Optimized treatment of wastewater containing cytotoxic drugs by living and dead biomass of the freshwater microalga, Chlorella vulgaris

The presence of recalcitrant cytotoxic drugs in aquatic environments pose significant harmful effects to the ecosystems and human health. Due to the problems associated with physicochemical methods in treatment of effluents containing cytotoxic agents, the present study aimed to evaluate the efficiency of microalgae in bioremediation of these compounds. Biosorption of the anticancer drug, Flutamide (FLU), was performed by living and dead biomass of Chlorella vulgaris. The living microalga showed a better performance in the drug removal considering the amount of biomass, pH and time of adsorption. A nonlinear regression approach revealed that the Freundlich and Langmuir isotherms could fit well to the adsorption data. Maximum sorption capacity of the living microalga (26.8 mg g(-1)) was higher than the dead biomass (12.5 mg g(-1)). Kinetic studies showed that adsorption process by living and dead microalga followed the modified Freundlich model. Optimization of the process by response surface methodology (RSM) indicated that at FLU concentration of 50 mu M, pH 7.4 and 10 min, 98.5% drug removal could be obtained by the living biomass. The results indicate that the use of microalga can be a promising technology for the treatment of wastewaters containing cytotoxic compounds.