Study on Adsorption Characteristics of Chitosan for Nickel / 环境与健康杂志

ABSTRACT

Objective To study the adsorption capability of chitosan(CTS)for Ni~(2+)in water.Methods The effects of different adsorption time(0-360 min),different temperature(25-60℃)and different initial pH value of the solution(4-8)on the adsorption were investigated.The adsorption kinetics and thermodynamics of CTS for Ni~(2+)in water were also studied and the IR of CTS and CTS-Ni~(2+)were determined.Results The maximal adsorption quantity could reach to 42.15 mg/g in the optimum condition that the temperature is 25℃,pH value was 7.0 and the adsorption time was 4 h.The adsorption kinetics showed that the pseudo-second-order equation was suitable for describing the adsorption of CTS for Ni~(2+)and the related correlation coefficients were more than 0.99.The calculated value of equilibrium adsorption quantity of Ni~(2+)was 45.05 mg/g.Study of adsorption thermodynamics showed that the linear regression equation of lnk and 1/T was lnk=-0.827 7/T+3.416 2,and the correlation coefficient was 0.998 9.The enthalpy change(△H~0)was 6.88 kJ/mol and the entropy change(△S~0)was 28.40 J/(mol?K).The IR showed that the coordination reaction occurred between-NH_2,-OH of CTS and Ni~(2+).Conclusion CTS can effectively remove Ni~(2+) in water.The adsorption of CTS for Ni~(2+)is spontaneous and endothermic.High temperature which is beneficial to the adsorption does not influence the adsorption quantity obviously.