Yanwen Lin

Biodegradation of phenol at high concentration by a novel fungal strain Paecilomyces variotii JH6.

A novel phenol-degrading filamentous fungus, strain JH6, was isolated from activated sludge and identified as a member of Paecilomyces variotii based on standard morphological and phylogenetic analysis. The degradation assays suggested that the strain was able to utilize phenol as the sole source of carbon and energy at concentrations up to 1800 mg/l. The strain exhibited optimum phenol degradation performance with the addition of 100 mg/l glucose at pH 5, 37°C. Haldanes model could be fitted to the growth kinetics data well over a wide range of initial phenol concentrations (100-1800 mg/l), with kinetic values μ(max)=0.312 h(-1), K(s)=130.4 mg/l, and K(i)=200 mg/l. The decay coefficient was found to be 0.0073 h(-1). Complete phenol degradation by strain JH6 could be achieved in the presence of other toxicants, such as m-cresol and quinoline, which were often found in the real phenol-containing wastewater.

Relating organic fouling of reverse osmosis membranes to adsorption during the reclamation of secondary effluents containing methylene blue and rhodamine B.

Dyes fouling of reverse osmosis (RO) membranes and its relation to adsorption had been investigated by using a crossflow RO filtration setup. Methylene blue (MB) and rhodamine B (RB) were used as model organic foulants. The calculated amount of the irreversible sorption was related to the irreversible flux decline. The characteristic fouling kinetics was accounted by Langmuir-Hinshelwood (L-H) kinetics model for initial fouling, with the fouling rate constant k=0.0556μm s(-1)min(-1) and k=0.0181μm s(-1)min(-1) for MB and RB fouling RO membrane CPA2, respectively. And the subsequent fouling was attributed to the growth of a dye cake. A remarkable correlation was obtained between the quantified irreversible sorption and irreversible flux decline under the solution chemistries investigated. In the presence of divalent cation, the extent of flux decline was related to the competition model.