Biodegradation of lincomycin in wastewater by two-level bio-treatment using chloroperoxidase and activated sludge: Degradation route and eco-toxicity evaluation

Abstract

Abstract Lincomycin, which has been found in wastewater treatment plants and groundwater, could cause potential environmental problems due to their adverse effects on people and aquatic environments. At present, conventional physical or chemical methods cannot efficiently remove this drug from effluent. In this study, a rapid and effective method of enzymatic degradation of lincomycin with the use of chloroperoxidase (CPO) is proposed. By using 1.5 × 10−8 mol ⋅ L−1 CPO, a lincomycin degradation efficiency of 90.16 % was achieved in 20 min at pH 3.0. The degraded products were detected by HPLC-MS, which indicated that lincomycin was decomposed into two fragments. The eco-toxicity evaluation by 72 h EC 50 determination with the use of Chlorella pyrenoidosa as indicator showed that the degraded lincomycin was less toxic than the original lincomycin molecule. Moreover, it was found that when this method of enzymatic degradation by CPO was followed by activated sludge treatment, the COD removal of lincomycin effluent could be significantly enhanced. Thus, the proposed two-level bio-treatment of lincomycin may have potential application in municipal sewage plant s for the complete removal of this drug. The immobilization of CPO on a dendritic mesoporous silica particle improved its application effectively.