Treatment of Industrial Wastewater by Advanced Oxidation Processes

Abstract

The industrial wastewater is the leading source of water pollution due to diverse nature of pollutants present in the effluents. The goal of this work was to establish methods for the treatment of petroleum refinery, soap & detergent and pulp & paper effluents as well as simulated solution of nonylphenol ethoxylates (NPEOs) using gamma and UV radiation in the presence of H 2 O 2 and TiO 2 . The degradation of pollutants was monitored through UV/Vis, FTIR, GC-MS and HPLC techniques. The efficiency of advanced oxidation processes (AOPs) was evaluated on the basis of extant of degradation, water quality parameters and detoxification. The toxicities were determined through various bioassays such as allium cepa, haemolytic, shrimp and Ames tests. The independent variables such as radiation dose, catalysts concentration, exposure time, pH, temperature etc. were optimized using response surface methodology for maximum degradation of pollutant. Through advanced characterization techniques, it was found that the AOPs were able to oxidize recalcitrant, toxic and non-biodegradable compounds to various intermediates and eventually to inert end products by generating intermediacy hydroxyl radicals. The gamma ray/H 2 O 2 treatment degrade the toxic residues, improve water quality and reduce the toxicity significantly, however, UV/TiO 2 /H 2 O 2 furnished better response. From the results, it is concluded that the AOPs (UV/TiO 2 /H 2 O 2 and gamma ray/H 2 O 2 ) could be successfully used for the treatment of petroleum refinery, soap & detergent and pulp & paper effluents as well as NPEOs since the water quality fall within the permissible limits recommended by the environmental agencies.