Adsorption of Food Dye onto Gelatin Microspheres: pH Effect in Kinetics and Mechanism

摘要

Gelatin microspheres (GMSs) prepared by the inverse suspension cross-linking reaction, was characterised by scanning electron microscopy. The influence of pH on kinetics and mechanism was verified. The kinetic models such as pseudo-first-order, pseudo-second-order and intraparticle diffusion models were selected to understand the reaction pathways and mechanism of adsorption process. Adsorption of food red 7 (FR7) and food yellow 2 (FY2) onto GMSs occurred by chemisorption. For both dyes, adsorption occurred by film and intraparticle diffusion, and the pH increase caused an increase in film diffusion resistance. The biomass GMSs had a substantial potential for removing food dye from wastewater owing to great adsorption capacity and adsorption rate to dye.