Abstract

Soil flushing, an in situ process, can be used to remove metals from the soil by water or additives. The use of biosurfactants to enhance remediation of contaminants has recently received increasing interest, though research in this area has been limited. In this study, column experiments were conducted in three main phases. The first phase was to investigate the main parameters that influence the foam quality and stability. Foam generated by a rhamnolipid solution displayed high qualities from 90% to 99% and stabilities varied from 17 to 41 minutes. The second phase was carried out to study the pressure gradient build-up in the soil column with foam flowing through under different conditions (flow rate, foam quality, biosurfactant solution concentration), which varied from 0.3 kPa/cm to 6.6 kPa/cm. In the third phase, the biosurfactant (JBR425, mixed rhamnolipids) foam enhanced removal of heavy metals (Cd, Ni) from the contaminated soil was investigated. The soil was characterized as a sandy soil contaminated with Cd (1706 ppm) and Ni (2010 ppm). (Abstract shortened by UMI.)