Application of immobilized laccase in the removal of oil from wastewater

The removal of oil from simulated oily wastewater by catalyzed oxidation with immobilized laccase was investigated. The effects of several main factors, such as pH, the amount of laccase, temperature, and reaction time, were discussed in detail. The results indicated that the optimum condition for immobilized laccase-catalyzed removal of oil was as follows: 25mL simulated oily wastewater with the oil concentration of 120mg/L in phosphate buffer (0.1M, pH4.5), reacted with 0.7696g immobilized laccase and 100mg/L chitosan at 25 degrees C for 6h. The oil removal efficiency was as high as 86% under the optimum conditions. Mg2+ and Cu2+ ions had little effect on the oil removal efficiency of immobilized laccase, but Fe2+ reduced the oil removal efficiency. The effect of the support on oil removal efficiency could be neglected. The immobilized laccase demonstrated a reliable and stable reusability.