Preparation of novel cerium(iv)-crosslinked carboxymethyl-β-cyclodextrin for efficient adsorption of the tetracycline antibiotic

Abstract

In this study, novel cerium(IV)-crosslinked carboxymethyl-β-cyclodextrin (Ce/CM-β-CD) was prepared through a chelation reaction between the carboxyl groups of CM-β-CD and Ce(IV) ions from cerium ammonium nitrate (H₈CeN₈O₁₈), and then applied for adsorption of tetracycline antibiotic from aqueous solutions. During the adsorption process, the maximum adsorption capacity of the Ce/CM-β-CD sorbent for tetracycline was 170.65 mg g⁻¹. The effects of adsorption factors, such as pollutant concentration, pH, adsorption temperature, ionic strength, actual water sample and the coexistence of double pollutants were mainly studied. The results showed that a pseudo-first-order rate equation described the adsorption kinetics mechanisms well, while the Langmuir model fitted different adsorption isotherms, respectively. In addition, the prepared adsorbent retained 87.0% of its initial adsorption capacity after six consecutive adsorption–desorption cycles. Thus, the advantages of simple and green fabrication, excellent adsorption capacity, and perfect regeneration ability demonstrated that the Ce/CM-β-CD adsorbent has potential for application in the treatment of environmental pollution. This study also provides new insights into the preparation of an advanced trifunctional CD polymer absorbent under simple and green conditions for water purification.