Abstract:

Biotoxicity of water samples from Dagu Drain River and Yongding New River in Tianjin was determined using the Photobacterium phosphoreum toxicity test method. The toxicity change of water samples was analyzed before and after hydrophilic-lipophilic balance (HLB) enrichment, and toxicity contribution rates of organic chemicals were calculated. Comprehensive toxicity intensity of water samples was evaluated on the basis of toxicity rank standard. The results show that the water samples from Dagu Drain River and Yongding New River had toxicity to  Photobacterium phosphoreum  and their toxicity grades were from low toxicity to dramatic toxicity. Generally, the biotoxicity of Dagu Drain River was higher than that of Yongding New River, and the toxicities of water samples before HLB enrichment were higher than those after HLB enrichment. The toxicity contribution rates of organic chemicals for five water samples to Photobacterium phosphoreum  were higher than 90%, while the toxicity contribution rates of organic chemicals for another seven samples were less than 40%, indicating that the main toxicity substances to Photobacterium phosphoreum could not be enriched by HLB.

Key words: Photobacterium phosphoreum; Dagu Drain River; Yongding New River; biotoxicity evaluation