铬渣动态淋滤重金属铬溶解释放规律研究

A Research on Dissolution and Releasing Regularity of Heavy Metal Chromium under Chromium Slag Dynamic Leaching

为了全面系统地研究铬渣中Cr(Ⅵ)和Cr(Ⅲ)溶解释放特征,以锦州和沈阳两地铬渣堆场为研究对象,通过动态淋滤试验,测定滤出液中Cr(Ⅵ)和总铬的质量浓度变化,分析铬渣淋滤液中Cr(Ⅵ)和Cr(Ⅲ)溶解释放规律。试验结果表明,锦州新铬渣和沈阳陈铬渣淋滤过程中,Cr(Ⅵ)和总铬浓度都经历先迅速下降再缓慢下降的过程;相较锦州新铬渣,沈阳陈铬渣Cr(Ⅵ)和总铬浓度下降都较慢,且初始浓度也较低;相比Cr(Ⅵ)的溶出,两地铬渣Cr(Ⅲ)的溶出量均较少,Cr(Ⅲ)溶出占比呈波动性上升趋势;锦州新铬渣和沈阳陈铬渣的Cr(Ⅵ)和总铬溶出浓度随淋出液体积分别呈双指数曲线衰减关系和幂函数曲线衰减关系。试验成果将为防治铬渣对地下水污染提供科学理论依据。

In order to comprehensively and systematically study the Cr（ Ⅵ） and Cr（ Ⅲ） release characteristics in chromium slag,taking the chromium slag from Shenyang and Jinzhou as an object,basing on dynamic leaching experiment,the mass concentration of Cr（ Ⅵ） and total chromium were measured,and Cr（ Ⅵ） and Cr（ Ⅲ） dissolution and releasing regularity in the chromium slag leachate were analyzed. Results show that the concentration of Cr（ Ⅵ） and total chromium decline rapidly at first and then decrease slowly in the leaching process of both the new chromium slag from Jinzhou and the old chromium slag from Shenyang. Compared with the new chromium slag from Jinzhou,Cr（ Ⅵ） and total chromium concentration of the old chromium slag from Shenyang decrease slowly with decreasing initial concentration. Compared with Cr（ Ⅵ）,the dissolution concentration of Cr（ Ⅲ） is less from the two chromium slags,and the Cr（ Ⅲ） dissolution ratio presents a rising trend of volatility. The leaching concentration of Cr（ Ⅵ） and total chromium are double exponential curve relationship and the power function curve relationship respectively with the leaching solution volume for the new chromium slag from Jinzhou and the old chromium residue from Shenyang. The experimental results will provide scientific theoretical basis for groundwater pollution.