铁钛锰复合材料的制备及其对废水中铊的吸附性能研究

Research on the preparation of iron-titanium-manganese composite and its adsorption properties for thallium in wastewater

  • 摘要: 锂云母制备碳酸锂过程中会产生含铊废水,对周边环境造成严重污染风险。本文通过共沉淀和煅烧法制备了一种新型铁钛锰复合材料,并将其作为吸附剂用于高效去除废水中的铊。研究了该复合材料的最佳吸附条件、吸附动力学以及共存离子对铊吸附效果的影响。采用X-射线衍射仪、扫描电子显微镜、氮气吸附-脱附分析仪和Zeta电位检测仪等对该吸附剂进行了系统表征与机理分析。结果表明,铁钛锰复合材料具有丰富的活性位点和含氧基团,其比表面积达到25.74 m²/g,且孔道结构发达,在较宽的pH范围内对铊表现出优异的吸附性能,铊的去除率达到了96%~99%。此外,在其他离子(如Na⁺、Ca²⁺、Mg²⁺)和有机物(如EDTA)共存的情况下,该材料仍表现出较强的选择性。Langmuir和Freundlich模型计算结果显示,常温下复合材料对铊的最大吸附量为71.85 mg/g,吸附动力学符合拟二阶模型。

     

    Abstract: Thallium-containing wastewater will be generated during the preparation of lithium carbonate from lithium mica, posing a serious pollution risk to the surrounding environment, wastewater containing high concentration of thallium is produced. In this paper, a new type of iron-titanium-manganese composite material was prepared by coprecipitation and calcination methods, and it was used as an adsorbent for the efficient removal of thallium from wastewater. The optimal adsorption conditions of the composite material, adsorption kinetics and the influence of coexisting ions on the adsorption effect of thallium were studied. The adsorbent was systematically characterized and the mechanism was analyzed by means of X-ray diffraction, scanning electron microscopy, nitrogen adsorption-desorption analyzer and Zeta potential detection. The results show that the iron-titanium-manganese composite material has abundant active sites and oxygen-containing groups, the specific surface area reaches 25.74 m²/g, and the pore structure is developed. It shows excellent adsorption performance for thallium in a wide pH range, and the removal rate of thallium reaches 96%~99%. In addition, in the presence of other ions (such as Na+, Ca2+, Mg2+) and organic substances (such as EDTA), the material still shows strong selectivity. The calculation results of Langmuir and Freundlich models show that the maximum adsorption capacity of the composite material for thallium at room temperature is 71.85 mg/g, and the adsorption kinetics conforms to the pseudo-second-order model.

     

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