Kinetic study of acid red "dye" removal by activated carbon and hyper-cross-linked polymeric sorbents Macronet Hypersol MN200 and MN300

The search for suitable sorbents for persistent organic pollutants (like dyes) removal from aqueous solutions has prompted the evaluation of polymeric resins incorporating new properties that solve many of the existing problems when using granular activated carbon (GAC). A new type of non-functionalized macroporous hyper-cross-linked polymers Hypersol Macronet (MN200 and MN300) has been evaluated and kinetics measurements on the extraction of azo dye (Acid red 14) were made. Analyses of the respective batch rate data with two kinetic models, the homogenous particle diffusion model (HPDM) and the shell progressive model (SPM) were carried out. Sorbent phase was confirmed as the rate-determining step of the dye sorption process. Effective particle diffusion coefficients (D-eff) were determined from the rate data proposed by both models. The Deff values from both HPMD and SPM equations varied from 5 x 10(-13) to 4 x 10(-16) m(2) s(-1). Weber and Morris intra-particle diffusion model showed a double contribution of the surface and pore diffusivities to the sorption process. Pore and surface diffusivities were calculated using a heterogeneous model. Hyper-cross-linked polymers reported a double contribution (pore and surface) to the overall diffusion process meanwhile GAC coefficients indicate a surface diffusion as the controlling mechanism. (c) 2007 Elsevier Ltd. All rights reserved.