Bicarbonate-activated hydrogen peroxide and efficient decontamination of toxic sulfur mustard and nerve gas simulants.

13 C NMR spectra showed that peroxymonocarbonate (HCO4 - ) was generated in the NaHCO3 -activated H2 O2 solution and pH was a key factor in its production. A cycle for the bicarbonate anion was proposed as HCO3 - →HCO3 → (CO2 )2 *→CO2 (aq)→HCO4 - (H2 CO4 )→HCO3 - (HCO3 ) basing on the results of NMR, electron paramagnetic resonance, chemiluminescence analysis. In this cycle, (CO2 )2 * was the key intermediate and (CO2 )2 *→2CO2 +hv was the rate controlling step. Thioanisole and paraoxon, the simulants of sulfur mustard gas and nerve gas, respectively, were efficiently decontaminated by the NaHCO3 -activated H2 O2 solution. While HCO4 - was the primary oxidant for the oxidation of thioanisole, O2 - generated during the decomposition of HCO4 - or H2 O2 led to the secondary oxidation of the sulfide. Paraoxon was degraded in the NaHCO3 -activated H2 O2 solution via nucleophilic substitution by OOH- and OH- , and the degradation rate increased exponentially with increasing pH. Alkali metal ions had a catalytic effect on the degradation of paraoxon. Mustard gas and soman degraded efficiently into nontoxic products in NaHCO3 -activated H2 O2 . A pH range of 9-10 was found to be optimum for the broad-spectrum decontamination of chemical warfare agents and other eco-toxicants using NaHCO3 -activated H2 O2 .