No description available.

Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2015. / This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa, and their ability to degrade two PAH compounds (acenaphthene and fluorene). A total of 19 bacterial isolates were obtained from the Diep- and Plankenburg Rivers. These microorganisms were first identified phenotypically on various selective and general media (such as nutrient agar, Eosine Methylene Blue and Mannitol Salts Agar), followed by staining and biochemical testing, followed by molecular identification using 16S rRNA and PCR. The isolates were then tested for acenaphthene and fluorene degradation first at flask scale and then in a Stirred Tank Bioreactor at varying temperatures (25ºC, 30ºC, 35ºC, 37ºC, 38ºC, 40ºC and 45ºC). All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Four of the 19 isolated microorganisms were identified as acenaphthene and fluorene degrading isolates. Three of the four microorganisms identified as PAH degrading isolates were Gram negative isolates. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded fluorene (99.90%, 97.90%, 98.40% and 99.50%) and acenaphthene (98.60%, 95.70%, 90.20% and 99.90%) at 37ºC, 37ºC, 30ºC and 35ºC, respectively. The degradation of fluorene was found to be more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Throughout the biodegradation experiments, there was an exponential increase in microbial plate counts ranging from 5 x 104 to 9 x 108 CFU/ml. The increase in plate count was observed to correlate with the efficient degradation temperature profiles and percentages. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and can be used on a larger, commercial scale to bioremediate PAH contaminated river systems. Other factors that influence the optimal expression of biodegradative potential of microorganisms other than temperature and substrate (nutrient) availability, such as pH, moisture and salinity will be investigated in future studies, as well as the factors contributing to the higher fluorene degradation compared to acenaphthene. Furthermore, the structure and toxicity of the by-products and intermediates produced during microbial metabolism of acenaphthene and fluorene should be investigated in further studies.

No description available.

Includes bibliographical references. / 1 v. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The mechanism(s) by which calcium stabilises soil organic carbon against microbial attack was investigated in this study. / Thesis (M.A.)--University of Adelaide, Dept. of Soil Science, 1989

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2007. / Innovation in biotechnology research has resulted in a number of fungi being identified for diverse industrial applications. One such fungus, which is the subject of this study and has been one of the most intensively studied, is Phanerochaete chrysosporium. Much research has been done in developing optimized membrane bioreactor systems for the cultivation of these fungi because of their potent industrial applications. This research, however, has been hampered by the lack of a thorough understanding of the kinematics of flow, as well as the dynamics of the flow through these devices. Previous analyses of momentum transfer in membrane bioreactors have been entirely based on horizontally orientated bioreactor systems, and ignored the different modes of operations of membrane bioreactors. These models also ignored the osmotic pressure effects brought about by the retention of solutes on the membrane surface. In this study, analytical and numerical solutions to the Navier-Stokes equations for the description of pressure, velocity, and volumetric flow profiles in a single fibre capillary membrane bioreactor (SFCMBR) were developed. These profiles were developed for the lumen and shell sides of the SFCMBR, taking into account osmotic pressure effects, as well as gel and/or cake formation on the lumen surface of the membrane. The analytical models developed are applicable to horizontal and vertical systems, as well as dead-end, continuous open shell, closed-shell, and shell side crossflow modes.

Harmful organic contaminants, such as petroleum hydrocarbons, are ubiquitous in coastal marine ecosystems around the world, a problem that will only be exacerbated with rising sea level and increased inundation of coastal urban areas. Therefore, it is necessary to understand the fate of these contaminants following their deposition on marine sediment, where they can potentially persist for long periods of time. As organic carbon remineralization rates depend on the respiration process employed by the bacteria in the sediment, it was the goal of this study to determine how the sediment redox environment, with an emphasis on Fe redox chemistry, affects the biodegradation of recalcitrant petroleum hydrocarbon compounds. While amendment of natural sediment with Fe minerals that are commonly transported to coastal areas following erosion from continental crust did successfully catalyze Fe reduction and inhibit sulfate reduction, the effect on the hydrocarbon biodegradation rate was negligible. However, inoculation of the sediment with Shewanella oneidensis, an exoelectrogenic, Fe reducing bacteria known to catalyze the degradation of hydrocarbon compounds found in crude oil, did significantly affect the redox environment and sediment microbial communities and alter the pattern of hydrocarbon loss in the sediment over time. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

