Biotreatment of industrial tannery wastewater using Botryosphaeria rhodina

Abstract

The treatment of a tannery wastewater was performed on the laboratory scale using the ascomyceteous fungus Botryosphaeria rhodina MAMB-05, a ligninolytic and a constitutive producer of laccases (EC: 1.10.3.2). The wastewater samples were collected in the retanning and dyeing steps and presented high values of chemical oxygen demand, COD (15,023±60.0 mg L-1), fifth-day biochemical oxygen demand, BOD5 (4374±0.1 mg L-1), total solids (28500±2.0 mg L-1), total organic carbon, TOC (4685 mg L-1), and chloride ion concentration (2911±0.3 mg L -1). The fungus was inoculated and after five days under agitation at 180 rpm at 28 °C, the COD was reduced by 91 %. The total organic carbon also decreased from 4685 to 375.0 mg L-1 and the turbidity from 331.0 to 6.5 NTU, indicating that the biological treatment was efficient as the fungus consumed almost all the organic compounds present in the wastewater. It was not necessary to add an additional carbon source for the treatment, indicating that the concentration of organic compounds presented in the tannery wastewater effluent were sufficient for microorganism growth, during which the COD and TOC were reduced by about 91 and 93 %, respectively.