Book Description

A field-scale plant for the treatment of explosives contaminated groundwater was designed and constructed at the Cornhusker Army Ammunition Plant (CAAP) near Grand Island, Nebraska. The target compounds were trinitrotoluene (TNT), trinitrobenzene (TNB), (N)-trinitro-1, 3 5%triazacyclohexane (RDX) and other nitrobodies. The process chosen was oxidation with a combination of ozone and hydrogen peroxide (Peroxone). The plant was capable of treating 25 gal-min' with a dose of ozone as high as 55 mg-L-1 in each of six bubble column reactors with hydraulic retention times of 24 minutes per reactor. Hydrogen peroxide was fed in the influent water prior to ozonation. The purpose of the study was to determine the feasibility and projected costs for reducing explosive compounds level to 2 mug-L-1 for the specific nitro-compounds and 30 mug-L-1 for total nitrobodies. The demonstration was carried out over a period of three months. The results showed that the Peroxone process is capable of oxidizing all of the target compounds but very large doses of ozone and hydrogen peroxide are required to reach the target level for TNB, the most recalcitrant target compound. An empirical model was developed as a design tool to provide information on system scale up to 1000 gal-min-1. This model provided not only technical feasibility on scale up, but also a preliminary cost evaluation. A report prepared by the project independent evaluator discusses cost implications in much more detail. Recommendations for further work and for potential cost minimization measures are presented.