1] Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dubendorf CH-8600, Switzerland [2] Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zurich CH-8092, Switzerland.
1] University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Institute for Ecopreneurship, Muttenz CH-4132, Switzerland [2] Department of Environmental Technology, Wageningen University, Wageningen 6708 WG, The Netherlands.
Nat Commun. 2014;5:3035. doi: 10.1038/ncomms4035.
Natural wetlands are well known for their significant methane emissions. However, trace element emissions via biomethylation and subsequent volatilization from pristine wetlands are virtually unstudied, even though wetlands constitute large reservoirs for trace elements. Here we show that the average volatile fluxes of selenium (<0.12 μg m(-2) day(-1)), sulphur (<37 μg m(-2) day(-1)) and arsenic (<0.54 μg m(-2) day(-1)) from a pristine peatland are considerable and consistent over two summers. We compare these fluxes with the total concentrations in the peat and show that selenium is up to 40 times more efficiently volatilized than arsenic, and over 100 times more efficiently volatilized than sulphur. We further show that the volatilization of selenium and arsenic increases with temperature, implying that emissions of these health-relevant trace elements will increase with global warming. We suggest that biomethylation and volatilization in wetlands play a crucial role in the mobilization and global biogeochemical cycling of trace elements.
自然湿地以其显著的甲烷排放而闻名。然而，尽管湿地是微量元素的巨大储存库，但原始湿地通过生物甲基化和随后的挥发而释放微量元素的情况实际上尚未得到研究。在这里，我们表明，在两个夏季中，从原始泥炭地中硒（<0.12μg m(-2) day(-1)）、硫（<37μg m(-2) day(-1)）和砷（<0.54μg m(-2) day(-1)）的平均挥发性通量相当可观且一致。我们将这些通量与泥炭中的总浓度进行了比较，结果表明，硒的挥发效率比砷高 40 倍，比硫高 100 倍以上。我们进一步表明，硒和砷的挥发随温度升高而增加，这意味着这些与健康相关的微量元素的排放将随着全球变暖而增加。我们认为，湿地中的生物甲基化和挥发作用在微量元素的迁移和全球生物地球化学循环中起着至关重要的作用。
