Maleic Anhydride Cross-Linked β-Cyclodextrin-Conjugated Magnetic Nanoadsorbent: An Ecofriendly Approach for Simultaneous Adsorption of Hydrophilic and Hydrophobic Dyes

Abstract

A magnetic nanoadsorbent with a cross-linked β-Cyclodextrin maleic anhydride polymer capable of simultaneous removal of hydrophilic and hydrophobic dyes was developed with high efficacy and desorption/recycling efficiency. The effect of various parameters (concentration, adsorbent dosage, contact time, pH, and temperature) was evaluated to assess the optimum adsorption conditions. The superparamagnetic nanoadsorbent (SPNA) could be easily separated by magnetic decantation and showed maximum removal of malachite green with 97.2% adsorption efficiency. Studies on simultaneous adsorption of dyes from a mixture were performed and the adsorption capacity was calculated. Interestingly, the phenomenon of competitive adsorption was observed. The adsorption process can be fitted well into the Langmuir isotherm model and follows pseudo-second-order kinetics. SPNA could be effectively regenerated and recycled at least five times without any significant loss in removal efficiency. SPNA could be an ideal adsorbent for water remediation because of excellent dye removal efficiency in addition to chemical stability, ease of synthesis, and better reusability.