Investigation of Alum Mixtures for the Removal and Decontamination V and G Type Chemical Warfare Agents from Aqueous Solutions

Truly environmentally friendly means of detoxifying chemical warfare agents have yet to be developed. Toward this end, Soman (GD), VX and agent simulants were treated with aqueous aluminum sulfate (alum), sodium aluminate, or mixtures of the two. The mixtures were prepared by combining varying volumes of the aqueous salts to give buffered solutions (pH 2-12). Reactions were tracked using phosphorus-31 nuclear magnetic resonance (NMR) and gas chromatography/mass spectrometry (GC/MS). Simulants studied were triethylphosphate (TEP), tributylphosphate (TBP), diisopropylphosphorofluoridate (DPF), O,O'-dimethylmethyl phosphonate (DMMP), and malathion. Saturated alum alone removed approximately 10%, 20%, and 94% of DMMP, TBP, and TEP, respectively, upon immediate mixing. The buffered alum solutions formed a flocculent aluminum hydroxide precipitate upon reaction, which was effective to varying degrees in removing or chemically altering simulants depending on pH. A basic buffer at pH 12.3 and an acidic buffer at pH 3.8 were used for most of the studies. Malathion was decomposed within 4 days by the basic buffer, but remained unreacted in the acidic buffer. VX was unaffected by the acidic buffer. GD was eliminated from the aqueous acidic buffer within 18 hours, with nearly 60% removed within the first 10 minutes. GC/MS confirmed that, after 24 hours, a chloroform extract of the precipitate formed by this GD reaction contained less than 4% of the original GD. Studies are continuing, but it appears that alum buffers may provide an effective alternate method for the destruction of G type nerve agents.