Removal of volatile organic compounds from contaminated groundwater by pervaporation

Effective removal of non-aqueous phase liquid pools in groundwater and volatile organic compounds (VOCs) from contaminated soils can be achieved by surfactant flushing. This surfactant-rich ground water contains VOCs like trichloroethylene (TCE), dichloroethylene (DCE), etc. Membrane pervaporation technique is employed here to remove TCE from these micellar systems where a very high percentage of the VOC is trapped inside the micellar core. The micellar solution flows through the bore of microporous hydrophobic hollow fibers wherein the micelles break down and release the surfactants and the TCE. The TCE is then removed through the pores and a nonporous thin silicone skin on the outside surface of the fiber, the other side of which is subjected to vacuum to allow pervaporation-based removal of the VOC. This research has characterized such a process for removal of TCE with or without surfactant. It was established that the presence of surfactant adversely affected the removal of TCE. The flux of TCE was found to be an increasing function of feed flow rate and Reynolds number. This research has also briefly explored the permeation of nonvolatile hydrocarbons such as dodecane from water flowing through the fiber bore by using a similar hollow fiber membrane