Dissertations / Theses on the topic 'Agricultural wastes as feed'

Thesis (M.Sc.) -- Hawkesbury Agricultural College, 1985.
"A thesis submitted to Hawkesbury Agricultural College in partial fulfilment of the requirements for the degree of Master of Applied Science."

Microalgae have a variety of commercial applications, the oldest of which include utilisation as a food source and for use in wastewater treatment. These applications, however, are seldom combined due to toxicity concerns, for ethical reasons, and generally the requirement for cultivation of a single algae species for use as a feed supplement. These problems might be negated if a “safer” wastewater such as that from agricultural and/or commercial food production facilities were to be utilised and if a stable algae population can be maintained. In this investigation preliminary studies were carried out using an Integrated Algae Pond System (IAPS) for domestic wastewater treatment to determine the species composition in the associated High Rate Algae Ponds (HRAPs). The effect of different modes of operation, continuous versus batch, on nutrient removal, productivity and species composition was also investigated. Furthermore, indigenous species in the HRAP were isolated and molecularly identified as, Chlorella, Micractinium, Scenedesmus and Pediastrum. Additionally, the effect of the nor amino acid, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) and its Cu-chelated derivative, on the growth and biochemical composition of Chlorella, Micractinium, Scenedesmus, Pediastrum and Spirulina was investigated. Species composition in the HRAP was stable under continuous operation with Micractinium dominating > 90% of the algae population. Under batch operation the population dynamic shifted; Chlorella outcompeted Micractinium possibly due to nutrient depletion and selective grazing pressures caused by proliferation of Daphnia. Higher species diversity was observed during batch mode as slower growing algae were able to establish in the HRAP. Nutrient removal efficiency and biomass productivity was higher in continuous mode, however lower nutrient levels were obtained in batch operation. HMTBA did not significantly affect growth rate, however treatment with 10 mg.L-1 resulted in slightly increased growth rate in Micractinium and increased final biomass concentrations in Chlorella, Micractinium and Spirulina (although this was not statistically significant for Micractinium and Spirulina), which are known mixotrophic species. Algae treated with Cu-HMTBA, showed reduced final biomass concentration with 10 mg.L-1, caused by Cu toxicity. Biochemical composition of the algae was species-specific and differed through the growth cycle, with high protein observed during early growth and high carbohydrate during late growth/early stationary phase. Additionally, 0.1 mg.L-1 HMTBA and Cu-HMTBA significantly reduced protein content in Chlorella, Micractinium, Scenedesmus and Pediastrum. In conclusion, operation of the HRAP in continuous culture provided suitable wastewater treatment with high productivity of an ideal species, Micractinium, for use in animal feed supplementation. This species had 40% protein content during growth (higher than the other species tested) and dominated the HRAP at > 90% of the algae population during continuous mode. Addition of HMTBA (> 1 mg.L-1) to algae cultivation systems and those treating wastewater, has the potential to improve productivity and the value of the biomass by enhancing protein content. Overall, the co-utilisation of microalgae for wastewater treatment and the generation of a biomass rich in protein, for incorporation into formulated animal feed supplements, represents a closed ecosystem which conserves nutrients and regenerates a most valuable resource, water.

Orientadores: Marlene Rita de Queiroz, Silvia Azucena Nebra
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: Na fabricação do suco de laranja concentrado congelado, para cada 100 kg de laranja são produzidos 55 kg de suco simples e os 45 kg restantes são os resíduos do processo constituídos de laranjas descartadas, casca, semente, borra de extração de óleo essencial, polpa lavada, que podem ser denominados, genericamente de "bagaço", material comumente destinado à produção de farelo de polpa cítrica alimentação animal. O consumo de energia térmica na fábrica de ração, setor responsável pela transformação do bagaço de laranja úmido em farelo de polpa cítrica é alto, principalmente para a secagem de bagaço peletizado. Levantamento realizado sobre o consumo e conservação de energia em uma unidade industrial no Estado de São Paulo mostrou que a demanda de energia térmica para produzir uma tonelada de ração foi equivalente ou superior à quantidade consumida para produzir uma tonelada de suco de laranja concentrado congelado. Este trabalho teve como objetivo o estudo com a finalidade de avaliar a utilização de um secador pneumático tipo "Flash" na produção do farelo de polpa cítrica para fabricação de ração animal, comparando-se sua eficiência com a do processo tradicional, no qual são utilizados secadores rotativos. Os secadores pneumáticos têm sido usados em escala crescente em muitos processos industriais, devido principalmente às vantagens inerentes a este tipo de equipamento e sua versatilidade na secagem, principalmente na remoção da umidade superficial. Considerando o universo dos trabalhos em secagem, são poucos os estudos encontrados na literatura que trata sobre o assunto, ainda mais os que envolvem estudos comparativos entre outros secadores. Deste modo torna-se importante o estudo destes secadores, sobretudo visando a obtenção de parâmetros energéticos, os quais constituem as informações básicas podendo se tornar uma alternativa aos métodos atualmente utilizados, sendo economicamente viável e especialmente apropriado a inúmeros tipos de produtos agrícolas. Foi efetuada a caracterização do material em relação à granulometria das partículas, volume específico real e aparente, ângulo de talude, velocidade terminal, poder calorífico, tanto para o resíduo úmido quanto para o seco. A determinação da eficiência térmica do secador Flash foi conduzida conforme Delineamento Central Composto Rotacional (DCCR) com três variáveis independentes: velocidade do ar no interior do secador, temperatura do ar de aquecimento e vazão de produto. Para a determinação do consumo energético foram utilizados indicadores, denominados figuras de mérito, relacionando a quantidade de energia necessária para evaporar 1 kg de água. Os resultados obtidos mostram um menor consumo energético no secador tipo Flash, mas se deve ter em mente que foi feita uma comparação entre um modelo de secador flash em escala piloto, não otimizado, com um industrial
Abstract: In the manufacture of frozen concentrate orange juice, if considered 100 kg of oranges, 55 kg of simple juice is extracted, producing in the end 45 kg of waste wich includes: discarded oranges, bagasse, peels, seeds, lees from essence oil extraction, washed pulp, which is generically called bagasse and is commonly used for animal feed food production. The consumption of thermal energy in the factories is high, especially in the dryng of pelleted bagasse. A survey carried on the conservation and consumption of energy in a industrial unit plant in the State of Sao Paulo showed that the demand for thermal energy to produce one ton animal feed was equivalent to or greater than the amount consumed to produce one ton of frozen concentrated orange juice. This study aimed at developing a research with the goal of evaluating the use of a pneumatic dryer type "Flash" in the production of dehydrated orange bagasse for the manufacturing of animal feed, in order to compare their efficiency with the traditional process which use rotary dryers. Pneumatic dryers have been widely used in industrial processes, due the advantages inherent in this type of equipment and its versatility in drying and specially in the removal of surface moisture. Within the universe of drying, studies, there are few examples in the literature that cope with the subject, even those involving comparative studies of other type of dryers, it's of great importance the study of these dryers, specially focusing on obtaining energy parameters, which constitute the basic information that may become an alternative to methods currently used. They are economically viable, especially suited to many types of agricultural products. A study was performed to characterize the material in relation to particle size, specific volume, real and apparent, angle of slope, terminal velocity, calorific value, for both wet and dry waste. The flash dryer thermal efficiency was determined in compliance to the Central Composite Rotable (CCR) with three independent variables: speed of the air inside the dryer, air temperature warming and flow of the product. For the determination of energy consumption indicators were used, called as figures of merit, relating the amount of energy required to evaporate 1 kg of water. The results show lower energy consumption in the dryer type Flash, it's necessary to emphasize that this comparison was made between a type of flash dryer for laboratory use, not optimized, with one for industrial use
Mestrado
Tecnologia Pós-Colheita
Mestre em Engenharia Agrícola

