Pollution characteristics and risk assessment of volatile organic compounds in groundwater drinking water sources in Klulun River Basin

In order to clarify the pollution characteristics and risk levels of volatile organic compounds (VOCs) in the groundwater drinking water sources of Klulun River Basin, a purge and trap gas chromatograph-mass spectrometer was used to analyze the pollution in the Klulun River in August 2020. Twelve water samples (7 surface water and 5 groundwater) collected in the basin were tested and analyzed, and the health risk and ecological risk assessment models recommended by US EPA were used to assess the risk of VOCs. The results showed that the degree of VOCs pollution in the water bodies of the study area was low, and the groundwater was generally slightly higher than the surface water. VOCs were detected in 12 sampling points, including 1,1-dichloroethane, 2,2-dichloropropane, 1,2-dichloropropane, 1,3-dichloropropane and1,1-dichloroethylene, and the detection rate of these VOCs were 100%. Among the detected VOCs, the concentration of 1,3-dichloropropane was the highest, with an average value of 2 524.01 ng/L, ranging from 1 186.44 to 4 677.97 ng/L; the concentration of o-xylene was the lowest, with an average value of only 0.99 ng/L. There was no non-carcinogenic health risks at each sampling site, the carcinogenic health risks were within an acceptable range, and there was moderate ecological risks to aquatic organisms.