硫酸盐类钙砷渣SO4-•自激发形成与砷(III)的氧化转型机制

冶金、化工等行业产生大量危险废物硫酸盐类钙砷渣，硫酸钠、砷(III)含量高，国内外现有包裹式稳定化方法对其安全处置极难，已成为行业重大环保难题。基于该类危废自身特征，率先提出利用钙砷渣的高浓度盐间隙水构建碳铁催化单元，激发体系中硫酸根产生高氧化活性的SO4-•自由基，以实现可溶态砷(III)氧化与固定的创新思路。拟研究：(1) 钙砷渣中SO4-•自由基自激发的形成规律；(2) SO4-•自由基扩散氧化砷(III)的机制；(3) 砷在渣相中的固-液界面行为及其转型机理。旨在形成硫酸盐类钙砷渣中可溶态砷(III)稳定化处置技术原型，丰富钙砷渣无害化的基础理论。

Metallurgical and chemical industries generate a lot of hazardous waste residue contains sulfate and arsenic, arsenic is easy to dissolve and difficult to stabilize by the method of physical package at home and abroad. So it’s can’t be ignored that the pollution caused by As (III) dissolving from the hazardous calcium arsenic residue was the major environmental problems in China. In this project, a catalytic system composed by salt gap water self-contained in the residue and carbon/iron materials was first proposed, while sulfate anion free radical should be produced by series catalytic reaction. Finally, oxidation and stabilization of As(III) in hazardous waste should be achieved by the free radical diffusion processes. The following aspects will be studied: (1) the formation and transformation mechanism of sulfate anion free radical in calcium arsenic residue, (2) the diffusion oxidation process of sulfate free radicals and the crystallization mechanism of arsenic, (3) the structure of stable arsenic crystals and their interface interaction between various solutions and residue in slag. The purpose of this study is to develop a highly toxic soluble As (III) stabilization prototype in calcium arsenic waste residue, and enrich the theory of calcium arsenic slag disposal.