凹凸棒石负载壳聚糖吸附废水中Cd^(2+)的研究

Adsorption of Cd^(2+) in Wastewater with Modified Attapulgite-Chitosan Adsorbent

根据凹凸棒石的离子交换特性和壳聚糖在酸性溶液中带有正电荷,以90%脱乙酰度壳聚糖为原料,对不同温度活化的凹土作表面改性,按壳聚糖溶胶与凹土质量比2∶1的比例,制备了凹土负载壳聚糖复合吸附剂。通过对壳聚糖包覆率的测定,确定凹土活化温度在700℃时,其负载率最大为32.6%。吸附废水中Cd2+最佳工艺条件是:凹凸棒石-壳聚糖颗粒吸附剂用量为15g/L,废水中Cd2+质量浓度不大于200mg/L,pH值为6～8,吸附平衡时间为5min,废水中Cd2+去除率为97%。

In order to offering theory for treatment of Cd^2＋ pollution wastewater, a compound adsorbent was prepared with the combination of chitosan and attapulgite. Attapulgite was added in chitosan slurry of 90% the degree of deacetylation to prepare adsorbent.The mass ratio of chitosan gel and attapulgite was 2 ： 1. Chitosan loading rate on attapulgite was 32.6% at 700℃. Its adsorptivity toward Cd^2＋ was studied and results show that when the dosage of the adsorbent is 15g/L, the mass concentration of Cd^2＋ in wastewater does not exceed 200mg/L, the pH value is 6-8, the adsorption equilibrium time is about 5min and Cd^2＋ removal efficiency is 97%.