Glycidyl methacrylate macroporous copolymer grafted with diethylene triamine as sorbent for Reactive Black 5

Abstract

In this paper, macroporous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer functionalized with diethylene triamine (PGME-deta), was evaluated as Reactive Black 5 (RB5) sorbent. Batch RB5 removal from aqueous solution by PGME-deta was investigated by varying pH, contact time, sorbent dosage, initial dye concentration and temperature. The sorption is pH sensitive having maximum at pH 2 (dye removal of 85%), decreasing with the increase of pH (dye removal of 24% at pH 11) after 60 min. Sorption kinetics was fitted to chemical-reaction and particle-diffusion models (pseudo-first-, pseudo-second-order, intraparticle diffusion and Mckay models). The pseudo-second-order kinetic model accurately predicted the RB5 amount sorbed under all investigated operating conditions, while the intraparticle diffusion was the dominant rate-limiting mechanism. The diffusion mechanism was more prevalent with the decrease in temperature and the increase in concentration. The isotherm data was best fitted with the Langmuir model, indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption, with the maximum sorption capacity of 353 mg g(-1). The calculated sorption rates improved with increasing temperature and an activation energy close to 40 kj mol(-1) was determined, suggesting that chemisorption was also rate-controlling.