Os elevados preços das matérias primas utilizadas em rações para a criação de animais monogástricos, tem obrigado a busca de novas fontes alimentares principalmente na forma de co-produtos. Dentre os diversos co-produtos advindos de atividades agroindustriais, podemos citar o resíduo de cervejaria com potencial para substituir parcialmente os alimentos convencionais das rações. Diante do exposto, foram realizados dois experimentos na Unidade de Ensino e Pesquisa de Avicultura do Campus Dois Vizinhos - UTFPR. No primeiro experimento, que teve período de duração de 1 a 21 dias, foram utilizados 714 pintainhos, com peso médio inicial de 44,7+/-0,3g, distribuídos em um delineamento inteiramente casualizado, com 6 níveis crescentes de inclusão de resíduo de cervejaria, com 7 repetições e 17 animais por unidade experimental. Enquanto que no segundo experimento, com período de 21 a 42 dias, foram utilizados 546 pintos de corte com 21 dias de idade, peso médio de 865 +/- 8 g, distribuídos em um delineamento e tratamentos semelhantes ao experimento I e com 14 aves por repetição. As aves foram pesadas na chegada, 21 e 42 dias no experimento I e aos 21 e 42 dias no experimento II para determinação do desempenho dos animais nestas fases. No experimento I, aos 21 dias, foram coletas amostras de sangue de 2 aves por unidade experimental, bem como abatidas 2 aves para avaliação da composição corporal e desenvolvimento das vilosidades intestinais e mais 2 aves aos 42 dias para avaliar os possíveis efeitos residuais dos tratamentos no rendimento de carcaça e cortes nobres. Enquanto que no experimento II, aos 42 dias de vida, também foram coletadas amostras de sangue de duas aves, bem como abatida 1 ave por unidade experimental para avaliação da composição corporal e outra 1 ave por repetição para avaliação do rendimento de carcaça e cortes nobres e desenvolvimento das vilosidades intestinais. Todas as aves foram sacrificadas por deslocamento cervical. As análises estatísticas dos níveis estudados foram realizadas pelo programa Sistema de Análises Estatísticas – SAEG (Universidade Federal de Viçosa – UFV, 1999).
The high prices of the raw materials used in diets for the creation of monogastric animals, is forced to search for new food sources mainly as byproducts. Among the various co-products arising from agro-industrial activities, we can mention the potential to brewery waste to partially replace conventional food rations. Given the above, two experiments were conducted at the Teaching Unit and Campus Poultry Research Dois Vizinhos - UTFPR. In the first experiment, which had duration of 1-21 days 714 chicks were used, with average weight 44,7+/- 0,3g, distributed in a completely randomized design with 6 increasing levels of brewery waste inclusion with 7 replicates of 17 animals each. While in the second experiment, with from 21 to 42 days, were used 546 broiler chicks at 21 days old, average weight of 865 +/- 8g, distributed in a design and treatments similar to the first experiment and 14 birds per repetition. The birds were weighed on arrival, 21 and 42 days in experiment I and at 21 and 42 days in the second experiment to determine the performance of animals in these phases. In the first experiment, 21 days, blood samples of two birds were collected by experimental unit and killed 2 birds to assess body composition and development of the intestinal villi and 2 birds at 42 days to assess the possible residual effects of treatments on carcass yield and prime cuts. While in the second experiment, after 42 days of life also blood samples of two birds were collected and slaughtered one bird per experimental unit for assessment of body composition and another one bird by repetition to evaluate the carcass yield and prime cuts and development of the intestinal villi. All birds were sacrificed by cervical dislocation. Statistical analyzes of the studied levels were carried out by the Statistical Analysis System program - SAEG (Universidade Federal de Viçosa - UFV, 1999).

Anaerobic digestion technology has not gained widespread acceptance on UK farms due mainly to the long return on investment periods involved. It has been suggested that co-digestion of agricultural and industrial wastes may enhance the economic viability of such installations. Batch and continuous digestion of cattle slurry and organic industrial wastes was carried out in specially constructed pilot plant digesters, to determine optimum mixtures of waste and digester loading rates. A total of 10 different wastes were tested, on a batch digestion basis, for their potential to co-digest with cattle slurry. Of these, 3 were chosen for continuous pilot plant trials, due to either a need to provide a disposal route for the waste, or positive effects of the waste on methane productivity. Chicken manure was found to slightly enhance methane productivity, but ammonia inhibition of methanogenic bacteria was noted over time. The organic fraction of municipal household waste (OFMSW) significantly enhanced digester methane productivity, while fish offal (FO) slightly enhanced methane productivity when added to the digester in small quantities, but quickly caused digester failure when added in larger amounts. An economic model of a digestion facility was developed and used to show the financial benefits of co-digestion.

Global cement production is continuously increasing from 1990 till 2050 and growing particularly rapidly in developing countries, where it represents a crucial element for infrastructure development and industrialisation. Every tonne of ordinary Portland cement (OPC) produced releases, on average, about 800 kg of CO2 into the atmosphere, or, in total, the overall production of cement represents roughly 7% of all man-made carbon emissions. The present paper aims to deepen the re-use of agricultural solid waste materials as partial replacement of OPC, which can positively contribute to the sustainability of the concrete industry because of their availability and environmental friendliness. In particular, rice-husk ash (RHA) and oat-husk ash (OHA), burned under the right conditions, can have a high reactive silica content, representing very potential pozzolans. The mechanical and physical characteristics of both materials are investigated to evaluate the influence on concrete properties. Subsequently, using the environmental product declarations (EPDs) of the material used, a comparative environmental impact analysis between RHA concrete and ordinary concrete having the same resistance class, is presented. It is concluded that the use of RHA as supplementary cementitious material can serve a viable and sustainable partial replacement to OPC for the reduction of CO2 emissions and global warming potential.
Den globala cementproduktionen ökar från 1990 till 2050 och växer särskilt snabbt i utvecklingsländer, där den utgör en viktig del för infrastrukturutveckling och industrialisering. Varje ton vanligt portlandcement (OPC) släpper i genomsnitt ut cirka 800 kg koldioxid i atmosfären, och, totalt, representerar den totala cementproduktionen ungefär 7% av alla koldioxidutsläpp från mänsklig verksamhet. Det här examensarbetet syftar till att fördjupa kunskapen om och därmed i förlängningen återanvändningen av fasta avfallsmaterial från jordbruket som delvis ersättning av OPC, vilket kan bidra till hållbarheten i betongindustrin på grund av deras tillgänglighet och miljövänlighet. I synnerhet kan risskalaska (RHA) och havreskalaska (OHA), som bränns under rätt process, ha en hög reaktiv kiseldioxidhalt, vilket representerar mycket potentiella puzzolaner. De mekaniska och fysiska egenskaperna hos båda materialen har undersökts för att utvärdera deras inverkan på betongegenskaper. Därefter presenteras en jämförande miljökonsekvensanalys mellan RHA-betong och OPC-betong med samma motståndsklass med användning av miljövarudeklaration (EPD) för det använda materialet. Man drar slutsatsen att användningen av RHA som alternativt bindemedel (SCM) till OPC kan hjälpa till att minska koldioxidutsläppen och den globala uppvärmningspotentialen.

2 pp.
The greatest management concern with animal wastes is the movement of nitrate into water supplies. Health problems in humans and livestock can result from excessive levels of nitrate in drinking water. This publication outlines the guidelines to minimizing the risk of contaminating your drinking water. It also lists a number of questions to check if your management practices in the collection and storage of animal wastes may pose a risk to your groundwater.

Increasing the content of omega-3 fatty acids in the fatty acid profile of the animal products humans consume is becoming increasingly important as a way of promoting health and reducing the risk of disease. To achieve an improved fatty acid profile in milk and meat from dairy cows, it is necessary to feed the animals with high omega-3 fatty acid content feed. Flaxseed is a feed ingredient which may suffice these needs, however the nature of the omega-3 fatty acids present certain problems at the level of digestion -biohydrogenation in the rumen. Also, the extrusion method of producing a cooked flaxseed ingredient enhances the release of the oil from the flaxseed itself, but in turn increases the opportunity for oil loss during storage and transport. To limit oil loss, flaxseed was combined with three different absorbent materials (alfalfa, soy hulls, gluten) at three different ratios of absorbent to flaxseed for each absorbent (15:85, 20:80, 25:75) and the ability of the extruded samples to retain oil under compression was measured. Of the three absorbents, alfalfa performed the best (p < 0.0001) at a ratio of 25:75 (p = 0.0002). The samples were characterized in terms of the protein fractions – soluble crude protein, neutral detergent insoluble crude protein (NDICP) and acid detergent insoluble crude protein (ADICP) – and the digestibility of dry matter (DM) and crude protein (CP). The effect of extrusion, type of absorbent and the ratio of absorbent to flaxseed on the nutritional quality and some physical properties of the samples were ascertained.
Accroitre la quantité d'acide gras omega-3 dans le profil des acides gras des animaux, destinés à la consommation humaine, gagne en importance en tant que bonne façon de réduire les risques de maladie et d'améliorer la santé générale. Pour obtenir un meilleur profil d'acide gras dans le lait et dans la viande des vaches laitières, il est nécessaire de nourrir l'animale avec des rations riches en acide gras oméga-3. La graine de lin, est un ingrédient parfait pour répondre à ce besoin. Cependant la nature des acides gras oméga-3 présente un certain problème au niveau de la digestion par biodéhydrogénation dans la panse des ruminants. Également, la méthode d'extrusion pour la production de lin cuit accroit la libération d'huile de la graine de lin, cependant ce processus augmente les chances de perte d'huile lors du stockage et du transport. Pour limiter les pertes d'huile, le lin a été combiné avec trois matériaux d'absorption (luzerne, écaille de soja, gluten) selon trois différents ratios de matériaux absorbant versus graine de lin (15:85, 20:80, 25:75). La capacité de rétention d'huile des échantillons extrudés face à la compression a été mesurée. Des trois absorbants, la luzerne possède la meilleure performance (p < 0.0001) avec un ratio de 25:75 (p = 0.0002). Les échantillons ont été caractérisés en terme des fractions de protéine – protéine brute soluble, protéine brute insoluble à détergent neutre (PBIDN) et protéine brute insoluble à détergent acide (PBIDA) – ainsi que la digestibilité des matières sèches (MS) et les protéines brutes (PB). Les effets de l'extrusion, des types d'absorbant et les ratios absorbant par rapport à la graine de lin sur la qualité nutritionnelle et quelques une des propriétés physiques des échantillons ont été établis.

