Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi 860000, China.
Int J Environ Res Public Health. 2020 Mar 11;17(6):1822. doi: 10.3390/ijerph17061822.
The nitrogen pollution of rivers as a global environmental problem has received great attentions in recent years. The occurrence of emerging pollutants in high-altitude rivers will inevitably affect the dissimilatory nitrate reduction processes. In this study, sediment slurry experiments combined with N tracer techniques were conducted to investigate the influence of pharmaceutical and personal care products (alone and in combination) on denitrification and the anaerobic ammonium oxidation (anammox) process and the resulting NO release in the sediments of the Yarlung Zangbo River. The results showed that the denitrification rates were inhibited by sulfamethoxazole (SMX) treatments (1-100 μg L) and the anammox rates decreased as the SMX concentrations increased, which may be due to the inhibitory effect of this antibiotic on nitrate reducing microbes. 2-Ethylhexyl-4-methoxycinnamate (EHMC) impacted nitrogen transformation mainly though the inhibition of the anammox processes. SMX and EHMC showed a superposition effect on the denitrification processes. The expression levels of the denitrifying functional genes and were decreased and NO release was stimulated due to the presence of SMX and/or EHMC in the sediments. To the best of our knowledge, this study is the first to report the effects of EHMC and its mixtures on the dissimilatory nitrate reduction processes and NO releases in river sediments. Our results indicated that the widespread occurrence of emerging pollutants in high-altitude rivers may disturb the nitrogen transformation processes and increase the pressure of global warming.
近年来，河流的氮污染作为一个全球性的环境问题受到了广泛关注。高海拔河流中新兴污染物的出现，必然会影响异化硝酸盐还原过程。本研究采用沉积物泥浆实验结合 N 示踪技术，考察了单独及组合存在的药品和个人护理用品（PPCPs）对雅鲁藏布江沉积物中反硝化和厌氧氨氧化（anammox）过程及由此产生的 NO 释放的影响。结果表明，磺胺甲恶唑（SMX）处理（1-100μg/L）抑制了反硝化速率，随着 SMX 浓度的增加，anammox 速率降低，这可能是由于这种抗生素对硝酸盐还原微生物的抑制作用。2-乙基己基-4-甲氧基肉桂酸（EHMC）主要通过抑制 anammox 过程来影响氮转化。SMX 和 EHMC 对反硝化过程表现出叠加效应。由于 SMX 和/或 EHMC 存在于沉积物中，反硝化功能基因 和 的表达水平降低，NO 释放受到刺激。据我们所知，本研究首次报道了 EHMC 及其混合物对河流沉积物中异化硝酸盐还原过程和 NO 释放的影响。我们的结果表明，高海拔河流中新兴污染物的广泛存在可能会干扰氮转化过程，增加全球变暖的压力。
