本实验旨在探究不同浓度余氯对小球藻和锦鲤的毒性效应,选取不同浓度的余氯水溶液作为实验组,以无余氯水溶液为对照组,分别对实验组和对照组的小球藻和锦鲤的损伤情况进行了显微观察.研究结果表明,余氯浓度(≤0.5mg/L)促进小球藻生长,而当余氯浓度升高时(>0.5mg/L),小球藻生长则受到抑制.同样地,余氯浓度(≤1.5 mg/L)对锦鲤影响较小,未出现游动异常、鳃丝损伤及死亡现象,而当余氯浓度升高时(>1.5mg/L),锦鲤开始出现游动异常、鳃丝损伤等情况,进一步升高则死亡率增加.研究表明,余氯对藻类和鱼类的毒性效应存在浓度和时间依赖性,亦即过高的余氯浓度会对藻类和鱼类在短时间内产生损伤或引起死亡,而藻类和鱼类长时间暴露在较低浓度的余氯环境中时也会对其造成损伤,甚至引起死亡.
The aim of this experiment was to explore the toxic effects of different concentrations of residual chlorine on chlorella vulgaris and koi carp.Different concentrations of residual chlorine aqueous solution were se-lected as the experimental group,and no residual chlorine aqueous solution was selected as the control group.The damage of chlorella vulgaris and koi carp in the experimental group and the control group were respectively ob-served.The results showed that low residual chlorine concentration(≤0.5 mg/L)promoted chlorella growth,but when the residual chlorine concentration increased(>0.5 mg/L),the growth of chlorella vulgaris was inhibited.Sim-ilarly,the low concentration of residual chlorine(≤1.5 mg/L)had little effect on koi carp,and no abnormality of swimming,gill filaments damage and death occurred.However,when the residual chlorine concentration increased(>1.5 mg/L),the koi carp began to show abnormality of swimming and gill filaments damage,and the mortality in-creased further.This study had shown that the toxic effects of residual chlorine on algae and fish were concentra-tion and time dependent,that was,excessive residual chlorine concentration would cause damage or death to algae and fish in a short period of time,and algae and fish would also cause damage or even death when exposed to a low concentration of residual chlorine environment for a long time.