DEGRADATION OF PENTACHLOROPHENOL IN BENCH-SCALE BIOREACTORS USING THEWHITE-ROT FUNGUS PHANEROCHAETE-CHRYSOSPORIUM

Biodegradation of pentachlorophenol by the white rot fungus Phanerocha ete chrysosporium was investigated in three bench scale bioreactors: m echanically mixed suspended bioreactor, upflow fixed-film bioreactor, and fluidized bed bioreactor. PCP disappearance was enhanced by increa sed ligninase activity in a mechanically mixed suspended bioreactor af ter initial adsorption onto the mycelium. Live fungal cultures were ab le to degrade PCP in the sorbed phase. PCP degradation data in the upf low fixed-film bioreactor was rapid and adequately explained with a qu asi-first order steady state model with a rate constant of 0.071 L/g b iomass-hr. In the fluidized bed bioreactor, effluent PCP concentration varied slightly at hydraulic residence times of 5 to 90 minutes. The steady state PCP degradation first order rate constant was 0.1 L/g bio mass-hr. Effluent PCP concentration was related to its influent concen tration at a 5 minute hydraulic retention time. The PCP removal effici ency was 37 to 72% and improved by increasing hydraulic retention time and decreasing influent PCP concentration. The fluidized bed bioreact or using P. chrysosporium shows considerable promise for the degradati on of PCP. Degradation was effective under conditions of short hydraul ic residence time and the process was stable in the face of large vari ations in influent conditions.