Cyclodextrin-based strategies for removal of persistent organic pollutants

Water could be considered one of the essential natural resources on our planet. However, water contamination has become virtually ubiquitous during the past decades due to several factors, e.g., world population growth, water use in chemical production, and agriculture. Among contaminants, persistent organic pollutants (POPs) were widely spread during the last few decades and are now present all around the world. POPs are connected with several different illnesses, and therefore the removal of these pollutants from water is a challenge for coming years. Cyclodextrins (CDs) are environmentally friendly and cheap pollutant adsorbents due to their peculiar physicochemical properties. Moreover, CDs are relatively easy to use, and many techniques are reported for their functionalization. In addition, several CD derivatives are known and some of them are commercially available. CDs and CD-functionalized materials could be used for removal of different pollutants by using various methods, e.g., adsorption/extraction, soil washing, and electrokinetic/catalytic processes. This is the first review article that provides an overview of CDs/CD-based materials and their use in the remediation of POPs listed under the Stockholm Convention. The mechanisms of the POPs removal by CDs are also discussed.