南方某铀矿山废水对生物的急性毒性研究

为探明铀矿山对周围环境的联合毒性机制,本研究以常用生物毒性测试菌种——发光细菌青海弧菌Q67和费氏弧菌以及禾花鲤为受试生物代表,实地采集的铀矿山废水为目标废水,研究铀矿山废水对发光细菌和禾花鲤的急性毒性。实验结果表明,矿山废水对3种生物的急性毒性存在显著的剂量-效应关系,毒性效应浓度EC_(50)(LC50)的大小顺序为禾花鲤幼鱼费氏弧菌青海弧菌Q67,Pb~(2+)/U~(6+)浓度分别为6.052/3.026 mg·L~(-1)、2.284/1.142 mg·L~(-1)、1.339/0.669 mg·L~(-1),均可有效指示矿山废水的毒性水平,其中发光细菌更为灵敏、快速;且青海弧菌Q67的EC_(50)值最小,灵敏度最高,可作为表征矿山废水毒性风险的首选指示物。研究结果能够为放射性矿区废水生态风险预警、安全处理处置、水质基准制定及流域水环境管理提供依据。

Study on the Biological Toxicity Assessment of one Southern Uranium Mine

In order to explore the joint toxicity mechanism of uranium mines to the surrounding environment, in this study, the luminescent bacteria Vibrio qinghaiensis Q67, and Vibrio fischeri as well as the fish Procypris merus, the common biotoxicity test strain, were used as the representatives of the tested organisms, and the wastewater collected from a uranium mine in the Southern China is the target wastewater. Furthermore, the acute toxicity test of uranium mine wastewater to luminescent bacteria and Hehua carp was conducted. The results showed that there was a significant dose effect relationship between mine wastewater and the three organisms. The order of toxicity effect concentration EC₅₀ (LC₅₀) is as follows: Procypris merus > Vibrio fischeri > Vibrio qinghaiensis Q67. The concentration of Pb²⁺/ U⁶⁺ were 6.052/3.026 mg L^-1, 2.284/1.142 mg L^-1, 1.339/0.669 mg L^-1, respectively. All of them can effectively indicate the toxicity level of mine wastewater, and the luminescent bacteria are more sensitive and rapid. Besides, the Vibrio qinghaiensis Q67 had the minimum EC₅₀ values and higher sensitivity, so it can be used as the first choice indicator to characterize the toxicity risk of mine wastewater. The research results can provide the basis for ecological risk early warning, safe disposal, water quality standard establishment and watershed water environment management in radioactive mining area.