Sorption Behavior of Methyl Violet onto Poly(acrylic acid-co-acrylamide)/Kaolin Hydrogel Composite

Poly(acrylic acid-co-acrylamide)/kaolin hydrogel composite was synthesized and characterized. Sorption behavior of methyl violet (MV) onto the composite was studied. Effect of adsorption conditions, including contact time, initial concentration of MV, pH values, adsorbent dosage and ionic strength, on the adsorption capacity and removal percentage was investigated in detail. The equilibrium adsorption capacity reached 908.0 mg/g as the initial concentration of MV was 1000 mg/L. Adsorption mechanisms were also speculated. Further studies showed that the adsorption process was spontaneous and satisfied the Redlich–Peterson model. The kinetic data showed that the adsorption was in accordance with the Lagergren pseudo–first-order kinetic model.