Enhanced Biomass Recovery During Phycoremediation of Cr(VI) Using Cyanobacteria and Prospect of Biofuel Production

Abstract

Utilization of cyanobacteria for remediation of pollutants and thereby large production of microalgae for sustainable biofuel production is a practicable option. In the present study, a cyanobacterial consortium of Oscillatoria subbrevis and Gloeocapsa atrata, collected from East Kolkata Wetland, a “Wetland of International Importance”, has been used for removal of Cr(VI) from simulated wastewater and the effect of Cr(VI) on biomass production was investigated. The Monod model has been used to depict growth kinetics of the cyanobacterial consortium in pure media. Maximum specific growth rate and saturation constant have been found to be 0.1562 day–1 and 0.024 g/L, respectively. The kinetic study on Cr(VI) removal shows that biomass and lipid production are more when the cyanobacterial consortium have been cultured in wastewater containing Cr(VI) than in pure media. The growth of the cyanobacterial consortium in relation to Cr(VI) removal as well as lipid production has been optimized using response surface methodology. Optimum metal removal has been achieved when initial Cr(VI) concentration, pH, inoculum size, and time are 11.08 ppm, 9.0, 0.39 g, and 9 days, respectively.