Intra-particle migration of mercury in granular polysulfide-rubber-coated activated carbon (PSR-AC).
Intra-particle migration of mercury in granular polysulfide-rubber-coated activated carbon (PSR-AC).
复制标题
颗粒状聚硫化橡胶涂层活性炭（PSR-AC）中汞的颗粒内迁移。
DOI：
10.1016/j.chemosphere.2011.11.012
复制
发表时间：
2012
期刊：
影响因子：
8.8
通讯作者：
Luthy,RichardG
中科院分区：
文献类型：
--
作者：
Kim,Eun-Ah;Masue-Slowey,Yoko;Fendorf,Scott;Luthy,RichardG
采用微x射线荧光（μ-XRF）成像技术和数学模型研究了汞离子与聚硫橡胶包覆活性炭（PSR-AC）反应后的深度分布。μ-XRF结果表明，在10ppm的hgcl2水溶液中，PSR-AC处理3个月后，汞浓度在颗粒外部0 ~ 100μm处。μ- x射线吸收近边光谱（μ-XANES）分析表明HgS是汞的主要种类，并表明汞在颗粒内的迁移涉及与PSR聚合物的化学反应。建立了基于Langmuir液相扩散吸附等温线（Langmuir模型）和表面扩散吸附动力学模型（动力学吸附模型）的粒子内传质模型。Langmuir模型预测了汞扩散的总体趋势，尽管其扩散速度比μ-XRF图所观察到的要慢。动力学吸附模型提出了更快的汞传输，这高估了汞离子通过快速和慢速反应位点之间的交换反应的移动。μ-XRF和数学模型结果都表明，由于PSR在交流颗粒内的表面积较大，汞的去除不仅发生在PSR-AC颗粒的外表面，而且还发生在一些内部区域。
The depth profile of mercuric ion after the reaction with polysulfide–rubber-coated activated carbon (PSR-AC) was investigated using micro-X-ray fluorescence (μ-XRF) imaging techniques and mathematical modeling. The μ-XRF results revealed that mercury was concentrated at 0–100μm from the exterior of the particle after 3months of treatment with PSR-AC in 10ppm HgCl2aqueous solution. The μ-X-ray absorption near edge spectroscopic (μ-XANES) analyses indicated HgS as a major mercury species, and suggested that the intra-particle mercury transport involved a chemical reaction with PSR polymer. An intra-particle mass transfer model was developed based on either a Langmuir sorption isotherm with liquid phase diffusion (Langmuir model) or a kinetic sorption with surface diffusion (kinetic sorption model). The Langmuir model predicted the general trend of mercury diffusion, although at a slower rate than observed from the μ-XRF map. A kinetic sorption model suggested faster mercury transport, which overestimated the movement of mercuric ions through an exchange reaction between the fast and slow reaction sites. Both μ-XRF and mathematical modeling results suggest mercury removal occurs not only at the outer surface of the PSR-AC particle but also at some interior regions due to a large PSR surface area within an AC particle.