| α-Fe2O3，γ-Al2O3纳米粒子及其混合体系酸碱性质及对重金属离子的吸附行为 |
| Surface Acid-Base Properties and Adsorption Behavior of Heavy Metal Ions in Aqueous Suspensions of α-Fe2O3 , γ-Al2O3 and Their Mixed System |
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| 摘要: 运用自动电位滴定技术分别研究了在纳米α-Fe2O3，γ-Al2O3单一体系及其混合体系中矿物表面的酸碱性质。依据表面配位理论恒电容模式，计算了相应的表面酸碱配位常数。实验和计算结果表明，按照等表面积原则混合α-Fe2O3、γ-Al2O3纳米粒子得到混合体系，其表面化学反应并非是单一体系的简单叠加，而是存在着不同矿物表面间复杂的交互作用。其表面酸碱性质和吸附重金属离子的行为可以用单表面模型拟合，混合体系表面反应平衡模式和相应的酸碱反应平衡常数分别为： ≡XOH＋H+(?) ≡XOH2+ lgK1=4.04 ≡XOH (?) ≡XO-＋H+ lgK2=-9.20根据重金属离子Cu2+、Pb2+、Zn2+在α-Fe2O3/γ-Al2O3混合体系表面的吸附行为，计算得出Cu2+、Pb2+、Zn2+在混合体系固体表面的配位反应平衡常数如下： ≡XOH＋M2+ (?) ≡XOM+ ＋ H+ lgK=-2.50、-2.25、-3.75(M=Cu、Pb、Zn) |
| 关键词: 氧化铁 氧化铝 酸碱性质 表面配位 吸附 |
| 基金项目: |
| Abstract: The surface acid-base and complexation behaviors of heavy metal ions in aqueous suspensions of α-Fe2O3, γ-Al2O3 and their mixed system were studied by potentiometric titration technique and the corresponding equilibrium constants were calculated using Constant Capacitance Model (CCM) according to surface complexation theory. The experimental and calculation results reveal that the surface chemical reactions in the mixed system are quite different from the sum of their individual single system due to complicated mutual interactions between the two mineral surfaces. The surface chemical reaction models and relevant equilibrium constants in the mixed system are established as: ≡XOH＋H+(?)≡XOH2+ lgK1=4.04 ≡XOH(?)≡XO-＋H+ lgK2=-9.20 and the surface complexation model and constants of Cu2+、Pb2+、Zn2+ in the mixed system can be well described by following reaction: ≡XOH＋M2+(?)≡XOM+＋H+ with log K of -2.50, -2.25, -3.75, where M represents Cu2+, Pb2+, Zn2+, respectively. |
| Keywords: Fe2O3 Al2O3 acid-base properties surface complexation adsorption |
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| 摘要点击次数: 1814 |
| 全文下载次数: 1945 |
| 刘 嘉,张卫民,吴震生,秦利红,孙仁贵,孙中溪.α-Fe2O3，γ-Al2O3纳米粒子及其混合体系酸碱性质及对重金属离子的吸附行为[J].无机化学学报,2010,26(11):1967-1974. |
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