北京市密云某私采金矿矿洞废水对大型溞的急性毒性研究

Acute Toxicity of Metallurgical Sewage from a Private Gold Mine in Miyun,Beijing on Daphnia magna

冶金废水中存在重金属、氰化物等多种生物毒性物质,但因其化学性质复杂、成分较多,目前相关的水生生物毒性研究较少。本研究基于真实环境损害案件,用水样的稀释倍数替代单一污染物的浓度,结合污水中总氰化物和重金属的检测结果,以大型溞(Daphnia magna)为受试生物,参考《化学品溞类急性活动抑制试验》(GB/T 21830—2008)和《水质物质对溞类急性毒性测定方法》(GB/T 13266—1991)中的实验方法,对北京市密云区某私采金矿矿洞中的5个废水水样进行生物急性毒性定性分析。研究了冶金废水对大型溞的形态行为和活动抑制率的影响,并根据总氰化物浓度等实验结果对水样的毒性类别进行判定。结果显示,培养24 h,大型溞半数被抑制时水样1~5的稀释倍数分别为392.46倍、228.67倍、134.68倍、134.28倍和481.46倍;培养48 h,大型溞半数被抑制时水样1~5的稀释倍数分别为831.26倍、754.14倍、347.34倍、853.24倍和481.46倍。根据危害水生环境物质的分类标准,本研究中的水样1~5均可认定为急性类别Ⅰ。这说明该废水水样对大型溞活动抑制效果明显,生物毒性强,对生态环境有较大损害。

There are many biological toxic substances in metallurgical sewage,such as heavy metals and cyanide.However,due to the complex chemical properties and components,there are few studies on the toxicity of aquatic organisms.Based on a real environmental damage case,the concentration of single pollutant was replaced by the dilution multiple of sewage samples.Refer to“Chemicals Daphnia acute activity inhibition test:GB/T 21830—2008”and“Method for determination of acute toxicity of water substances to Daphnia:GB/T 13266—1991”,Daphnia magna was used to analyze the qualitative acute biological toxicity of five sewage samples from a private gold mine in Miyun District,Beijing.The detection results of total cyanide and heavy metals in sewage were combined.The effect of metallurgical sewage on the morphological behavior and activity inhibition rate of Daphnia magna was studied.According to the total cyanide concentration and other experimental results,the toxicity of sewage was determined.The results showed that the dilution multiples of sewage samples 1~5 were 392.46,228.67,134.68,134.28 and 481.46 times when Daphnia magna were half inhibited after 24 h,and 831.26,754.14,347.34,853.24 and 481.46 times when Daphnia magna were half inhibited after 48 h.According to the classification of the aquatic environment harm standard,the sewage samples 1~5 were considered of acuteⅠ.The results show that the inhibition effect of sewage on Daphnia magna is obvious.The biological toxicity is strong,which has great damage to the ecological environment.