Highly elevated emission of mercury vapor due to the spontaneous combustion of refuse in a landfill
Highly elevated emission of mercury vapor due to the spontaneous combustion of refuse in a landfill
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DOI：
10.1016/j.atmosenv.2013.07.016
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发表时间：
2013-11
影响因子：
5
通讯作者：
Wei Zhu;J. Sommar;Zhonggen Li;Xinbin Feng;Che-Jen Lin;Guanghui Li
中科院分区：
文献类型：
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作者：
Wei Zhu;J. Sommar;Zhonggen Li;Xinbin Feng;Che-Jen Lin;Guanghui Li
垃圾处理（例如，填埋和焚烧）已被认为是全球汞（Hg）排放的一个重要人为来源。然而，对发生逸散自燃的垃圾填埋场或垃圾倾倒场所汞排放的现场测量尚未见报道。对西南某填埋场垃圾自燃附近的气态单质汞（Hg0）浓度和排放通量进行了观测。垃圾表面上的环境氢浓度在42.7±20.0 ~ 396.4±114.2 ng m−3之间，由于自燃而增加了10倍。利用2004 - 2013年hg0数据的箱形模型，我们估计垃圾的hg0排放量由于自燃而放大了8-40倍。在燃烧点下风位置配置了基于松弛涡积累的微气象通量测量系统，对hg0排放进行了量化。在测量足迹上的高汞浓度事件期间，检测到极大的湍流沉积通量（平均可达- 128.6 μg m - 2h - 1,20 min）。温度、水分和光照对hg0交换的影响被垃圾燃烧羽流富集空气中hg0的大量沉积所掩盖。研究表明，垃圾的逸散性自燃可以促进垃圾填埋场的汞排放。该排放代表了汞库存估算中被忽视的人为来源。
Refuse disposal (e.g., landfilling and incineration) have been recognized as a significant anthropogenic source of mercury (Hg) emission globally. However, in-situ measurements of Hg emission from landfill or refuse dumping sites where fugitive spontaneous combustion occurs have not been reported. Gaseous elemental mercury (Hg0) concentration and emission flux were observed near spontaneous combustions of refuse at a landfill site in southwestern China. Ambient Hg0concentrations above the refuse surface ranged from 42.7 ± 20.0 to 396.4 ± 114.2 ng m−3, up to 10 times enhancement due to the spontaneous burning. Using a box model with Hg0data obtained from 2004 to 2013, we estimated that the Hg0emission from refuse was amplified by 8–40 times due to spontaneous combustion. A micrometeorological flux measurement system based on relaxed eddy accumulation was configured downwind of the combustion sites to quantify the Hg0emission. Extremely large turbulent deposition fluxes (up to −128.6 μg m−2h−1, 20 min average) were detected during periods of high Hg0concentration events over the measurement footprint. The effect of temperature, moisture and light on the air–surface exchange of Hg0exchange was found to be masked by the overwhelming deposition of Hg0from the enriched air from the refuse combustion plumes. This research reveals that mercury emission from the landfill refuse can be boosted by fugitive spontaneous combustion of refuse. The emission represents an anthropogenic source that has been overlooked in Hg inventory estimates.