污染场地水平修复井技术的研究进展及应用实践

常用的污染场地原位修复技术主要通过竖直井实现,但竖直井修复技术存在单井接触范围小、精准度低、难以在地表设施较多的场地实施等问题。污染场地水平修复井技术通过水平定向钻进手段协同化学氧化/还原、气相抽提、地下水抽出处理等修复方式靶向去除场地土壤/地下水污染区域的污染物,克服了竖直井修复技术的不足,适用于在产设施和构筑物下方的土壤/地下水修复。针对该技术的应用原理、技术优势及局限性、国内外研究进展等方面进行探讨。该技术在J省N市某石油烃污染场地进行了工程示范,并结合软件模拟论证,采用水平修复井技术协同碱活化的过硫酸钠药剂注入。结果表明:该技术的实施不受修复区域地表市政设施的限制,对场地及周边环境扰动小,单井接触范围大,修复精度更高,工期100 d内石油烃浓度降低了96.47%,达到修复目标值。该技术的成功示范可为我国原位修复技术的发展提供切实可行参考,其推广和使用前景广阔。

RESEARCH ADVANCES AND APPLICATION OF HORIZONTAL REMEDIATION WELLS IN SITE REMEDIATION

In-situ remediation of soil and groundwater is mainly realized through vertical remediation wells technology, but this technology has a series of problems. The horizontal remediation wells(HRWs) technique is an innovative in-situ soil/groundwater remediation technology at contaminated sites, which can fully overcome the shortcomings of vertical wells. It can be used to target and clean up the contaminants precisely by means of horizontal directional drilling collaborated with conventional methods, such as chemical oxidation/reduction, soil vapor extraction, groundwater pump and treat, etc. It is mainly used at sites where conventional vertical drilling or trenching would be undesirable or impractical, and is especially suitable for contaminated soil and groundwater remediation beneath surface obstructions and active facilities. At present, the research and application of HRWs technology have not been conducted widely in China. The research advances of HRWs were introduced in the aspects of principles and characteristics, advantages and limitations as well as the history and development trend.This new technology was applied and tested at a petroleum hydrocarbon contaminated site in N City, J Province. The results show that the implementation of this technology is not limited by the active surface facilities with little disturbance to the surrounding environment. It has a greater contact area with contamination. The overall concentration of petroleum hydrocarbon in groundwater reached the remediation target value and was reduced by 96.47%. The successful demonstration of this technique can provide a practical reference and new vision for the development of in-situ remediation technology in China.