Two experiments were conducted to evaluate the effects of dietary inclusion level of a low lignin hull, high-oil groat (CDC SO-I) oat on the performance, carcass characteristics and rumen degradation characteristics of feedlot cattle. In the first trial, 200 crossbred steers (average weight of 427.3 ± 22.4 kg) were allocated to 20 pens. Five treatments, formulated by replacing barley with increasing levels of CDC SO-I oat (Barley grain:CDC SO-I oat ratios of 100:0; 75:25; 50:50; 25:75 and 0:100 ; DM basis) were used. Four pens were randomly allocated to each treatment diet. Over the entire study there was a linear decrease (P< 0.01) in DMI and ADG with increasing inclusion level of CDC SO-I oat, whereas feed efficiency (gain:feed) decreased (P= 0.03) quadratically. Days on feed also increased (P= 0.03) quadratically for the steers fed the higher levels of CDC SO-I oat. Increasing the inclusion level of CDC SO-I oat in the diet also decreased (P< 0.01) carcass weight, dressing percentage and grade fat linearly. However, there was no effect of treatment on rib eye area and lean yield percentage. There was no significant effect of treatment on marbling score. While the results of this trial point to a negative effect of CDC SO-I oat on finishing performance, there were minimal differences between cattle fed 100% barley as the concentrate versus those fed 75% barley: 25% oat blend.<p> Trial 2 involved a metabolism trial to determine the effect of CDC SO-I oat inclusion level on rumen fermentation parameters of 5 fistulated heifers fed the same diets used in Trial 1. A 5 × 5 Latin square experiment design was used. Rumen degradation parameters (rumen pH, VFA, osmolality and ammonia nitrogen levels) and feeding behavior (time spent eating, ruminating, chewing and drinking) were measured. Mean rumen pH for the barley-based diet was 5.88 which was not different (P> 0.05) than the mean pH of 5.5 for the oat-fed cattle. Treatment did not affect (P> 0.05) time spent below pH cutoff values of 5.8, 5.5 and 5.2. No effect of oat inclusion level (P> 0.05) was observed on total VFA levels, molar proportion of individual fatty acids and osmolality while isobutyrate (P= 0.05) and ruminal ammonia nitrogen concentrations decreased linearly (P= 0.02) with the higher inclusion of CDC SO-I oat. Time spent eating was linearly (P< 0.01) increased with higher inclusion level of CDC SO-I oat.<p> Over all, the results of this study indicate that the replacement of barley by CDC SO-I oat in finishing diets decreases dry matter intake and as a result leads to reduced ADG, increased days on feed and lower slaughter and carcass weights. The reduced performance might be the result of higher fat content, high hull and/or faster degradation rate of oat starch leading to subacute ruminal acidosis in cattle fed higher levels of oat. However, replacing barley with CDC SO-I oat does not significantly change the rumen environment. The results of this study indicate that CDC SO-I oat can be successfully included up to a maximum level of 25% without any adverse effect on performance and carcass characteristics in the diets of finishing cattle.

