Zone of flow : A new finding on the characteristics of airflow within the zone of influence during air sparging in aquifers

Crown Copyright © 2023. Published by Elsevier B.V. All rights reserved..

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 dp, that is, 0.55- 0.62 for channel flow (dp < 1- 2 mm), while 0.75- 0.82 for bubble flow (dp > 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.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:255

Enthalten in:

Journal of contaminant hydrology - 255(2023) vom: 01. Apr., Seite 104165

Sprache:

Englisch

Beteiligte Personen:

Cheng, Kuang [VerfasserIn]
Zhang, Te [VerfasserIn]
Peng, Kairan [VerfasserIn]
Feng, Yahang [VerfasserIn]
Liu, Hongshuai [VerfasserIn]
Medawela, Subhani [VerfasserIn]

Links:

Volltext

Themen:

Air sparging
Airflow flux distribution
Groundwater remediation
Journal Article
Research Support, Non-U.S. Gov't
Volatile Organic Compounds
Zone of flow
Zone of influence

Anmerkungen:

Date Completed 01.05.2023

Date Revised 01.05.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jconhyd.2023.104165

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM353189782