铁改性竹炭去除水中的As(Ⅲ)和As(Ⅴ)

Removal of As(Ⅲ) and As(Ⅴ) from water by iron-modified bamboo charcoal

利用竹炭负载铁氧化物制备了复合吸附剂,并用粉末X射线衍射对负载的铁进行了表征。通过静态吸附实验,对比研究了改性竹炭对水溶液中As(Ⅲ)和As(Ⅴ)阴离子的吸附特性。结果表明,载铁竹炭对As(Ⅲ)和As(Ⅴ)的最佳吸附pH分别为8和2。改性竹炭对砷阴离子的吸附过程可符合准二级动力。Freundlich等温方程式能很好地描述As(Ⅲ)和As(Ⅴ)在改性竹炭上的吸附。在相同初始浓度和吸附剂投加量下,改性竹炭对As(Ⅴ)的吸附量大于As(Ⅲ)。

A composite adsorbent for arsenic removal from aqueous solution was synthesized by loading iron onto bamboo charcoal.The modified bamboo charcoal was characterized using x-ray diffraction.And the arsenic adsorption characteristics onto the iron-modified bamboo charcoal were investigated in batch tests.The results showed that the corresponding optimum pH ranges for As（Ⅲ） and As（Ⅴ） removal were 8 and 2,respectively.The pseudo-second-order kinetic model explained the kinetic of both the As（Ⅲ） and As（Ⅴ） adsorption processes.And Freundlich isotherm was suitable to describe the adsorption of arsenic with the resulting composite adsorbent.The adsorption capacity of As（Ⅴ） was higher than that of As（Ⅲ） at the same initial arsenic concentration and adsorbent dose.