures were monitored on a regular basis. Windrow 1 largely mimicked environmental temperature, and could not sustain a true thermophilic phase during the experimental period. Windrow 2 did achieve a short lived thermophilic phase during the first few days of the composting process, however could not sustain its temperature over the whole period. In contrast Windrows 3 and 4 sustained temperature above 40°C for the largest part of the experimental period, regardless of environmental temperature. No significant difference (p < 0.05) could be observed between average moisture levels in the 4 windrows. Internal moisture profiles were however found to differ significantly, especially on the surface of the windrows. Moisture was also lost faster in Windrows 1 and 2 compared to Windrows 3 and 4. Chemical analysis showed differences between the four windrows constructed. A higher amount of nitrogen was lost in Windrows 1 and 2, mostly due to a sub-optimal initial C:N ratio in these windrows. Windrow 2 contained the highest values for plant nutrients P, Mg, Ca, Mn and Cu. Microbial population dynamics were observed using PCR-DGGE of samples collected throughout the composting of various treatments. Various commercial DNA extraction kits where tested in a previous study for their ability to remove PCR inhibitory substances, such as humic acids. The Machery-Nagel Soil DNA isolation kit was used as it gave amplifiable DNA from all samples. Samples were amplified using a nested PCR approach primer sets 27f-1492r \ 341f(GC)-907r and EF3-EF4 \ EF4(GC)-fung5 (where “GC” indicates a GC-rich clamp) for prokaryotic and eukaryotic species respectively. The PCR products were analyzed by agarose gel electrophoresis, and equal amounts of product were subjected to denaturing gradient gel electrophoresis (DGGE). Bands obtained from these polyacrylamide gels where then re-amplified using the same secondary primer sets (without the GC-clamp), and sequenced. A total of 454 prokaryotic bands in 55 distinct rf-positions were observed. Seven distinct rf-positions were observed in eukaryotic DGGE profiles. Prokaryotic profiles were aligned and the microbial diversity was analyzed by means of Ward’s clustering algorithm and the dice coefficient of similarity, as well as Simpson’s reciprocal, Shannon-Weaver and Species richness indices. Canonical correspondence analysis (CCA) was also performed on both the banding patterns as well as the bands present, together with the physico-chemical results obtained. Several bands were successfully identified as being influenced by physico-chemical parameters. Temperature, C:N ratio, ash, and moisture showed a correlation on CCA bi-plots. Sixteen bands were sequence identified. These sequences were compared to two different databases. The 16S rRNA database for Bacteria and Archaea gave identities to genus level, however maximum identity scores were low. Of the 16 sequences, 12 sequences were identified as uncultured bacteria when compared to the nucleotide collection database. In comparing the sequences with sequences collected in the nucleotide collection database, 12 were either first described in composts and soils, or animal manures. Results indicated mostly members of the genus Bacillus and Paenibacillus. The addition of a carbon source greatly affected the microbial metabolism, resulting in a thermophilic phase being achieved in amended windrows. As no thermophilic phase was observed in windrows that were not amended with woodchips, it could be concluded that the use of a carbon source is irremissible when composting broiler litter. A zeolite amendment is also strongly advised, as this further increased temperatures within the windrow.<br>Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.

