Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 127-136). / x, 136 leaves, bound ill. 29 cm

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.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 80)

Thesis (M.S.)--Bowling Green State University, 2007. / Document formatted into pages; contains vii, 46 p. : ill., 1 map. Includes bibliographical references.

Efficient treatment of waste materials from agricultural operations is a problem in most of the countries of the world. This is particularly true where livestock are being reared in large high-production confinement housing systems. There are several treatment systems available to handle the wastes from this type of operation. These systems are described with particular emphasis on thermophilic fermentation. Thermophilic treatment of wastes offers several advantages over the other types of waste treatment systems. The thermophilic system at the University of British Columbia differs from most other high-temperature systems in that no external heat source is provided. Experiments were carried out which show that the heat necessary to maintain the temperature in the thermophilic range comes solely from microbial activity. The actions of agitation and aeration do not provide any input of heat into the fermenter. The foam which forms on the top of the liquid during a fermentation was shown to be a good insulator. Feeding trials conducted with the liquid product from thermophilic fermentation demonstrated that this liquid can be substituted for water in the diet of pigs older than twenty-eight days of age with no harmful effects. It is possible that pigs older than fifty-six days of age will be able to utilize the nutrients in the liquid more efficiently and increase their rate of gain without increasing the amount of feed consumed. Experiments with larger sized fermenters resulted in a commercial design for a thermophilic waste treatment system with a total capacity of six thousand gallons. Finally, preliminary trials utilizing lignocellulose as a substrate for thermophilic bacteria indicated that these bateria are able to utilize cellulose as a nutrient source. / Land and Food Systems, Faculty of / Graduate

The annual national production of peanut hulls averages about two hundred million pounds. These hulls are generally disposed of as fuel in the plante processing the nuts or discarded as waste material. Similar cellulosic wastes have been profitably utilized in the past as activated ohars. It was the purpose of this work to determine the conditions by which peanut hulls could be converted to liquid adsorbent chars. / Master of Science

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on Jan. 7, 2010. Major professor: Dr. Sean Hurley. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Agribusiness." "December 2009." Includes bibliographical references (p. 75-77).

In South Africa, sustainable development is set in the context of two separate economies. The second of these economies consists of the rural population and is characterised by poverty and stagnant development. Sustainable development is an increasingly topical concept which highlights the need for development to proceed in a manner that does not deplete natural resources. In addition to narrowing the gaps between the various classes (layers) in an economy, the key ‘ingredients’ of sustainable economic development include “natural resource management, food, water, and energy access, provision and security” (Blignaut, 2009: cited in Blignaut and van der Elst, 2009: 14). A biodigester is a potential solution to some of the difficulties faced by remote rural populations. Biodigester systems are submerged tanks capable of producing a nutrient rich fertiliser and combustible gas when consistently fed with organic matter and water. A biodigester may be one simple answer to the key ingredient needs of sustainable development – reducing the depletion of natural resources, providing clean burning energy for cooking and fertiliser for growing food. The potential is clear for biodigesters to aid in the process of sustainable development. The question to be analysed is whether this technology would be financially and economically feasible for installation and use in rural households. This thesis focuses on a typically remote and rural community in KwaZulu-Natal, South Africa, in order to assess the potential feasibility of a biodigester system. The appraisal takes the form of a Cost Benefit Analysis (CBA) and aims to establish whether or not this technology is financially feasible for individual rural households and/or economically beneficial to society. / Thesis (M.Com.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Mar. 19, 2009). Vita. Includes bibliographical references.