Study on adsorption of low-concentration methyl mercaptan by starch-based activated carbon.

The development of a low-concentration methyl mercaptan adsorbing material for an efficient decontamination has become a hot research topic. In this study, carbonization activation was employed with starch and urea as carbon and nitrogen sources, respectively, to prepare a type of starch-based activated carbon. Subsequently, the product was used to adsorb low-concentration methyl mercaptan. Based on sorption experiments and molecular simulations, the underlying mechanism of the adsorption effect of the adsorbent's pore structure and surface oxygen- and nitrogen-containing functional groups on methyl mercaptan molecules were discussed. The results indicated that when the methyl mercaptan equilibrium concentration was 0.197 mg/L, the adsorption capacity of SUAC-16-2 for methyl mercaptan was 78.16 mg/g. Its adsorption performance was better than that of its previously reported counterparts. The well-developed microporous structure of SUAC-16-2 promoted the adsorption of methyl mercaptan. In addition, methyl mercaptan molecules could be broken down to produce CHS and H by the effect of the surface functional groups. Adjacent carbon atoms containing nitrogen and oxygen functional groups could better adsorb CHS and H, and further strengthen the methyl mercaptan adsorption performance of activated carbon. The study could help to develop new technology for treatment of low concentration of methyl mercaptan in the air.