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The effects of three long chain fatty acids (LCFAs) on glucose fermentation at 37 degrees C were examined during this study. Linoleic acid (LA) was more inhibitory than oleic acid (OA) and stearic acid (SA). During glucose fermentation, the carbon flow was diverted towards the production of more reduced volatile fatty acids (VFAs) in cultures fed with unsaturated LCFAs. In cultures inoculated with LA and OA, butyrate was produced with elevated levels observed in cultures inoculated with LA. Propionate degradation was unaffected by the presence of SA; however, elevated levels and longer removal times were observed in cultures receiving LA and OA. Acetate accumulation indicated the acetoclastic methanogenic population was affected only by OA and LA.

The effects of long chain fatty acids (LCFAs) on glucose degradation were examined at 21 degrees C. A competitive inhibition model was used to determine the kinetics of glucose degradation. Half velocity constants (Ks) were a function of LCFA concentration only at 100, 300 and 500 mg l(-1). The inhibitor constants (KI) for individual and mixed LCFAs were statistically the same. Glucose degradation rates for cultures receiving saturated (stearic acid (SA)) and monounsaturated (oleic acid (OA)) LCFAs were statistically the same but statistically different when compared to cultures fed with a polyunsaturated LCFA (linoleic acid (LA)). Individual and mixed LCFAs inhibited glucose degradation at threshold levels of 300 and 500 mg l(-1), respectively.

Modified bench scale jar tests were conducted to evaluate a treatment strategy for combined sewer overflow (CSO) generated during wet-weather conditions in Windsor, Ontario, Canada. Alum and an anionic polymer (Polymer A-3330) were used as a primary coagulant and coagulant aid, respectively. Commercially available silica sand was employed as the micro carrier. Under the operating conditions optimized in the study, alum dose of 9.7 - 17.8 mg l(-1) as Al3+ and polymer dosage of 1.0 - 1.8 mg l(-1) were observed to be the most effective in solids removal. Addition of the micro carrier (MC) up to 3 g l(-1) significantly increased the settleability of suspended solids, and about a five-fold increase in settleability was observed with 3 g l(-1) MC. In the size range of300 microm and at 3 g l(-1) concentration, the effect of MC size on the performance of the process was observed to be insignificant. Using the developed process, suspended solids and BOD removal efficiencies of98% and60%, respectively, were obtained with wet-weather flow after 8 minutes of settling, under both low and high suspended solids conditions.