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采用共沉淀法制备了一种新型铈锰复合氧化物吸附剂,对其进行了表征,并对磷吸附行为与机制进行了研究.表征结果分析表明,此氧化物由纳米级颗粒组成;铈锰复合氧化物中的铈氧化物有类似水合氧化铈的无定形结构;BET比表面积为157 m2·g-1,等电点为6.5.吸附实验结果表明,Langmuir吸附等温线模型可以更好地拟合铈锰复合氧化物对磷的吸附,最大吸附量为28.6 mg·g-1(p H=7.0);铈锰复合氧化物对磷具有较高的吸附速率,更符合准二级动力学模型;溶液p H对铈锰复合氧化物吸附磷的影响较为明显,随p H升高,吸附量降低;离子强度则影响不大;共存阴离子对吸附影响的大小顺序为Si O2-3>CO2-3>Cl-≥SO2-4.通过对铈锰复合氧化物吸附磷前后Zeta电位和红外谱图(FTIR)分析,可以推断磷在铈锰复合氧化物表面发生了特性吸附,磷酸根主要通过取代复合氧化物表面的金属羟基而被吸附去除.
A new type of cerium manganese composite oxide adsorbent was prepared by co-precipitation method, characterized and characterized for phosphorus adsorption behavior and mechanism. Characterization results show that the oxide is composed of nano-scale particles; cerium manganese The cerium oxide in the composite oxide has an amorphous structure similar to the hydrated cerium oxide with a BET specific surface area of 157 m2 · g-1 and an isoelectric point of 6.5. The adsorption experiments show that the Langmuir adsorption isotherm model can be better Cerium-manganese composite oxide on phosphorus adsorption, the maximum adsorption capacity of 28.6 mg · g-1 (p H = 7.0); cerium manganese composite oxide has a higher adsorption rate of phosphorus, more in line with quasi-second order kinetics model ; The effect of solution p H on phosphorus adsorption by cerium-manganese composite oxide is obvious. With the increase of p H, the adsorption capacity decreases; the ionic strength has little effect; the order of the influence of coexisting anions on adsorption is Si O2-3> CO2- 3> Cl-≥SO2-4. By Zeta potential and FTIR analysis of phosphorus before and after phosphorus adsorption on cerium manganese composite oxide, it can be inferred that the adsorption of phosphorus on the surface of cerium manganese composite oxide occurs. The metal oxide on the surface of the composite oxide is adsorbed and removed.