Hammarby Sjöstad is a new district of southern Stockholm built with focus on reduced environmental impact by recirculation of materials and sustainability. The environmental goals aim to cut the water consumption by half and a separate storm water treatment. Thus, the wastewater will be more concentrated and will originate from the households only. The Sjöstad project includes the idea of a local treatment plant for the household wastewater. To evaluate this possibility, Sjöstadsverket, an experimental treatment plant was constructed. New wastewater treatment processes are tested and evaluated and compared to conventional methods including both aerobic and anaerobic treatment processes. One of the aerobic treatment processes includes enhanced biological phosphorus removal (EBPR or Bio-P) as the method for the removal of phosphorus. In biological phosphorus removal the wastewater is alternately being exposed to anaerobic and aerobic conditions, which favours a certain bacteria, which can accumulate more phosphorus than is required for their growth. For this phosphorus accumulation the bacteria need volatile fatty acids (VFA) to cover their energy demand, but normally there is a shortage in VFA in the incoming wastewater. The main purpose of this master thesis work has been to create the best possible conditions in order to produce VFA by hydrolysis and fermentation of primary sludge. In this way the organic material in the incoming wastewater can be used in biological phosphorus removal. The sludge temperature, total solids (TS) and retention time are regarded as important parameters for a successful biological phosphorus removal and a laboratory study was set up to investigate these conditions for the wastewater at the Hammarby Sjöstad experimental plant. These laboratory-scale hydrolysis experiments showed that high temperature and high TS favours VFA-production. The results have also shown that four to five days retention time is suitable at a process temperature higher than 23°C, but also that the retention time likely should be extended at lower temperatures. In a full-scale process experiment, primary sludge was pumped from a primary clarifier to a hydrolysis tank and then back to the primary clarifier. The hydrolysis gave rise to increased VFA-production when TS was increased. A temperature difference between the primary sludge and the hydrolysis sludge of 3°C was observed. The reason behind the difference has not been determined, but is considered important, since the temperature affects the VFA-production. Further on, analyses with gas chromatograph (GC) have shown that acetate has been the most frequently occurring VFA, although significant levels of other VFA, such as propionate, has also been detected. Phosphorus release tests in laboratory-scale, where phosphorus was released during an anaerobic phase and taken up during an aerobic phase, proved that biological phosphorus removal occurred at the full-scale experimental train. The full-scale hydrolysis experiment has shown that the VFA contribution by the hydrolysis tank to the biological phosphorus removal was low. The main reason is that the sludge-flow through the hydrolysis tank has been insignificant compared to the incoming wastewater flow. The problem is most likely connected to the incoming wastewater characteristics, since the low share of suspended solids (SS) entailed that not enough organic material in the primary clarifier settled. / I figur 57 på sidan 76 stämmer inte trendlinjernas ekvationer i den tryckta versionen. Dessa är nu korrigerade i den elektroniska versionen, så att rätt ekvationer finns i den aktuella figuren.

Two experiments were conducted to evaluate the effects of dietary inclusion level of a low lignin hull, high-oil groat (CDC SO-I) oat on the performance, carcass characteristics and rumen degradation characteristics of feedlot cattle. In the first trial, 200 crossbred steers (average weight of 427.3 ± 22.4 kg) were allocated to 20 pens. Five treatments, formulated by replacing barley with increasing levels of CDC SO-I oat (Barley grain:CDC SO-I oat ratios of 100:0; 75:25; 50:50; 25:75 and 0:100 ; DM basis) were used. Four pens were randomly allocated to each treatment diet. Over the entire study there was a linear decrease (P< 0.01) in DMI and ADG with increasing inclusion level of CDC SO-I oat, whereas feed efficiency (gain:feed) decreased (P= 0.03) quadratically. Days on feed also increased (P= 0.03) quadratically for the steers fed the higher levels of CDC SO-I oat. Increasing the inclusion level of CDC SO-I oat in the diet also decreased (P< 0.01) carcass weight, dressing percentage and grade fat linearly. However, there was no effect of treatment on rib eye area and lean yield percentage. There was no significant effect of treatment on marbling score. While the results of this trial point to a negative effect of CDC SO-I oat on finishing performance, there were minimal differences between cattle fed 100% barley as the concentrate versus those fed 75% barley: 25% oat blend.<p> Trial 2 involved a metabolism trial to determine the effect of CDC SO-I oat inclusion level on rumen fermentation parameters of 5 fistulated heifers fed the same diets used in Trial 1. A 5 × 5 Latin square experiment design was used. Rumen degradation parameters (rumen pH, VFA, osmolality and ammonia nitrogen levels) and feeding behavior (time spent eating, ruminating, chewing and drinking) were measured. Mean rumen pH for the barley-based diet was 5.88 which was not different (P> 0.05) than the mean pH of 5.5 for the oat-fed cattle. Treatment did not affect (P> 0.05) time spent below pH cutoff values of 5.8, 5.5 and 5.2. No effect of oat inclusion level (P> 0.05) was observed on total VFA levels, molar proportion of individual fatty acids and osmolality while isobutyrate (P= 0.05) and ruminal ammonia nitrogen concentrations decreased linearly (P= 0.02) with the higher inclusion of CDC SO-I oat. Time spent eating was linearly (P< 0.01) increased with higher inclusion level of CDC SO-I oat.<p> Over all, the results of this study indicate that the replacement of barley by CDC SO-I oat in finishing diets decreases dry matter intake and as a result leads to reduced ADG, increased days on feed and lower slaughter and carcass weights. The reduced performance might be the result of higher fat content, high hull and/or faster degradation rate of oat starch leading to subacute ruminal acidosis in cattle fed higher levels of oat. However, replacing barley with CDC SO-I oat does not significantly change the rumen environment. The results of this study indicate that CDC SO-I oat can be successfully included up to a maximum level of 25% without any adverse effect on performance and carcass characteristics in the diets of finishing cattle.

