用于场地土壤修复的电阻加热技术研究进展

我国目前存在大量地质条件复杂,常规抽提技术难以快速有效地修复污染场地。电阻加热(electrical resistance heating,ERH)技术受土壤异质性影响小,处理深度大,加热速度快,能快速有效地去除地质条件复杂的土壤渗流区和饱和区中的挥发性有机物。但该技术在国内应用较晚,相关研究较少。简述了ERH技术的修复机制,包括促进污染物的迁移和提高污染物的降解速率;土壤电导率、电场强度、地下水流动和土壤异质性等因素如何影响ERH的修复效率。介绍了ERH技术与原位化学氧化、原位生物修复及其他原位热处理技术的耦合,ERH场地实施的建井方法、设备布署和部分国外的场地实施案例等。最后,针对ERH技术在实际应用中存在的问题,指出了ERH技术研究的发展方向。

RESEARCH PROGRESS OF ELECTRICAL RESISTANCE HEATING FOR SOIL REMEDIATION

There are currently a large number of contaminated sites with complex geological conditions in China. Conventional technologies like soil vapor extraction are inefficient in remediating these sites quickly and effectively. Electrical resistance heating (ERH) technology is less affected by soil heterogeneity, and it has a large processing depth and a fast heating speed. It could quickly and effectively remove volatile organic compounds from the unsaturated and saturated zone in soil with complex geological conditions. However, the application of ERH in China begins relatively late, and there are few application cases. To support the further research and application of ERH, this paper first introduces the remediation mechanism of ERH (including promoting the evacuation of pollutants and increasing the degradation rate of pollutants) and how factors such as soil conductivity, electric field strength, groundwater flow and soil heterogeneity affect the efficiency of ERH remediation. The coupling of ERH with other in-situ remediation technologies were reviewed as well. It also describes how to deploy electrode wells and equipment during an ERH process implemented on site. Finally, related soil remediation cases using ERH technologies are discussed, and the future direction of ERH research is pointed out.