Adsorption mechanism of adsorbents for mercaptan foul-smelling substances: A review

As an environmental pollutant with low olfactory threshold, mercaptan foul-smelling substances have caused great harm to human production and life. Among the existing mercaptan treatment technologies, adsorption method has been widely studied and applied because of the advantages of high efficiency and renewable adsorbents. In this paper, the adsorption mechanisms of mercaptan on zeolite molecular sieves, carbon-based materials, metal-organic frameworks and metal oxides are reviewed, and it is concluded that the main mechanisms for their adsorption of mercaptan are micropore filling and chemical bonding, but some of the adsorbents also have mechanisms such as sieve effects, free radical reactions and π-π interactions. It is also pointed out that the green and low-cost modification of zeolite molecular sieves and the maintenance of the structural stability of metal-organic frameworks are the bottlenecks that need to be solved for the future development of efficient adsorption of thiols materials, and the development of composite materials of nanocarbon and metal oxides is the trend for the future development of high-efficiency adsorbents. The aim of this paper is to provide a theoretical reference for the in-depth study of the mechanism of mercaptan adsorption and the construction of new efficient mercaptan adsorbents.