Bai Jing, Zhao Yong-Sheng, Sun Chao, Qin Chuan-Yu, Yu Ling
Huan Jing Ke Xue. 2014 Oct;35(10):3775-81.
A two-dimension simulated sand box was set up to investigate the influencing factors, such as the initial groundwater level, aeration rate and the initial groundwater rate, that affect groundwater circulation well (GCW) by determining the intensity of groundwater circulation which was characterized by the variation of groundwater level before and after aeration. The optimal operating parameters were used to remediate nitrobenzene contaminated aquifer. The results demonstrated that: GCW could be well operated under the conditions of 45 cm groundwater level, 0.7 m3 · h(-1) aeration rate. The effects of groundwater velocity less than 1.0 m · d(-1) could be ignored. The lateral mobility rate of nitrobenzene was faster than that of longitudinal. The average concentration of nitrobenzene was 246.97 mg · L(-1) on day 50 of leakage. During the remediation of circulation well, an efficient organics remediation region was gradually formed around the circulation well. The organics in this region was removed preferentially, and the concentration decreased continuously. Besides the efficient remediation region, there was a transient region, where the concentration of organics was influenced by the combined effects of adsorption/desorption and migration potential of organics. During the whole remediation process, the concentration of nitrobenzene went through three stages described as rapid removal, slow removal. After 14h aeration, the nitrobenzene average concentration was reduced to 71.19 mg L(-1). The residual nitrobenzene was distributed in regions far away from GCW. Therefore, nitrobenzene contaminated aquifer could be well remediated by GCW, and there were optimal operation conditions and appropriate remediation time which guaranteed the best remediation effect.
搭建了一个二维模拟砂箱，通过测定曝气前后地下水位变化所表征的地下水循环强度，来研究影响地下水循环井（GCW）的初始地下水位、曝气速率和初始地下水流速等影响因素。采用最优运行参数修复硝基苯污染含水层。结果表明：在地下水位45 cm、曝气速率0.7 m³·h⁻¹的条件下，地下水循环井能够良好运行。地下水流速小于1.0 m·d⁻¹时的影响可忽略不计。硝基苯的横向迁移速率快于纵向迁移速率。泄漏第50天时硝基苯的平均浓度为246.97 mg·L⁻¹。在循环井修复过程中，循环井周围逐渐形成一个高效的有机物修复区域。该区域内的有机物被优先去除，浓度持续下降。除高效修复区域外，还存在一个过渡区域，该区域内有机物的浓度受有机物吸附/解吸和迁移势综合作用的影响。在整个修复过程中，硝基苯浓度经历了快速去除、缓慢去除三个阶段。曝气14 h后，硝基苯平均浓度降至71.19 mg·L⁻¹。残留的硝基苯分布在远离地下水循环井的区域。因此，地下水循环井能够很好地修复硝基苯污染含水层，且存在最优运行条件和合适的修复时间，以保证最佳修复效果。
