This study investigated the removals of 53 micropollutants (MPs), including 10 per- and polyfluoroalkyl substances (PFAS), 25 pharmaceuticals and personal care products (PPCPs), 7 pesticides, 3 endocrine disrupters (EDCs), 3 disinfection byproducts (DBPs) and 3 taste and odor compounds (TNOs), during three oxidation treatment processes (ozonation, chlorination and UV/H₂O₂) currently used in water treatment plants (WTPs). The removal of selected MPs were compared using distilled water and two surface waters (the Han River and the Nak-Dong River in South Korea) having different DOC levels. In addition, multiple linear regression models were constructed to predict the kinetics and removal of each MP in three oxidation processes, and these models were validated through pilot scale experimental data (flow rate : 30 m³/day, Han River tributary influent (DOC : 3.2 mg/L)). The result showed that each MP showed different removal pattern in the selected treatment processes (Fig. 1). While most PFASs were ineffective by three processes, and DBPs and TNOs were ineffective by chlorination, EDCs showed a relatively good removals in chlorination. Especially, chlorination showed poor removal for MPs having electron-withdrawing groups because it can effectively react with electron-rich groups. Ozone, which has a higher reactivity than chlorine, thus tends to remove MPs (especially TNOs) more effectively than chlorine. However, UV/H₂O₂ process, which generates OH radical, removed the most MPs. Compared to deionized water, the average k_obs values during all three process decreased from 0.34 min^-1 to 0.12 min^-1 in surface water samples, implying suppression of MP removal by the presence of DOC. Among the models constructed, the models for 17 PPCPs and 2 pesticides showed relatively good accuracies (error < 10%) during chlorine and UV/H₂O₂ processes. The results obtained in this study can provide important information for MP control strategy in WTP by predicting MP removal in WTP.

Figure 1. The Comparison of the 53 micropllutants removal in three processes.

Yong-Hoo Park

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