| Title: | Zone of flow: A new finding on the characteristics of airflow within the zone of influence during air sparging in aquifers |
| Author(s): | Cheng K; Zhang T; Peng K; Feng Y; Liu H; Medawela S; |
| Address: | "College of Civil Engineering & Architecture, Hebei University, Baoding 071002, China; Institute of Geotechnical Engineering, Hebei University, Baoding 071002, China. Electronic address: kcheng@hbu.edu.cn. College of Civil Engineering & Architecture, Hebei University, Baoding 071002, China; Institute of Geotechnical Engineering, Hebei University, Baoding 071002, China. College of Civil Engineering & Architecture, Hebei University, Baoding 071002, China; Institute of Geotechnical Engineering, Hebei University, Baoding 071002, China. Electronic address: liuhs1975@hbu.edu.cn. Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007, Australia. Electronic address: subhani.medawela@uts.edu.au" |
| DOI: | 10.1016/j.jconhyd.2023.104165 |
| ISSN/ISBN: | 1873-6009 (Electronic) 0169-7722 (Linking) |
| Abstract: | "Air sparging (AS) is a popular technology for the in-situ remediation of groundwater contaminated by volatile organic compounds. The scope of the zone within which injected air exists, i.e., zone of influence (ZOI) and the airflow characteristics within ZOI are of great interest. However, few studies have shed light on the scope of the zone within which air flows, namely, the zone of flow (ZOF) and its relation with the scope of ZOI. This study focuses on the ZOF characteristics and its relation with ZOI based on quantitative observations of ZOF and ZOI using a quasi-2D transparent flow chamber. The relative transmission intensity obtained by the light transmission method presents a rapid and continuous increasing near the ZOI boundary, providing a criterion for the quantitative determination of ZOI. An integral airflow flux approach is proposed to determine the scope of ZOF based on the airflow flux distributions through aquifers. The ZOF radius decreases with the growth of particle sizes of aquifers; while it increases first and then keeps constant with the increase of sparging pressure. The ZOF radius is around 0.55- 0.82 times of the ZOI radius, which depends on air flow patterns related to particle diameters d(p), that is, 0.55- 0.62 for channel flow (d(p) < 1- 2 mm), while 0.75- 0.82 for bubble flow (d(p) > 2- 3 mm). The experimental results show that the sparged air is entrapped with little flowing inside ZOI regions that are outside the ZOF, which should be considered carefully in the design of AS" |
| Keywords: | *Volatile Organic Compounds Particle Size *Groundwater Air sparging Airflow flux distribution Groundwater remediation Zone of flow Zone of influence; |
| Notes: | "MedlineCheng, Kuang Zhang, Te Peng, Kairan Feng, Yahang Liu, Hongshuai Medawela, Subhani eng Research Support, Non-U.S. Gov't Netherlands 2023/02/23 J Contam Hydrol. 2023 Apr; 255:104165. doi: 10.1016/j.jconhyd.2023.104165. Epub 2023 Feb 16" |
