Desorption of bis(2-chloroethyl) sulfide, mustard agent, from the surface of hardened cement paste (HCP) wafers

The decontamination of surfaces exposed to chemical warfare agents is an interesting scientific topic. The desorption behavior of bis(2-chloroethyl) sulfide (sulfur mustard, HD) from the surface of the HD-contaminated hardened cement paste (HCP) was investigated under different weather conditions, which should provide scientific reference data for protection and decontamination projects involving HD-contaminated HCP in different conditions. The desorption of HD from the surface of HCP wafers was studied, and the effects of the purge air flow rate, water content, sorption temperature, and substrate age were investigated. HD desorption was detected from the surface of HD-contaminated HCP, but the desorption velocity was relatively slow. The desorption quantity remained within an order of magnitude throughout a time span of 36 h (25 °C at 200 mL/min of purge air), and the amount of HD that was desorbed from each square meter of HCP surface was approximately 1.1 g (25 °C at 200 mL/min of purge air), which was approximately 5.5 percent of the total HD that was initially applied. A higher flow rate of the purge air, increased water content, and longer substrate age of HCP all increased the HD desorption. In contrast, increased temperatures suppressed HD desorption.

The sorption, desorption and degradation of sulfur mustard (HD) from hardened cement paste (HCP) wafers were investigated, and significant influencing factors were discussed.Figure optionsDownload as PowerPoint slideHighlights
► HD desorption could be detected from the surface of HD-contaminated HCP.
► The desorption for HD is relatively slow for the new HD-contaminated HCP surface.
► A higher flow rate of purge air and increased water content would increased HD desorption.
► In contrast, increased temperature suppressed HD desorption.
► HD would be removed by desorption or degradation.