Sorption behavior of rhodamine 6G onto sodium alginate graft poly(acrylic acid-co-2-acrylamido-2-methyl propane sulfonic acid ) / kaolin composite hydrogel

Removal of rhodamine 6G from aqueous solutions using sodium alginate graft poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid) /kaolin composite hydrogel was sudied.The factors influencing the adsorption capacity such as initial concentrations of rhodamine 6G,contact time and pH values were discussed.Adsorption thermodynamics and kinetics were also investigated.Maximal adsorption capacity was 710 mg /g.It showed that the adsorption process was spontaneous and the adsorption isotherms were in good agreement with both Freudlich and Redlich-Peterson equations,the kinetics fit pseudo-second-order equation.