Synthesis of Cyclodextrin-based Adsorbents and its Application for Organic Pollutant Removal from Water

Background: Organic pollutants are common and exist widely in ecosystems, particularly in aqueous solution, and they are a serious threat to humans. Many technologies have been applied to wastewater treatment, and adsorption is a good method for organic pollutant removal that has been universally applied. Cyclodextrins (CDs) are excellent adsorbents due to their unique cavity, which can form stable inclusion complexes with some pollutants, and they are low-cost, non-toxic and renewable. Because cyclodextrins are greatly soluble in water, the actual application of cyclodextrin-based adsorbents was designed by crosslinking or immobilizing the CDs. Objective & Methodology: This article details synthetic methods for various cyclodextrin-based adsorbents and summarizes the information about the broad applications of cyclodextrin-based adsorbents for the removal of different substances and studies of better fixed kinetic and isotherm models for the adsorption process. We also provide a possible mechanism of adsorption. In addition, the effects of various operational parameters are summarized, including the pH, initial pollutant concentration, adsorbent dosage and ionic strength. Finally, the advantages and disadvantages of the adsorption of organic pollutants on cyclodextrin-based adsorbents and some advice for future studies are proposed. Many papers have focused on cyclodextrin-based adsorbents and that proved they are excellent. However, few articles have reviewed the use of cyclodextrin for the adsorption of organic pollutants. Keywords: Cyclodextrin, adsorption, organic pollutant, removal, adsorbent, ionic strength.