Manufactured Gas Plant
KEMRON was contracted to perform a remedy screening treatability study on two contaminated materials sampled from a former manufactured gas plant (MGP) site located in Stockton, California. The treatability study was conducted was for an in-situ solidification contractor on behalf of an electric and natural gas distributor, to evaluate the feasibility of in situ solidification / stabilization for treatment of sludges sampled from the site.
Two candidate site materials were subjected to ISTD distillation treatment performed at two target temperatures and two retention times. During treatment, De-Ionized (DI) water was injected into the test material via a low volume peristaltic pump. The quantity of water injected was outlined by TerraTherm and included specified pore volumes, based on the treatment duration.
Throughout treatments, KEMRON performed constant temperature monitoring of the soil and injected water, and organic vapors in the off-gas via a flame ionization detector (FID). All vapors were passed through a distillation treatment and indicated that total volatile organic compound concentrations were reduced by more than 98%, and Diesel Range Organics (DROs) were reduced by more than 87%. Total semi-volatile organic compounds were reduced for many compounds but in general proved more difficult to treat than the volatile compounds.
The mobilization of DNAPL was evaluated by passing a specified pore volume of chilled water through the test soil while at ambient temperature. An additional specified pore volume of water was then passed through the test soil during heating. Throughout testing, KEMRON monitored the soil and water injection temperatures, the pressure within the test system, and visual clarity of the water exiting the system.
Geotechnical testing of certain treated site soil types was performed to ensure that thermal treatment did not adversely affect the physical properties of the site soils.