The spread of tetracyclines through agricultural systems is causing the present bacteria to develop antibiotic resistance. The spread of this bacteria, as well as the tetracycline antibiotics in the environment is dangerous because these antibiotics pose health hazards for humans. The overuse of antibiotics, which are added to livestock feed, results in the antibiotics being released into the environment via animal feces. In this research, we have attempted to design an analytical method to isolate antibiotics from agricultural wastes with subsequent detection using liquid chromatography and mass spectrometry (LC-MS). The antibiotics investigated in this study were tetracycline, chlortetracycline, and oxytetracycline. The analytical procedure involves mixing the agricultural samples with an organic solvent, such as methanol, which solubilizes these antibiotics. Next, samples are centrifuged to remove solid particulates. A polymeric weak cation cartridge was used to concentrate and separate the antibiotics from the unwanted organic chemical compounds found in the samples. The antibiotics were released with methanol with small amounts of acid and then detected and quantified using LC-MS and high performance liquid chromatography with a photodiode array detector (HPLC-PDA).

Aqueous solutions are becoming increasingly contaminated in all parts of the world (2015). Heavy metals are toxic contaminants that are mainly distributed in urban stormwater run-off and industrial wastewaters as a result of some mining operations, electronic assembly planting, battery manufacturing, and etching operations (Kadirvelu et al. 2001). Pb (II) is a heavy metal that causes significant damage in the human body. Drinking lead-contaminated water even at low concentrations may cause lifethreatening conditions such as cancer, kidney damage, brain damage, and liver problems (El-Said 2010). Therefore, it is necessary to remove lead from aqueous solutions. Several conventional physical, chemical, and biological systems have been used to eliminate Pb (II) ions from contaminated aqueous solutions, including membrane filtration (Song et al. 2011), electrolysis (Deng et al. 2010), chemical precipitation (Cort 2005), magnetic base methods (Ma et al. 2017), water filtration (Gohari et al. 2013, Magni et al. 2015), and adsorption techniques (Pehlivan et al. 2009). However, the cost of some of the cited techniques is prohibitively high, while others cannot remove low Pb (II) ion concentrations efficiently (Babel and Kurniawan 2003, Volesky and Holan 1995). Although adsorption is a reasonable process for removing dissolved lead from contaminated water, the cost of using conventional media (e.g. activated carbon and resin) make it cost inhibitive for the treatment of large quantities of wastewater (Cutillas-Barreiro et al. 2016, Demirbas 2008). It also takes a long time in some cases to achieve adsorption equilibrium (Czinkota et al. 2002). In recent decades, interest in the use of cost-effective adsorbents to reduce the expense of water treatment processes has intensified. Attention has been focused on natural agricultural waste materials such as seeds (Gilbert et al. 2011), fruit peel (Mallampati et al. 2015), nut shells (Taşar et al. 2014) , crop residues (El-Said 2010), and fruit shells (Zein et al. 2010) as low-cost and environmentally friendly adsorbents which are highly efficient and generally available in large quantities (Ibrahim et al. 2010). Against this backdrop, many agricultural residues are being produced every day, and they need to be managed. Using agricultural wastes to treat contaminated water is a low-cost and effective approach that deal with waste management and water treatment at the same time. This project describes an economically viable and practical way to utilize crop residues as adsorbents to remove toxic Pb (II) ions from lead-contaminated water. These agricultural waste adsorbents have a number of advantages; they are cheap and biodegradable, they have a porous surface, and are able to eliminate Pb (II) ions from contaminated water quickly and effectively. Therefore, in this research two Western Australian crop residues were used as adsorbents to eliminate lead ions from aqueous solutions. The study was carried out in four phases: the first phase involved the selection and preparation of different local Western Australian agricultural wastes. Lupin straw and canola stalk were collected from local farms and studied for their efficiency as two low-cost natural adsorbents that can remove dissolved Pb2+ ions from synthetic wastewater. In the second phase, experiments were carried out to understand the equilibria of Pb (II) adsorption onto adsorbents. The effect of various environmental conditions such as contact time, pH, initial adsorbent dosage and adsorbate concentration were investigated. The presence of different functional groups, chemical compositions, and the surface characteristics of the adsorbents were analysed in the third phase using energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) devices. In the final phase, the obtained experimental data were validated using different isotherm models developed by Langmuir, Freundlich, Harkins-Jura, Redlich- Peterson and Halsey to describe the adsorption process based on the homogeneity of the surfaces of the adsorbents. Pseudo-first-order, pseudo-second-order, intra-particle diffusion, Elovich, and fractional power kinetic models were utilized to investigate the dynamic mechanism of lead adsorption onto adsorbents over time.

Thesis (M.S.)--University of New Orleans, 2005.
Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering"--Thesis t.p. Vita. Includes bibliographical references.

Food waste as a dominant fraction of municipal solid waste was in most of cases buried in landfills creating a burden on big cities with large populations such as Hong Kong. Composting provided an environmentally viable technology to divert food waste to resource utilization for the production of valuable organic fertilizer. The main problem associated with food waste composting was the intensive acidification prior the commencement of the composting process, which is commonly adjusted by the addition of alkaline materials such as lime. However, more than 50% of the initial nitrogen will be lost as ammonia, which not just reduces the nutrient value of the compost but also leads to serious odour generation. Therefore the objective of this study was to develop means to reduce the nitrogen loss through struvite formation. The first experiment of this research investigated the feasibility of controlling the nitrogen loss through struvite formation during food waste composting. Struvite forms when magnesium (Mg), phosphorus (P) and nitrogen (N) salts exist in equimolar ratio at a slightly alkaline pH. Thus to fix the ammonia, MgO and K2HPO4 were added to food waste indifferent molar ratios (P1, 0.05M/kg MgO and 0.05M/kg K2HPO4; P2, 0.05M/kg MgO and 0.1M/kg K2HPO4) to induce struvite formation that can fix the compost-borne ammonia during composting. The pH of the composting mass of P1 was below 5 for more than one. However, the pH of P2 was controlled in a narrow range from 6.8 to 8.7. This slightly alkaline pH ensured a good microbial activity and improved the degradation rate as well as the precipitation of struvite. In treatment P2, the formation of struvite effectively reduced the nitrogen loss from 40.8% to 23.3% when compared to treatment with lime amendment. However, electrical conductivity (EC) of the compost increased to 6.4 mS/cm due to the addition of Mg and P salts. High salinity of the compost retarded seed germination which required further investigation to reduce the salinity while maintaining good nitrogen removal. To overcome this issue, lime as the more effective alkaline amendment, was supplemented in different concentrations along with struvite salts (to P1 treatment having less Mg salt that could reduce the salinity) to alleviate the low pH and struvite formation. The pH of the composting masses were effectively increased with increasing lime dosages and 2.25% lime was sufficient to maintain the pH in alkaline condition that significantly improved the degradation of active organic compounds resulting in increased dissolved organic carbon (DOC) and soluble organic nitrogen (SON) contents. With 2.25% lime and struvite salts, ammonia emission was significantly reduced from 44.3 to 27.4% through struvite formation compared with lime alone treatment. Furthermore, the EC were also decreased from 5.21to 3.40 mS/cm when lime amendment rate increased from 0.75% to 3%. However, the ammonia emission increased with an increase in lime dosage. Interfering ions such as calcium and potassium were reported to affect the struvite formation and pH control. Therefore, in the subsequent experiment, the influence of different types of P salts was investigated to reduce the salinity as well as N loss. When K2HPO4, Na2HPO4 and H3PO4 were used as the supplementary P salts, there were no significant differences on nitrogen conservation. In addition, the results indicated that K+ and Na+ were attached on the surface of struvite rather than constituted the crystal structure. Compared with other P salts, the presence of K+ in K2HPO4 also made a contribution to total nutrient content that benefited the final product. When CaO was gradually substituted with MgO as pH amendment, ammonia emission was significantly reduced implying that Ca2+ ions would influence the struvite formation, either by competing for phosphate ions or by interfering with the crystallization. However, this negative effect could be ignored when the Ca2+/Mg2+ ratio was below 1:2. Considering the cost of MgO, supplementation of Ca2+/Mg2+ ratio at 1:2 (0.15M CaO and 0.3M MgO) with 0.05M K2HPO4 was identified as the optimum conditions (Treatment M0.3) that effectively reduced the nitrogen loss to 28% in contrast to 46% with lime addition. The significant reduction of ammonia emission through struvite formation was observed with the optimum condition that the odour unit (OU) of ammonia emission was reduced to 1.8×104 when compared with lime treatment (3.0×104) indicating a significant reduction of OIMAX (maximum odour index). Meanwhile, the well-controlled pH of this technology ensured the effective decomposition of organic matter that significantly reduced the emission of volatile fatty acids (VFAs) also. The population of total bacteria was also improved due to the addition of phosphate salts. The total nutrient content of struvite composts of treatment with optimum condition (M0.3) was 4.14% (1.5% N, 0.44% P and 2.2% K) that was higher than normal lime treated compost 2.92% (1.3% N, 0.34% P and 1.28% K). In pot experiment, soil was amended with composts at 0, 2.5%, 5% or 10% (w/w dry wt. basis). At the same application rate, the biomass yields of Chinese cabbage and cherry tomato plants were improved by struvite compost when compared tonormal compost. Considering the increasing salinity of soil with high application rate, the optimum dosage of 5% struvite compost is recommended. To conclude, a food waste composting technology was developed to achieve good nitrogen conservation and decomposition that alleviated odour issue and produced compost with higher nutrient contents, which increased its application value

