典型城市黑臭河道水体生物毒性研究

以黑臭为特征的城市内河污染近来受到关注,检测和分析污染河流水质的生物毒性对水质标识和生态评价十分必要。本研究逐月检测了温州市九山外河(JS River)和山下河(SX River)两条典型黑臭河道水样对斑马鱼、发光细菌和热带爪蟾胚胎的毒性效应。结果显示,黑臭河道水体对斑马鱼、发光细菌(青海弧菌Vibrio Qinghaiensis Q67)和爪蟾胚胎均具有毒性效应。以斑马鱼死亡率和发光细菌相对抑光率表征的水质综合毒性较一致,且以发光细菌更为敏感。爪蟾胚胎致畸实验主要通过存活率和畸形率来表征水体的毒性。3类生物监测均显示SX水体毒性明显高于JS整体毒性,这与两条河黑臭程度相一致。通过发光细菌检测水体综合毒性的分析,显示SX和JS水体毒性在5月-8月的夏季较高,冬春季节较低,表明黑臭河道水质毒性季节性变化与水体温度(T)和溶解氧(DO)值关系密切。本研究结果可为污染水体生物毒性检测和黑臭水体综合评价及后续治理提供依据。

Study on Biotoxicity of Typical Urban Black-odor River Water

The pollution of urban black-odor rivers receives attention recently. Survey and analysis on biological toxicity of black-odor river water are necessary to identify and evaluate the water quality. In present study, biological toxicity of water in two typical black-odor rivers in Wenzhou city Jiushanwai River (JS) and Shanxia River (SX) to Brachydanio rerio Luminescent bacteria test and Xenopus tropicalis embryos were monthly detected. Results indicated that water from the two rivers was toxic to the three organisms. Toxicological effects of black-odor river water measured using mortality of zebrafish was in good agreement with measured using the relative inhibitory light rate of Luminescent bacteria. Comparatively, Luminescent bacteria were more sensitive to black-odor river water than zebrafish. In Xenopus tropicalis embryos test, toxicological effects of black-odor water were characterized by embryos survival rate and teratogenic rate. All of the three species tests showed that toxicity of SX water was higher than that of JS water, which was consistent with the black-odor degree of the rivers. Statistical analysis results of Luminescent bacteria toxicity test showed that the comprehensive toxicity of SX and JS was higher in summer from May to August than that in winter and spring. The seasonal changes of water toxicity of the black-odor rivers was closely related to temperature and dissolved oxygen values (DO) of water. The present study can provide the evidence for the bio-toxicological test of contaminative water to evaluate and treat black-odor river water.