ADSORPTION AND BIODEGRADATION OF PENTACHLOROPHENOL BY POLYURETHANE-IMMOBILIZED FLAVOBACTERIUM

Flavobacterium cells immobilized in polyurethane foam were used to degrade pentachlorophenol (PCP). Adsorption of PCP by the polyurethane immobilization matrix played an important role in reducing the toxicity of PCP. The adsorption followed the Langmuir model with q(m) = 21.3 mg of PCP/g of dry foam and K(d) = 28.7 mg/L for cell-free foams. Cell growth contributed significantly to PCP removal rates especially when the degradation medium was supplemented with a utilizable carbon source. A substrate inhibition growth model described PCP consumption by Flavobacterium with model parameters mu(m) = 0.005 min-1, K(s) = 25 mg/L, K(i) = 1.5 mg/L, Y(X/S) = 0. 12 g of cell/g of PCP, and k(d) = 3.33 x 10(-5) min-1. PCP removal was enhanced by the presence of utilizable compounds such as sodium glutamate and glucose and was inhibited by non-utilizable p-cresol. For process applications, a dynamic bed reactor, which created convective flow through the immobilization matrix, was designed to enhance the mass transfer rates of PCP into foam and CO2 elution from the foam.