State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), 1#, Dongsanlu, Erxianqiao, Chengdu, 610059, Sichuan, China.
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), 1#, Dongsanlu, Erxianqiao, Chengdu, 610059, Sichuan, China.
Environ Res. 2024 Dec 15;263(Pt 1):119995. doi: 10.1016/j.envres.2024.119995. Epub 2024 Sep 12.
The poor remediation performance of groundwater circulation well (GCW) on semi-volatile organic contaminants (such as aniline) has severely limited its practical application. To address the challenges posed by the low volatility and solubility of these contaminants, an innovative integration of GCW with in-situ thermal remediation (ISTR) was proposed to create a thermal enhanced circulation well (GCW-ISTR) in this study. Laboratory experiments and model simulations were performed to evaluate the heat transfer and enhanced remediation effect by GCW-ISTR. Results demonstrate that the heat transfer process is controlled by the water circulation around GCW-ISTR and is influenced by factors such as aeration flow rate, groundwater velocity and aquifer permeability. Heating area is directly proportional to the seepage velocity of groundwater which can be analyzed by multiplying the water head difference between the upper and lower screens with the aquifer permeability. Therefore, the heat transfer model, based on Darcy's seepage theory and the energy conservation equation, effectively simulates the heat transfer with an error margin of less than 10%. Compared to individual GCW, GCW-ISTR exhibits a 25.8% improvement in aniline remediation efficiency, resulting in a decrease in the average concentration from 97.95 mg/L to 0.168 mg/L within 48 h, effectively mitigating the occurrence of tailing phenomena. This study provides a feasible method of enhancing the remediation of GCW on semi-volatile contaminants and is anticipated to broaden the applicability of GCW in site application.
地下水循环井（GCW）对半挥发性有机污染物（如苯胺）的修复效果不佳，严重限制了其实际应用。为了解决这些污染物挥发性和溶解度低带来的挑战，本研究提出将 GCW 与原位热修复（ISTR）相结合，形成热增强循环井（GCW-ISTR）。通过实验室实验和模型模拟，评估了 GCW-ISTR 的传热和增强修复效果。结果表明，传热过程受 GCW-ISTR 周围水的循环控制，并受到曝气流量、地下水速度和含水层渗透性等因素的影响。加热面积与地下水的渗流速度成正比，可通过上下筛之间的水头差乘以含水层渗透率来分析。因此，基于达西渗流理论和能量守恒方程的传热模型能够有效地模拟传热，误差小于 10%。与单独的 GCW 相比，GCW-ISTR 使苯胺的修复效率提高了 25.8%，在 48 小时内将平均浓度从 97.95mg/L 降低至 0.168mg/L，有效地减轻了拖尾现象的发生。本研究为增强 GCW 对半挥发性污染物的修复提供了一种可行的方法，有望拓宽 GCW 在现场应用中的适用性。
