Treatment of tannery effluent by passive uptake-parametric studies and kinetic modeling.

Galactomyces geotrichum was utilized as a potential biosorbent for the treatment of tannery effluent under controlled environmental conditions. Tannery effluent treatment was studied through parametric experiments to study the effect of effluent pH (3.0-10.0), initial COD (1100-4400 mg/L), and biosorbent dosage (0.3-3.0 g/L).The zeta potential of the biosorbent was determined and found to influence the optimal pH. Increase in effluent COD values resulted in decreased COD removal percentages which attributed to limited availability of surface active sites. The equation relating the COD removal efficiency and biosorbent dose was proposed. Two popular kinetic models, namely pseudo-second order and power function models, were employed to the experimental data. Pseudo-second order model proved to be a good fit with high values of regression coefficient (R 2 > 0.960). Potential application of a fungal biosorption process was explored and the optimal process parameters were identified.