Occurrence and Treatment of DEHP in Water Treatment Plants: Case study in South Korea

Currently, a toxic plasticizer, di(2-ethylhexyl) phthalate (DEHP), is recognized as a ubiquitous pollutant in aquatic environments due to the massive utilization of plastics. However, there is still a limited understanding of the occurrence and treatment of DEHP during the potable water utilization due to a lack of long-term field data in the full-scale process of water treatment plants (WTPs). In this study, we investigated the occurrence and removal of DEHP in six conventional WTPs located at various river basins in South Korea from June 2019 to December 2021. During the observation periods, DEHP was found in all samples at concentrations ranging from 0.3 to 8.2 mu g/L. Among the unit processes, the removal of DEHP was positively correlated with dissolved organic carbon removal, majorly in sand filtration and the GAC process. The advanced oxidation process exhibited low selectivity for DEHP removal efficiencies in the presence of natural organic matter due to its inhibition effect. The potential risks of DEHP on human health still exist in the surface water of South Korea for drinking water supplies, and thus, DEHP needs to be carefully monitored throughout the entire water treatment process.