Ever since 1976, livestock farmers in Fiji have been intrigued about biogas digesters as an animal waste management measure, but the concept has never evolved into one that is sustainable. Renewed interest came in 1997 after a better Chinese Modified Dome (CMD) design was established, with this came government funding, however by 2002, some failure was also observed. This study set out to investigate the reasons why biogas digesters have never been established as a sustainable concept, its effectiveness as an animal waste management tool and what changes if any, can be made to try and influence the further development of the concept in Fiji. In order to achieve the objectives, which were simply obtaining the answers to the questions presented above, several different approaches had to be followed. This study was the first on biogas digesters in Fiji and it was unique in the sense that the major component dealt with the social aspects of farmers in relation to their biogas digesters. Basically the study was carried out in two parts - desktop studies and field studies. Desktop studies were done to better understand the situation while the field studies included semi-structured interviews with the farmers as well as the collection of biophysical data. Twelve outcomes are presented in chapter 7 of this paper. Two in particular are the improvement of construction and maintenance, which can only come about through training. The research questions are also answered in chapter 7, with recommendations put forward on possible directions to take in terms of trying to influence the development of the concept in Fiji / Master of Science (Hons)

The most cost effective treatment scheme for effluent from Midfield Meats, an abattoir in Warrnambool, Australia, was evaluated via a series of laboratory and commercial scale experiments. Effectiveness was measured in terms of suspended solids (SS) and biological oxygen demand (BOD) reduction. Economic assessment was based on predicted reduction in trade waste charges versus infrastructure and running costs. From the range of potential treatment technologies, those deemed most appropriate for trialling included pre-screening, sedimentation, coagulation and flocculation treatment and dissolved air floatation (DAF). Prior to evaluation of treatment types, flow, loads and contaminant characterisation of the waste streams was conducted to aid in selection of treatment type and capacity. Prescreening was found to be the most cost effective, followed by sedimentation, coagulation and flocculation treatment and finally DAF. The most economical treatment scheme that satisfied the requirements of Midfield Meats included a combination of prescreening and sedimentation. DAF and coagulation and flocculation treatment satisfactorily treated the wastewater, however were not cost effective under the current trade waste agreement.

Thesis (Ph. D.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 134 pages. Includes vita. Includes bibliographical references.

published_or_final_version / Botany / Master / Master of Philosophy

Thesis (M.S.)--Virginia Polytechnic Institute, 1953. / Vita. Includes bibliographical references (leaves ix-xii). Also available via the Internet.

Thesis (M. Phil.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 191-199).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 75 p. : ill. Includes abstract. Includes bibliographical references (p. 50-51).

Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-16Bitstream added on 2014-06-13T18:52:23Z : No. of bitstreams: 1 morales_mm_me_botfca.pdf: 1349350 bytes, checksum: ac263a80451de053fe1de89f84f2d4cd (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / O Brasil apresenta grandes potencialidades na produção de alimentos, porém as formas empregadas para atendimento desta demanda têm levado ao aumento da geração de resíduos, fato que justifica o estudo de práticas de reciclagem, tais como a compostagem e a biodigestão anaeróbia desses materiais, pois, além da agregação de valor devido à transformação de resíduos potencialmente poluidores em adubo orgânico e geração de energia (biogás) ainda contribui para um saneamento eficaz. No desenvolvimento deste trabalho foi realizada a caracterização dos resíduos produzidos no sistema de abate de bovinos em dois ensaios: avaliação dos resíduos sólidos (conteúdo ruminal) e caracterização dos resíduos líquidos (água residuária). No primeiro ensaio, avaliação dos resíduos sólidos, foi realizada a compostagem, durante a qual monitorou-se diariamente a temperatura das leiras confeccionadas com o resíduo de abatedouro de bovinos. Foram avaliadas quatro leiras, divididas em dois ciclos: verão e outono. Para tanto, foram avaliados os teores de sólidos totais (ST) e de sólidos voláteis (SV), carbono orgânico (C) e quantificação dos teores nitrogênio (N), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg), cobre (Cu), ferro (Fe), manganês (Mn), zinco (Zn) e sódio (Na). Com os resíduos sólidos in natura previamente secos, foram determinados o poder calorífico superior com agregação de sebo, também produzido no processo nas concentrações de 0%, 10%, 20%, 30% e 40%. No segundo ensaio, caracterização dos resíduos líquidos, realizaram-se coletas e análise de amostras compostas de oito pontos do processo de tratamento de resíduos do abatedouro: antes do flotador, depois do flotador, antes da peneira, depois da peneira, efluente do biodigestor 1, efluente do biodigestor 2, afluente das lagoas de polimento e efluentes das lagoas de polimento. / Brazil has feed production high potential, but the way used to attend its demand had led to an increasing of generated residues. This fact justifies the recycling practices study like composting and anaerobic biodigestion. More over value aggregation due the residues potentially pollutants transformation to organic fertilizers and energy (biogas) still contributes to an efficient sanitation.`During the experiment the bovine slaughter residues characterization was done in two experiments: solid residues evaluation (ruminal content) and liquid residues characterization (residual water). At first experiment a composting was done using solid residues from cattle slaughter, which the pile temperature was checked daily. Four piles were analyzed, divided in two cycles: summer and autumn. Was analyzed Total Solids (TS) Volatile Solids (VS), Organic Carbon (C), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Cupper (Cu), Iron (Fe) Manganese (Mn), Zinc (Zn), and Sodium (Na). With in natura residues priory dried, superior calorific power was determined adding fat also produced in the slaughtering process, at 0%, 10%, 20%, 30% and 40% concentrations. The second experiment was done collecting eight small samples per sample at the residue treatment process: before floater, after floater, before sieve, after sieve, biodigestor effluent 1, biodigestor effluent 2, polishing pond affluent, and polishing pond effluent. TS, VS, pH, Chemical Oxygen Demand, (COD) Biochemical Oxygen Demand (BOD), N, P, K, Ca, Mg, Co, Fe, Cu, Zn, Mn elements quantification plus affluent and polish pond effluent Na and Ni content. Viable helminth eggs, Salmonella sp., total and fecal coliform were analyzed in the polish pond affluent and effluent. About the autumn compost piles, they had 10% more volume reduction than the summer ones. The average temperatures were 40ºC during summer and 33ºC during autumn.

