印染废水对3种水生生物的毒性作用

为合理评估印染废水对水环境造成的影响,以斜生栅藻(Scenedesmus obliquus)、大型溞(Daphnia magna)和太湖花(鱼骨)(Hemibarbus maculates)为受试生物,印染废水分别用标准稀释液7346-2按照几何级数稀释成为100.00％、50.00％、25.00％、12.50％和6.25％的系列试验液,研究印染废水对3种水生生物的毒性效应.结果表明,印染废水对水生态系统中不同营养层次的3种生物均有一定的毒性,对斜生栅藻24、48h的半数生长抑制浓度(EC50)分别为(51.55±4.12)％、(20.40±6.27)％,对大型溞24、48h的EC50分别为(78.20±4.31)％、(53.10±1.88)％,对花(鱼骨)卵裂期胚胎、囊胚期胚胎、原肠期胚胎、初孵仔鱼和25日龄仔鱼96h的半数致死浓度(LC50)分别为(19.89±1.68)％、(25.95±2.14)％、(27.24±0.88)％、(19.61±2.21)％和(49.27±3.27)％.研究得出印染废水对水生生物的安全浓度为1.96％,生产中应严格控制其排放.

Toxicity of Printing-Dyeing Wastewater to Aquatic Organisms

To evaluate impact of printing-dyeing wastewater on aquatic ecological systems,an experiment was carried out using Scenedesmus obliquus,Daphnia magna and Hemibarbus maculates as subjects for test of toxicity of printing-dyeing wastewater.In the experiment the wastewater was diluted with 7346-2 standard diluent into solutions different in concentration,i.e 100.00%,50.00%,25.00%,12.50%,and 6.25%.Results show that the wastewater was somewhat toxic to all the three kinds of aquatic organisms in the aquatic ecosystem regardless of its nutrient level.The 24 and 48 h-EC50(effective concentration for reduction of growth by 50%) of the wastewater was(51.55±4.12)% and(20.40±6.27)%,respectively,to S.obliquus,and(78.20±4.31)% and(53.10±1.88)%,respectively,to D.magna.The 96h-LC50 of the wastewater to cleavage stage,blastula stage,gastrula stage,lava,and 25-day fingerlings of H.maculates was(19.89±1.68)%,(25.95±2.14)%,(27.24±0.88)%,(19.61±2.21)%,and(49.27±3.27)%,respectively.The safe concentration of the wastewater to aquatic organisms was 1.96%.So,discharge of such wastewater should be strictly controlled in practice.