Assessment of Volatile Organic Compounds Removal in Kuwait Wastewater Treatment Plants

Abstract

This study presents the results of an analysis of the most common Volatile Organic Compounds (VOCs) in wastewater samples from one of the largest wastewater treatment plants in Kuwait. Samples from four different locations (plant influent, aeration tank inlet, aeration tank, and plant effluent) were collected weekly and were analyzed for toluene, benzene, xylene, 1, 3, 5 trimethylbenzene, dichloromethane and chloroform. The results showed that all the selected VOCs were detected except benzene. The average concentrations of VOCs that entered the treatment plant were as follows: chloroform 0.22 ± 0.03 μg/mL, dichloromethane 0.18 ± 0.05 μg/mL, toluene 0.08 ± 0.01 μg/mL, O-Xylene 0.03 μg/mL, M-Xylene 0.01 μg/mL, P-Xylene 0.02 μg/ml, and 1,3,5-trimethylbenzene 0.02 μg/mL. The concentration of VOCs during the treatment processes decreased for all the selected VOCs (treatment efficiency >98%), except chloroform, which has increased. The disinfection process in the treatment plant might have generated byproducts (such as chloroform) which could have increased chloroform concentration. In conclusion, all of the analyzed VOCs in this study were lower than the maximum level of VOCs in treated wastewater.