In this study, production of organic acids from cheese-whey was studied. Optimization of organic acids production was performed in semi-batch and batch reactors. Two sets of experiments were performed. First set of experiments were performed in semi-batch reactors for the optimization of organic loading rate (OLR) and hydraulic retention time (HRT). As a result of Set 1 experiments optimum OLR was found to be 15 g COD l-1. Second set of experiments were performed in batch reactors by using the optimum OLR found in Set 1 experiments. Set 2 experiments were conducted to study the effect of using different seed cultures and Basal Media (BM) on Volatile fatty avid (VFA) production. Main acidogenesis products were acetic acid (Hac), butyric acid (Buty) and propionic acid (HPr) with smaller quantities of i-butyric acid (i-Buty), valeric acid (Val) and caproic acid (Cap). It was seen that BM had a suppressive effect on ethanol (EtOH) production while it stimulated the VFA production. Higher VFA productions and variety of VFA types were observed in Test Reactors seeded with acidogenic culture (R3 and R6).

Six ruminally fistulated steers (average BW 317 kg) were used in a 5 X 5 + 1 Latin Square design to determine effects of humic/fulvic acid (HFA) on serum urea nitrogen (SUN), rumen pH, rumen ammonia nitrogen (RAN), and rumen VFA production in Holstein steers. Treatments included a control (0%), 0.5, 1.0 or 1.5% HFA, and a diet containing monensin (33 mg/kg). A quadratic feed intake response was observed; with intake lowest for 0.5 and 1.0 and highest for 1.5 relative to control steers. No treatment x time interaction was observed for RAN, pH, SUN, total VFA or individual VFA. No treatment differences were observed for total VFA concentrations (mM), or for molar proportion of acetate, propionate, butyrate or valerate. A quadratic response was observed for butyrate and isovalerate. However, HFA does not alter rumen fermentation in the same mode of action as monensin.

Vinasse is the liquid waste removed from the base of sugarcane ethanol distillation columns at a ratio of 12-15 liters per liter of alcohol, resulting in an estimated production of approx. 350 billion liters in 2012/2013 in Brazil. Vinasse has a low pH and high chemical oxygen demand, which can cause land desertification when indiscriminately used as fertilizer. Also, underground water contamination is being observed in some regions. We evaluated the potential of vinasse as nutrient source for biohydrogen and volatile fatty acids production by means of anaerobic consortia. Two different vinasse-based media were proposed, using sugarcane juice or molasses as carbon source, and were compared to fermentation in a sucrosesupplemented medium. Pure cultures (4) and consortia (7) were cultured in the propose media and evaluated for volatile fatty acids (VFAs) and biohydrogen production. The consortium LPBAH1, originated from faeces of fruit bat, was selected for fermentation of vinasse supplemented with sugarcane juice and resulted in a higher H2 yield of 7.14 molH2/molsucrose and hydrogen content in biogas of approx. 31% after process optimization. Similarly, the optimized process using the consortium LPBAH2, originated from a lake of a dairy farm, resulted in 3.66 molH2/molsucrose and 32.7% hydrogen content in biogas. The proposed process is of great importance for giving a more rational destination to vinasse and expanding Brazilian energy matrix, reducing the dependence of fossil fuels.

