This site was a former automobile accessory factory in Nanjing. The factory had been relocated in 2013. The site will be redeveloped. Organic contamination in soil and groundwater in some areas of the site was found during the investigation. The main contaminants of concern were chlorinated hydrocarbons and petroleum hydrocarbons with a total contamination area of approximately 5000m2 and the maximum contamination depth of 10 meters. Light non-aqueous phase fluids (LNAPLs) were found in some areas. Greenment was entrusted to develop the groundwater remediation scheme.
Based on the significant differences in different contaminated areas, the site was divided into three contaminated zones and different remediation technologies were proposed.
1）For the TPH (mainly C10~C14 compounds) zone, in-situ chemical oxidation was proposed. The recommended oxidation reagent was proprietary persulfate;
2）For the LNAPL zone, the most effective approach was direct recovery of LNAPL. Therefore, multi-phase extraction was proposed;
3）For the complex contamination zone, multi-phase extraction combined with in-situ chemical reduction was proposed. The recommended reagent for in-situ chemical reduction remediation was patented EHC.