甘蔗渣吸附剂的制备及其对Pb^2＋、Cu^2＋、Cr^3＋的吸附动力学研究

Preparation of Bagasse Adsorbents and Investigation of their Adsorption Kinetic of Pb(Ⅱ),Cu(Ⅱ) and Cr(Ⅲ)

通过用三氯氧磷对甘蔗渣进行改性,制备了含有强吸附能力的磷酸基团的甘蔗渣吸附剂,研究了磷酸化反应条件对离子吸附性能的影响。产物的结构通过红外光谱进行了表征,同时也测试了所制备的甘蔗渣吸附剂的一些物理性质如表面积、孔径和平均颗粒大小。在恒温及恒定pH条件下,用静态吸附法研究了磷酸化甘蔗渣对Pb2+、Cu2+、Cr3+的吸附动力学,并运用3种动力学模型对吸附过程进行拟合,结果表明二级动力学模型对试验数据最为吻合。所制备的改性甘蔗渣吸附剂对这3种离子的吸附量为Cr3+>Cu2+>Pb2+。

An adsorbent was prepared based on bagasse by modification with phosphorus oxychloride in the presence of pyridine, for the purpose of introducing some functional phosphorylated groups to enhance its adsorption ability toward heavy metal ions. The effects of preparation conditions on the Pb （ Ⅱ ）, Cu （ Ⅱ ） and Cr （ Ⅲ ）, and adsorption properties of the Pb （ Ⅱ ）, Cu （ Ⅱ ）, Cr （ Ⅲ ） by the bagasse adsorbent were investigated. The structure of the modified materials was characterized using Fourier Transform Infrared （FT-IR） analysis. The surface area, porosity and particle sorption on the bagasse mean size were also measured. Batch experiments of Pb （ Ⅱ ）, Cu （Ⅱ ） and Cr （ Ⅲ ） adadsorbent were performed at the constant temperature and pH value. The pseudo-first-order, pseudo-second-order and intra-particle diffusion models were used to determine the adsorption kinetics of Pb （ Ⅱ ）, Cu （ Ⅱ ） and Cr （ Ⅲ ）. The result showed that the data determined from pseudo-second-order model fitted well with the experiment value. The maximal adsorption capacities varied in the following order： Cr （Ⅲ） 〉 Cu （Ⅱ） 〉Pb （Ⅱ）.