Bio-remediation of acephate–Pb（II） compound contaminants by Bacillus subtilis FZUL-33

Removal of Pb2+and biodegradation of organophosphorus have been both widely investigated respectively. However, bio-remediation of both Pb2+and organophosphorus still remains largely unexplored. Bacillus subtilis FZUL-33, which was isolated from the sediment of a lake, possesses the capability for both biomineralization of Pb2+and biodegradation of acephate. In the present study, both Pb2+and acephate were simultaneously removed via biodegradation and biomineralization in aqueous solutions.Batch experiments were conducted to study the influence of p H, interaction time and Pb2+concentration on the process of removal of Pb2+. At the temperature of 25°C, the maximum removal of Pb2+by B. subtilis FZUL-33 was 381.31 ± 11.46 mg/g under the conditions of p H 5.5, initial Pb2+concentration of 1300 mg/L, and contact time of 10 min. Batch experiments were conducted to study the influence of acephate on removal of Pb2+and the influence of Pb2+on biodegradation of acephate by B. subtilis FZUL-33. In the mixed system of acephate–Pb2+, the results show that biodegradation of acephate by B. subtilis FZUL-33 released PO43+, which promotes mineralization of Pb2+. The process of biodegradation of acephate was affected slightly when the concentration of Pb2+was below 100 mg/L. Based on the results, it can be inferred that the B. subtilis FZUL-33 plays a significant role in bio-remediation of organophosphorus-heavy metal compound contamination.