Liquid film coated porous sorbents to trap gaseous acetaldehyde

Abstract

Acetaldehyde has been assigned as Group 2B carcinogen and it accounts for 70 % in aldehydes chemicals in the mainstream smoke that caused a serious environment pollution. To fabricate new effective capturer of acetaldehyde through physical rather than chemical modification, zeolites and other porous sorbents were assessed at first in the gaseous adsorption of acetaldehyde to select suitable carriers. Then MCM-22 zeolite, SBA-15 and activated carbon (AC), representing the sorbent with ordered microporous, mesoporous and gross porosity, were chosen for liquid film modification with glycerol to improve their adsorption capability through extending the contact between sorbent and adsorbate. MCM-22 among zeolites showed the best adsorptive quantity of acetaldehyde (1.3 mmol g−1), close to that of AC (1.4 mmol g−1) in gaseous phase, and the value increased about 60 % after the liquid film modification meanwhile a negative impact appeared on modified AC with the removal quantity of 1.0 mmol g−1. Similarly, the liquid film on the mesoporous sorbent SBA-15 made the adsorption capacity enhanced by 66 % (0.5 mmol g−1) than parent SBA-15 (0.3 mmol g−1), though this value is still inferior to that of AC and zeolite. Liquid film modified is proven to be efficient for zeolite to trap gaseous acetaldehyde, which offers an economic and eco-friendly strategy to control air pollution. Finally, these sorbents were tried to adsorb the acetaldehyde in cigarette smoke and among them SBA-15 showed a better performance than MCM-22 and AC, demonstrating the superior of mesopores in the face of hundreds of harmful substances.