Fungal treatment for wastewater containing recalcitrant compounds

Due to rapid industrialization and urbanization, large amounts of wastewater are discharged into the environment. Most of the municipal wastewaters contain biodegradable substances which can be treated by conventional biological treatment methods such as activated sludge process, aerated lagoon and aeration pond. Industrial wastewater generated from the pulp and paper industry, and from dyeing and dye manufacturing, cannot be treated by these conventional methods due to the presence of recalcitrant compounds. These compounds are found to be toxic, carcinogenic and mutagenic. White rot fungi, which have the ability to degrade lignin, can be used for the treatment of effluent generated from these industries. These fungi have a non-specific enzyme system, which oxidizes the recalcitrant compounds present in the wastewater. In this paper, the application of fungal treatment for wastewater from pulp and paper plant and dye industries using the white rot fungus Trametes versicolor is reported. Batch experiments were carried out in shake flasks. The effect of carbon source (glucose or sucrose) concentration, pH and initial color concentration on decolorization efficiency was evaluated. It was found that the presence of easily biodegradable primary carbon source was required for the growth of the fungus and decolorization. From these investigations, it was concluded that the fungal treatment could be used as primary treatment before conventional secondary treatment.