Kinetics and Mechanism of Cationic Dyes Adsorption onto Modified b-Cyclodextrin Microspheres

摘要

The kinetics and mechanism of the removal of methylene blue(MB) and neutral red (NR) from aqueous solution using pyromellitic dianhydride (PMDA) grafted β-Cyclodextrin (β-CD) as adsorbent have been investigated. The effects concerning contact time and initial dye concentration were studied in batch experiments. The experiments results showed that this adsorbents exhibited high sorption capacities toward MB and NR. The equilibrium process was described well by the monolayer adsorption isotherm. It was found that kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by chemical adsorption. The maximum adsorption capacities were 504.1 mg g-1 and 561.8mg g-1 for MB and NR, respectively.