Characteristics of Nonylphenol and Octylphenol Discharge from Wastewater Treatment Facilities in Southern Gyeonggi-do

Abstract

This study aimed to evaluate the discharge characteristics of nonylphenol (NP) and octylphenol (OP) in the effluent of wastewater treatment facilities in the southern Gyeonggi-do. The detection rates of NP and OP were found to be 39.3% and 43.1%, respectively, with median values ranging from 1 to 3 μg/L across all industries. The industries that showed a detection rate of 50% or more were car wash, chemical experiment, fabric leather, paper wood, and plating facilities, with rates ranging from 50% to 75%, while other industries had detection rates of 21.7% to 36.8%. In terms of facility size, small-size establishments such as Type 4 and Type 5 showed higher detection rates in the "Na" region where somewhat relaxed standards are applied on a regional basis. This is because the proportion of Type 4 and Type 5 industries, including various concentration distributions of chemical experiments, research facilities, car washes, petrochemical, and plating industries, is higher than 77.7% overall and concentrated at a rate of 55.6% or higher in the “Na” region. Furthermore, the correlation coefficient (R) between NP and OP exhibited moderate association with values of 0.45 and 0.60 for car washes and plating industries, respectively. Chemical experiments, paper and wood, electrical and electronic, and medicine and hospital facilities showed strong association with correlation coefficients of 0.83, 0.82, 0.82, and 0.79, respectively. The findings in this study can be expected to serve as fundamental data for NP and OP in the establishment of water quality pollutants designation and discharge standards (draft) currently being pursued.