Optimization of Process Parameters for Biodegradation of Resorcinol in Presence of Toxic Heavy Metals by Response Surface Methodology (RSM)

Abstract

Environmental pollution is caused by industrial effluents releasing toxic phenolics like phenol, cresol, resorcinol, etc. along with various heavy metals to the environment. It is difficult to degrade these pollutants by common soil microflora and persists for a long time in nature causing environmental pollution and adverse health conditions. Thus the objective of the present work is to study the biodegradation of resorcinol by a mixed bacterial culture isolated from the soil near to the outer limit of effluent discharge of tannery. The mixed bacterial culture was acclimatized to resorcinol by gradually increasing the concentration of resorcinol in the MS media to 500 mg/L. A batch kinetic study was carried out for the degradation of 500 mg/L of resorcinol by the mixed bacterial culture in the presence of different toxic heavy metals such as Mercury (Hg), Lead (Pb), and Chromium (VI) in concentrations of 5 ppm, 25 ppm, and 50 ppm. Removal efficiency of resorcinol in 20 h in presence of mercury was 44%, for lead was 68.8%, and for chromium (VI) was 86%. Optimization of the process parameters of the present system was done by Response Surface Methodology using DesignExpert11.0 software. The various physicochemical parameters viz. aeration (with/without) and concentration of the toxic metals were optimized for maximum degradation of resorcinol and removal efficiency of resorcinol. Removal efficiency of resorcinol as obtained under optimized conditions was 90.82%.