[Measured and Predicted Aquatic Life Criteria and Risk Assessment of Chromium (VI) in Liaohe River].

In this study, toxicity data of aquatic species in Liaohe River for heavy metal chromium (VI) was collected and selected. The aquatic life criteria for chromium (VI) in Liaohe River was derived based on these toxicity data. Moreover, water samples of 25 sites in Liaohe River were collected, and the concentrations of chromium (VI) in these samples were analyzed. Finally, ecological risk assessment of chromium (VI) in Liaohe River was performed. Moreover, interspecies correlation estimation method (ICE) established by US EPA was used to predict the acute toxicity of species in Liaohe River, and aquatic life criteria based on predicted toxicity data was derived. The results showed that: the measured CMC (criteria maximum concentration), measured CCC (criteria continuous concentration) and the predicted CMC were 17. 73, 12. 15 and 13. 97 µg . L -1, respectively. Therefore, the ICE method could be used to predict the aquatic life criteria, because the predicted criteria value was very similar to the measured criteria value. Analysis of chromium (V) showed that the chromium (VI) concentrations of the 25 sites in Liaohe River were all below Class I or Class II water quality standards (GB 3838-2002), and the water quality was in good condition. However, for the potential risk of chromium (VI) exposure to the aquatic life of Liaohe River, the result of ecological risk assessment showed that chromium (V) concentrations in 7 sites exceeded the CCC in July, and chromium (VI) concentrations in 6 sites exceeded the CCC in December. Therefore, unacceptable effect on aquatic species caused by chromium (VI) exposure might have occurred in some sites of Liaohe River.