In situ Remediation of 1,4-Dioxane using Electrical Resistance Heating

- By: ,

Courtesy of TRS Group, Inc.

An increasing number of states are establishing enforceable 1,4-dioxane cleanup goals due to recent improvements in analytical detection methods and existing carcinogenic risk information for 1,4-dioxane. Historically, 1,4-dioxane was used as a stabilizer for chlorinated solvents, primarily 1,1,1-trichloroethane. In addition, 1,4-dioxane has been used in a broad range of products including but not limited to paint, antifreeze, shampoos, cosmetics, aircraft deicing fluid, and fumigants. If released, 1,4-dioxane presents significant remediation challenges as it is highly mobile. Due to its high solubility, 1,4-dioxane will readily dissolve in groundwater. The low octanol-water partition coefficient causes the transport of any 1,4-dioxane in groundwater to be minimally slowed by sorption to soil particles or suspended sediments. In addition, a low Henry’s Law constant suggests that transfer of 1,4-dioxane from water to air is negligible under ambient conditions. Furthermore, 1,4-dioxane is resistant to biodegradation by indigenous soil microorganisms. (Mohr, 2010)

The treatment of 1,4-dioxane has been reported with limited success. 1,4-dioxane has been shown to be resistant to treatment by conventional technologies including sparging, soil and vapor extraction, bioremediation, and select oxidation processes. Effective remedial treatment has been largely limited to expensive, predominantly ex situ treatment by advanced chemical oxidation using processes that produce hydroxyl radicals. (EPA, 2006) (DiGuiseppi W, 2007)

Electrical Resistance Heating (ERH) was conducted to treat tetrachloroethene (PCE), trichloroethene (TCE), dichloroethene (DCE), trichlorobenzene, xylenes, and Freon 113 at a site where 1,4-dioxane was also present. While not part of the treatment goals, 1,4-dioxane was detected prior to ERH treatment with a maximum concentration of 140 µg/L. In the course of successfully reducing concentrations of the contaminants of concern at this site, the concentration of 1,4-dioxane was also substantially reduced to 1.4 µg/L resulting in a 99.0% removal, as shown in Table 1. Furthermore, pre-ERH 1,4-dioxane concentrations were reduced in another monitoring well from 44 µg/L to non-detect. The minimum detection limit was 0.5 µg/L therefore greater than 98.9% reduction of 1,4-dioxane was achieved. In situ remediation of 1,4-dioxane to this degree had not been reported before, therefore further research and development efforts were conducted to further understand the substantial concentration reductions.

Reviews disabled

Reviews have been disabled for In situ Remediation of 1,4-Dioxane using Electrical Resistance Heating.