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最复杂、最重要的科学问题之一，它影响着广泛的修复技术。汞/碳的相互作用目前已知在很大程度上取决于气相和水相中的次要成分，最佳捕获需要针对特定废物流调整碳表面化学性质。我们的目标是了解汞/碳多相化学在一个网站的基础上，以指导合成和碳吸附剂的混合废物应用程序的应用。实现这一目标的具体目标是： a）最近测量了新型碳纳米材料上的汞蒸气吸附动力学/能力 在布朗大学用分子工程技术合成的。这些材料具有均匀的、取向有序的表面，允许对石墨烯平面和边缘位点的单独贡献进行独特的研究。B）测量瞬时解吸行为和氧化态变化，以提供关于吸附汞的化学形式和结合能的信息。 c）扩展（a）和（B）的测试矩阵，以包括在热修复废气中含有常见次要成分的二元和三元混合物。d）在同一组新的表面工程碳纳米上进行水相汞吸附实验，作为pH值和氯化物浓度的函数。e）利用（a-d）的结果，根据废物流组成的知识，制定一个全面的汞/碳机制、新的吸附剂配方和系统地改变碳表面的准则。f）与SBRP伙伴合作，对罗得岛含汞混合废物流进行案例研究， 并利用（a-f）的结果来确定和展示涉及新吸附剂配方的有效捕获技术。

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.