Lau Kan Lung. / Thesis submitted in: November 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 286-312). / Abstracts in English and Chinese. / List of Symbols and Abbreviations --- p.I / List of Figures --- p.III / List of Tables --- p.XII / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Polycyclic aromatic hydrocarbons (PAHs) --- p.1 / Chapter 1.1.1 --- Physical and chemical properties of PAHs --- p.1 / Chapter 1.1.2 --- Formation of PAHs --- p.5 / Chapter 1.1.3 --- Sources of PAHs --- p.9 / Chapter 1.1.4 --- Regulations for contamination of PAHs --- p.13 / Chapter 1.1.5 --- Pollution of PAHs in environments of Hong Kong --- p.17 / Chapter 1.1.6 --- Toxicity of PAHs --- p.18 / Chapter 1.1.7 --- Fate of PAHs --- p.22 / Chapter 1.1.7.1 --- Sorption --- p.24 / Chapter 1.1.7.2 --- Volatilization --- p.25 / Chapter 1.1.7.3 --- Photooxidation --- p.25 / Chapter 1.1.7.4 --- Chemical oxidation --- p.27 / Chapter 1.1.7.5 --- Microbial degradation --- p.28 / Chapter 1.1.8 --- General principles of metabolism of PAHs --- p.30 / Chapter 1.2 --- Spent mushroom compost (SMC) --- p.35 / Chapter 1.2.1 --- Production of SMC --- p.35 / Chapter 1.2.2 --- Physical and chemical properties of SMC --- p.36 / Chapter 1.2.3 --- Availability of SMC --- p.40 / Chapter 1.2.4 --- Conventional applications of SMC --- p.43 / Chapter 1.2.5 --- Alternate use of SMC --- p.44 / Chapter 1.3 --- Objectives of the study --- p.48 / Chapter 1.4 --- Research strategy --- p.51 / Chapter 1.4.1 --- Effect of initial PAH concentration --- p.51 / Chapter 1.4.2 --- Effect of initial pH --- p.52 / Chapter 1.4.3 --- Effect of incubation time --- p.53 / Chapter 1.4.4 --- Effect of incubation temperature --- p.54 / Chapter 1.4.5 --- Putative identification of intermediates and/or breakdown products --- p.54 / Chapter 1.4.6 --- Isotherm plots and fitting into monolayer models --- p.55 / Chapter 1.4.6.1 --- Langmuir isotherm --- p.56 / Chapter 1.4.6.2 --- Freundlich isotherm --- p.58 / Chapter 1.4.7 --- Toxicological study by Microtox test --- p.59 / Chapter 1.4.8 --- Removal of PAH mixtures --- p.60 / Chapter 1.4.9 --- Specific goals of the study --- p.61 / Chapter 2 --- Materials and Methods --- p.62 / Chapter 2.1 --- Materials --- p.62 / Chapter 2.2 --- Physical and chemical analysis of SMC --- p.62 / Chapter 2.2.1 --- pH --- p.63 / Chapter 2.2.2 --- Electrical conductivity --- p.63 / Chapter 2.2.3 --- Salinity --- p.63 / Chapter 2.2.4 --- Ash content --- p.63 / Chapter 2.2.5 --- Metal contents --- p.64 / Chapter 2.2.6 --- Water-soluble anion contents --- p.65 / Chapter 2.2.7 --- "Carbon, hydrogen, nitrogen and sulfur contents" --- p.65 / Chapter 2.2.8 --- Infrared spectroscopic study --- p.66 / Chapter 2.2.9 --- Chitin content --- p.66 / Chapter 2.3 --- Soil collection and characterization --- p.67 / Chapter 2.4 --- Optimization for extraction --- p.67 / Chapter 2.5 --- Removal of PAHs --- p.68 / Chapter 2.5.1 --- Experimental design --- p.68 / Chapter 2.5.1.1 --- Pretreatment and incubation --- p.68 / Chapter 2.5.1.2 --- Extraction of sorbed PAHs in soil system or in SMC --- p.69 / Chapter 2.5.1.3 --- Extraction of PAHs in water system --- p.70 / Chapter 2.5.1.4 --- Putative identification and quantification of PAHs --- p.71 / Chapter 2.5.2 --- Assessment criteria --- p.72 / Chapter 2.5.3 --- Stability of PAHs --- p.77 / Chapter 2.5.4 --- Optimization for removal of PAHs --- p.78 / Chapter 2.5.4.1 --- Effects of initial PAH concentration and amount of SMC --- p.78 / Chapter 2.5.4.2 --- Effect of initial pH --- p.79 / Chapter 2.5.4.3 --- Effect of incubation time --- p.79 / Chapter 2.5.4.4 --- Effect of incubation temperature --- p.79 / Chapter 2.5.5 --- Putative identification of intermediates and/or breakdown products --- p.80 / Chapter 2.5.6 --- Isotherm plots and fitting into monolayer models --- p.80 / Chapter 2.5.6.1 --- Langmuir isotherm --- p.80 / Chapter 2.5.6.2 --- Freundlich isotherm --- p.81 / Chapter 2.5.7 --- Toxicological study of Microtox® test --- p.82 / Chapter 2.5.8 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.82 / Chapter 2.5.9 --- Removal abilities of different sorbents towards PAHs in water --- p.83 / Chapter 2.5.10 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.83 / Chapter 2.5.11 --- Statistical validation --- p.83 / Chapter 3 --- Results --- p.85 / Chapter 3.1 --- Characterization of soil --- p.85 / Chapter 3.1.1 --- Physical and chemical properties of soil --- p.85 / Chapter 3.1.2 --- GC-MS analysis of soil --- p.85 / Chapter 3.2 --- Calibration curves of PAHs --- p.85 / Chapter 3.3 --- Optimization for extraction --- p.91 / Chapter 3.4 --- Stability of PAHs --- p.101 / Chapter 3.4.1 --- Soil system --- p.101 / Chapter 3.4.1.1 --- Effect of incubation time --- p.101 / Chapter 3.4.1.2 --- Effect of incubation temperature --- p.101 / Chapter 3.4.2 --- Water system --- p.103 / Chapter 3.4.2.1 --- Effect of incubation time --- p.103 / Chapter 3.4.2.2 --- Effect of incubation temperature --- p.103 / Chapter 3.5 --- Characterization of SMC --- p.103 / Chapter 3.5.1 --- Physical and chemical properties of SMC --- p.103 / Chapter 3.5.2 --- GC-MS analysis of SMC --- p.106 / Chapter 3.5.3 --- Infrared spectroscopic study and chitin content --- p.106 / Chapter 3.5.4 --- Removal abilities of different sorbents towards PAHs in water --- p.121 / Chapter 3.5.5 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.121 / Chapter 3.6 --- Optimization for removal of PAHs --- p.124 / Chapter 3.6.1 --- Naphthalene --- p.124 / Chapter 3.6.1.1 --- Soil system --- p.124 / Chapter 3.6.1.1.1 --- Effects of initial naphthalene concentration and amount of straw SMC on removal efficiency --- p.124 / Chapter 3.6.1.1.2 --- Effects of initial naphthalene concentration and amount of straw SMC on removal capacity --- p.128 / Chapter 3.6.1.1.3 --- Effect of initial pH --- p.128 / Chapter 3.6.1.1.4 --- Effect of incubation time --- p.128 / Chapter 3.6.1.1.5 --- Effect of incubation temperature --- p.131 / Chapter 3.6.1.1.6 --- Putative identification of intermediates and/or breakdown products --- p.131 / Chapter 3.6.1.2 --- Water system --- p.134 / Chapter 3.6.1.2.1 --- Effects of initial naphthalene concentration and amount of straw SMC on removal efficiency --- p.134 / Chapter 3.6.1.2.2 --- Effects of initial naphthalene concentration and amount of straw SMC on removal capacity --- p.137 / Chapter 3.6.1.2.3 --- Effect of initial pH --- p.137 / Chapter 3.6.1.2.4 --- Effect of incubation time --- p.139 / Chapter 3.6.1.2.5 --- Effect of incubation temperature --- p.139 / Chapter 3.6.1.2.6 --- Putative identification of intermediates and/or breakdown products --- p.143 / Chapter 3.6.2 --- Phenanthrene --- p.145 / Chapter 3.6.2.1 --- Soil system --- p.145 / Chapter 3.6.2.1.1 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal efficiency --- p.145 / Chapter 3.6.2.1.2 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal capacity --- p.145 / Chapter 3.6.2.1.3 --- Effect of initial pH --- p.148 / Chapter 3.6.2.1.4 --- Effect of incubation time --- p.148 / Chapter 3.6.2.1.5 --- Effect of incubation temperature --- p.151 / Chapter 3.6.2.1.6 --- Putative identification of intermediates and/or breakdown products --- p.151 / Chapter 3.6.2.2 --- Water system --- p.155 / Chapter 3.6.2.2.1 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal efficiency --- p.155 / Chapter 3.6.2.2.2 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal capacity --- p.155 / Chapter 3.6.2.2.3 --- Effect of initial pH --- p.157 / Chapter 3.6.2.2.4 --- Effect of incubation time --- p.157 / Chapter 3.6.2.2.5 --- Effect of incubation temperature --- p.161 / Chapter 3.6.2.2.6 --- Putative identification of intermediates and/or breakdown products --- p.163 / Chapter 3.6.3 --- Benzo[a]pyrene --- p.163 / Chapter 3.6.3.1 --- Soil system --- p.163 / Chapter 3.6.3.1.1 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal efficiency --- p.163 / Chapter 3.6.3.1.2 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal capacity --- p.167 / Chapter 3.6.3.1.3 --- Effect of initial pH --- p.167 / Chapter 3.6.3.1.4 --- Effect of incubation time --- p.168 / Chapter 