Environmental NMR Centre and Department of Physical and Environmental Sciences, University of Toronto, Toronto, Ontario, M1C 1A4, Canada.
Environmental Monitoring & Reporting Branch, Ontario Ministry of the Environment, Conservation, and Parks, Toronto, Ontario, M9P 3V6, Canada.
Environ Sci Pollut Res Int. 2019 Mar;26(9):9014-9026. doi: 10.1007/s11356-019-04318-8. Epub 2019 Feb 4.
Consumer products such as perfluorooctanesulfonic acid (PFOS) and pharmaceuticals (PCPPs) enter aquatic ecosystems through inefficient removal during wastewater treatment. Often, the sterilization process of wastewater includes the addition of sodium hypochlorite that can react with PCPPs and other organic matter (i.e., dissolve organic matter) to generate disinfection by-products and can cause the final effluent to be more harmful to aquatic organisms. Here, we exposed Daphnia magna to two stages of wastewater, the pre-chlorinated wastewater (PreCl) and the final effluent. In addition, we exposed D. magna, to the final effluent with a concentration gradient of added PFOS, to investigate if this persistent contaminant altered the toxicity of the final effluent. After 48 h of contaminant exposure, we measured the daphnids metabolic responses to the different stages of wastewater treatment, and with the addition of PFOS, utilizing proton nuclear magnetic resonance spectroscopy and liquid chromatography tandem mass spectrometry. We found few significant changes to the metabolic profile of animals exposed to the PreCl wastewater; however, animals exposed to the final effluent displayed increases in many amino acids and decreases in some sugar metabolites. With the addition of PFOS to the final effluent, the metabolic profile shifted from increased amino acids and decreased sugar metabolites and energy molecules especially at the low and high concentrations of PFOS. Overall, our results demonstrate the metabolome is sensitive to changes in the final effluent that are caused by sterilization, and with the addition of a persistent contaminant, the metabolic profile is further altered.
消费品，如全氟辛烷磺酸（PFOS）和药品（PCPPs），通过废水处理过程中的低效去除而进入水生生态系统。通常，废水的消毒过程包括添加次氯酸钠，它可以与 PCPPs 和其他有机物（即溶解有机物）反应，生成消毒副产物，并可能导致最终出水对水生生物更有害。在这里，我们让大型溞分别暴露于两个阶段的废水，预氯化废水（PreCl）和最终出水。此外，我们还让大型溞暴露于添加了 PFOS 的最终出水中，以调查这种持久性污染物是否改变了最终出水的毒性。在污染物暴露 48 小时后，我们利用质子核磁共振波谱和液相色谱串联质谱法测量了大型溞对不同阶段废水处理的代谢反应。我们发现，暴露于 PreCl 废水中的动物的代谢谱几乎没有明显变化；然而，暴露于最终出水中的动物的许多氨基酸增加，一些糖代谢物减少。在最终出水中添加 PFOS 后，代谢谱从增加的氨基酸和减少的糖代谢物和能量分子转变，尤其是在 PFOS 的低浓度和高浓度下。总的来说，我们的结果表明，代谢组对消毒引起的最终出水变化很敏感，并且添加持久性污染物后，代谢谱进一步改变。
