Aerobic degradation of nitrobenzene by immobilization of Streptomyces albidoflavus in polyurethane foam

Streptomyces albidoflavus Z2 was immobilized in polyurethane foam and its ability to degrade nitrobenzene was investigated. Batch experiments showed that polyurethane-foam-immobilized cells (PFIC) possessed a higher degradation capacity. Compared to freely suspended cells (FSC), PFIC degraded nitrobenzene more efficiently under alkali and acid conditions, as well as higher temperature. Kinetic of nitrobenzene degradation by PFIC was well described by Andrews inhibition equation, which demonstrated that PFIC tolerated higher concentration of nitrobenzene than FSC and degraded nitrobenzene at a quicker speed. Moreover, in the presence of NaCl (<= 7%, w/v), phenol (<= 250 wmg L-1) and aniline (100 mg L-1), respectively, PFIC exhibited better tolerance toward salinity and toxic chemicals than FSC. Therefore immobilization could be a promising method for treating nitrobenzene industrial wastewater.