抛光污泥掺杂Fe3O4复合微球吸附剂对Sb（Ⅲ）的吸附性能研究

Adsorption characteristics of Sb（Ⅲ） by polished sludge doped Fe3O4 composite microspheres adsorbent

为去除水中Sb(Ⅲ),采用改进的共沉淀法制备抛光污泥掺杂Fe3O4吸附剂(HCO/Fe3O4),并采用海藻酸钠(SA)固化交联形成HCO/Fe3O4复合微球吸附剂(SAB);利用吸附序批实验考察了pH、温度和共存离子对SAB吸附Sb(Ⅲ)效果的影响。结果表明,制备SAB的HCO/Fe3O4和SA最佳质量分数分别为2.5%和2.0%。在pH为7,温度为25℃时吸附72 h,投加4.0 g/L SAB对初始质量浓度为20.0 mg/L的Sb(Ⅲ),去除率达到80%以上。NO-3和SO2-4对SAB吸附Sb(Ⅲ)没有显著影响,而10 mmol/L PO3-4对SAB吸附Sb(Ⅲ)有微弱的促进作用。SAB对Sb(Ⅲ)的吸附符合Langmuir模型和准二级动力学模型,吸附过程结合了化学吸附(离子交换)与物理吸附(扩散反应)作用。

To remove Sb(Ⅲ)from water,polished sludge doped Fe3O4 adsorbent(HCO/Fe3O4)was prepared by improved co-precipitation method,and sodium alginate(SA)was used to solidify and cross-link to form HCO/Fe3O4 composite microsphere adsorbent(SAB).The effects of pH,temperature and coexisting ions on the adsorption of Sb(Ⅲ)on SAB were investigated by sequential batch adsorption test.The results showed that the optimal mass fraction of HCO/Fe3O4 and SA were 2.5%and 2.0%,respectively.SAB with dosage of 4.0 g/L had a high Sb(Ⅲ)removal rate of above 80%when pH was 7,temperature was 25℃,initial Sb(Ⅲ)was 20.0 mg/L and adsorption time was 72 h.NO-3 and SO2-4 had no significant effect on the adsorption of Sb(Ⅲ)by SAB,while PO3-4 of 10 mmol/L had a weak promotion.The adsorption of Sb(Ⅲ)on SAB obeyed Langmuir model and pesudo-second-order kinetic model,which was mainly combined with chemical adsorption(ion exchange)and physical adsorption(diffusion reaction).