3.6.3.1.5 --- Effect of incubation temperature --- p.168 / Chapter 3.6.3.1.6 --- Putative identification of intermediates and/or breakdown products --- p.172 / Chapter 3.6.3.2 --- Water system --- p.172 / Chapter 3.6.3.2.1 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal efficiency --- p.172 / Chapter 3.6.3.2.2 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal capacity --- p.176 / Chapter 3.6.3.2.3 --- Effect of initial pH --- p.178 / Chapter 3.6.3.2.4 --- Effect of incubation time --- p.178 / Chapter 3.6.3.2.5 --- Effect of incubation temperature --- p.181 / Chapter 3.6.3.2.6 --- Putative identification of intermediates and/or breakdown products --- p.183 / Chapter 3.6.4 --- "Benzo[g,h,i]perylene" --- p.183 / Chapter 3.6.4.1 --- Soil system --- p.183 / Chapter 3.6.4.1.1 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal efficiency" --- p.183 / Chapter 3.6.4.1.2 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal capacity" --- p.187 / Chapter 3.6.4.1.3 --- Effect of initial pH --- p.187 / Chapter 3.6.4.1.4 --- Effect of incubation time --- p.187 / Chapter 3.6.4.1.5 --- Effect of incubation temperature --- p.189 / Chapter 3.6.4.1.6 --- Putative identification of intermediates and/or breakdown products --- p.189 / Chapter 3.6.4.2 --- Water system --- p.192 / Chapter 3.6.4.2.1 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal efficiency" --- p.192 / Chapter 3.6.4.2.2 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal capacity" --- p.196 / Chapter 3.6.4.2.3 --- Effect of initial pH --- p.198 / Chapter 3.6.4.2.4 --- Effect of incubation time --- p.198 / Chapter 3.6.4.2.5 --- Effect of incubation temperature --- p.198 / Chapter 3.6.4.2.6 --- Putative identification of intermediates and/or breakdown products --- p.201 / Chapter 3.7 --- Isotherm plots and fitting into monolayer models --- p.205 / Chapter 3.7.1 --- Sorption of naphthalene --- p.205 / Chapter 3.7.2 --- Sorption of phenanthrene --- p.205 / Chapter 3.7.3 --- Sorption of benzo[a]pyrene --- p.208 / Chapter 3.7.4 --- "Sorption of benzo[g,h,i]perylene" --- p.208 / Chapter 3.8 --- Toxicological study of Microtox test --- p.208 / Chapter 3.8.1 --- Soil system --- p.214 / Chapter 3.8.2 --- Water system --- p.214 / Chapter 3.9 --- Operable conditions of SMC for removal of PAHs --- p.214 / Chapter 3.10 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.214 / Chapter 3.10.1 --- Soil system --- p.216 / Chapter 3.10.2 --- Water system --- p.216 / Chapter 4 --- Discussion --- p.221 / Chapter 4.1 --- Characterization of SMC --- p.221 / Chapter 4.2 --- Removal abilities of different sorbents towards PAHs in water --- p.223 / Chapter 4.3 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.226 / Chapter 4.4 --- Extraction efficiencies of PAHs --- p.227 / Chapter 4.5 --- Factors affecting removal of PAHs by SMC --- p.229 / Chapter 4.5.1 --- Initial PAH concentration and amount of straw SMC --- p.229 / Chapter 4.5.2 --- Initial pH --- p.237 / Chapter 4.5.3 --- Incubation time --- p.237 / Chapter 4.5.4 --- Incubation temperature --- p.242 / Chapter 4.6 --- Putative identification of intermediates and/or breakdown products --- p.247 / Chapter 4.7 --- Isotherm plots and fitting into monolayer models --- p.257 / Chapter 4.8 --- Toxicological study of Microtox® test --- p.258 / Chapter 4.9 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.261 / Chapter 4.10 --- Comparison of removal efficiencies of benzo[a]pyrene by layering and mixing of straw SMC with soil --- p.265 / Chapter 4.11 --- Comparison of removal efficiencies of benzo[a]pyrene in different scales of experiment setup --- p.267 / Chapter 4.12 --- Effect of age of straw SMC on removal of PAHs --- p.270 / Chapter 4.13 --- Removal of benzo[a]pyrene by an aqueous extract of SMC --- p.270 / Chapter 4.14 --- Advantages of using SMC in removal of PAHs --- p.273 / Chapter 4.15 --- Limitations of the study --- p.278 / Chapter 4.16 --- Further investigation --- p.280 / Chapter 5 --- Summary --- p.282 / Chapter 6 --- Conclusion --- p.285 / Chapter 7 --- References --- p.286

