Decomposition for Chemical Warfare Agent Sarin: Comparation Between Plate-to-Plate and Plate-to-Pin Dielectric Barrier Discharge

Abstract

The degradation of chemical warfare agent (CWA) sarin using plate-to-plate and plate-to-pin electrode structure dielectric barrier discharges (DBDs) was studied in this work. The discharge characteristics, optical emission, decomposition efficiency, and decomposition products in the above apparatus were well investigated. With initial pure sarin of <inline-formula> <tex-math notation="LaTeX">$20 ~\mu \text{L}$ </tex-math></inline-formula>, the decomposition amount per unit time and decomposition efficiency were obtained to be <inline-formula> <tex-math notation="LaTeX">$14.68 \times 10^{-3}$ </tex-math></inline-formula> mg/s and <inline-formula> <tex-math notation="LaTeX">$0.25 ~\mu \text{g}$ </tex-math></inline-formula>/J, for plate-to-plate DBD, and <inline-formula> <tex-math notation="LaTeX">$9.16 \times 10^{-3}$ </tex-math></inline-formula> mg/s and <inline-formula> <tex-math notation="LaTeX">$0.167 ~\mu \text{g}$ </tex-math></inline-formula>/J, for plate-to-pin DBD, respectively. The decomposition products containing isopropyl methylphosphoric acid (IMPA), methylphosphoric acid (MPA), fluoro(methyl)phosphinic acid (MPFA), di-isopropyl methane phosphate (DIMP), and phosphoric acid (PA) were observed in both DBD devices, with MPA and PA as the final products. The production level of PA was highest among all the products in plate-to-plate DBD. However, in plate-to-pin DBD, the concentration of PA and MPA were at the same level. The different decomposition efficiency between two DBD devices were mainly ascribed to the different input energy and their configuration. Our results confirmed that plate-to-plate DBD was a high-efficiency decomposition technology for sarin decomposition.