Open environmental flow is a multivariable, non-linear, unsteady flow system which presents a challenge to those who engage in understanding, monitoring and predicting it. This thesis sets the foundation for future work and suggests best practice techniques for the numerical simulation of such flow taking into account important phenomena and assumptions. These factors include boundary conditions, location and size of the control volume and level of resolution. The use of more comprehensive techniques such as Computational Fluid Dynamics proposed herein, compared to those currently employed by regulating agencies, may take into account local meteorology and topography in order to provide a more accurate estimation of pollutant dispersion by site specific investigation. Wind flow and effluent pollutant dispersion was examined for idealised flat and hilly terrains where topography was seen to largely influence wind flow phenomena and later pollution dispersion. These simulations assumed an incompressible, steady state air, flowing isothermally over vertical and horizontal line sources positioned near ground and upstream one or two sinusoidal axisymmetric hills in a single row. Results suggest that the wind speed increases on the upslopes of hills. Then the flow recirculates strongly on the downslope of a hill or the lee of any bluff body such as a house or trees. Furthermore, a case study has been carried out for two locations in the UK, employing techniques and conclusions from idealised simulations. A proposed compost site, located in South Yorkshire was examined, where the local topography is characterised by sloping terrain and large woods; such factors were seen to influence wind flow and dispersion of particles and concentration. Results from the compost site were compared to results from a contrasting flat-land green waste processing plant in West Midlands. All simulations assumed an incompressible, steady state wind over three presumed compost piles. For all cases studied herein, Lagrangian particle tracking was employed to show particle dispersion from the alleged compost piles and calculate average travel distances for trapped particles and entrapment probability. Particle tracking results show that particulate pollutants can get trapped at recirculation areas, in-between trees and village houses. Mass-less particles travel further before hitting an obstacle when released in low winds and their orbit is largely affected by topography when released from near ground sources. In addition, Species Transport was enabled to examine the effect of topographical and meteorological conditions to pollutant concentrations. Species transport results for the examined composting sites show an increased number of particles trapped in-between rows of compost piles and a decrease of emissions to near background values within 200m from the source. However, it was evident that flat land favours the spread of species which can reach nearby houses at larger percentages.

In-house windrow composting of broiler litter has been studied to reduce microbial populations between flocks. Published time-temperature goals are used to determine the success of the composting process for microbial reductions. Spatial and temporal density of temperature measurement can influence the ability to determine what portion of a windrow pile has achieved specified time-temperature goals. Based on this motivation, an investigation of the heating profile in windrowed litter and the identification of the effects of spatial and temporal sampling densities on the prediction of the heating profile in windrowed broiler litter were executed. Likewise, an investigation of the effects of moisture content on heat generation during composting of broiler litter was conducted. Ultimately, the research projects were designed with the goal of determining the efficacy of windrow composting as a treatment method for reducing microbial populations in broiler litter and to produce recommendations for the implementation of future windrow temperature monitoring investigations. While past investigations have reported success of windrow composting for microbial population reductions, a lack of intense spatial and temporal temperature monitoring has likely mis-represented the pile heating profile and resultant effects on microbial populations.

Bioaerosol emissions from open windrow composting facilities are becoming of increasing concern due to the negative health effects associated with bioaerosols, and the fact that emissions from open windrow facilities are not contained. Current bioaerosol monitoring techniques provide only a snapshot of bioaerosol concentrations spatially and temporally, whereas dispersion models have the potential to offer a more continual overview of bioaerosol levels, alongside existing sampling methods. However, dispersion models have not been successful at accurately predicting bioaerosol concentrations from open windrow composting facilities, generally under predicting concentrations by at least one order of magnitude. This is predominantly due to a lack of knowledge and data surrounding the complex nature of bioaerosol release and transportation, particularly when the compost is agitated. This study aimed to improve the reliability in the outputs of the ADMS dispersion model, specifically in the open windrow composting scenario, by performing several model tests alongside selected input parameter quantification improvements. This involved completing a sensitivity analysis, and a model calibration and validation specific to this scenario for the first time. Results from the sensitivity analysis showed that the use of wet and dry deposition modules is significant, and the majority of model inputs associated with the representation of the source of the emission are sensitive. These findings helped select the model input parameters for quantification improvements. Novel preliminary measurements of bioaerosol temperature, velocity and concentration at the source of composting agitation activities were completed. These values provided more accurate model inputs. Collectively, these results allowed the model to be successfully calibrated, and consequently, validated for the first time for this specific scenario, resulting in model outputs corresponding to within one order of magnitude to measured data. This has helped to generate an initial set of modelling recommendations, allowing modellers to use the ADMS dispersion model in a reliable manner, when applied to the open windrow composting scenario. Eventually, these improved model outputs may be used to predict bioaerosol exposure levels at sensitive receptors, particularly in conditions where current monitoring methods are not feasible.

