Simultaneous Removal of MTBE and Benzene from Contaminated Groundwater Using Ultraviolet-Based Ozone and Hydrogen Peroxide

Abstract

Efficiency of ultraviolet-ozone (UV/O3) and ultraviolet-hydrogen peroxide (UV/H2O2) processes was investigated for simultaneous removal of methyl tertiary butyl ether (MTBE) and benzene from contaminated ground water. The photoreactor employed housed 15-watt low pressure (LP) and 150-watt medium pressure (MP) mercury UV lamps. Oxidation of contaminants was studied at two different levels of ozone and hydrogen peroxide. Brackish groundwater samples were spiked with MTBE and benzene up to a concentration of 500 μg L−1. Removal potential was evaluated at different parameters such as UV type and intensity and peroxide and ozone dosages, as well as contact time. Results indicated that no removal of the contaminants was attained when treated with hydrogen peroxide or ozone alone. However, about 50% and 30% removal of MTBE were achieved in 30 minutes when irradiated with MP-UV and LP-UV lamps, respectively. On the other hand, UV/H2O2process was found to be superior in removal of MTBE (90% in 10 min.) and benzene (95% in 5 min.) compared to UV/O3process. Furthermore, removal of benzene was comparatively easier than MTBE in both approaches. It is hence concluded that higher UV intensities and elevated doses of H2O2accelerate simultaneous removal of MTBE and benzene from water.