A microbiological and economic study of methane production from dairy cattle waste was performed. The profit potential of producing methane and other vendable products from dairy cattle wastes was studied using a computerized cost model. The unit gas cost ($/cu. ft. methane) was determined for refractory volatile solids (VS) concentrations between 52% and 28% (W/W). Reaction rate constants (RKO) between 5.92 x 109 and 1.24 x 1011 were used. Retention time (RT) was varied between 1 and 10 days. Total solids (TS) concentration was varied between 8% and 14%. Analyses were performed with and without a fertilizer plant option for upgrading digester effluent solids. Unit gas cost (UGC) decreased as RKO increased and as the refractory VS concentration decreased when determined without the fertilizer option. UGC decreased at short retention times as RKO increased when the fertilizer option was included. The unit gas costs were always above $8.00 per M. cu. ft. CH4 without a fertilizer plant, and were consistently lower than the current intrastate market price of $3.18 per M. cu. ft. CH4 when a fertilizer plant was incorporated into the system. Microbiological studies were conducted using a multistage multistream digester. The design consisted of a 1,700 liter central digester with a working volume of 1,200 liters and 10, 50 liter satellite digesters with a working volume of 40 liters each. The digester design allowed for the automatic addition of substrate to the central digester once per hour and three times per hour to the satellites. The digester was operated at 55┬░C and 10% TS with a 6 day RT in the central digester and 2 days RT in the satellites. Manure from a commercial dairy was utilized for substrate. Methane production was directly related to the type of cattle feed ration. It ranged between 1.27 and 0.3 liters CH4 per liter of reactor fluid per day at a 6 day RT. Alkalinity, volatile fatty acids (VFA) and ammonia concentrations were related to methane production. VFA concentrations were lower and methane production slightly higher in the satellite digesters. Analysis of the digester effluent for fertilizer value was investigated by drying for 10 days on a as and drying bed at an initial depth of 10 cm. Total nitrogen, phosphorous (as P2O5) and potassium (as K2O) concentrations were: 1.8%, 1.1% and 7.2% for undigested manure; 4.5%, 2.3%, and 9.1% for 6 day RT effluent; 2.0%, 1.1% and 7.5% for 8 day RT effluent. Our economic studies indicate that digester operating conditions should include a 3-5 day RT, 10-12% TS, minimal changes in feed ration and recovery of solids for upgrading to fertilizer.

Dried rumen microblota were isolated from fistulated steers. Proximate analyses were conducted and the amino acid composition and B-vitamin content were determined. Protein quality tests were carried out using the Bender-Miller method. The data obtained from the investigation indicated that the protein quality of dried rumen microbiota is comparable with that of dried defatted egg, dried milk, fish meal and meat meal, but it is better than that of a soy protein and wheat gluten. No amino acid deficiency appeared in the feeding trials even though the amino acid composition showed that the dried rumen microbiota might be deficient in sulfur-containing amino acids. / Master of Science