Made available in DSpace on 2014-06-11T19:23:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-09-27Bitstream added on 2014-06-13T19:08:56Z : No. of bitstreams: 1 steil_l_me_araiq.pdf: 799428 bytes, checksum: ea2cd9b8adbc44bdd76ac6b53c7d3a09 (MD5) / Investigou-se a influência da utilização de inóculos sobre a digestão anaeróbia de resíduos de aves de postura, frangos de corte e suínos em biodigestores modelo batelada com volume útil de 60 L operados à temperatura ambiente, por meio da caracterização do potencial e distribuição da produção de biogás ao longo do tempo, o estudo da redução de sólidos, a análise das características dos efluentes quanto à concentração de ácidos graxos voláteis e por meio da determinação do número mais provável (NMP) de coliformes fecais e totais nos afluentes e efluentes. Avaliou-se também a atividade metanogênica nos biodigestores com 10 % de inóculo. Foram testadas três concentrações de inóculo: 0, 10 e 15 %. Os resultados mostraram que os resíduos de aves de postura, frangos de corte e suínos são bons substratos para o processo de digestão anaeróbia, apresentando potenciais médios que variaram de 0,3828 a 0,4403 m3, de 0,3495 a 0, 3915 m3, e de 0,1949 a 0,4466 m3 de biogás por kg de ST adicionados, respectivamente para resíduos de aves de postura, frangos de corte e suínos. Com base em todos os parâmetros estudados, as concentrações de inóculo que promoveram melhores resultados foram 10 % para resíduos de aves de postura e frangos de corte, e 15 % para resíduos de suínos. O tratamento anaeróbio revelou-se eficiente na remoção de coliformes totais e fecais independente da concentração de inóculo, alcançando porcentagens médias de redução de NMP que variaram de 99,71 % de 1,09 x 102 a 100 %. A atividade metanogênica específica foi mais elevada nas amostras provenientes dos biodigestores operados com resíduos de aves de postura (0,0340 mmol CH4 g-1 SV h-1), seguida pelos resíduos de frangos de corte (0,0188 mmol CH4 g-1 SV h-1) e suínos (0,0029 mmol CH4 g-1 SV h-1). Estes resultados parecem estar mais associados aos teores... / This study was carried out in 60 L volume batch digesters at ambient temperature and investigated the inoculums concentration effects on anaerobic digestion of laying hens, poultry and piggery wastes through evaluation of potential and distribution of biogas production along the time, solids removal, analyze of volatile fatty acids efluent concentration and by monitoring the most probable number (MNP) of total and faecal coliforms in the inffluents and effluents. Specific methanogenic activity (SMA) into the 10 % inoculum digesters was also measured. Three inoculum concentrations (0, 10 and 15 %) were tested. Results showed that laying hens, poultry litter and piggery wastes are good substrats to anaerobic digestion. The potential biogas production varied from 0.03828 to 0.4403 m3, 0.3495 to 0.3915 m3 and 0.1949 to 0.4466 m3 of biogas kg-1 of total solids added, respectively for laying hens, poultry and piggery wastes. The best results for inoculum concentration were 10 % for laying hens and poultry wastes, and 15 % for piggery wastes. Anaerobic digestion was efficient for reduction of the most probable mean number of total and faecal coliforms. Reduction of MNP mean varied from 99.71 of 1,09 x 102 to 100 %. SMA test showed the best activity was from laying hens wastes (0,03400 mmol CH4 g-1 SV h-1), followed by poultry wastes (0,01877 mmol CH4 g-1 SV h- 1) and by piggery wastes (0,00293 mmol CH4 g-1 SV h-1). Results of SMA test appear to be most affected by volatile solids content of the samples than the best ability of the microrganisms to convert substrate. The best organic load rate for activity test were 0,25 g DQO g-1 SV.

