PULSED OZONATION TO REMEDIATE MGP RESIDUALS,CHLORINATED SOLVENTS AND DICYCLOPENTADIENE

摘要

In situ chemical oxidation has been used successfully to remediate soil and groundwaterrncontamination at numerous industrial facilities contaminated by chlorinated solvents andrnpolycyclic aromatic hydrocarbons (PAHs). The Sempra Energy Utilities former MGP site in LosrnAngeles, California was the site of a number of industrial activities following the termination ofrnMGP operations. The site contains soils impacted MGP residuals, predominantly polynuclearrnaromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and dicyclopentadienern(DCPD). A treatability study determined that ozone (O3) was an effective in situ treatmentrnoption for the Site. The pilot test area for the DCPD and MGP residuals is a sand and gravelrnalluvial formation. Groundwater is encountered at a depth of 30 feet below grade. Initialrnconcentrations within the alluvium were as high as 1900 ppm in soil. Ozone, generated on siternwas pulsed into twelve, multi-level O3 injection points. Vapor monitoring verified that ozonernsparging and injection has distributed ozone uniformly throughout the subsurface. Significantrnreductions in concentrations were observed in the soil and groundwater after the completion ofrnthe three-month pilot test.