China

GEO Makes History in China with the First Remediation Site in Chinese History

In Situ Thermal Remediation was used to successfully treat benzene and chlorobenzene in Suzhou, China. This was the first time thermal remediation was used in the history of Chinese remediation efforts. In partnership with JSDDBS, GEO's Gas Thermal Remediation (GTR™), using Thermal Conductive Heating (TCH), raised the temperature of the soils in the treatment zone to 100° Celsius.

Design

The target treatment area (TTA) was 100m² and from surface to 18m bgs. The soil type of the site was clay and silt with heterogenous hydrogeology. The GTR™ design included 22 heating wells and the target treatment temperature was set at 100° C to remove benzene, chlorobenzene, and TPH. Groundwater level was about 1.5m bgs with groundwater velocity between 1*10-5 to 5*10-4 cm/s. Total of 17 multiphase extraction (MPE) wells were applied to maintain the hydraulic control and NAPLs extraction.Extracted vapor was treated with cooling and GAC system before releasing to atmosphere. Produced water from condensation and MPE extraction was treated with neutralization settling tanks.

Results

A record achievement considering the remediation goal was achieved within 60 days, including installation, heating time, and demobilization! Four graphs are shown below with temperature thermocouples responses vs. time and comparing the results to our predicted model, illustrating excellent performance compared to GEO's proprietary thermal design numerical model. The before and after photos of the contaminated soils reveals complete removal of the contaminants, water, and much of the organic matter resulting in cleaner soils with light brown coloration.

The pilot test confirmed the proof of concept requirement of the Chinese government for ISTCH applicability in highly polluted sites with low permeability with more than 16m of groundwater in the target treatment zone.

Soil Before   |   Soil After

Water Before   |   Water After