Study on copper(II) adsorption from an aqueous solution by the graft copolymer of cross-linked starch/acrylonitrile

In this research, a graft copolymer of cross-linked starch/acrylonitrile(CLSAGCP) was used as an adsorbent for the removal of Cu(II) ions from an aqueous solution. Adsorption experiments were conducted under various conditions, i.e., initial concentration, temperature, and pH. The results showed that the conditions for the adsorption system was: temperature 30 degrees C, pH5, an equilibrium adsorption time of 90 min, leading to a: maximum percentage removal of Cu(II) ions > 97%. The adsorption capacity (Q(0)) of CLSAGCP was 90 mg/g at 30 degrees C and pH5. The adsorption thermodynamics and kinetics for Cuffl) were consistent with the Freundlich equation and the Lagergren equation, which is a pseudo-first-order rate expression. Furthermore, the thermodynamic parameters, i.e., standard free energy(Delta G(circle minus)), standard enthalpy (Delta H-circle minus), and standard entropy (Delta S-circle minus), of the, adsorption process were calculated. The results obtained are discussed in detail. The adsorption capability of various starches was compared: grafting copolymer of cross-linked Starch/Acrylonitrile(CLSAGCP)> grafting copolymer of original starch/Acrylonitrile(OSAGCP)> cross-linked starch(CLS)> original starch(OS).