Thesis (Ph. D.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xvii, 233 p.; also includes graphics (some col.). Includes bibliographical references (p. 185-192). Available online via OhioLINK's ETD Center

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits carcass composing to only private land. Therefore, the purpose of this work was to determine the efficacy of killing pathogens by composting using bench top composting models. Ultimately, our goal is to provide “proof of concept” data in order to gain permission for a full-scale carcass compost pile to be set up at Cal Poly San Luis Obispo. Using thermo tolerant Salmonella senftenberg as an indicator organism, we performed bench top trials of traditional and carcass compost in the lab. Samples were inoculated with S. senftenberg and kept at 55°C for 15 days in accordance with the California EPA and Test Method for the Examination of Composting and Compost (TMECC). Samples were then plated and processed for multiple tube analysis and most probable number. Samples were also partitioned for a viability qPCR with propidium monoazide (PMA) to compare to the classic techniques. Using these methods we were then able to track and produce thermal death time data for S. senftenberg in both traditional and carcass compost. By comparing the types of compost, we were able to determine that the composting method presented by the California EPA and the TMECC produces safe, pathogen free compost, even when inoculated carcasses were introduced. However, even with removal of dead cells by PMA, qPCR did not outperform the classical microbiological methods for as tracking pathogen killing.

In July 2001 in the region of Kastri Platanistou in Evia, Greece a wind power park of 5 MWinstalled capacity, began its commercial power production under the supervision of the companyMELTEMI-KASTRI.During these 6 years of its operation significantly reduced incomes were recorded compared to theinitial study financial analysis. Apparently loss of income occurred due to technical failures;nevertheless more costly might have been a suboptimal primary energy analysis.Herein, the collected data from the nacelle of the wind turbines and a net installed in the site wereanalyzed in order to estimate the site’s wind energy potential and gain knowledge of the parametersthat so far affected the overall production. The analysis was performed through Windrose andWAsP software.Aiming to maximize the exploitation of the site’s wind energy potential, several wind turbinemodels in different installation points were examined. Further analysis of the exported resultsindicated the optimum scenario, finally suggested to the owners of the wind farm.

Made available in DSpace on 2015-03-26T13:28:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4583937 bytes, checksum: 1a468cd29ffe0a374735416f7a0a678b (MD5) Previous issue date: 2012-01-20<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The reutilization of poultry litter is an alternative way that producers found to deal with the high cost of the materials used to cover the floor on their farms. To reuse this poultry litter, it has to suffer changes on its physical, chemical and biological characteristics, perhaps compromising the process of chicken growth. To make it safe, is required that the producer treats this material; for example reducing the biological load and promoting ammonia to be released. With this present work, as the main focus, it s pursued the evaluation of the composed material as a methodology for treating the poultry litter beyond its reutilization. All the experiments were conducted at Laboratório de Engenharia Sanitária e Ambiental , regarding to the Civil Engineering Department, at Universidade Federal de Viçosa. It was made in four experiments. Experiment 1 was done by assembling a windrow of poultry litter, aerated, with fans cycles. During experiment 2, was compared the efficiency of different methods of composed materials applied at the treatment of the poultry litter in order to reutilize it, using one windrow poultry litter and two overturning cells; was also evaluated its influence on the substratum maker of the poultry litter on this process. On experiment 3, was evaluated the decay of nitrogen, on its normal and ammoniac forms, still using the windrow system. On experiment 4, was possible to determine the amount of volatile ammonia from the process of composed and the treated poultry litter. During the processes, temperature, water contamination, pH, solid contamination, organic carbon contamination, nitrogen and fecal contamination organisms were submitted to tests. The results show that, long cycles of aeration at the windrow system, make it harder to get the composed material done, because it make the material dry faster; the overturning cells show better efficiency reducing the biological load and releasing ammonia when it s compared to the windrow system. Summing up, the composed material obtained from the aerated windrow system, presents good efficiency in order to reduce the total and ammoniac nitrogen from the poultry litter.<br>A reutilização da cama de frango é uma alternativa encontrada pelos produtores como solução ao alto custo de aquisição de material para cobertura do piso. No reuso, a cama de frango sofre alterações em suas características físicas, químicas e biológicas, podendo comprometer o processo de criação de frangos. Para que o reuso seja seguro, é necessário que se faça um tratamento, a fim melhorar as características do resíduo, como reduzir a carga biológica e promover a liberação de amônia. Com a realização deste trabalho objetivou-se avaliar a compostagem como metodologia para o tratamento da cama de frango visando sua reutilização. Os experimentos foram conduzidos no Laboratório de Engenharia Sanitária e Ambiental, do Departamento de Engenharia Civil, da Universidade Federal de Viçosa. Foram montados quatro experimentos. O Experimento 1 consistiu na montagem de uma leira estática de cama de frango, aerada com diferentes ciclos de funcionamento do ventilador. Durante o Experimento 2, comparou-se a eficiência de diferentes métodos de compostagem aplicados no tratamento da cama de frango visando sua reutilização, com a montagem de 1 leira estática aerada e 2 pilhas por reviramento, avaliou-se também a influência do substrato formador da cama de frango no processo. No Experimento 3, avaliou-se o decaimento do nitrogênio, em sua forma total e amoniacal, da cama de frango submetida ao processo de compostagem por leira aerada estática. No Experimento 4, determinou-se a quantidade de amônia volatilizada da cama de frango durante o processo de compostagem e da cama tratada. Durante os tratamentos, foram realizadas análises de temperatura, teor de água, pH, teor de sólidos, teor de carbono orgânico total, nitrogênio e de organismos indicadores de contaminação fecal. Os resultados mostraram que ciclos de aeração muito prolongados realizados em leiras estáticas aeradas dificultam a realização da compostagem, pois ressecam rapidamente o material; a compostagem realizada em pilhas reviradas apresenta melhor eficiência na redução da carga biológica e na promoção da liberação de amônia se comparada ao método de leiras estáticas aeradas; a compostagem realizada em leiras estáticas aeradas apresenta boa eficiência na redução de nitrogênio total e amoniacal da cama de frango.

