Effect of Surface Treatment by O3 and Chemical Activation by Alkali Metal on the Performance of ACFs on Adsorption and Desorption of BTX Gases.

Jung Hee Jang,Gi Bo Han

doi:10.3390/ijerph17155422

Abstract

In order to investigate the adsorption characteristics of activated carbon fibers (ACFs) with improved surface morphologies towards volatile organic compounds (VOCs), a commercial low-grade ACF was surface modified by successive surface treatment (ST) and chemical activation (CA) process. O3 was used as an ST agent for the formation of oxygen-containing functional groups on the carbon matrix of ACFs. CA was carried out after ST, using a KOH solution. After the successive ST-CA process, Brunauer-Emmett-Teller (BET) surface area and average pore diameter of ACFs were increased from 1483 m2/g to 2743 m2/g and enlarged from 1.931 nm to 2.512 nm, respectively. The successive ST-CA process also resulted in the adsorption capacities of benzene, toluene, and xylene of the ACFs to increase from 0.22 g−Ben./g−ACFs, 0.18 g−Tol./g−ACFs, and 0.19 g−Xyl/g−ACFs up to 0.37 g−Ben./g−ACFs, 0.35 g−Tol./g−ACFs, and 0.38 g−Xyl/g−ACFs, respectively.

Highlights

Volatile organic compounds (VOCs), such as benzene, toluene, and xylene, are air pollutants which are directly related to human health and various environmental problems due to their toxicity.VOCs are emitted during various industrial processes, such as color printing works, paint manufacturing processes, or from gas stations, among others
activated carbon fibers (ACFs) prepared through chemical activation, without prior surface treatment, was larger than that of of ACFs prepared through chemical activation, without prior surface treatment, was larger than that the untreated ACFs, and the peak corresponding to maximum pore volume was located at 0.63 nm
This indicates that the pore structure and pore size were increased during the chemical activation nm

Summary

Introduction

VOCs are emitted during various industrial processes, such as color printing works, paint manufacturing processes, or from gas stations, among others They can affect human health by affecting the eyes or the nose and could cause cancer when people are exposed to them for a long time, even at low concentrations [1,2,3]. Emission of VOCs is controlled by stringent environmental regulations, and removal processes have been developed for the efficient control of their presence in the atmosphere Developed technologies, such as thermal incineration and wet scrubbing, have weak points which are usually their high cost and low efficiency, plus their applicability in the especial cases and areas when VOCs are emitted at low concentrations. These technologies show high efficiency and effectiveness towards VOC treatment when conditions such as flow rate, temperature, and VOC concentration are appropriately optimized

Methods

Results

Conclusion