有色冶炼含砷废渣长期稳定性的分子机制及调控

有色冶炼含砷废渣是地表环境砷污染的主要源头，我国近年由此造成的水土砷污染问题日益严重。废渣中砷的赋存形态及其在环境条件下的转化是决定含砷废渣长期稳定性的本质因素，对该问题的清晰认识是评估废渣砷污染风险的关键，也是建立原位调控方法的前提。目前，国内外学者在这方面的研究较为缺乏，认识尚不清晰，相关基础研究和理论积累难以支撑重点防控区砷污染的预防及有效治理。本项目将以我国典型有色冶炼含砷废渣为研究对象，通过现场研究和室内实验研究，采用化学分析、热力学计算、光波谱表征及其它矿物结构分析手段，系统研究不同类型废渣中砷的赋存形态及其在不同贮存环境条件下的转化规律，评估其水土污染风险，揭示含砷废渣长期稳定性的分子机制，阐明废渣砷稳定性的微生物及物理化学调控原理，并初步建立原位调控方法。项目研究对充实与发展砷的环境地球化学理论体系、从源头阻控废渣砷污染的发生及遏制日益恶化的环境砷污染态势具有重要意义。

Arsenic-bearing solid waste from non-ferrous metal smelting industry is an important source of arsenic pollution in surface environment, which caused increasingly serious soil and water pollution in recent years. The speciation of arsenic and its transformation in the environment are the key factors controlling the long-term stability of the solid wastes. Better understanding of these questions is important for the risk assessment of arsenic pollution and the prerequisite for the establishment of in-situ pollution control technologies. However, the research on these issues is not enough to support the remediation of arsenic pollution in badly contaminated areas. This project will take several typical non-ferrous metal industries as cases and investigate the speciation and transformation of the arsenic-bearing solid wastes by means of chemical analysis, thermodynamic calculation, spectroscopic characterization and other mineral structure analysis techniques. The objectives of this project are to shed more light on the speciation and transformation of arsenic from molecular level and its impact on the stability of arsenic in the smelting tailings, to evaluate its pollution risk, to understand the principles of pollution control by microbial/physiochemical methods, and to establish in-situ remediation technology. Successful implementation of this project is theoretically and practically important to efficient control of arsenic pollution and prevention of serious incidence of arsenic pollution.