Degradation of bisphenol A enhanced by dialysis membrane enclosed laccase catalysis

Abstract

Bisphenol A (BPA) as an important industrial material has attracted substantial interests due to its environmental concerns. Here in dialysis membrane enclosed laccase catalysis (DMELC) strategy was adopted firstly to degrade BPA. The feasibility and efficiency of DMELC (81.7% increase) for enhancing BPA degradation were demonstrated experimentally by comparing with the process without dialysis membranes. The enhanced BPA degradation with DMELC could be realized by varying the execution time, initial BPA concentration, pH, temperature, running mode, laccase concentration, surface area-to-volume ratio (SA: V), and laccase mediators. BPA degradation with DMELC was not significantly affected by rotating speed. Four degradation products of BPA with DMELC including 4-(prop-1-en-2-yl) phenol, 3-methyl-2,3-dithtdrobenzofuran, 2-methyl-2,3-dithtdrobenzofuran, and 1-methyl-4-(prop-1-en-2-yl)cyclohex-2-en-1-ol were identified by GC–MS, and the possible degradation pathways were proposed. According to Cramer rules 4-(prop-1-en-2-yl) phenol has a low toxicity, and the other products had high toxicity. In addition, 4-(prop-1-en-2-yl) phenol and 1-methyl-4-(prop-1-en-2-yl)cyclohex-2-en-1-ol are easily biodegradable compounds, whereas 3-methyl-2,3-dithtdrobenzofuran and 2-methyl-2,3-dithtdrobenzofuran are persistent chemicals. The toxicological risk and biodegradability of the degraded products should be investigated experimentally further. The findings provide new insights into the elimination of hazardous pollutants by enzymes and highlight the potential applications in the industrial waste water treatment. • Enhancing BPA degradation by 81.7% was obtained by DMELC. • Substrate structural features induce the behavior difference of rotating speed. • BPA degradation pathway by DMELC was clarified. • Influencing mechanisms of DMELC on BPA degradation were evaluated.