Role of sulfur trioxide (SO3) in gas-phase elemental mercury immobilization by mineral sulfide
Role of sulfur trioxide (SO3) in gas-phase elemental mercury immobilization by mineral sulfide
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三氧化硫 (SO3) 在矿物硫化物气相元素汞固定中的作用
DOI：
10.1021/acs.est.8b07317
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发表时间：
2019
影响因子：
11.4
通讯作者：
Kaimin Shih
中科院分区：
文献类型：
--
作者：
Zequn Yang;Hailong Li;Wenqi Qu;Mingguang Zhang;Yong Feng;Jiexia Zhao;Jianping Yang;Kaimin Shih
矿物硫化物基吸附剂是传统活性炭固定化工业烟气中单质汞（Hg0）的优良替代品。首次系统地研究了三氧化硫（SO3）对纳米级硫化铜（nano - cu）吸附hg0的影响。研究发现，so3显著抑制了纳米cu上hg0的去除，部分原因是so3将对汞具有高亲和力的还原性硫（硫化物）氧化为其氧化的硫（硫酸盐）。此外，一种全新的“氧化-还原”机制导致硫化物在固定化硫化汞（HgS）上同时氧化和还原汞，这是抑制效果的原因。尽管HgS中汞还原释放的hg0可以被so3氧化成硫酸盐形式（HgSO4）并被吸附剂重新捕获，但“氧化-还原”机制仍然损害了纳米cu的hg0捕获性能，因为沉积在吸附剂表面的HgSO4在环境暴露时很容易浸出。这些关于so3在纳米cu捕获hg0中的作用的新见解可以帮助确定可能的解决方案，并促进矿物硫化物吸附剂作为活性炭在工业烟气中固定化hg0的杰出替代品的应用。
Mineral sulfide based sorbents were superior alternatives to traditional activated carbons for elemental mercury (Hg0) immobilization in industrial flue gas. A systematical study concerning the influence of sulfur trioxide (SO3) on Hg0adsorption over a nanosized copper sulfide (Nano-CuS) was for the first time conducted. SO3was found to significantly inhibit the Hg0removal over Nano-CuS partially because SO3oxidized the reduced sulfur species (sulfide) with high affinity to mercury to its oxidized sulfur species (sulfate). Moreover, a brand new “oxidation-reduction” mechanism that led to a simultaneous oxidation of sulfide and reduction of mercury on the immobilized mercury sulfide (HgS) was responsible for the inhibitory effect. Even though the released Hg0from the reduction of mercury in HgS could be oxidized by SO3into its sulfate form (HgSO4) and recaptured by the sorbent, the “oxidation-reduction” mechanism still compromised the Hg0capture performance of the Nano-CuS because HgSO4deposited on the sorbent surface could be easily leached out when environmentally exposed. These new insights into the role of SO3in Hg0capture over Nano-CuS can help to determine possible solutions and facilitate the application of mineral sulfide sorbents as outstanding alternatives to activated carbons for Hg0immobilization in industrial flue gas.