Evasion of Elemental Mercury from a Boreal Peatland Suppressed by Long-Term Sulfate Addition

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• 作者：Johannes Fritsche ; Stefan Osterwalder ; Mats B. Nilsson ; J枚rgen Sagerfors ; Staffan 脜kerblom ; Kevin Bishop ; Christine Alewell
• 刊名：Environmental Science & Technology Letters
• 出版年：2014
• 出版时间：October 14, 2014
• 年：2014
• 卷：1
• 期：10
• 页码：421-425
• 全文大小：216K

文摘

We investigated the evasion of TGM (total gaseous mercury) from experimental plots on a boreal peatland that had been exposed for 15 years to different combinations of atmospheric sulfur (S) and nitrogen (N) deposition as well as greenhouse treatments simulating climate change. Shaded dynamic flux chamber measurements during the summer in 2009 showed emission of TGM to the atmosphere from most of the treated plots (0.7 卤 0.94 ng m^鈥? h^鈥?). However, TGM exchange rates were significantly lower, occasionally indicating Hg uptake, on plots subjected to S addition at rates of 20 kg ha^鈥? year^鈥?. Enhanced nitrogen deposition and greenhouse treatment had no significant effect on TGM fluxes. We hypothesize that the lower Hg evasion from the sulfur-treated plots is related to either earlier Hg evasion or Hg binding to S in organic matter, making Hg less susceptible to volatilization and more prone to transport in runoff.