To reinforce cement against the attack of supercritical CO2 in a storage site, agricultural wastes (POFA and RHA) and Nano particles (Nano Silica) were used. Post-carbonation tests of agricultural wastes and Nano Silica based cement were done according to the API standard and it was found that almost all samples have a lesser carbonated area then the neat cement except 5 wt% POFA. Nano Silica based cement seem to be the best choice.

A compost-bioremediation approach was adopted in this study to explore more sustainable and economically viable methods of degrading pollutant hydrocarbons in oil-field drill cuttings and coal tar impacted soils (CTIS). The compost amendments used were agricultural waste products including grass cuttings, spent mushroom compost and straw. Laboratory-scale compost experiments were conducted to test the performance of different compost blends comprised of each contaminated medium and organic amendments in different mix ratios for 53 days. The compost mix type which produced the greatest reduction in pollutant hydrocarbon concentrations was further scaled-up and tested in an outdoor pilot scale compost treatment for 56 days. At the end of the lab-scale treatments, degradations in total petroleum hydrocarbon (TPH) concentrations of 85.1% and 90.6% were recorded for the drill cuttings and CTIS, compared to 36.7% and 28.4% that was achieved in the control experiments, respectively. The concentrations of total n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were significantly decreased in the best performing compost mix types, however most of the 5 and 6-ring PAH compounds in the CTIS treatment compost mix exhibited recalcitrance to degradation and some even appeared to increase in concentration which is ascribed to increased PAH availability to solvent extraction and reduction in the compost mass during the composting-biodegradation process. The best performing compost mix type for treatment of CTIS was subsequently tested in outdoor tumbler compost bins after being scaled-up by a factor of 600; this was found to produce 78% degradation of TPH concentration at the end of the treatment period. Concentrations of total nalkanes and PAHs were also significantly lowered by biodegradation. Low molecular weight (2 and 3-ring) PAHs were almost completely removed and 4-ring PAHs from the coal tar, including fluoranthene, pyrene, benzo[a]anthracene and chrysene were significantly degraded but not the 5 and 6-ring PAH compounds. Phytotoxicity assays showed that the seed germination in the treated matrix was 70% and 20% more, for corn and pea, respectively, 5 days after planting and 78% more for mustard 3 days after planting. Phosphatase enzyme activity was found to decrease in the treated matrices possibly due to the short time between end of composting and testing. The results generated from the chemical and toxicity assays of this study showed the efficacy of the composting treatment for hydrocarbon removal from these contaminated matrices and identified the best performing compost mix types (DGMSt3 and SGSt3) which can be further tested in field scale trials.

This research aimed to develop and validate new effective analytical methods for microorganism-derived livestock feed supplements. Qualitative as well as quantitative analyses of important nutrient profiles in the microbial products, such as lipids and polar metabolites, were included in this study. Detailed amino acid and lipidomic analyses were performed to obtain nutrient profiles of different microorganisms grown using low-cost media derived from livestock waste. The knowledge and results gathered from this study have contributed to the development and evaluation of a rapid analytical method for nutrient profiling of new microorganism-derived feed supplements.

Environmentally sound treatment of by-products in a value-adding process is an ongoing challenge in animal agriculture. Thermophilic anaerobic digestion of wastes originating from agricultural production and animal processing represents a potential waste treatment technology to address environmental concerns such as odor emissions and removal of pathogenic microorganisms, while at the same time producing renewable energy (biogas) as a by-product. However, thermophilic digestion is subject to inhibition by ammonia and long chain fatty acids (LCFA), both of which are prevalent in manure and animal processing wastewater. Several swine manure collection methods under development separate the urine from the feces, which creates the opportunity to operate a digester on feces only, greatly reducing the ammonia load to the digester. One objective of this study was to determine whether operation on feces only would yield significant performance improvements for a thermophilic anaerobic digester operating on swine waste. Effluent from a continuously stirred tank reactor (CSTR) was used as the inoculum for batch tests in which the substrate contained three different concentrations of urine (urine-free, as-excreted urine:feces ratio and double the as-excreted urine:feces ratio). Inocula were acclimated to these same urine:feces ratios to determine methane production. Results show that both urine-free and as-excreted substrates were not inhibitory to anaerobic inocula. Anaerobic microorganisms can be readily acclimated to substrate with double the as-excreted urine concentration, which contained TKN concentrations up to 7.20 g-N liter-1. The sludge collected from the dissolved air flotation (DAF) wastewater treatment process in swine processing facilities is an example of a high-lipid substrate containing potentially inhibitory levels of LCFA. A second objective of this study was to determine the fundamental performance parameters for thermophilic anaerobic digestion of DAF sludge. Testing in a semi-continuous stirred tank reactor and in batch reactors was conducted to determine substrate degradation rates and biogas yield. Stable operation could not be achieved using pure DAF sludge as a substrate, possibly due to inhibition by long chain fatty acids or to nutrient deficiencies. However, a 1:1 ratio (w/w, dry basis) of DAF sludge and swine manure (feces only), resulted in stable and productive digester operation. In the semi-continuous stirred reactor at 54.5ï°C, a hydraulic residence time of 10 days, and an organic loading rate of 4.68 gVS/day/L, the methane production rate was 2.19 L/L/day and the specific methane production rate was 0.47 L/gVS (fed). Maximum specific methanogenic activity (SMA) in batch testing was 0.15 mmolesCH4 hr-1 gVS-1 at a manure/DAF substrate concentration of 6.9 gVS liter-1. Higher substrate concentrations cause an initial lag in methane production, possibly due to long chain fatty acid or nitrogen inhibition.

Protein upgrading of orange peel waste was carried out by Solid Substrate Fermentation using an Aspergillus sp. inoculum in a waste peel mixture containing peel waste, potassium dihydrogen orthophosphate (KH2 PO4), ammonium sulphate [(NH4)2SO4] and molasses. Fermentation lasted 72 hours at 30C. after which crude protein level in the substrate increased from 5% to 13%. Factors found to be important in determing the efficiency of the fermentation process included fermentable sugar content of the medium, nitrogen and mineral levels, initial temperature, PH, moisture, agitation of the medium, and size of particles constituting the substrate. Protein quality of the fermented peel was evaluated by PEP assay and a PER value of 0.78 was recorded. It is suggested that a low level of total amino acids is the major contributory factor to this low PEP value. Total amino acid level measured 5.75g per 100g fermented peel waste.
Master of Science (Hons)

In this work, adsorption of cadmium and lead from waste solutions by activated carbon was investigated. The activated carbons were produced from ion exchange resins and agricultural wastes in previous thesis studies under different conditions. BET surface areas of the activated carbons were given in previous studies. They were further characterized in this study. Slurry pH was measured by change in pH of water in which activated carbon was added. Methylene blue numbers were determined by adsorption of methylene blue onto activated carbons. Isoelectric points were determined by measuring zeta potential of activated carbons at different equilibrium pH. Results of the first part of sorption experiments showed a strong dependency of adsorption on pH since adsorption mechanism was exchange of heavy metal ions with H+ ions on the surface. Activated carbon produced from hazelnut shell had the highest removal efficiency with 95% Pb removal and 50% Cd removal at pH 6. However, activated carbon produced from apricot stone removed only 25% and 80% of Cd and Pb, respectively at the same pH. Initial concentration had positive effect on percent removal as shown by the second part of sorption experiments. This can be explained with saturation of available active sites as initial concentration increased. Activated carbon produced from hazelnut shell could remove 42% of Cd and 85% of Pb, but the one produced from synthetic resin couldn&
#8217
t remove Cd and Pb more than 20% and 35%, respectively at initial concentration of 100 mg/l. Langmuir and Freundlich isotherms were plotted and both isotherms were in good agreement with experimental data.

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.

