Simultaneous removal of copper and biodegradation of BDE-209 with soil microbial fuel cells

Abstract

The microbial fuel cells (MFCs) were developed in the present study to remove copper (Cu) and decabromodiphenyl ether (BDE-209) from an artificially contaminated soil. The performance of electricity generation, BDE-209 degradation and Cu removal were investigated. Soil enzyme activity, BDE-209 mineralization and microbial community structures were analyzed. Experimental results showed that the removal of BDE-209 and Cu was effectively enhanced by the application of soil MFCs. After 60-day MFC operation, total Cu was removed by 69.2%, 66.4% and 62.5% for an initial Cu content of 250, 500 and 1000 mg/kg, respectively. More than 80% Cu removed was transformed to pure copper and deposited on the cathode plates. Soil enzyme activity and BDE-209 removal (85.5%) were both highest in the case of 500 mg/kg Cu. Genomic sequencing results indicates that electrogenic and debromination bacteria survived together in the soil MFCs. The MFC operation promoted the growth and reproduction of electrogenic bacteria. These results demonstrate that the soil MFCs can be employed as a durable and effective approach for detoxicating organic-metal co-contaminated soil.