Efficient degradation of a sulfur mustard simulant by a hydrogen peroxide/guanidine system: mechanism and performance

Hydrogen peroxide (H₂O₂) as a decontaminant has been paid attention in the world. The activation system of H₂O₂ by organic activators has recently become a research hotspot in the decontamination of chemical warfare agents and hazardous chemicals. In this paper, the activation mechanism of H₂O₂ by guanidine activators had been investigated via some in-situ analytic methods, such as laser Raman spectroscopy (LRS), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), chemiluminescence (CL) and so on. The results showed that 1-acetylguanidine (ACG) effectively activates H₂O₂ to generate multiple reactive oxygen species (ROS), including peroxyimide ions, HOO^-, ·O₂^-, ¹O₂, and ·OH, with ¹O₂ being the dominant species. The optimum activation conditions included that, the molar ratio of reactive oxygen species (ROS) and ACG should be the range of 1:1-1:3; the pH value of the active reaction solution could be between 8.0 and 10.0; the activation reaction temperature was about 30 ℃. Meanwhile, the active solution of H₂O₂/ACG under the best conditions had been used to decontaminate 2-chloroethyl ethyl sulfide (2-CEES) which was a simulant of chemical warfare agent sulfur mustard. When the volume ratio of decontaminant solution and 2-CEES liquid drops was about 50:1, the decontamination efficiency of 2-CEES had been reached to 99.9% after 30 min in the H₂O₂/ACG solution. Compared with traditional decontamination formulations, the H₂O₂/ACG system offers advantages of mild reaction conditions and excellent environmental compatibility, holding promising application prospects in the remediation of specially contaminated environments and emergency disposal of hazardous chemicals.