复合硅钙质废水吸附材料对铅和铜离子的竞争吸附特性

Competitive adsorption of Pb(Ⅱ) and Cu(Ⅱ) onto a porous Si-Ca composite adsorbent

以牡蛎壳和硅微粉为主要原料,经烧结和水热改性合成了一种可再生使用的高效型体多孔复合硅钙质废水吸附材料,对其微观结构和性能进行了表征。开展了单一体系和二元体系吸附实验,探讨了不同初始p H值、初始浓度、吸附时间等因素对竞争吸附的影响,确定最佳吸附p H为5.0。吸附剂对单一离子的饱和吸附容量分别为Cu2+0.87 mg/g,Pb2+0.71 mg/g,竞争吸附实验显示吸附剂对Cu2+、Pb2+的结合优先顺序为Cu2+>Pb2+,吸附机理以物理吸附为主。

A porous Si-Ca composite adsorbent was prepared by using oyster shell and silicon powder as raw materials following calcining and hydrothermal process,and its microstructure and properties were characterized.Single and binary solute adsorption of Pb^2 ＋and Cu^2 ＋were performed by batch tests.The influences of initial p H,initial ion concentration,and time on competitive adsorption were discussed.The results show that the suitable p H for competitive adsorption is 5.0.The maximum adsorption capacities for single ion are 0.87 mg / g for Cu^2 ＋and 0.71 mg / g for Pb^2 ＋.The competitive adsorption results show that the affinity order of two metal ions by the adsorbent is Cu^2 ＋ 〉Pb^2 ＋.The adsorption mechanism is mainly physical adsorption.