Factors Governing Degradation of Phenol in Pharmaceutical Wastewater by White-rot Fungi: A Batch Study

Abstract

Phenol is a major contaminant in the industrial water effluent, including pharmaceutical wastewaters. Although several physic-chemical methods for removal of phenol exist, they are of high cost, low efficiency, and generate toxic by-products. Thus, there is a need to develop technologies for biological removal of phenol from wastewater. In this study, the degradation of phenol in pharmaceutical wastewater by monoculture of white-rot fungi was studied. The degradation rate of total phenol in batch flasks by four fungal monocultures of Trametes versicolor, Phanerochaete chrysosporium, Gloeophyllum trabeum and Irpex lacteus in synthetic medium was compared. The results showed that white-rot fungus T.Versicolor was the most effective of the species. Further selection tests of optimal conditions of biomass concentration, pH and temperature were done, indicating that optimal conditions of degradation are at pH 5-6, temperature 25 °C, and biomass inoculum 10% (v/v). Under optimal conditions, total phenol was reduced by 93%, concentration of total phenol decreasing from 420±12 mg/l to 29±1 mg/l in seven days, with T.Versicolor specie. This study suggested that biological treatment with fungi may effectively be used as a pre-treatment stage for removal of phenol before polishing wastewater with conventional biological methods.