Investigation of the light-enhanced emission of mercury from naturally enriched substrates
Investigation of the light-enhanced emission of mercury from naturally enriched substrates
复制标题
DOI：
10.1016/s1352-2310(02)00329-1
复制
发表时间：
2002-07-01
影响因子：
5
通讯作者：
Kim, CS
中科院分区：
文献类型：
--
作者：
Gustin, MS;Biester, H;Kim, CS
据报告，入射辐射会促进土壤中的汞释放。在这项研究中，光对汞排放量的影响，从基板修订与纯合成汞物种，并从自然和汞富集的基板进行了研究，使用实验室实验和原位通量测量。光增强的排放被发现发生从衬底修订与硫化汞，从元素汞（Hg-0）和氯化汞修订氧化铁和有机物的基板。自然基板的光增强发射的幅度范围从1.5到116倍，发生在黑暗中，在相同的基板温度。含有堇青石、变辰砂和“基质结合汞”（与有机或无机相结合）的基质相对于主要含有辰砂的基质表现出更高程度的光增强发射。实验室和现场数据计算的活化能表明，光还原是一个过程与光增强的排放。活化能，来自使用原位汞通量和土壤温度，表明光还原是一个占主导地位的过程，促进释放汞从衬底与日出。活化能，使用白天的数据计算，小于那些计算为日出。据推测，这是由于汞池正在开发与光还原在第一光，是释放土壤温度和对流传热增加在白天。这项研究表明，光能是更占主导地位的过程控制汞排放的自然富集基板比土壤温度。(C)2002爱思唯尔科技有限公司版权所有。
Incident radiation has been reported to facilitate mercury release from soils. In this study the influence of light on mercury emissions from substrates amended with pure synthetic mercury species, and from naturally and anthropogenically mercury-enriched substrates were investigated using laboratory experiments and in situ flux measurements. Light-enhanced emissions were found to occur from substrates amended with HgS, and from elemental mercury (Hg-0) and HgCl2 amended iron oxide and organic containing substrates. The magnitude of light-enhanced emissions for natural substrates ranged from 1.5 to 116 times that occurring in the dark at the same substrate temperature. Substrates containing corderoite, metacinnabar and "matrix bound mercury" (that bound to organic or inorganic phases) exhibited a higher degree of light-enhanced emissions relative to that containing predominantly cinnabar. Calculated activation energies for both laboratory and field data indicate that photo-reduction is a process associated with the light-enhanced emissions. Activation energies, derived using in situ mercury fluxes and soil temperatures, indicated that photo-reduction was a dominant process facilitating release of Hg from substrates with sunrise. Activation energies, calculated using daytime data, were less than those calculated for sunrise. This is hypothesized to be due to a pool of Hg being developed with photo-reduction at first light that is released as soil temperatures and convective heat transfer increase during the day. This study demonstrated that light energy is the more dominant process controlling mercury emissions from naturally enriched substrates than soil temperature. (C) 2002 Elsevier Science Ltd. All rights reserved.