Agricultural activities produce a large quantity of waste each year in the Mekong Delta. For example, appropriately 26.86 million tons of rice straw, 5.37 million tons of rice husks, 1.33 million tons of bagasse and 0.59 million tons of corn straw were produced in 2016. Despite such a huge quantity of agricultural waste, the waste has been rarely used effectively. Around 54.1 - 98.0% of rice straw is normally burnt on the field; only 20 - 50% of rice husk is used for pellet or energy purposes; a few sugar-cane factories apply bagasse feeding to steam cookers, and a small quantity of corn straw is used as livestock feeding. If this biomass source is used for electricity generation, in theory, for the period of 2006 - 2020, it is estimated that this source can potentially generate 1203 million MWh/year from rice straw, 236 million MWh/year from rice husk, 45 million MWh/year from bagasse, and 40 million MWh/year from corn straw. Electricity generation of biomass source will not only solve the problem of environmental pollution caused by agricultural waste but also meet increasing energy demands for socio-economic development in this region.
Hàng năm lượng chất thải phát sinh từ một số loại hình canh tác nông nghiệp chính ở ĐBSCL rất lớn. Chỉ tính riêng năm 2016 ghi nhận thải ra khoảng 26,86 triệu tấn rơm rạ; 5,37 triệu tấn vỏ trấu; 1,33 triệu tấn bã mía và 0,59 triệu tấn thân cây bắp. Lượng chất thải phát sinh lớn nhưng các biện pháp sử dụng những nguồn sinh khối này chưa đa dạng, rơm rạ phần lớn được người dân đốt trực tiếp ngay trên đồng ruộng chiếm 54,1 - 98,0% lượng rơm rạ thải ra; chỉ có khoảng 20 - 50% lượng vỏ trấu được sử dụng; bã mía chỉ được một số nhà máy sử dụng để đốt cho lò hơi; một lượng nhỏ thân cây bắp được người dân sử dụng cho chăn nuôi. Nếu có thể tận dụng các nguồn sinh khối này để sản xuất điện thì tiềm năng lý thuyết ước tính từ năm 2005 đến 2020 của rơm rạ là 1203 triệu MWh/năm; vỏ trấu là 236 triệu MWh/năm; bã mía là 45 triệu MWh/năm; và thân cây bắp là 40 triệu MWh/năm. Sản xuất điện từ các nguồn sinh khối này không chỉ giải quyết lượng phế phẩm nông nghiệp phát sinh, giảm thiểu ô nhiễm môi trường mà còn có thể tạo ra nguồn điện cung cấp cho nhu cầu phát triển của vùng.

The following investigation was carried out in the Agricultural Experimental Center Condoriri (CEAC), dependent on the Faculty of Agricultural Livestock Sciences and Veterinary Medicine, located to the North of the Province border of the Department of Oruro, a distance of 12 km from the town of Caracollo and 49 km from the city of Oruro. The production of llamas and alpacas in our country is an activity of ecological, social, and especially ecological importance for Andean inhabitants. In nutrition, the fundamental factor is the power of absorption; this is because the yield of animal production depends on the quantity and quality of forage consumed. Digestibility in animals is established based on basic consumption comparison and the values of digestibility of the food. For this reason, as previously expressed, we propose in the following research "Living digestibility of alfalfa and barley in llamas in the CEAC" to establish parameters of digestibility, with the following objectives: To evaluate the characteristics of production: consumption of food, consumption of water, excretion of wastes, elimination of urine and gain of living weight. To determine the digestibility of the nutrients: dry matter, raw protein, ash, air intake, raw fiber, nitrogen free extract, and total digestible nutrients. For this purpose 4 male llamas (sarijos) were utilized, taking into account the live weight, age, and breed. The investigation had two evaluation groups: the first group with a supply of alfalfa and the second group with a diet of barley. The investigation's duration was a total of 30 days, considering the following variables: characteristics of production (consumption of food, consumption of water, wastes excreted, volume of urine, and behavior of body weight); digestibility of nutrients (raw protein, ash, raw fiber, air intake, nitrogen free extract, and total digestible nutrients); leading to the following conclusions: > The average consumption of alfalfa by the llama is 6.49 kg/MF per day, of which 1344.5 g is MS, superior and distinct in respect to the fodder barley with 4.92 kg of MF/day and 1328.4 g of MS/day. Water consumption by the llama with the supply of alfalfa is of 0.77 liters; with barley it is 0.35 liters. The llamas with the supply of alfalfa excreted an average of 1.44 kg of waste, of which is 365.9 g of MS and the group with barley registered an average of 1.27 kg and 359.9 g of MS. With regard to the elimination of the volume of urine was between 2.80 and 1.22 liters per day respectively. Live weight at the start of the study was of 116.25 kg per llama and subsequent to the experimental stage of live digestibility the weight averaged 117.69 kg. Therefore, the increase of live weight during the experimental phase was equal to 1.44 kg. The daily increase of living weight in the llamas submitted to the consumption of alfalfa came to an average of 142.9 g/day/animal with a conversion allowance of 9.4. In contrast, the animals fed with barley registered a greater gain of 257 g/day/animal and a conversion allowance of 5.2. > The ratio of digestibility demonstrated by the Coefficients of Digestibility (%) of the alfalfa: MS = 72.85, C = 57.30, PC = 81.49, EE= 85.52, FC = 58.61, ELN = 77.96 and NDT = 69.17. In contrast, the coefficients of digestibility with the barley they were of 72.88% of MS, 33.13% of Ash, 74.62% PC, 84.19% of EE, 65.29% of FC, 77.08% of ELN and 68.74% of NDT.

Hydrogen production by means of anaerobic fermentation was researched utilizing three different substrates. Synthetic wastewater, dairy manure, and cheese whey were combined together at different concentrations under batch anaerobic conditions to determine the optimal hydrogen producing potential and waste treatment of each. Cheese whey at a concentration of 55% was combined with dairy manure at a concentration of 45% to produce 1.53 liters of hydrogen per liter of substrate. These results are significant because the control, synthetic wastewater, which was a glucose-based substrate, produced less hydrogen, 1.34 liters per liter of substrate, than the mixture of cheese whey and dairy manure. These findings indicate that cheese whey and dairy manure, which are of little value, have potential to produce clean combusting hydrogen fuel. The effluent from the anaerobic hydrogen fermentations was then placed into a second continuous-fed reactor as part of a two-phase anaerobic digestion system. This system was designed to produce hydrogen and methane for a mixture of approximately 10% hydrogen. The two-stage process also further treated the synthetic wastewater, dairy manure, and cheese whey. The two-phase anaerobic methanogenic reactor was shown to produce more methane in the second phase (56 L IBR anaerobic digester), 1.36 mL per minute per liter substrate, as compared to the single-phase anaerobic reactor (56 L IBR), which produced 1.22 mL per minute per liter substrate. In general, this research has suggested that agricultural and food processing wastes provide the needed nutrients for hydrogen production and that a two-phase anaerobic digestion system is ideally set up to produce hydrogen-methane mixtures while treating wastes for discharge into the environment.

