Mechanisms of Hg Adsorption from Mixed Pollutant Streams

汞与碳吸附剂表面的相互作用是汞管理领域中最复杂和最重要的科学问题之一，它影响着广泛的修复技术。目前已知HG/C相互作用高度依赖于汽相和水相中的二次组分，最佳捕集需要针对特定的废流定制碳表面化学。我们的目标是在逐个地点的基础上了解汞/碳的非均相化学，以指导混合废物应用中碳吸附剂的合成和应用。追求这一目标的具体目标是： A)最近测量新的碳纳米材料对汞蒸气的吸附动力学/容量 在布朗大学使用分子工程技术合成的。这些材料具有均匀的、定向有序的表面，允许对石墨烯平面和边缘位置的单独贡献进行独特的研究。B)测量瞬时解吸行为和氧化状态变化，以提供有关吸附汞的化学形态和结合能的信息。 C)扩大(A)和(B)的测试矩阵，以包括热修复尾气中含有常见二次组分的二元和三元混合物。D)在同一套新的表面工程碳纳米形式上进行水相汞吸附实验，作为pH和氯离子浓度的函数。E)利用(a-d)的结果来开发一个全面的汞/碳机制、新的吸着剂配方以及根据废气成分知识系统地修改碳表面的指南。F)与SBRP合作伙伴就涉及含汞混合废流的罗德岛案例研究开展合作， 并利用(a-f)的结果来识别和展示涉及新的吸着剂配方的有效捕集技术。

The interactions of mercury with carbon sorbent surfaces is one of the most complex and important scientific questions in the area of Hg management, and it impacts a broad range of remediation technologies. Hg/C interactions are now known to be highly dependent on secondary components in both vapor and aqueous phases and optimal capture requires the tailoring of carbon surface chemistry for specific waste streams. Our goal is to understand Hg/C heterogeneous chemistry on a site-by-site basis to guide the synthesis and application of carbon sorbents for mixed waste applications. The specific Aims in pursuit of this goal are to: a) Measure mercury vapor adsorption kinetics/capacities on new carbon nanomaterials recently synthesized at Brown using molecular engineering techniques. These materials have uniform, orientationally ordered surfaces that allow a unique study of the separate contributions of graphene planes and edge sites. b) Measure transient desorption behavior and oxidation state changes to provide information on the chemical form and binding energies of adsorbed mercury. c) Extend the test matrix of (a) and (b) to include binary and ternary mixtures incorporating common secondary components in thermal remediation off-gases. d) Carry out aqueous phase Hg adsorption experiments as a function of pH and chloride concentration on the same set of new surface-engineered carbon nanoforms. e) Use the results from (a-d) to develop a comprehensive Hg/C mechanism, new sorbent fomulations, and guidelines for systematically modifying carbon surfaces from knowledge of waste streams composition. f) To work with SBRP partners on Rhode Island case studies involving Hg-containing mixed waste streams, and to use the results of (a-f) to identify and demonstrate effective capture technologies involving the new sorbents formulations.