制浆造纸废水对水生生物急性毒性研究

目前我国工业废水排放的监督和管理主要以理化监测为主,而理化分析并不能实际反映出水污染源对水体中受害生物的综合毒害强度。该研究同时采用鱼类急性毒性试验、溞类急性毒性试验、发光细菌急性毒性试验和藻类生长抑制试验测定制浆造纸排放废水的生物毒性大小,根据上述毒性实验所测定的半数效应的体积百分比浓度,筛选出对该行业废水最为敏感的毒性试验方法和试验生物,同时结合毒性单位法和废水中的常规污染物浓度与特征污染物对该排放废水进行了综合评价。试验结果表明:该制浆造纸废水对斑马鱼的96 h LC50为33.24%、33.33%和32.96%,属中毒;对大型溞的48 h LC50为27.01%和37.47%,属中毒;对青海弧菌Q67的15 min EC50远远小于10%,属高毒或剧毒;对斜生栅藻的96 h EC50为50%~100%,属低毒。可见,发光细菌毒性试验方法对制浆造纸废水最为灵敏;同时测定4类生物急性毒性的方法为建立我国重点废水排放行业的生物毒性监测方法体系和适合不同污染源废水的试验生物目录库奠定了基础;虽然部分制浆造纸废水的理化指标已经达标,但是其生物毒性较强,这说明采用生物毒性监测配合理化监测方法监测水污染源排放的废水,才能更深刻了解污染物对水生态环境的实际影响,水生生物毒性试验是化学试验的必要补充。

Acute Toxicity of Pulp and Papermaking Wastewater to Aquatic Organism

To overcome the drawbacks of current water quality monitoring based on sole physical and chemical indexes,test of acute toxicity of contaminants of papermaking effluents to aquatic organisms was conducted including acute toxicity to fish,daphnia,luminescent bacteria and the algal growth inhibition test.The percent concentrations of median effect in volume were obtained based on which test organism and the most sensitive toxicity test method was screened out for monitoring papermaking wastewater.It was proven that test of acute toxicity of luminescent bacteria was the most sensitive method for pulp and papermaking wastewater.Meanwhile,the acute toxicity test using the above-mentioned four species of aquatic organisms could be used as the fundamental method for monitoring pulp/papermaking industries.The fact that part of the pulp/papermaking factories could meet the national standard in terms of physicochemical parameters in their effluents that were still presenting rather toxicities to the aquatic organism can be used to explain the necessity of application of aquatic organism toxicity test as a supplement to the current physicochemical based test in the environmental monitoring.