Thesis (MEng)--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: Peach and apricot shells are agricultural waste products. These waste products accumulate around canneries and food-processing plants in South Africa. No effort is being made to utilise these waste products. This study is the first part of the product development from these products i.e. peach shell activated carbon and apricot shell activated carbon. By producing activated carbon from peach and apricot shells the solid waste problem is addressed, but most of all a profit can be made. But why activated carbon? Activated carbons are unique and versatile adsorbent with a vast amount of adsorption applications. It can be produced via a simple oxidation reaction with steam and the nature of peach and apricot shells are such that it is expected that activated carbons with good adsorption properties can be produced from it. The single largest consumer of activated carbon in South Africa is the gold mining industry that uses imported coconut shell activated carbon for gold adsorption in the gold recovery process. Activated carbon is also used as water purification adsorbents. During this study activated carbons were produced in a fluidized bed reactor at various activation conditions: 700 - 900°C, 0.0425 - 0.0629 g steamlg char.min and 30 - 60 min. This was done in order to find the optimum activation conditions within the activation parameter range. The optimal activated carbons were defined as peach and apricot shell activated carbons that showed good microporous as well as mesoporous character. The optimal activated carbons produced are: peach shell activated at 875°C, 0.0533 g stearnlg char. min, 60 min and apricot shell activated carbon at 850°C, 0.0533 g steamlg char.min, 60min. The possible use of these optimal activated carbons and two other activated carbons produced (Peach shell activated carbon 900°C, 0.0425 g steamlg char. min, 60 min and apricot shell activated carbon 900°C, 0.0425 g steamlg char.min, 60min) were tested in gold recovery and water purification. The gold adsorption properties of peach and apricot shell activated carbons were found to be better than two commercial coconut shell activated carbons (Chemquest 650 and GRC 22). No definite conclusions could, however, be drawn about the replacement of coconut shell activated carbon with peach or apricot shell activated carbon, because abrasion test work and thermal regeneration of the experimental carbons still have to be performed. The experimental activated carbons displayed good phenol adsorption characteristic, although further test work is required.
AFRIKAANSE OPSOMMING: Perske- en appelkoospitte is landbouafvalprodukte. Hierdie afvalprodukte versamel rondom inmaakfabrieke en voedselververkingsaanlegte. Tans word daar geen poging in Suid-Afrika aangewend om hierdie afvalprodukte te benut nie. Hierdie studie is die eerste deel van die ontwikkeling van die produkte: Perskepitdop-geaktiveerde koolstof en appelkoospitdop-geaktiveerde koolstof. Deur geaktiveerde koolstof van die perske- en appelkoospitdoppe te maak, word nie net 'n antwoord op die vastestofafvalsprobleem gevind nie, maar daar kan ook geld gemaak word. Hoekom geaktiveerde koolstof? Aktiveerde koolstowwe is veelsydige en unieke adsorbente met 'n groot verskeidenheid adsorpsie toepassings. Dit kan vervaardig word via 'n eenvoudige oksidasie reaksie met stoom en die aard van die perske- en appelkoospitdoppe is sodanig, dat verwag kan word om geaktiveerde koolstowwe met goeie adsorpsie eienskappe daarvan te kry. Die grootste enkelverbruiker van geaktiveerde koolstof in Suid-Afrika is die goudmynbedryf, wat kokosneutdop geaktiveerde koolstof invoer om goud te herwin. Geaktiveerde koolstof word ook gebruik vir watersuiwering. Tydens hierdie studie IS geaktiveerde koolstowwe by verskillende aktiveeringskondisies in 'n gevloeïdiseerde bed vervaardig: 700 - 900oe, 0.0425 - 0.0629g stoornlg gepiroliseerde pitdoppe.min en 30 - 60 mm. Die aktiveringskondisies is gevarieer om sodoende die optimale aktiveringskondisies binne die aktiveringsparameterreeks te kry. 'n Geaktiveerde koolstof is as optimaal geklassifiseer as dit 'n goeie mikro- sowel as mesostruktuur getoon het. Die optimaal geaktiveerde koolstowwe is: geaktiveerde koolstof vervaardig van perskepitdoppe by 875°e, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60 mm en geaktiveerde koolstof vervaardig van appelkoospitdoppe by 850oe, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60min. Die gebruik van die twee optimale geaktiveerde koolstowwe sowel as twee ander geaktiveerde koolstowwe (perskepitdop-geaktiveerde koolstof, 900oe, 0.0425 g stoornlg gepiroliseerde pitdoppe.min, 60 min en appelkoospitdop-geaktiveerde koolstof, 850°C, 0.0533 g stoom/g gepiroliseerde pitdoppe.min, 60min) is VIr goudadsorpsie en watersuiwering ondersoek. Die goudadsorpsie eienskappe van die perske-en appelkoospitdop-geaktiveerde koolstowwe was beter as die van twee kommersiële kokosneutdop-geaktiveerde koolstowwe (Chemquest 650 and GRC 22). Daar kan egter geen definitiewe gevolgtrekkings gemaak word oor die vervanging van kokosneutdop geaktiveerde koolstowwe met dié van perske of appelkoospitdoppe nie, aangesien daar nog toetsresultate oor die slytweerstand en reaktiverings eienskappe van die eksperimentele geaktiveerde koolstowwe uitstaande is. Die eksperimentele geaktiveerde koolstowwe toon goeie adsorpie ten opsigte van fenol, maar verdere toetswerk is egter nodig.

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.

Food waste accounts for about 1/3 of the municipal waste generated in Hong Kong. Using food waste as major ingredients to produce fish feed pellets could ease part of the disposal pressure on the existing landfill sites. The present study focused on the use of food wastes and feed supplements (prebiotic fibres and Chinese herbs) for rearing freshwater fish (grass carp, bighead, mud carp and Nile tilapia) in Hong Kong. Two isonitrogenous formulations, Food Waste Diet A (FWA), consisted of 53% cereal, 10% fruit and vegetables, 8% bone meal, 4% other food waste, 10% fishmeal, 15% corn meal and Food Waste Diet B (FWB), consisted of 25% meat, 28% cereal, 10% fruit and vegetables, 8% bone meal, 4% other food waste, 10% fishmeal, 15% corn meal were manufactured by Kowloon Biotechnology Ltd, were used as feeds for rearing grass carp, bighead, mud carp and Nile tilapia. The essential amino acid profiles and proximate compositions (crude protein, crude lipid and total phosphorous) of the two food waste based feed pellets were compared with other common feed items, including Napier grass, rice bran, breads, noodles, soybean dreg (remains of soybean after juicing for soybean milk) and the commercial feed pellets (Jiefeng® 613). Jiefeng® 613, FWA and FWB possessed 5.83%, 5.76% 5.79% (% protein) of lysine, which could satisfy the dietary requirements of both grass carp and Nile tilapia. Results indicated all the fish feed pellets possessed sufficient essential amino acids and suitable proximate compositions (crude lipid, crude protein, crude fibre and non-fibrous carbohydrate) for both grass carp and Nile tilapia. A field trial was conducted using the three feed pellets (Jiefeng® 613, FWA and FWB) to study their effects on fish growth (grass carp, bighead and mud carp) as well as water quality. FWA that possessing a higher P content (2770 μg/g feed, while control= 967 μg/g feed and FWB= 1942 μg/g feed) favoured the growth of plankton and led to better growth of bighead carp (in terms of length gain, wet weight gain and productivity), while grass carp fed with FWB showed significant better growth (in terms of length gain, wet weight gain, productivity, feed conversion ratio, specific growth rate and protein efficiency ratio), probably due to the relatively lower amount of carbohydrate (24.2%) and CHO:L ratio (1.83) than Control and FWA. Mud carp grew equally well in ponds fed with the three diets. FWB was subsequentially selected for further feeding experiments. A laboratory feeding trial was conducted to study the effects of feeding grass carp and Nile tilapia with FWB on their growth performance in terms of relative weight gain (RWG), feed conversion ratio (FCR), specific growth rate (SGR) and protein efficiency ratio (PER), and protein digestibility. Both fish fed with FWB showed similar growth performances to groups fed with control diet (Jiefeng® 613), while grass carp showed impaired protein digestibility when compared to group fed with control diet. FWB supplemented with 0.3% of vitamin-mineral premix (VMP) significantly improved the growth performance of both fish species and protein digestibility for grass carp. Results suggested that FWB incorporation with VMP would be necessary as it significantly enhanced growth of the fish. Four dietary supplements (inulin, mannan-oligosacharride, huangqi and goji, at the rates of 0.2% or 2%, w/w) were incorporated into FWB for further enhancing fish growth as well as non-specific immunity of grass carp and Nile tilapia. Grass carp fed with 0.2% and 2% inulin, 2% MOS and 0.2% goji, and Nile tilapia fed with 0.2% goji had significantly enhanced growth (RWG, FCR, SGR and PER). Both prebiotic fibres and Chinese herbs boosted the tested non-specific immune parameters (total serum immunoglobin, serum bactericidal activity and anti-protease activity) of both species. Among all the dietary supplements, 0.2% goji appeared to be the best supplement for both grass carp and Nile tilapia as it significantly enhanced the growth among all experimental diets. Grass carp and Nile tilapia fed with 0.2% showed about 10% and 30% higher RWG, 10% and 30% lower FCR value, respectively, than groups fed with other experimental diets. Moreover, all the tested non-specific immune parameters (total serum immunoglobin, serum bactericidal activity and anti-protease activity) were significantly enhanced when compared with the groups fed with control diets (Control and FWB without supplementation) . The present study demonstrated the feasibilities of using food wastes incorporated with feed supplements (prebiotic fibres and Chinese herbs) to enhance fish growth and immunity, for the sustainable development of Hong Kong inland aquaculture.

Nowadays, lot of attention is devoted both to the application of bio-based polymers as promising alternative to the currently used petro-based polymers, and to the recycling of waste materials coming from agriculture industry. However, a series of economic barriers hinder the application of bio-based polymers in large scale. The aim of this study was to evaluate the application of PLA composites containing up to a 30 %wt of wastes deriving from coffee production. The waste was coffee silverskin which is the main byproduct of coffee roasting process. The composites were formulated in three different proportions of waste including 10 %wt, 20 %wt, and 30 %wt of the composites. The mechanical properties, microstructure, and crystallinity of the composites, as well as thermal stability, water uptake, and contact angle have been evaluated. The results show that coffee silverskin did not compromise the thermal stability and degree of crystallinity of the composites, while it changed the mechanical properties. Specifically, tensile strength gradually decreased on addition of coffee silverskin, while the Young’s modulus slightly increased. The distribution of filler throughout the matrix was almost homogeneous without porosities in the composites. An increase in the value of water uptake was obtained, but the water absorption behavior was not modified. Furthermore, the values of contact angle were constant for all the composites. Due to the production conditions of this study, in order to obtain acceptable properties for the composites, the amount of waste should be limited up to 20 %wt. The simple and low cost operations performed on the waste for obtaining the filler, lead to a decrease in material price on account of PLA reduction. Moreover, using coffee waste as filler in production of green composites, in addition to adding value to agricultural waste, would results in minimizing the dependency on petro-based polymers.

