Acute toxic effect of typical chemicals and ecological risk assessment based on two marine microalgae, Phaeodactylum tricornutum and Platymonas subcordiformis.

With the increasing demand for typical hazardous and noxious substances (HNS) in chemical industry, there is an increased leakage risk of these HNS during transportation by vessel and storage nearby seashore. In this study, the acute toxicity of nonylphenol, butyl acrylate and 1, 2-dichloroethane to Phaeodactylum tricornutum (P. tricornutum) and Platymonas subcordiformis (P. subcordiformis), was investigated to assess their ecological risk. The results showed that the three kinds of HNS showed significant time- and dose-dependent patterns on the growth inhibition of two marine microalgae. The 96 h-EC of nonylphenol, butyl acrylate and 1, 2-dichloroethane on P. tricornutum was 1.088, 45.908 and 396 mg L, respectively, and the 96 h-EC of that on P. subcordiformis was 0.851, 52.621 and 389 mg L, respectively. It was a common method to evaluate the harm of pollutants to organisms by calculating HC value (the minimum pollutant concentration value harmful to 95 % of the studied species, which was no-effect concentration) with Species Sensitivity Distribution (SSD). On the basis of EC, the ecological risk assessment was further carried out, and HC value of nonylphenol and 1, 2-dichloroethane to aquatic organism was 0.079 and 44 mg L, respectively.