碩士<br>國立屏東科技大學<br>動物科學與畜產系所<br>105<br>Several methods have shown varying effectiveness in reducing pathogens on the farm, one of which is in-house windrow composting. In-house windrowing of broiler litter between flocks has been suggested as an effective method to reduce pathogens and improve the quality of the house environment in which new chicks are placed. This technique uses heat released by microorganisms during the degradation of organic material to kill pathogenic bacteria. The objectives of this study were to evaluate the effect of in-house windrow composting process on the pathogenic microbes levels of broiler litter. The broiler litter from previous flock was used as composting materials. Three trials were carried out: Trial 1 was divided into a control and six treatment groups. The broiler litter was paved on the floor with 5 cm of thickness, without adding water and turning as a control. The treatment groups was a 3 × 2 factorial design with three level of moisture content (35 ± 2%, 40 ± 2% and 45 ± 2%) and two difference depth (55, 75 cm) of compost pile. All experiment groups were windrow composted in-house for 11 days, and were turned on the 4th and 8th day. Trial 2 treatment groups was a 2 × 2 factorial design with two kinds of moisture content (30 ± 2%, 37 ± 2%) and difference depth (40, 55 cm) of compost piles. All experiment groups were windrow composted in-house for 12 days, and were turned on the 5th and 8th day. Trial 3 treatment groups was a 2 × 2 factorial design with two kinds of moisture content (32 ± 2%, 42 ± 2%) and two turning frequency (twice, three times) of compost piles. All the experiment groups were windrow composted in-house for 9 days at a depth of 55 cm. The results showed that the core and surface temperature of the composting pile were above the sterilize temperature (55℃) for over three days for all of the treatment groups. The population of total viable aerobic count, coliforms, Staphylococcus aureus, Salmonella, Campylobacter jejuni and Clostridium in the broiler litter significantly declined during the composting processes (P < 0.05). In conclusion, the basic requirement for sterilization of broiler litter (> 55℃ for 3 days) can be reached by in-house windrow composting. The population of the pathogenic microbes in the broiler litter significantly declined during after the composting process. The broiler litter after the in-house windrow composting process can be reused to reduce the consumption of fresh bedding material and reduced the yield of litter manure in broiler farm, and ameliorate the pollution of broiler litter.

