Derivation of water quality criteria for representative water-body pollutants in China

Abstract

In this study, toxicological data for zinc (Zn), cadmium (Cd), hexavalent chromium (Cr (VI)), benzene, and nitrobenzene were collected from various databases and publications, screened and then constructed into species sensitivity distribution (SSD) curves. Then water quality criteria (WQC) were derived for protection of the freshwater aquatic life in China against five representative pollutants. The values derived in this study were compared with those issued by the US Environmental Protection Agency and the Chinese national environmental standard for surface water to identify factors underlying the differences. The results showed that the SSD curves for the five pollutants differed significantly, with the examined aquatic species being generally more sensitive to Zn, Cd, and Cr (VI) than benzene and nitrobenzene. The acute WQC were: 48.43 μg L−1 for Zn, 0.4218 μg L−1 for Cd, 45.79 μg L−1 for Cr (VI), 2651 μg L−1 for benzene, and 1426 μg L−1 for nitrobenzene. The chronic WQC were: 20.01 μg L−1 for Zn, 0.2428 μg L−1 for Cd, 14.22 μg L−1 for Cr (VI), 530.2 μg L−1 for benzene, and 286.2 μg L−1 for nitrobenzene. The results of this comparative study of representative pollutants may offer guideline values for future WQC studies for China.