Enhanced removal of low-concentration methyl mercaptan by synergetic effect between surface functional group and metallic site

Abstract

Methyl mercaptan (MM) is a typical malodorous gas, and low-concentration MM makes human body uncomfortable. Although activated carbon and its modifications were widely investigated, seldom work focused on the synergetic effect between surface functional group and metallic site. To cover this insufficiency, this work modified a commercial activated carbon by different steps, and applied the obtained carbons in low-concentration MM removal. As a result, an acid-treated carbon removed 2.5 mg·g−1 of MM. After Fe was loaded on the acid-treated carbon, the removal capacity was increased to 57.6 mg·g−1, i.e., the removal capacity was increased by 24 times. However, these carbons had a similar specific surface area (900 m2·g−1). Temperature programmed decomposition (TPD), Thermogravimetry and mass spectrometry (TG-MS), and X-ray photoelectron spectroscopy (XPS) analyses indicated that surface functional group and Fe combined after a thermal treatment, exposed a great number of empty sites, thus resulting in the excellent adsorption ability. The main results of this work were in favor of understanding the adsorption mechanism for MM. These results would also help the development of equipment for effective odor-gas purification.