Abstract not available

Bibliography: leaves 134-148. The objectives of this study are to determine if and how inorganic matrices influence organic matter decomposition with particular emphasis on the biochemical changes which occur as decomposition progresses. The influence of inorganic matrices (sand, sand + kaolin and loamy sand) on the decomposition of straw and Eucalyptus litter during incubations was followed by various chemical and spectroscopic methods to aid in the understanding of the mechanism of physical protection of organic matter in soils.

This study investigated the effect of plant surface area (plant density) on the efficiency of organic carbon removal in a bench-scale constructed wetland. Constructed wetlands are commonly assumed to be biofilm reactors in which organic carbon removal occurs primarily through sedimentation and aerobic degradation by attached microbial biofilms. In conventional biofilm reactors, aerobic degradation of organic carbon is proportional to the amount of surface area for microbial attachment, provided that sufficient oxygen is available. In contrast, current design equations for constructed wetlands assume that the amount of surface area is not an important parameter. A bench-scale simulation of a constructed wetland was conducted, using bulrushes planted at varying plant densities in soil with a free water surface depth of about 0.27 m. The carbon source was diluted ENSUR (TM). Total organic carbon (TOC) removal was measured. Concentration of TOC was correlated with biochemical oxygen demand (BOD). Tests were conducted in conditions of light and dark, and under two different carbon loadings. Performance of bulrushes was compared with that of inert acrylic rods. The rate of carbon removal by mature bulrushes was found to increase with increasing plant density until oxygen became depleted. Higher densities degraded carbon at rates much faster than those predicted by current design equations. Young bulrushes degraded carbon at faster rates than mature bulrushes. Once oxygen was depleted, rates of degradation were reduced to rates anticipated by current models. When plant density was 15% or greater, oxygen became depleted in less than 6 hours. Removal efficiency was greater at higher loadings (70 mg/l BOD) than at lower loadings (25 mg/l BOD). Bulrushes performed significantly better than inert rods, sometimes by a full order of magnitude. The microbial community on the bulrushes appeared to be more complex and robust than that on the rods. Also, the presence of light did not significantly increase degradation rates for the bulrushes but was significant for the rods. The microbial community on the rods contained a larger proportion of epiphytic algae. The presence of light did result is greater overall efficiency of removal for both bulrush and rods. Currently, a major drawback of constructed wetlands in wastewater treatment has been their demand for large areas of land. This study suggests that it would be possible to reduce the land area requirements for constructed wetlands for both carbon removal and nitrification/denitrification provided designs gave more consideration to oxygen supply. Using current designs, a retention time of 4-8 days typically results in 70% BOD removal. This experiment suggests that wetlands with a retention time of about 1 day could provide the same performance if additional oxygen were supplied. / Graduation date: 1995