The sugar refinery process used by Lantic Sugar Ltd generates three by-products having characteristics that give them potential as soil amendments or fertilizers, particularly as a phosphorous and calcium source. Laboratory and a field trials were conducted in order to examine the changes in agronomic properties of soil produced by the application of these residues.
During the laboratory experiment, the by-products examined were spend bone char (SBC), filter-press mud (FPM), clarification scum (SCU) and a compost (COM) produced using FPM and SCU, where as in a field experiment, COM, SBC and a mixture (MIX) made of FPM and SCU, were compared to a commercial fertilizer (TSP) and non-treated soils.
The orthic humic gleysol of clay texture and low pH soil conditions in which the field experiment was conducted resulted in high P fixation of all the applied residues. Contrasts analysis showed that TSP behaved as the soils unamended P for all nutrient concentrations in tissues over two cropping seasons (1993 and 1994), on two crops, namely wheat (Triticum aestivum, L.) and corn (Zea mays, L.). Treatments (residues at different rates of application) did not significantly increase the Ca levels in COM plots nor did they increase the wet aggregate stability of soil under either crop. (Abstract shortened by UMI.)

The guinea pig (Cavia aperea porcellus) is an alternative to improve human nutrition because its meat is of excellent taste and quality. Thus, it is an important nutritional source. The feed conversion index was determined under the basic (forage) and mixed (forage and concentrate) diets during the growth phase. This was done with both sexes located in the Tamborada and MEJOCUY populations, using the AUQUI, and San Luis lines. This was done in order to quantify how many kilograms of feed an animal must eat to gain one kilogram of live weight. The animals were randomly distributed into individual pools based on population, line, and sex for the period from 14 to 56 days old. Depending on the feeding system used, they received alfalfa forage and/or concentrated feed. In addition, they were weighed before and after feeding so the difference between food eaten and food rejected could be calculated. At the end of the 42 days of investigation, the feed conversion indexes were 5, 5.1, 4.8, and 4.6 for the basic diet and 5, 5.5, 4.9, and 4.9 for the mixed diet for the guinea pigs of the Tamborada and MEJOCUY populations and the AUQUI and San Luis lines respectively. The male and female animals had indexes of 4.7 and 5.3 respectively. Generally speaking, the San Luis line has the best feed conversion index, followed by the AUQUI line, the Tamborada population, and lastly the MEJOCUY population.

This research reports on the determination of the effects of fish size and feed pellet size on the settling characteristics of Rainbow trout (Salmo gairdneri) culture, tank cleaning wastes. Flocculant particle settling curves (Type II) were developed from settling column analysis of cleaning wastes from 11-311 gram Rainbow trout fed a moist pellet diet (Oregon Moist Pellet ®). Four feed pellet sizes were investigated: 3/32, 1/8, 5/32 and 3/16 inch. Overall non-filterable residue removal curves and individual particle settling velocity distribution curves, derived from the Type II settling curve of each fish size and feed pellet size group, were compared. Slopes and y-intercepts of the linearized overall non-filterable residue removal curves and individual particle settling velocity distribution curves were compared using the Equality of Slope Test (S:SLTEST). Results of the test for a common regression equation indicated there were no significant differences in the proportional distribution of particle sizes within the cleaning wastes. Variations observed in the initial rates of removal within the overall non-filterable residue removal curves were considered insignificant Settling trials were pooled in order to obtain single curves, characterizing the overall solids removal rate and the individual particle settling velocity distribution of the waste solids.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate

Thesis ( MTech (Business Administration))--Cape Peninsula University of Technology, 2016.
Capital investment in bioethanol production requires sound economic feasibility studies. This study investigated the economic feasibility of using maize as a feedstock to produce bioethanol in South Africa. There is a huge opportunity to use dedicated underutilised arable land to grow maize which can be used for both consumption and bioethanol production. The study used 200 000 ton/year of maize that could have been exported to SADC countries to size a plant that produces 80 million litres per year of bioethanol. An advanced bioethanol processing technology that separates the fibre/bran which is burnt in a steam boiler to produce process steam was selected owing to advantages such as low energy consumption and capital expenditure on fermentation and distillation equipment. This study employed a combination of qualitative and quantitative methods to gather data. The findings from a qualitative instrument indicated that a majority of respondents were in favour of the decision of excluding maize made by the South African government. Putting security of food at risk and uncertainty in the profitability of a maize-fed bioethanol plant in the South African context, were two of the primary reasons the respondents opted for an explicit exclusion of maize as a feedstock. Findings from quantitative analysis revealed that the profitability of the bioethanol plant was largely influenced by the prices of feedstock and bioethanol. The 2016 fiscal year indicated the worst case scenario in terms of economic viability of the bioethanol. The astronomically high price of maize due to drought (R5000/ton) rendered the project unprofitable as all of the economic indicators were negative. In the same marketing year, however, the trade balance of maize was positive, indicating a surplus. The study recommended that all of the surplus maize should be exported because it is not economically viable to build a bioethanol plant. The 2011 fiscal year indicated the best case scenario in terms of the economics of the project. This was due to the decrease in price of maize (R1726/ton) and a slight increase in the price of bioethanol. All of the economic indicators were positive, suggesting the benefits of investing in bioethanol production. It was recommended that under normal conditions of maize production in South Africa, a bioethanol plant can be operated simultaneous to maize exportation to other countries without compromising food security, because a maize-fed bioethanol plant uses only a small proportion of maize (14.3%) from the total volume of maize that is exported. Furthermore, it generates more revenue (99.9%) compared to the maize export revenue. It was recommended that sensitivity analysis should be conducted in a holistic manner whereby all variables in the economic model must be adjusted to assess the impact of each on the overall project profitability.

