An investigation was carried out to study whether long-chain fatty acids (LCFAs) have an effect on digestion of waste sludge under anaerobic conditions. Four different kinds of LCFAs were used in this study. The 18 carbon series with 0, 1, 2 and 3 double bonds were studied to evaluate the degree of saturation on fatty acid degradation. Due to their molecular structure, unsaturated LCFAs are more soluble than saturated LCFAs. Oleic, linoleic, linolenic acid with an ascending number of double bonds were tested as representatives for three different degrees of saturation. In addition, stearic acid, a saturated fatty acid was also tested. LCFAs were added to sewage sludge at concentrations ranging from 5% to 20% on a weight basis and the pH, solids reduction and COD reduction were determined. The results suggested that in addition to degrading in the digesters, all unsaturated acids contributed additional solids removal, compared to the control group. In contrast, stearic acid did not affect the solids removal. The COD reduction was similar to solids reduction in that additional COD was destroyed when unsaturated LCFAs were added to the sludge. The mechanism for additional solids reduction is not known. / Master of Science

The Induced Bed Reactor (IBR) was developed at Utah State University to apply high-rate anaerobic digestion techniques to high solids content substrates. This technology has been successfully implemented at full-scale multiple installations in the United States and Canada as a waste treatment and energy production technology, but the physical processes necessary to further optimize the system were not well understood. Bench scale IBRs were operated as anaerobic digesters at 35°, 45°, and 55° C under three organic loading rates and three corresponding hydraulic retention times. Reactor performance was monitored at steady state for residence time distribution and substrate reduction. The results show that the IBR behaves as a retained biomass reactor with fluid mixing that most closely approximates Completely Stirred Tank Reactor (CSTR) behavior when operated under the study conditions. A compartment real CSTR model, incorporating elements of dead zone and bypass flow, appears to be the most appropriate representation of the data. Mixing is likely due to a combination of energy inputs from thermal gradients induced by heat flux through the reactors and reactor and shear rates induced by gas evolution in the sludge bed.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nutrition and Food Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 332-370. / by Alejandro Angel Herrero-Molina. / Ph.D.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21298号 / 医博第4387号 / 新制||医||1030(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 中川 一路, 教授 木原 正博, 教授 小池 薫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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MSc(Eng), Faculty of Engineering and the Built Environment, University of the Witwatersrand, 2010

The effects of low carbohydrate (CHO), high fat (LCHF) diets on adaptations to high-intensity exercise have recently gained interest. Consuming a LCHF may potentially decrease the ability to use CHO during exercise and impair high-intensity exercise adaptations. Therefore, the purpose of this investigation was to examine the importance of CHO timing while consuming a LCHF diet and completing a high-intensity exercise program. Eighteen resistance trained males were randomized into two treatment groups. Both groups completed 6 weeks of a high-intensity exercise training program with the first 2 weeks serving as familiarization to resistance training (RT) 3 days per week and completing one high-intensity interval training (HIIT) session. During the final 4 weeks, participants trained 5 days per weeks, three days of RT and two days of HIIT (repeated 30 s all out sprints). All participants consumed a LCHF diet (~25%, ~25%, and ~50% of daily kilocalorie intake coming from CHO, protein, and fat). The supplemented (SUPP) group (n=9) consumed 30 g of CHO during exercise and 40 g of CHO immediately after each exercise session. The remainder of the SUPP groups daily CHO intake came outside of training. The non-supplemented (NONSUPP) group (n=9) consumed an artificially flavored placebo during exercise. The NONSUPP group had the same daily CHO intake as the SUPP group, with the only difference being CHO timing. Dependent variables measured pre-and post-training included back squat and bench press one-repetition maximums, peak oxygen consumption (V̇O2 peak), power output (Wingate test), body composition, fasted glucose, insulin, and testosterone, and gastrointestinal distress (GID) during exercise. Both groups significantly improved back squat and bench press strength, biceps thickness, absolute and relative V̇O2 peak, and power output. Respiratory exchange ratio was significantly lower and time to exhaustion significantly increased during the post V̇O2 peak test. However, there were no changes in resting glucose, insulin, and testosterone or body fat. RT and HIIT caused significant increases in GID, independent of beverage content, with no differences between training. Our results suggest that CHO timing has no impact on adaptations to exercise training, but favorable training adaptations can be made while consuming a LCHF diet.

Nitrogen pollution in the environment creates challenging problems globally and locally and can be effectively controlled by a significant reduction in nitrogen release into the natural water system. In addition, nutrients in high-strength wastewater can be recovered as valuable resources such as different types of ammonium solutions for industrial and agricultural utilizations. Selective ammonia separation from high-strength wastewater can be achieved by bipolar membrane electrodialysis (BMED), a relatively new ion exchange technology. A series of 8 bench-scale BMED experiments with bipolar membranes and cation exchange membranes were performed under various voltage applications. Ammonia in the wastewater was rapidly separated and recovered as a high purity ammonium hydroxide solution. BMED operation for 30 minutes at 5.0 V per cell pair was found to be ideal for high purity ammonium hydroxide production and low electrical energy consumption. Additionally, effective organic fouling control and low energy consumption were achieved. The experiments showed a decrease in the feed pH making it ideal for applications in solid-state anaerobic digestion with leachate recirculation. The application of leachate recirculation in solid-state anaerobic digestion (SSAD) has proven effective for mobilizing nutrients and diluting toxic byproducts to enhance biogas production. The leachate after recirculation contains accumulated ammonia and an increased pH and requires water and chemicals for dilution and pH adjustment prior to recirculation. The data from the experiments were used to construct a numerical model for a hypothetical lab-scale and pilot-scale bipolar membrane electrodialysis and solid-state anaerobic digestion with leachate recirculation (BMED-SSAD) system. A final ammonia concentration of less than 2000 mg-N/L in the reactor was found to be achievable by lab-scale (6 mA/cm2) and pilot-scale (12 mA/cm2) BMED-SSAD and low electric energy consumption. The results suggest that BMED is an attractive solution for ammonia separation from high-strength wastewater. / Thesis / Master of Applied Science (MASc)

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No description available.