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In this study, filamentous bacteria (Nocardia amarae) were identified as the major causal microorganism in foaming sludge. The results of growth kinetics study indicated that N. amarae had a relatively strong affinity for non-readily biodegradable fatty acids. N. amarae was able to consume various fatty acids at a constant growth yield from 0.413 to 0.487 g/gCOD. Under common F/M ratio (less than 0.5 g BOD/gMLSS/d) used in activated sludge processes, specific growth rate of N. amarae was found to be more significant than that of non-filamentous bacteria. Based on this feature, a novel technique feast-fast operation (FFO) was developed for the foaming control. The sludge volume index (SVI) rapidly decreased from 300 to 80 mL/g and further stabilized at about 70 mL/g and the system was free from stable foam, while the BOD removal efficiency was maintained above 95%. This control technology effectively suppressed the overgrowth of filaments and improved the settleability of activated sludge without adverse effects on the treatment performance and the process stability.

In this study, a novel fibrous bioreactor was developed for treating odorous compounds present in contaminated air. The first stage of this work was a preliminary study which aimed at investigating the feasibility of using the fibrous bioreactor for the removal of malodorous volatile fatty acids (VFA) that is a common odorous contaminant generated from anaerobic degradation of organic compounds. The kinetics of microbial growth and VFA degradation in the selected culture, and the performance of the submerged bioreactor at different VFA mass loadings were studied. Above 95% of VFA removal efficiencies were achieved at mass loadings up to 22.4 g/m(3)/h. In the second stage, the odour treatment process was scaled up with system design and operational considerations. A trickling biofilter with synthetic fibrous packing medium was employed. The effects of inlet VFA concentration and empty bed retention time (EBRT) on the process performance were investigated. The bioreactor was effective in removing VFA at mass loadings up to 32 g/m(3)/h, beyond which VFA started to accumulate in the recirculation liquid, indicating the biofilm was unable to degrade all of the VFA introduced. Although VFA accumulated in the liquid phase, the removal efficiency remained above 99%. This suggested that the biochemical reaction rather than gas-liquid mass transfer was the limiting step of the treatment process. In addition, the biotrickling filter was stable for long-term operation with relatively low and steady pressure drop, no clogging and degeneration of the packing material occurred during the four-month study.

In this study, the optimal fermentation type and the operating conditions of anaerobic process in continuous-flow acidogenic reactors was investigated for the maximization of bio-hydrogen production using mixed cultures. Butyric acid type fermentation occurred at pH>6, propionic acid type fermentation occurred at pH about 5.5 with E(h) (redox potential) >-278mV, and ethanol-type fermentation occurred at pH<4.5. The representative strains of these fermentations were Clostridium sp., Propionibacterium sp. and Bacteriodes sp., respectively. Ethanol fermentation was optimal type by comparing the operating stabilities and hydrogen production capacities between the fermentation types, which remained stable when the organic loading rate (OLR) reached the highest OLR at 86.1kgCOD/m(3)d. The maximum hydrogen production reached up to 14.99L/d.

Polyhydroxyalkanoates (PHAs) production was carried out under various C:N ratios. A ratio of 100 resulted best polymer yield. C-source was an important factor in synthesis. For example, as the ratio of valeric acid (C5) to butyric acid (C4) in N-free medium was increased, the mole fraction of HV in the copolymer increased. When soy waste was used as a C-source a copolymer, a high HV mole fraction (HB:HV, 75:25) was produced while when malt waste was used, a much lower HV mole fraction (HB:HV, 90:10) was generated. It was concluded that activated sludge bacteria could be induced to produce PHAs using food wastes as C-sources and this could be the basis for production of biodegradable plastics.

Crossflow microfiltration experiments were carried out with oily wastewater using alpha-Al(2)O(3) membranes with 0.05 microm pore size. The influence of parameters such as transmembrane pressure (TMP), crossflow velocity (CFV), oil concentration, pH and salt concentration on the microfiltration behaviors were studied based on the measurements of permeate flux, total organic carbon (TOC) removal efficiency, and size and zeta potential of the emulsion droplets. The results showed that there were different degrees of effect on the membrane separation performance by these parameters. The TOC removal efficiencies higher than 92.4% were achieved under all experimental conditions. A non-steady model of accumulation volume of permeation was developed. It was found that the calculated values were in good agreement with the experimental results. Sensitivity analysis was also conducted to identify the degree of influence of the parameters on the accumulation volume of permeation. The results indicated that the accumulation volume of permeation was significantly affected by the TMP.

The O-methyltransferase of tobacco cell culture was resolved to its meta and para directing forms by chromatography on DEAE-cellulose. Despite similarities in molecular weights and pI values of the two forms, however, evidence from pH optima, SH-group inhibitors, methylation ratios, SDS-acrylamide gels and mixed substrate experiments indicates the existence of two discrete enzymes acting at the meta and para positions of caffeic acid and quercetin, respectively; though the latter enzyme was less substrate specific than its meta counterpart.

5 min foot-shock resulted in an elevation in levels of immunoreactive (ir)-dynorphin (DYN) and ir-vasopressin (VP) in the hypothalamus whereas their levels were not significantly modified in the neurointermediate pituitary. In the anterior pituitary, however, a fall in ir-DYN in the absence of any change in ir-VP was detected. Further, in the thalamus and medulla/pons, respectively, a decrease and increase in levels of ir-VP was observed whilst the content of ir-DYN therein was not significantly affected. These findings support the concept of a common origin and co-modulation of DYN and VP in the hypothalamic-neural lobe axis and that, extrinsic to this, DYN and VP are localized and modulated independently of each other.

The distribution of immunoreactive-dynorphin (ir-dyn) in the pituitary, discrete regions of brain and the spinal cord, and the influence of 5 min foot-shock stress (FS) upon levels of ir-dyn in these structures, were examined in rats. FS produced a significant fall in the anterior pituitary lobe (AL) content of ir-dyn but no significant change in its neurointermediate (NIL) counterpart. In the hypothalamus, in contrast, a significant elevation in levels of ir-dyn was observed. With the exception of the frontal cortex, in which a decrease in levels of ir-dyn was found, in all other brain regions examined no significant changes emerged. A significant diminution in concentrations of ir-dyn in both the lumbosacral and thoracic sections of the spinal cord was, however, detected.