基于风险管控的历史遗留硫磺冶炼废渣综合治理效果

Comprehensive Treatment Effects of Historical Sulfur Smelting Waste Slag Based on Risk Management and Control

为解决赤水河源头流域(云南段)历史遗留硫磺冶炼废渣40多年无序堆积导致流域水体持续酸化的污染问题,通过对“自然衰减”“异位修复”“风险管控”等治理途径分析,提出“风险管控+生态修复”模式开展了该区域内酸性废渣和废水的示范工程治理。在查明治理区域污染因子的基础上,采取“废渣防流失、复合阻隔控制、适生植物配比、污水收集处理和运行监测管理”的集成风险管控技术,分析工程实施前、实施中和实施后的固废属性,以及地表水、地下水和废渣渗滤液中污染因子的变化。结果表明:在投加0.35%~0.65%比例生石灰条件下,固废属性从第Ⅱ类一般工业固废改性为第Ⅰ类一般工业固废;工程完工时,地下水pH即可达标,硫酸盐超标倍数从最大5.3倍削减至1.2倍;工程实施3个月后,渗滤液pH稳定达标,硫酸盐超标倍数从最大3.2倍削减至1.7倍;工程实施7个月后地表水pH达标。基于风险管控的历史遗留硫磺冶炼废渣综合治理,能够满足管控目标,并初步完成了技术推广和应用。

In order to solve the problem of continuous acidification of watershed in Chishui River headwater basin(Yunnan section)caused by the disorderly accumulation of historical sulfur smelting waste residue for more than 40 years,the model project of“risk management+ecological restoration”was proposed to carry out demonstration project treatment of acid waste residue and wastewater in this area through analysis of treatment approaches such as“natural attenuation”,“ex-situ restoration”and“risk management and control”.On the basis of identifying the pollution factors in the treatment area,the integrated risk control technology of“waste residue anti-loss,composite barrier control,suitable plant ratio,sewage collection and treatment,and operation monitoring and management”was adopted to analyze the solid waste properties before,during and after the implementation of the project,as well as the changes of pollution factors in surface water,groundwater and waste residue leachate.The results show that the property of solid waste is modified from ClassⅡgeneral industrial solid waste to ClassⅠgeneral industrial solid waste under the condition of adding 0.35%—0.65%lime.When the project is completed,the pH value of groundwater can meet the standard,and the times of exceeding the standard of sulfate is reduced from the maximum of 5.3 times to 1.2 times.Three months after the implementation of the project,the pH value of leachate is stable and meets the standard,and the times of exceeding the standard of sulfate is reduced from the maximum of 3.2 times to 1.7 times.7 months after the implementation of the project,the pH value of the surface water meets the standard.The comprehensive management of historical sulfur smelting waste residue based on risk management and control can meet the management and control objectives,and the technology promotion and application have been preliminarily completed.