Emerging Methods, Aquatic Contaminants Research Division, Water Science and Technology, Environment Canada, 105 McGill Street, Montréal, QC, Canada.
Environ Sci Pollut Res Int. 2013 Mar;20(3):1706-18. doi: 10.1007/s11356-012-1174-8. Epub 2012 Sep 21.
The present study sought to examine the performance of six different wastewater treatment processes from 12 wastewater treatment plants using a toxicogenomic approach in rainbow trout hepatocytes. Freshly prepared rainbow trout hepatocytes were exposed to increasing concentrations of influent (untreated wastewaters) and effluent (C(18)) extracts for 48 h at 15 °C. A test battery of eight genes was selected to track changes in xenobiotic biotransformation, estrogenicity, heavy metal detoxification, and oxidative stress. The wastewaters were processed by six different treatment systems: facultative and aerated lagoons, activated sludge, biological aerated filter, biological nutrient removal, chemically assisted primary treated, and trickling filter/solids contact. Based on the chemical characteristics of the effluents, the treatment plants were generally effective in removing total suspended solids and chemical oxygen demand, but less so for ammonia and alkalinity. The 12 influents differed markedly with each other, which makes the comparison among treatment processes difficult. For the influents, both population size and flow rate influenced the increase in the following mRNA levels in exposed hepatocytes: metallothionein (MT), cytochrome P4503A4 (CYP3A4), and vitellogenin (VTG). Gene expression of glutathione S-transferase (GST) and the estrogen receptor (ER), were influenced only by population size in exposed cells to the influent extracts. The remaining genes-superoxide dismutase (SOD) and multidrug resistance transporter (MDR)-were not influenced by either population size or flow rate in exposed cells. It is noteworthy that the changes in MT, ER, and VTG in cells exposed to the effluents were significantly affected by the influents across the 12 cities examined. However, SOD, CYP1A1, CYP3A4, GST, and MDR gene expression were the least influenced by the incoming influents. The data also suggest that wastewater treatments involving biological or aeration processes had the best performance. We found that the effects of municipal effluents on gene expression depended on the population size, the initial properties of the incoming influent, and the wastewater treatment method applied. Considering that the long-term goals of wastewater treatment is to produce clean effluents for the aquatic biota and independent of the incoming influent, more research is needed in developing treatment processes to better protect aquatic life from anthropogenic contamination.
本研究旨在利用毒理基因组学方法在虹鳟鱼肝细胞中检测 12 个污水处理厂的 6 种不同污水处理工艺的性能。将新鲜制备的虹鳟鱼肝细胞在 15°C 下用进水（未经处理的废水）和出水（C(18)）提取物的递增浓度处理 48 小时。选择了一组 8 个基因的测试电池来跟踪外来生物转化、雌激素、重金属解毒和氧化应激的变化。废水由 6 种不同的处理系统处理：兼性和充气池、活性污泥、生物曝气滤池、生物营养去除、化学辅助一级处理和滴滤/固体接触。根据废水的化学特性，处理厂通常能有效去除总悬浮固体和化学需氧量，但对氨和碱度的去除效果较差。12 个进水彼此之间差异显著，这使得处理过程之间的比较变得困难。对于进水，种群规模和流量都会影响暴露于肝细胞中的以下 mRNA 水平的增加：金属硫蛋白 (MT)、细胞色素 P4503A4 (CYP3A4) 和卵黄蛋白原 (VTG)。暴露于进水提取物的细胞中，谷胱甘肽 S-转移酶 (GST) 和雌激素受体 (ER) 的基因表达仅受种群规模的影响。其余基因-超氧化物歧化酶 (SOD) 和多药耐药转运蛋白 (MDR)-在暴露细胞中既不受种群规模也不受流量的影响。值得注意的是，暴露于流出物的细胞中 MT、ER 和 VTG 的变化受到 12 个研究城市检查的进水的显著影响。然而，SOD、CYP1A1、CYP3A4、GST 和 MDR 基因表达受进入的进水影响最小。数据还表明，涉及生物或曝气过程的废水处理具有最佳性能。我们发现，城市污水对基因表达的影响取决于种群规模、进入进水的初始特性和应用的废水处理方法。考虑到废水处理的长期目标是生产对水生生物无影响的清洁废水，并且不受进入进水的影响，因此需要更多的研究来开发处理工艺，以更好地保护水生生物免受人为污染。