碩士<br>國立交通大學<br>環境工程系所<br>97<br>Food waste and green waste are the most organic sources in municipal solid wastes, which can be reused as soil amendments or fertilizer for land application. However, incinerating food waste is problematic due to its high moisture and salt contents; if treated by landfilling, the unpleasant odors and copious leachate generated by kitchen waste is another area of concern. Therefore, composting is often presented as a low-technology and low-investment process to convert organic solid wastes to a soil amendment known as compost. In this study the effect of co-composting of green waste and food waste with bulking agent at various climatic conditions controlled watering and seeding. Condition were investigated i.e. Run 1 is 5% initial sewage sludge and no watering；Run 2 is initial 0% sewage sludge and addition of 1% SS every period/no watering；Run 3 is initial 0% sewage sludge and addition of 1% SS every period/watering；Run 4-1 to 4-3 were performing Run 1, Run 2, and Run 3 at the same time and properties, respectively Each windrow composting reached 55oC within 2 days and maintained above 55oC over 8 days. The end pH of every windrow was about 8. The compost obtained in all the runs as Class B biosolid. Turning of windrow increased the temperature increased in most instance. The germination indices of Runs 4-1 to 4-3 were 171%, 183%, and 154%, respectively. According to the heavy metal and germination tests, the composting end product showed no phytotoxicity to plant growth. The windrow composting with controlled seeding and watering (Run 4-3) showed the best result.

碩士<br>國立高雄第一科技大學<br>環境與安全衛生工程研究所<br>100<br>Yard wastes include tree limbs, leaves and grass clippings in yard or park. Each year about 1600~2400 tons of tree limbs were cleared and conveyed, and more than 90 percent were sent to the incinerators in Kaohsiung City from 2007 to 2011. It is not only save money but also recycled yard wastes if composting instead of incineration. Most of the studies on composting are food wastes, manure, agricultural wastes, or two of them to co-composting. It is uncommon for composting, base on plant wastes and large scale. Pile A and pile B is 5 and 9 tons respectively, were composted by yard wastes and yard wastes compost product, sawdust and soybean residues for bulking agent. During the 13 weeks for windrow composting, study the changes of physical, chemical and biological properties and find an indicator which is suitable and simple for estimate the maturity of yard wastes composting. Then, it is advantageous to popularize the yard waste windrow composting in campus and community. Results showed that：There are physical indicators to estimate whether the composting mature or not：Temperature in the center of composting did not rise after turned, original shape of leaves is disintegrated and the appearance of composting changes to dark brown. In the chemical indicators：C/N, electrical conductivity, organic matter and water soluble organic carbons are tending steady after 30 days. However, pH and germination rate are not suitable for the yard waste as maturity indicator. When mix composting with soil to plant Brassica chinensis, it is maturity on condition that germination rate is above 80% and no weeds. Compare with the required time that chemical indicators become stable, color change from paperchromatography is conformable. Paperchromatography is a simple maturity indicator for the yard waste composting.

The land application of poultry litter as a fertilizer is a common practice due to the low cost and high availability of poultry litter in some regions. However, land application can create concerns related to runoff water quality and odor. An experiment was conducted to determine the effectiveness of in-house windrow composting (IWC) of poultry litter prior to land application in terms of bacteria, odors and nutrients compared to untreated (fresh) litter. In the second part of the research, the objective was to quantify the number and distribution within poultry houses of selected water quality indicator bacteria in litter. Comparison of fresh and IWC litter showed that Escherichia coli (E. coli) was present in very low concentrations on day 1 in fresh litter (20 cfu/g) and IWC litter (55 cfu/g), but the levels were undetectable in both litter types on day 9 in Trial 1. In Trial 2, E. coli levels were undetectable in IWC litter before and after the IWC process. Similarly, fresh litter had undetectable E. coli levels on day 1, but 185 cfu/g on day 10. Additionally, nutrient analysis and moisture content results showed no significant differences between fresh and IWC litter. To evaluate odor differences between fresh and IWC litter, volatile gases were collected onto sorbent tubes and into Tedlar bags from wind tunnel flux chambers placed directly on litter piles prior to land application. The concentrations of 13 compounds commonly associated with animal manure were then determined by GC/MS. Analysis of volatile gas samples resulted in significant changes of various individual odorants, while olfactometry analysis of Tedlar bag air samples resulted in reduced detection threshold values for IWC litter compared to the fresh litter. These results indicate the possible mitigating effects IWC may have on odors associated with litter. In the survey of bacterial distribution within poultry houses, litter counts varied greatly within house sections and between farms. Regression analysis revealed that bacterial counts and litter moisture content are significantly related, thus explaining much of the variation in litter bacterial counts within a house. These results indicate that IWC could be a useful best management practice to reduce E. coli levels and odor associated with poultry litter prior to land application, but factors such as moisture content, initial bacteria concentrations, and windrow size all affect the level of bacteria and odor reduction.

