Biodegradation of high concentration phenol containing heavy metal ions by functional biofilm in bioelectro-reactor

Functional microorganisms to high concentration phenol containing Cr6 and Pb2 were cultured and biofilm was formed on polypropylene packings in bioe lectro-reactor. It was found that the biodegradation capability of such biofilm to phenol changed with the applied voltage. Under the optimal electric field con ditions (voltage of 3.0 V, electric field of strength 17.7 V/m and current densi ty of 1.98 A/m2), biodegradation efficiency of phenol aof concentration of 120 0 mg/L increased 33% compared to the instance without applying electric field. However, voltage had inverse effect on biodegradation, as microorganisms were kil led under strong electric field. Voltage had little effect on heavy ions elimina tion. Higher absorption rate of Cr6 and Pb2 was observed when changing pH from acidic to neutral. The experiment results indicated that, after treatment, 10 L phenol of 2400 mg/L was biodegraded completely within 55 h and concentrations o f Cr6 and Pb2 dropped to less than 1 mg/L within 12 h and 6 h, from initial va lues of 50 mg/L and 30 mg/L, respectively.