赤泥-粉煤灰-石灰协同固化Cu^(2+)污染高岭土的力学及电化学特性研究

Mechanical and Electrochemical Properties of Cu^(2+)-Contaminated Kaolin Solidified by Red Mud-Fly-Ash Lime

重金属污染场地的修复一直是一个难题。为高效、便捷、低成本的修复重金属污染场地,运用固废、赤泥和粉煤灰作为固化剂,修复Cu^(2+)污染高岭土,并对修复后的固化体进行电化学阻抗谱测试、无侧限抗压强度检测以及浸出毒性测试。试验结果表明:当赤泥与粉煤灰的配比(质量比)为7∶3时,污染土中Cu^(2+)的固化效果最佳,且各项测试指标均达到了国家标准。该方法减少了固化成本且符合固废再利用的原则,适用于重金属污染场地的修复。同时本研究证明了电化学阻抗谱技术是评价Cu^(2+)固化效果的一种便捷、准确、无损的手段。

The treatment of heavy metal-contaminated soil has been a difficult problem for many years.In order to repair heavy metal-contaminated sites with high efficiency,convenience,and low cost,solid wastes red mud and fly ash were used as main curing agents to repair Cu^(2+)-contaminated kaolin.Electrochemical impedance spectroscopy,unconfined compressive strength,and leaching toxicity measurement were carried out.The experimental results show that when the ratio of red mud to fly ash was 7∶3,the solidification effect of Cu^(2+)in contaminated soil was the best,and all test indexes complied with the national standards.Moreover,Electrochemical impedance spectroscopy was proved to be a convenient,accurate,and non-destructive method for evaluating solidification effect.Through this solidification method,the remediation cost can be reduced,and the principle of solid waste reuse car be met.The method is suitable for the remediation of heavy metal-contaminated sites.