Laboratory experiments to characterize accumulation and gas escaping in air sparging tests

• Grant number: 15/08492-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2015
• End date: July 31, 2016
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Carlos Alberto Mendonça
• Grantee: Matheus Carlos de Souza Santos
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The air-sparging method has achieved growing importance in the remediation of contaminated areas, mainly those ones with gas-phase substances in the vadose zone of the soil. Its operation is based on infusion of pressured atmospheric air in selected ports down a well in order to remove gas-phase pollutants in upper levels and capture then by suction ports in the near surface. The air-sparging application also induces the biodegradation of the organic pollutants in the saturated anoxic zone, by fostering faster aerobic processes with the insertion of atmospheric oxygen. Although effective and environmentally friendly (no toxic substances are applied in amending), the air-sparging procedure is difficult to be monitored. In some cases, the air that is injected escapes vertically, not spreading laterally and covering a significant volume. This project aims to analyze the conditions that favor the imprisonment and volume expansion of injected air in porous media, by simulating this process in a laboratory conditions. Results of this study may give directions to apply field experiments to remediate areas with trapped methane that has been studied by our research group.