Optimum removal conditions of aniline compounds in simulated wastewater by laccase from white-rot fungi

BackgroundAniline compounds are widely applied as important chemical raw materials. However, they are so toxic and harmful to humans and environment that they need to be removed by an effective and economic approach, such as enzymatic reaction, which is in line with contemporary green development concepts.MethodsThe effects of major factors, such as temperature, reaction time, concentration of laccase and the initial concentration of substrate on the removal of substrate were investigated by OFAT approach. After simulated wastewater is treated with enzymes, aniline concentration was determined by N-(1-Naphthyl)ethylene-diamine dihydrochloride spectrophotometric method. Concentration of o-phenylenediamine was determined by ferric ammonium alum spectrophotometric method.ResultsFor the removal of aniline, the optimum conditions were as follows: 50 degrees C, initial aniline concentration of 80mg/L and laccase concentration of 1g/L. In this case, the total removal of aniline reached 97.1% after 8h, this also involves the volatilization of aniline itself. The optimum conditions of o-phenylenediamine were as follows: 50 degrees C, initial concentration of 100mg/L and laccase concentration of 1g/L. Under the above condition, the o-phenylenediamine could be removed completely after 60min.ConclusionThe results show that the removal of aniline compounds by laccase from white-rot fungi has good effect and potential application prospect.