Foram objetivos do presente experimento estudar os efeitos da administração da enramicina, em comparação com a monensina sódica, sobre a fermentação ruminal e a digestibilidade total em bovinos. Doze fêmeas bovinas não-gestantes e não-lactantes (675 kg ± 63 de PV) foram distribuídas inteiramente ao acaso aos três tratamentos formados por um grupo controle (ausência de antibiótico), um grupo tratado com enramicina (antibiótico não-ionóforo) e outro tratado com monensina (antibiótico ionóforo). A enramicina foi administrada na dose de 20 mg/animal/dia e a monensina na dose de 300 mg/animal/dia. O experimento teve duração total de 21 dias, sendo os 10 últimos destinados à aplicação do marcador (15 g de óxido crômico/animal/dia) e os últimos 5 dias destinados à coleta de fezes e amostragem dos alimentos. O 21º dia foi utilizado para colheitas de líquido ruminal realizadas às 0, 2, 4, 6, 8, 10 e 12 horas após a 1a refeição para determinação dos AGVs, pH e nitrogênio amoniacal. A monensina aumentou a concentração total de AGVs no tempo 12 horas após a alimentação e diminuiu a relação acético:propiônico nos tempo 0 e 6 h, em relação à enramicina, mas não em relação ao controle. Nenhum dos antibióticos testados alterou a proporção molar dos ácidos acético, propiônico e butírico, bem como o pH ou a concentração ruminal de nitrogênio amoniacal. Também não alterou o comportamento de consumo, avaliado em atividades de alimentação, ruminação e ócio. Nenhum dos antibióticos testados alterou a digestibilidade da matéria seca, proteína bruta, extrato etéreo, extrativo não nitrogenado, fibra bruta, fibra em detergente ácido, fibra em detergente neutro, amido, energia bruta ou os nutrientes digestíveis totais / The objective of this trial was to study the effects of enramycin administration, compared to sodium monensin, on ruminal fermentation and on total digestibility of diet nutrients in bovine. Twelve non-pregnant and non-lactating cows (675 ± 63 kg of BW) were randomly assigned to three treatments: control group (non-antibiotic), enramycin-treated group (non-ionophore antibiotic) and monensin-treated group (ionophore antibiotic). Treatments were 20 mg/animal/day of enramycin or 300 mg/animal/day of monensin. Trial lasted 21 days, the last 10 used for external marker administration (15 g of chromic oxide/animal/day) and the last 5 for feces collection and feed sampling. The 21st day was used for ruminal fluid sampling at 0, 2, 4, 6, 8, 10 and 12 hours after 1st meal to determine VFA, pH and ammoniacal nitrogen. Monensin increased total VFA concentration 12 h after feeding and decreased the acetic:propionic ratio at times 0 and 6 h, in relation to enramycin, but not when compared to control. The two antibiotics tested did not influence the molar proportion of acetic, propionic or butiric acids, pH, ammoniacal-N concentration, or dry matter intake and intake behavior, evaluated during activities of feeding, rumination and idleness. The two antibiotics tested did not alter the digestibility of dry matter, crude protein, ether extract, nitrogen-free extract, crude fiber, acid detergent fiber, neutral detergent fiber, starch, gross energy and total digestible nutrients (TDN), or the intake of digestible dry matter or TDN

This work focused a pH readjustment strategy has been applied for the enhancement ofbiohydrogen production form food waste hydrolysate in a semi-pilot scale bioreactor seededwith selectively enriched mixed microbial culture. Different initial pH (pH 6, pH 7, and pH8) was selected for biohydrogen production from FW. When hydrogen production was terminated due to the accumulation of volatile fatty acids in the bioreactor, then the pHof the bioreactor was again readjusted to its initial pH. Highest hydrogen production rate of1.13 L/h (CHP: 58.48 L) was achieved with pH 8 operation which was almost double thanpH 6 and pH 7 operation. Volatile fatty acids (VFA) production was also influenced by thisstrategy. Higher acetic and butyric acids (2471.4mg/L and 947.37mg/L) were observed. Highest buffering capacity (0.1ßmol) significantly contributed towards higher biohydrogenproduction via this pH adjustment strategy. This strategy not only enhanced H 2 productionbut it also increased the waste conversion efficiency towards other biobased productsproduction during acidogenesis of FW.

