Optimization studies on electrochemical and biosorption treatment of effluent containing nitro benzene by RSM

A novel process combining Electrochemical Oxidation and Biosorption treatment was presented for Nitrobenzene abatement. The electrochemical oxidation was investigated batch-wise in the presence of NaCl (2g L-1) electrolyte with lead as anode and copper as cathode electrodes. The conditions were optimized using response surface methodology (RSM), which result in 76.4% reduction of COD was found to be maximum and the optimum conditions were satisfied at current density 3.56 A dm-2, time 3 hours, flow rate 40 L hr -1, volume 9 L occur at minimum power consumption of 30.3 kWhr / kg COD. It is followed by biosorption treatment in the presence of biosorbents such as maize and rice stems at 15 g L-1. From this study it was observed that the maximum % of COD reduction was 97.7 % for the optimized time 4 days and volume 6 L for pretreated effluent containing nitrobenzene.