Gangrenous dermatitis (GD) has become a major health problem among broiler flocks in the United States, resulting in high mortality, carcass condemnations, and trimmed parts. There are large economic losses due to GD. Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus are the etiologic agents associated with GD. Gangrenous dermatitis has been associated with birds that have a compromised immune system. It is known that the gastrointestinal (GI) tract plays a crucial role in animal health and performance. The development of a healthy normal microflora in the GI tract benefits the host by improved resistance to pathogens. Our hypothesis is the application of commercial disinfectants, probiotics, vitamins, acidifiers, and windrowing technologies will reduce Clostridium levels in poultry operations. The objective of the first study was to administer probiotics to commercial broilers on three farms periodically throughout the grow-out cycle to conclude if bird health and performance was improved. The objective of the second study was to use commercial disinfectants, vitamins, acidifiers, and windrowing technologies on three farms in multiple houses and determine their effects on broiler production parameters. During grow-out, standard production practices were followed in all experiments and standard production parameters were measured. On all three farms in this study, the probiotic-treated houses had no mortality due to GD and an increase (P </= 0.05) in body weight gain was observed unlike their respective control houses. These experiments indicate that the application of probiotic in this field trial significantly altered the onset of GD by providing the birds with normal GI flora that contributed to their overall health during a commercial field study. When evaluating the different products and field technologies to control GD, our laboratory observed that treatment houses that were windrowed and received added vitamins did break with GD. Houses that were treated with peroxymonosulfates and monoglyceride, peroxymonosulfates, or glutaraldehyde litter disinfectants; acidifiers or vitamins had higher gross and net pounds weight gain at processing than their respective control houses. In conclusion, the significance of this work was to determine if products and technologies can be used by growers in commercial broiler houses to eliminate disease.

Waste minimisation is implemented worldwide and has become an urgent priority in South Africa as evidenced in the promulgated National Environmental Management Waste Act (2008). The most common waste disposal method in South Africa is by landfill, which is unacceptable. Local municipalities have made little progress towards waste minimisation. The aim of this study was to present a solution to waste minimisation for the City of Tshwane Metropolitan Municipality (CTMM) by determining the feasibility of establishing composting facilities on landfill sites. One third of all municipal waste consists of green waste, which is compostable and can be converted on landfill sites. Nine municipal landfill sites were screened. The four most feasible sites were evaluated further by applying identified parameters that address physical, social and operational requirements. It is a possible to establish composting facilities on all four sites investigated, with Hatherley ranking as the most suited. The findings of this study clearly provided the basic parameters and requirements for constructing a composting facility and practical procedures applicable within a South African context. The evaluation method used can be applied as a model to evaluate similar studies in other municipalities to aid them in the decision-making process for waste minimisation.<br>Environmental Management<br>M.A. (Environmental Management)

Aqueous ammonia treatment of organic material to increase enzymatic digestibility is a growing area of research for animal fodder and biofuel production. The application of this treatment in the municipal composting process has not previously been investigated. Litterbags were used to investigate the effects of an aqueous ammonia treatment prior to composting on source-separated organic waste. The treatment consisted of soaking organic material in aqueous ammonia prior to introducing the material back into the composting process. Dry mass, ash content, ash-free dry mass, and water-solubility were measured. Three experiments were performed: one in the laboratory, one in an in-vessel system, and one in windrows. The aqueous ammonia treatment removed more dry mass compared to controls; however, the results indicate that the majority of the loss occurred during the soak. This treatment may be of interest for compost facilities if the leachate produced can be used in an economically beneficial way.<br>Ontario Centres of Excellence