壳聚糖对Cu^(2+)的吸附与解吸

Cu^(2+) ADSORPTION AND DESORPTION BY CHITOSAN

研究了溶液pH值、Cu2+初始浓度、吸附剂投加量、吸附时间及温度对壳聚糖吸附Cu2+的影响,并对达到吸附平衡的壳聚糖进行了解吸研究。结果表明,壳聚糖对Cu2+的吸附量随pH值的升高而增大,在pH值为4.7时,基本达到吸附平衡;吸附过程同时符合Langmuir模型和Freundlich模型,最大吸附量为142.9 mg/g;与拟一级动力学模型相比,拟二级动力学模型可以更好地描述吸附过程;吸附剂最佳投加量为1 g/L。用0.03 mol/L H2SO4溶液做脱附液,搅拌10 min,脱附率为73.4%;经过4次脱附-吸附循环,壳聚糖平衡吸附量变化不大,具有良好的重复使用性。

The effects of effective parameters including solution pH,initial Cu(II) concentration,contact time,mass of adsorbent and temperature were assessed on Cu(II) adsorption on chitosan.The desorption of Cu(II) from equilibrated chitosan was also studied.The results show that adsorption capacity of Cu( II) on chitosan increases with increasing solution pH,and adsorption equilibrium is approximately reached at pH 4.7.Adsorption behavior fits both Langmuir and Freundlich equilibrium adsorption models well.The maximum adsorption capacity is around 142.9 mg /g.Compared to the pseudo-first-order model,the kinetic data fit the pseudo-second-order model much better.The optimized amount of adsorbent used is found to be 1 g /L.With 0.03 mol /L sulfuric acid as desorption solution,coordination with 10 min mixing,the desorption rate can reach 73.4%.After four adsorption-desorption cycles,the equilibrium adsorption capacity only changes slightly,an indicative of chitosan's good reusability.