Thesis (MBA)--Stellenbosch University, 2008.
ENGLISH ABSTRACT: The goal of this study was to investigate the feasibility of a small-scale biomass gasification system within the context of a cooperative wine cellar operation in the Western Cape of South Africa. Central to this goal was the questions whether the time for the implementation of such small-scale renewable energy technologies in South Africa has arrived, in light of the status quo which has changed drastically from the days of abundant and cheap coal-based electricity, and whether the new opportunities afforded by the CDM can help foster financial feasibility. There are various macro-drivers contributing to the current-day emphasis on renewable energy and cogeneration projects. The first and most pressing driver is the global climate change imperative, while the others include the increased aspiration of countries towards energy security, the realization of the importance of sustainable development and the subsequent renewable energy policies that falls within the ambit of sustainable development. Small-scale biomass gasification technology still poses some challenges, particularly when it comes to the gasification of agricultural residues, as with grape residues in the case of this project. The most important technical feasibility problem to overcome is the low ash agglomeration temperature of grape residues reported in the literature. Although the local equipment manufacturer foresees no problem in this regard with their system design - since they have conducted tests on sunflower seed residues, which have similar ash properties, without experiencing any agglomeration problems - the seriousness of this aspect will be confirmed during pilot trials. In order to be eligible for emissions reduction trading under the CDM, the project must adequately demonstrate that the emissions reductions are additional to the business-as-usual scenario, in both the environmental and financial sense. The project will satisfy the environmental additionality requirement, since in its absence the wine cellar will continue its full reliance on coal-based electricity from the grid. Financial additionality, in its strictest sense, requires for the project to be infeasible if it does not pursue CDM participation, which the financial feasibility modeling results indicated to be true in this case. A feasibility model was developed to - subject to the input parameter values assumed and basic assumptions made - be able to assess the financial viability of the project. The main assumptions were that the private feed-in into the national electricity grid was available to all IPPs, in spite of the fact that in its Medium Term Power Purchase Program me (MTPPP) of May 2008 Eskom had only requested expressions of interest from IPPs that had a generating capacity of 5MW and higher to install private base load capacity. This assumption is commensurate with the country's renewable energy targets and the official government aim of achieving a 30% contribution from IPPs to the national electricity mix. The second assumption was that the 65 to lOOclkWh offered by Eskom in its MTPPP will be applicable to sub-SMWe IPPs as well (Creamer, 2008), and that this lower bound electricity price of 65clkWh can be applied over the whole project lifetime. Inherent to this assumption is the further supposition that the progressive decline of electricity prices to an eventual level of 35clkWh by 2018 foreseen by Eskom will not materialize, due both to the sustained pressure an expanding South African economy will put on the considerable but time-consuming supply-side initiatives launched by Eskom, and the likelihood for price premiums to be introduced for clean electricity in order to meet the country's renewable energy targets. From the assumed input parameter values the initial capital and COM expenditures, operating revenues and costs over the project lifetime were determined, and then used to calculate the net cash flows, where after the NPV was computed to serve as the deciding criterion on financial feasibility. A discount rate of 18% was assumed, corresponding with the subjectively judged risks that the project posed as a small-scale renewable energy system within the wine cellar operations. In the case where the project excluded all CDM aspects, the NPV was negative at - ZAR342 573, but this improved to ZAR325 193 if the project participated in the CDM. Thus it was concluded that the project will only be financially feasible if it includes CDM participation, and that this positive contribution can be leveraged by pursuing a programmatic CDM approach. This entails the development of this project as part of a larger program in which similar projects are implemented as they arise, up to the official UN limit of 15MWe in total to still qualify as a small-scale program. The nature of the assumptions that form the backbone of this study indicate that the positive financial feasibility result in the case where the project includes COM participation will become practically relevant only over the short- to medium-term as these assumptions become reality in South Africa. Therefore, although the time for such small-scale renewable energy projects has clearly not arrived as yet, it would seem that it is indeed around the corner.
AFRIKAANSE OPSOMMING: Die mikpunt van die navorsing was om die lewensvatbaarheid van 'n klein-skaal biomassa vergassing sisteem binne die konteks van 'n kooperatiewe wynkelder in die Wes-Kaap van Suid-Afrika te ondersoek. 'n Sentrale aspek was die vrae of die tyd aangebreek het om klein-skaal volhouhare energie projekte in Suid-Afrika tot uitvoering te bring, gesien in die lig van 'n status quo wat drasties weg beweeg het van die tydperk toe elektrisiteit volop en goedkoop was, en of die geleentheid wat die CDM bied sulke projekte finansieel lewensvatbaar kan maak. Daar is verskeie eksterne makro-drywers wat bydrae tot die huidige fokus op sulke volhoubare energie projekte. Hieronder tel globale klimaatsverandering as die dringendste drywer, terwyl die res onder andere die hernuwe strewe van lande tot verbeterde energie-sekuriteit, die besef van die belangrikheid van volhoubare ontwikkeling en die daaropvolgende volhoubare energie beleid stappe insluit. Daar bestaan nog etlike tegniese uitdagings tot die toepassing van klein-skaal biomassa vergassing tegnologie, spesifiek met betrekking tot die vergassing van afval landbou byprodukte, soos wat die geval is met druiwe afval in hierdie projek. Die belangrikste tegniese uitvoerbaarheids-aspek wat aandag verg is die lae smeltpunt van druifafval-as wat in die literatuur rapporteer word. Alhoewel die plaaslike toerustings-vervaardiger nie enige probleme in hierdie verhand voorsien nie, aangesien toetse met sonneblom afval - met as-eienskappe rofweg identies aan die van druiwe-afval - geen smelting van die as getoon het nie, sal dit tog nogsteeds aan verdere toetse onderwerp word. Vir die projek om te kwalifiseer as geskik vir verhandeling in kweekhuisgas vermindering deur middel van die COM, moet dit voldoende bewys kan word dat alle uitlaatgas vermindering addisioneel is tot wat die geval sou wees in die gewone gang van besigheid. Hierdie addisionaliteit is relevant in beide 'n omgewings- en finansiele sin. Hierdie projek sal orngewings-addisionaliteit bevredig deurdat die wynkelder in sy afwesigheid volkome afhanklik van die steenkool-gebaseerde elektrisiteit vanaf die nasionale netwerk sou bly, terwyl finansiele addisionaliteit bewys is deur die finansiele lewensvatbaarheids-model wat getoon het dat die projek slegs ekonomies uitvoerbaar sal wees indien dit CDM deelname insluit. Die lewensvatbaarheids-model is ontwikkel om die ekonomiese uitvoerbaarheid van die projek te evalueer, onderworpe aan die aangenome inset parameter waardes en basiese aannames in die studie. Die hoof-aanname was naamlik dat privaat terugvoer in die nasionale elektrisiteits-netwerk vir alle grootte IPPs moontlik is, ten spyte van die feit dat Eskom se MTPPP van Mei 2008 slegs kapasiteite van 5MW en groter aanvaar bet. Hierdie aanname is gebaseer op Suid-Afrika se volhoubare energie teikens en die regering se offisiele mikpunt om 30% van alle krag-voorsiening vanaf IPPs te bekom. Die tweede hoof-aanname was dat die 65 tot 100clkWh wat Eskom in sy MTPPP aangebied het, ook van toepassing sal wees op sub-SMW IPPs (Creamer, 2008), en dat die laer prys-limiet van 65c/kWb oor die hele projek-leeftyd toegepas kon word. Inherent tot hierdie aanname is die verdere veronderstelling dat die progressiewe daling in elektrisiteits-pryse tot 'n eventuele vlak van 35clkWh voorsien deur Eskom nie sal realiseer nie, beide as gevolg van die volgehoue druk wat die groeiende Suid-Afrikaanse ekonomie op die aansieniike, maar tydrowende, opwekkings-kapasiteit uitbreidings van Eskom behoort te plaas, en ook die hoe waarskynlikheid dat prys premiums vir skoon elektrisiteit ingestel word sodat Suid-Afrika sy volboubare energie telkens kan bereik. Die aanvanklike kapitaal en CDM uitgawes, en bedryfsuitgawes en - inkomstes oor die projekleeftyd is vanaf die aangenome inset parameter waardes afgelei, waarop die NPV van die projek uitgewerk is om te dien as die beslissende maatstaf van ekonomiese haalbaarheid. 'n Diskontokoers van 18% is gebruik, ooreenstemmend met die subjektief beraamde risikos wat die projek inhou as 'n klein-skaal volhoubare energie sisteem. Die resultate van die finansiele lewensvatbaarheids-model het getoon dat in die geval waar die projek geen CDM aspekte bevat nie, die NPV hoogs negatief sou wees met 'n waarde van -ZAR342 573, terwyl dit verbeter na ZAR325 193 as die projek CDM deelname insluit. Die gevolgtrekking is dus gemaak dat die spesifieke projek slegs ekonomies haalbaar sal wees indien dit wel CDM deelname insluit, en dat hierdie positiewe finansiele bydrae van die CDM geoptimaliseer kan word deur 'n programmatiese CDM benadering te volg. Dit behels die ontwikkeling van die projek as deel van 'n groter program waarin soortgelyke projekte mettertyd geimplementeer word soos hulle ontstaan, tot by die offisiele VN limiet van 15MWe om sodoende nog te kwalifiseer as 'n algehele klein-skaalse program. Die aard van die hoof-aannames in hierdie studie is indikatief dat die positiewe finansiele lewensvatbaarheid in die geval waar die projek CDM deelname insluit, eers oor die kort- tot medium-termyn prakties relevant sal word soos die aannames bevredig word. Dus, alhoewel die era van klein-skaalse volhoubare energie projekte nog nie aangebreek het in Suid-Afrika nie, lyk dit tog asof dit om die draai is.

Thesis (Masters of Environmental Health)--Cape Peninsula University of Technology, 2018.
In the Western Cape, South Africa and other regions globally, grape pomace (GP) is one of the abundant agro-waste from the winery industry. This study reports on the hyper-extraction of fermentable sugars from GP treated with white rot fungi (WRF) Phanerochaete chrysosporium BKMF 1767 to facilitate improved biovalorisation for total reducing sugars (TRS) extraction in conjunction with Nepenthes mirabilis digestive fluids. TRS were quantified using the 3,5-dinitrosalicylic acid (DNS) reagent method. The free readily dissolvable sugars from the GP recorded for the bio-treated (BT) samples was 206.39 ± 0.06 mg/L and for the untreated (UT) samples was 271.05 ± 0.02 mg/L. Overall, the TRS yield for the Bio-treated (BT) and untreated (UT) samples was recorded as 205.68 ± 0.09 and 380.93 ± 0.14 mg/L, respectively, using hot water pretreatment (HWP) with 2266.00 ± 0.73 (BT) and 2850.68 ± 0.31 mg/L (UT), respectively, for dilute acid pretreatment (DAP); with 2068.49 ± 6.02 (BT) and 2969.61 ± 8.054 mg/L (UT) respectively, using the cellulase pretreatment (CP) method. Using the HWP as a reference, the relative increases imparted by the biotreatment was higher (51%) for DAP and low (33%) for CP. The combination of conventional used pre-treatment methods (hot water pretreatment, dilute acid pre-treatment, and cellulase pre-treatment) in a single pot system was also done while monitoring the total residual phenolics (TRPCs) in the samples. Furthermore, powder X-ray diffraction (pXRD) were used to measure the crystallinity index (CrI) and functional groups of pre- and post-pretreated GP to ascertain the efficiency of the pre-treatment methods, with quantification of lignin, holocellulose, and ash. Overall, the TRS yield for N. mirabilis pre-treated agro-waste was 951 mg/L ± 4.666 mg/L, with biomass having a lower CrI of 33%, and 62% residual lignin content. Furthermore, reduced TRPCs were observed in hydrolysate, suggesting limited inhibitory by-product formation during N. mirabilis pre-treatment