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

13C NMR spectra showed that peroxymonocarbonate (HCO4-) was generated in the NaHCO3-activated H2O2 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- (H2CO4)→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 H2O2 solution. While HCO4- was the primary oxidant for the oxidation of thioanisole, O2- generated during the decomposition of HCO4- or H2O2 led to the secondary oxidation of the sulfide. Paraoxon was degraded in the NaHCO3-activated H2O2 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 H2O2. 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 H2O2.