Innovative adsorbent for sulphur dioxide: synergy of activated carbon, polyionic liquids, and chitosan

In response to the growing threat of pollution and its adverse effects on human health, a novel and innovative method for preparing SO₂ adsorbents has been developed. The present study introduces a unique approach that combines activated carbon (AC), chitosan (CS), and polyionic liquids (PILs) to create highly effective composite adsorbents. Incorporating 4%, 7%, and 10% by weight of butyl and octyl PILs into the composite beads led to a significant enhancement in SO₂ adsorption capabilities. The PILs were synthesized through direct polymerization and meticulously characterized using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), confirming their successful synthesis and high thermal stability. The activated carbon was effectively impregnated with the PILs, and the resulting composite beads were shaped into CS beads. Gas adsorption studies revealed that the AC-CS-PIL beads impregnated with butyl and octyl PILs nearly doubled the adsorption capacity compared to raw activated carbon. Notably, the 10% octyl AC-CS-PIL composite exhibited the highest breakthrough time of 37.08 min and an impressive adsorption capacity of 445 mg/g, which is 2.4 times greater than that of raw AC. These results highlight the promising potential of this innovative adsorbent in effectively combating pollution and improving air quality.