印染废水处理前后对三种营养级水生生物毒性作用的评价

摘要

To evaluate impact of dyeing wastewater on aquatic organisms,Selenastrumca Pricornutum Printz,Daphnia magna and Brachydanio rerio were employed to test the toxicity of influent and effluent of dyeing wastewater treatment. The results show influent has toxicity effect on each organism and 24 h IC50 / LC50 of three organisms are 97. 9%,< 0. 05% and 0. 03%,respectively. Daphnia magna and Brachydanio rerio are sensitive to the influent. After treated,the effluent has lower toxicity effect on Selenastrumca PricornutumPrintz and Daphnia magna,whose 48 h IC 50 / LC50 are > 100% and 65. 6%,respectively. That is to say,the national dyeing wastewater discharge standards only set a limit on the physico-chemical indicators,which can not protect the aquatic organisms well. Thus,the biological toxicity standards should be added in dyeing wastewater industry's comprehensive discharge standards for protecting the aquatic organisms.%为了评估印染废水对水生生物的影响，采用羊角月牙藻、大型溞、斑马鱼对某印染企业废水处理系统的进水和出水的毒性进行了评价。结果表明进水对三种水生生物均有较强的毒性，其24 h IC50／ LC50分别为97．9％、＜0．05％和0．03％，其中大型溞和斑马鱼具有较强的敏感性。经过废水处理系统后，出水毒性显著降低，但对羊角月牙藻和大型溞仍然具有一定的毒性，其48 h IC50／ LC50分别为＞100％和65．6％。这表明目前排放标准单纯采用物理化学指标用于废水排放的监控已经不能完全保护水生态系统，因此亟须在废水排放标准中引进水生生物毒性指标，以便更有效地保护地表水体的生态安全。