Title: | Effects of different permeable lenses on nitrobenzene transport during air sparging remediation in heterogeneous porous media |
Author(s): | Yao M; Bai J; Yang X; Li X; Chang Y; Zhao Y; |
Address: | "Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, No 2519 Jiefang Road, Chaoyang District, Changchun, Jilin, 130021, China. Electronic address: yaomeng@cczu.edu.cn. Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, No 2519 Jiefang Road, Chaoyang District, Changchun, Jilin, 130021, China. Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China. Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, No 2519 Jiefang Road, Chaoyang District, Changchun, Jilin, 130021, China. Electronic address: zhaoyongsheng@jlu.edu.cn" |
DOI: | 10.1016/j.chemosphere.2022.134015 |
ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
Abstract: | "Air sparging (AS) is considered an effective remediation technology for groundwater contaminated by volatile organic compounds. However, the effects of AS remediation of heterogeneous aquifers with lenses of different permeability are still unclear, which limits the application of AS technology. In this study, the effects of different permeable lenses on nitrobenzene (NB) transport were quantitatively analysed by tracking the temporal and spatial evolutions of the NB concentration and using light transmission visualisation technology to observe airflow. Experimental results showed that the NB outside the airflow zone of the heterogeneous aquifer containing a gravel lens was rapidly removed, which is a special phenomenon. Through moisture content monitoring and colour tracer technology, the bubble-induced water circulation zone in a gravel lens was discovered during AS. At this time, the zone of influence (ZOI) included air flow zone and water circulation zone, while previous studies believed that the ZOI only contained the air flow zone. The presence of water circulation zone in the heterogeneous aquifer with a gravel lens increased the ZOI area and average contaminant removal flux by 5 and 2.3 times, respectively, compared with those in homogeneous aquifer. These findings have modified the conventional cognition about the ZOI and are conducive to an in-depth understanding of the remediation mechanisms and a better design of AS technology in heterogeneous aquifers with different permeable lenses" |
Keywords: | "*Environmental Restoration and Remediation *Groundwater/analysis Nitrobenzenes Porosity Water/analysis *Water Pollutants, Chemical/analysis Air sparging Bubbly flow Heterogeneous porous media Lens Nitrobenzene transport Water circulation zone;" |
Notes: | "MedlineYao, Meng Bai, Jing Yang, Xinru Li, Xiaoyu Chang, Yuehua Zhao, Yongsheng eng England 2022/02/20 Chemosphere. 2022 Jun; 296:134015. doi: 10.1016/j.chemosphere.2022.134015. Epub 2022 Feb 16" |