To explore biodegradation of 2-naphthol and its metabolites accumulated in wastewater treatment,a series of bio-degradation experiments were conducted.Two main metabolites of 2-naphthol,1,2-naphthalene-diol and 1,2-naphthoquinone,were identified by high-performance liquid chromatography with standards.Combining fungus Aspergillus niger with bacterium Bacillus subtilis in the treatment enhanced 2-naphthol degradation efficiency,lowered the accumulation of the two toxic metabolites.There were two main phases during the degradation process by the kinetic analysis:2-naphthol was first partly degraded by the fungus,producing labile and easily accumulated metabolites,and then the metabolites were mainly degraded by the bacterium,attested by the degradation processes of 1,2-naphthalene-diol and 1,2-naphthoquinone as sole source of carbon and energy.Sodium succinate,as a co-metabolic substrate,was the most suitable compound for the continuous degradation.The optimum concentration of 2-naphthol was 50 mg/L.The overall 2-naphthol degradation rate was 92%,and the COD Cr removal rate was 80% on day 10.These results indicated that high degradation rate of 2-naphthol should not be considered as the sole desirable criterion for the bioremediation of 2-naphtholcontaminated soils/wastewater.
