Characteristics of copper removal and ion release during copper biosorption by Stenotrophomonas maltophilia in presence of benzo[a]pyrene

Abstract

The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+ from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene (BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+ by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3− reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+ removal and ion release. Although 2 mg/L Cu2+ increases the release of PO43−, K+, NH4+ and Ca2+, 10 mg/L Cu2+ has strong oxidation on cell, and then decreases NO3− reduction and hinders the release of K+, NH4+ and Ca2+. Exogenous cations inhibit the Cu2+ biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+ from 52% to 88%.