M.Sc. (Chemistry) / Volatile fatty acids (VFAs) play a pivotal in the process of nutrient removal by biological processes particularly the enhanced biological nutrient removal process with a side-stream elutriation process using activated sludge. These acids are said to act as intermediates which provide feed for the organisms in a biological phosphorus and nitrogen removal (BNPR) system, such as phosphorus-accumulating organisms (PAOs) and nitrate-accumulating bacteria (NABs). In wastewater treatment plants, VFAs play a vital role as intermediate organic compounds during the fermentation processes which generate methane gas and when present at elevated levels they are known to cause microbial stress, acidification as well as the poor performance of anaerobic digesters. For these reasons, the routine monitoring of VFA levels in wastewater treatment plants is crucial as they will act as indicators of the efficiency and optimal operation performance of the anaerobic digesters. Normally the VFAs that are commonly produced during the anaerobic fermentation process include acetic acid, propionic acid, butyric acid, and valeric acid and of these, acetic and propionic acids form the major VFAs that are generated, thus the yields of these two compounds provide a useful measure of the anaerobic digester performance. For example, the ratio of propionic acid to acetic acid is always used as an indicator of digester imbalance while high concentrations of acetic acid (e.g. > 800 mg/ℓ) or a propionic acid to acetic acid ratio greater than 1.4 is an indication of digester failure. This study was thus aimed at establishing the complete VFA profile at the Johannesburg Water (JW) Northern Works Wastewater Treatment Plant in Johannesburg, South Africa, by developing analytical methods to quantify the VFAs in the wastewater treatment plant. In addition, the level of VFAs quantified was used to evaluate the efficiency of the fermentation treatment process in wastewater treatment systems in order to give an indication of the bacterial activities in the systems; to determine the ratios of the VFAs, especially the propionic acid to acetic acid ratio, to establish the performance and efficiency of various wastewater treatment plants; and to determine whether there is any imbalance in the anaerobic digesters. Two analytical methods for the determination of VFAs were successfully developed and applied to real wastewater samples. The first method developed was a liquid-liquid extraction method using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS. The method involved two extracting solvents, namely dichloromethane (DCM) and methyl-tert-butyl ether (MTBE). The extraction capacity of these two solvents was compared. The second method successfully developed and optimised headspace-solid phase microextraction (HS-SPME) using GC-TOF-MS. The microextraction fibre used was a polydimethylsiloxane (PDMS) fibre. Studies to validate the developed methods were also carried out by calculating the limit of detection (LOD) and limit of quantification (LOQ). Ratios of propionic acid to acetic acids were determined as well as the concentrations of acetic acid for both developed methods in order to evaluate the performance and efficiency of the treatment process. The results of the study show that the extraction procedure using solvents DCM and MTBE showed that exhaustive extraction was achieved by MTBE. Higher concentrations of acetic acid and propionic acid were obtained by MTBE. The overall fermentation performance for all three units in the period when the samples were collected, which was measured by the ratio of propionic to acetic acid was good since the ratio did not exceed 1.4. The acetic acid concentration in mg/ℓ was < 800 mg/ℓ for all units thus it can be said that the reactor balance was maintained for the period studied. The method LOD ranged from 0.034 mg/ℓ to 0.21 mg/ℓ and the method LOQ ranged from 0.11 mg/ℓ to 0.70 mg/ℓ. Optimisation of extraction parameters was achieved for headspace solid-phase microextraction using the PDMS fibre method. The extraction method was conducted for 60 min using a sample volume of 4 mℓ and the amount of sodium salt added was 1.50 g. The desorption temperature and time was 210ºC and 5 min, respectively. The LOD values ranged from 0.079 to 2.07. The PDMS fibre was found to be suitable for extracting higher carbon chain fatty acids as compared to lower carbon chain fatty acids. The plant performance for the period studied was on par as indicated by ratios of propionic acid to acetic acid which all fell below 1.4. There were no digester failures for the period studied. The acetic acid concentration in mg/ℓ was < 800 mg/ℓ for all 3 units.