纤维素强阴离子交换剂对Cr(Ⅵ)的吸附性能

Adsorption Properties of Cellulosic Strong Anion Exchangers to Cr(Ⅵ)

利用农副产品废弃物麦秆、荞麦皮、锯末、稻壳中的纤维素制备纤维素强阴离子交换剂 ,用静态方法测定了它们对模拟电镀废水中 Cr( )的去除率 .讨论了离子交换剂的用量、离子交换时间、p H值对 Cr( )的去除率的影响 .结果表明 :离子交换剂的用量为 0 .3 g、离子交换时间为 3 0 min;p H值为 2 .5～ 3 .5 ,对 Cr( )的去除率可达 99.5 %以上 .用动态方法测定了阴离子交换剂对 Cr( )的饱和吸附容量 ,用 w(Na OH)为 8%的溶液解吸再生 ,再生率可达 90 %以上 .该类纤维素强阴离子交换剂 ,特别是麦秆纤维素强阴离子交换剂对 Cr( )有良好的吸附能力 ,吸附容量可达76 .4mg· g-1。

Cellulosic strong anion exchangers are synthesized with celluloses obtained from wheat straw, sawdust, buckwheat husk and rice husk. Their removal efficiencies of Cr(Ⅵ) in the simulated electroplating wastewater are determined by static method. The factors of influencing the removal efficiencies, such as the amount of ion exchanger, ion exchanging time and pH value are discussed. When the amount of ion exchanger is 0.3g, ion exchanging time is 30min and pH value is 2.5~3.5, the removal efficiency keeps above 99.5%. Their saturated adsorption capacities to Cr(Ⅵ) are determined by means of dymanic method. The absorbents are regenerated by NaOH solution of 8%, and the regeneration efficiencies can reach above 90%. The result shows that the cellulosic strong anion exchangers are good adsorbents. Especially wheat straw is a kind of very good adsorption material, its adsorption capacity is 76.4mg/g.