Removal of 2,4-difluoroanilne and Cu2+ by Diaphorobacter sp. DFA4 assisted magnetic biochar

Abstract

Ferric chloride and nickel-manganese ferrite magnetic mesoporous biochars(designated as FBC and MBC, respectively) were synthesized by utilizing orange peels as the biomass feedstock and ferric chloride and nickel-manganese ferrite as magnetic media simultaneously. Subsequently, the characteristics of the FBC- and MBC-mediated coupling system with Diaphorobacter sp. DFA4 for the simultaneous removal of 2, 4-difluoroanine and Cu2+ in the aqueous phase were investigated. The results demonstrated that FBC and MBC at concentrations ranging from 0.5 g/L to 2.0 g/L significantly enhanced the ability of Diaphorobacter sp. DFA4 to remove 2, 4-DFA and Cu2+. In the presence of FBC and MBC, the degradation efficiency of 2, 4-DFA increased by 2.24-4.04 times or 1.96-4.71 times, respectively, compared to the pure Diaphoractor sp. DFA4 culture system, when the initial concentration of 2, 4-DFA was 100 mg/L to 900 mg/L. The removal efficiency of Cu2+ also increased from 59.70%-69.95% to 88.57%-93.20% and 82.12%-88.20%, respectively. Moreover, at pH levels ranging from 6.0 to 8.0, compared to the pure Diaphoractor sp. DFA4 culture system, the removal efficiency of 2, 4-DFA in the MBC- and FBC-mediated coupling systems increased by 15.35%-36.32% and 22.43%-37.42%, respectively. The removal rates of Cu2+ also increased by 37.63%-42.34% and 43.61%-47.83%, respectively. When the salinity increased from 0 to 4%, both coupling systems maintained removal rates of 2, 4-DFA above 85%, while the pure Diaphorobacter sp. DFA4 culture system exhibited a decrease from 77.98% to 55.19%. Mechanistic analysis revealed that the coupling systems induced the secretion of more humic acid, and under alkaline conditions, FBC was more conducive to promoting the secretion of humic acid from Diaphorobacter sp. DFA4.

Keywords

• cu2+
• 2,4-difluoroaniline
• magnetic biochar
• diaphorobacter sp. dfa4