Effects of Nonylphenol and Octylphenol on Wastewater Discharge Facilities in Northern Gyeonggi Province

This study examines the emission characteristics of nonylphenol (NP) and octylphenol (OP) in the discharged water of Northern Gyeonggi Province, South Korea, where the textile industry predominates. We evaluated 104 individual wastewater discharge facilities, six public wastewater treatment plants (WWTPs), and the Shincheon River. Our findings reveal that NP and OP concentrations were notably high in the textile industry, with median levels of 0.53 µg/L and 0.43 µg/L, respectively, in individual wastewater discharge facilities. Furthermore, monitoring NP and OP levels in the influent and effluent of WWTPs and river water demonstrated that WWTP effluent has a remarkable impact on NP and OP concentrations in the river. The removal rates of NP and OP in WWTPs averaged 69.6% and 41.8%, respectively, and these rates tended to increase with higher temperatures and influent concentrations. The average concentrations in the Shincheon River were 0.31 µg/L for NP and 0.45 µg/L for OP, slightly exceeding EU standards. It is essential to closely monitor NP and OP levels to protect aquatic ecosystems.