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Evaluating Ozone as a Remedial Treatment for Removing RDX from Unsaturated Soils |
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| Authors: | Michael Adam Steve Comfort Daniel Snow David Cassada Matthew Morley Wilson Clayton |
| Affiliation: | 1Univ. of Nebraska, Lincoln, NE 68583-0915; presently, USEPA, MC: 5102G,1200 Pennsylvania Ave. NW, Washington, D.C. 20460. E-mail: adam.michael@epa.gov 2Professor, Univ. of Nebraska, 256 Keim Hall, Lincoln, NE 68583-0915 (corresponding author). E-mail: scomfort@unl.edu 3Water Sciences Laboratory, Univ. of Nebraska, 103 Natural Resource Hall, Lincoln, NE 68583-0844. E-mail: dsnow1@unl.edu 4Water Sciences Laboratory, Univ. of Nebraska, 103 Natural Resource Hall, Lincoln, NE 68583-0844. E-mail: dcassada1@unl.edu 5Dept. of Civil Engineering, Univ. of Nebraska, W348 Nebraska Hall, Lincoln, NE 68583-0531. E-mail: mmorley2@unl.edu 6Aquifer Solutions, Inc., 3081 Bergen Peak Dr., Ste. 140, Evergreen, CO 80439. E-mail: wclayton@aquifersolutions.com |
| Abstract: | Years of wastewater discharge at the Department of Energy’s Pantex Plant have contaminated the vadose zone and underlying perched aquifer with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Because the vadose zone is acting as a continual source of groundwater contamination, removing RDX from the unsaturated zone is paramount to prevent further contamination. We determined the efficacy of ozone to degrade and mineralize RDX. Solution experiments showed that ozone (27?mg?L?1; 150?mL?min?1) was effective in mineralizing 80% of the RDX (30?mg?RDX?L?1) provided that some Pantex soil was present to buffer the solution pH. Soil columns treated with ozone produced 50% RDX mineralization within 1 day and >80% within 7 day. Experiments designed to evaluate aerobic biodegradation following partial ozonation of a RDX solution showed that ozone-generated RDX products were much more biodegradable than untreated controls in aerobic microcosms (35 versus <0.3% cumulative mineralization). These results support the use of ozone as a remedial treatment for the contaminated vadose zone at the Pantex facility. |
| Keywords: | Oxidation Contamination Ground-water pollution Chemical treatment Remedial action Explosives |
