铁铜双金属氧化物对水体中Sb(Ⅴ)的吸附去除研究

Adsorption removal of Sb(Ⅴ)from aqueous solution by Fe-Cu binary oxide

通过化学共沉淀法制备铁铜双金属氧化物,并采用扫描电镜、X射线衍射、氮吸附脱附实验对其化学组成及表面积进行分析。通过静态吸附与固定床动态吸附实验考察铁铜双金属氧化物对废水中Sb(Ⅴ)的吸附去除能力,并分析了吸附动力学与反应机制。结果表明,制得的铁铜双金属氧化物并不仅是铜氧化物与铁氧化物的简单混合,其比表面积远大于铁氧化物和铜氧化物;静态吸附实验显示,铁铜双金属氧化物对Sb(Ⅴ)溶液的吸附去除率明显高于铁氧化物和铜氧化物,当Sb(Ⅴ)溶液初始pH为6.0,初始质量浓度为20mg/L,溶液体积100mL,振荡速度100r/min,吸附时间为24h,0.03g铁铜双金属氧化物对Sb(Ⅴ)的吸附去除率高达95.6%,吸附数据符合伪二级动力学方程;固定床动态吸附实验表明,随着进水流量的增加,床层耗竭时间缩短;铁铜双金属氧化物对Sb(Ⅴ)去除以化学吸附为主,铁铜双金属氧化物在吸附过程中生成铁置换的黝铜矿。

Fe-Cu binary oxide was fabricated through a co-precipitation process and characterized with XRD, SEM,and Nz adsorption-desorption measurements. The removal ability of Sb（ V ） from aqueous solution by Fe-Cu bi- nary oxide was studied through both batch experiment and column experiment, and the adsorption dynamics and reac- tion mechanism were also analyzed. Results demonstrated that the Fe-Cu binary oxide was not the mixture of ferri- hydrite and CuO,and its specific surface area was higher than that of both iron oxide and copper oxide. Batch experi- ment indicated that the Sb（ V ） removal ability of Fe-Cu binary oxide was significantly higher than that of iron oxide and copper oxide. When the initial Sb（ V ） concentration was 20 mg/L,solution volume was 100 mL,pH was 6.0,and vibrating rate was 100 r/min,95.6% of 20 mg/L Sb（ V ） was removed by Fe-Cu binary oxide after 24 h reaction. Fur- thermore,the removal of Sb（V ） by Fe-Cu binary oxide followed the pseudo-second-order kinetic. Column tests re- suits showed that as the flow rates increased, adsorption saturation time became shorter. Sb（V） adsorption onto Fe-Cu binary oxide was mainly controlled by the chemisorption process, and the iron-substituted tetrahedrite was formed.