造纸群尾水景观再生利用的潜在生态风险研究

Potential Ecological Risks of the Reclaimed Paper Wastewater into River as Landscape Water

造纸废水再生回用于河流生态景观将对水体中的水生生物带来潜在的安全风险。该文以斑马鱼为测试生物,分别测定某造纸群污水处理厂的进水、景观回用再生水及受纳河流水样的急性毒性、胚胎毒性、内分泌干扰毒性、基因毒性等多种生物毒性效应,评价造纸废水深度处理后作为河流生态景观补给水的潜在生态风险。结果表明,造纸群污水处理厂进水与景观回用再生水对斑马鱼的96 h急性毒性LC50为0.43和0.82,对斑马鱼胚胎的致死率分别为53.1%与42.7%;它们对雄性斑马鱼体内VTGS有显著诱导效应,对DNA有很强的氧化损伤效应。由此可见,虽然造纸废水经深度处理后常规水质指标已达到国家景观再生水回用标准,但是它对河流的鱼类等水生生物仍具有多种生物毒性效应。因此,造纸废水作为生态补给水再生回用到河流水体时,需合理设计深度处理工艺来有效削减或去除毒害污染物质,确保受纳水体生态安全。

Aquatic biological toxicity and potential ecological risk is the main restrictive factors of pulp and paper industry wastewater reused as ecological landscape water.Tests of acute toxicity, toxicity of the embryo and the yolk sac larvae stage short-term toxicity, endocrine disruptors toxicity, the genetic toxicity are all applied to the toxicity test by using zebrafish as the typical species in this study. Water samples from papermaking group of sewage treatment plant, landscape reuse of reclaimed system and the accepted-river are the research object for elaluating their potential ecological risks of the reclaimed paper wastewater into river. The results show that zebrafish acute toxicity LC50 is 0.43 after 96 hours, embryo toxicity is 46.9%and VTGS is 27.5 ng/g of the water in papermaking group of sewage treatment plant. Zebrafish acute toxicity LC50 is 0.82 after 96 hours, embryo toxicity is 57.3% and VTGS is 22.5 ng/g of the landscape reuse of reclaimed water. The significant induction effect for the VTGS of male zebrafish and strong oxidative damage for DNA can be observed. Although the physical and chemical indicators of the papermaking wastewater after advanced treatment has been up to the national standard for recycling as landscape water, there is still a variety of biological toxicity effect for aquatic organisms such as fish.Therefore, the reasonable design of the depth treatment technology for the eclogical safety should consider the factors including the biological toxicity.