Biological decolorization of textile dyestuff containing wastewater by Coriolus versicolor in a rotating biological contactor

Biologic decolorization of textile dyestuff Everzol Turquoise Blue G, a phthalocyanine type reactive dyestuff, by white-rot fungi Coriolus versicolor MUCL was studied in a rotating biological contactor (RBC). The effects of different operating parameters such as, disc type, rotational speed (10–40 rpm), glucose (5–10 g/L) and dyestuff concentration (50–500 mg/liter) on the decolorization performance of white rot fungi were investigated. The system was operated in repeated- batch mode with 48 h hydraulic retention time. The environmental conditions were adjusted to T = 28°C and pH = 4.5–5.0. TOC, glucose and dyestuff concentrations were determined throughout the experiments. Three different disc types; plastic, metal mesh covered plastic discs and metal mesh discs were used and the plastic disc was found to be the most suitable one. The highest decolorization efficiency (80%) was obtained with a rotational speed of 30 rpm. Minimum glucose concentration for 77% decolorization efficiency was 5 g/L. Decolorization efficiency was around 80% for 50–200 mg/liter initial dyestuff concentrations and decreased to 33% for 500 mg dyestuff/liter.