A mechanism study of airflow rate distribution within the zone of influence during air sparging remediation

摘要

In this study, an improved laboratory two-dimensional airflow visualization device was developed for the quantitative analysis of airflow distribution at different heights from the sparger (20,30, and 40 cm) within the zone of influence (ZOI). The results indicated that the measured airflow rate distribution appeared Trapezium when the height was 20 cm; however, the airflow rate matched a Gaussian distribution when the heights became 30 cm and 40 cm. The conical shape of the ZOI was observed in the experimental processes. The experimental results verified that the airflow distribution within the ZOI conformed to turbulent jet theory. According to turbulent jet theory, the distribution of the airflow rate changes from Trapezium to Gaussian, and the jet boundary mixed layer is a linear extension in the processes of jets. Through our study, it was found that this theory could be applied to airflow distribution and predictive models for the ZOI in air sparging remediation. The shape of the ZOI should be cone-like and the boundary layer of the ZOI is a linear extension in air sparging process. All the results from this study can provide theoretical support for the design and prediction of air sparging remediation for groundwater pollution.