| 不同环境因子对纳米羟基磷灰石在饱和填充柱中迁移规律的影响 |
| 摘要点击 1914 全文点击 2715 投稿时间：2010-09-06 修订日期：2010-11-22 |
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| 中文关键词 纳米羟基磷灰石（Nano-HAP） 腐殖酸（HA） pH 离子强度（IS） ζ电位 吸附效率（α） DLVO理论 |
| 英文关键词 hydroxyapatite nanoparticles (Nano-HAP) humic acid (HA) pH ionic strength (IS) ζ potential attachment efficiency (α) DLVO theory |
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| 中文摘要 |
| 选用石英砂填充柱模拟土壤体系，通过测量纳米羟基磷灰石（Nano-HAP）ζ电位、出流比等来考察不同环境因素（腐殖酸浓度、pH和离子强度）对其在饱和石英砂柱中迁移规律的影响．结果表明，随着腐殖酸浓度的增加，Nano-HAP胶体的ζ电位相应增加（绝对值增加），吸附效率（α）相应降低，当溶液中腐殖酸浓度由0增加为10 mg/L时，Nano-HAP胶体的ζ电位由-15 mV增加至-55 mV，吸附效率由1.0减小为0.012，迁移能力增加；此外，随着本体溶液pH增加，Nano-HAP胶体的ζ电位亦随之增加，吸附效率相应降低，因此有利于其在饱和体系中的迁移．然而，随着本体溶液离子强度增加，Nano-HAP胶体的双电层被压缩，ζ电位逐渐减小，吸附效率相应增加，且二价阳离子对Nano-HAP迁移能力的影响要远大于单价阳离子的影响．当本体溶液离子强度（支持电解质为单价阳离子Na+）由1 mmol/L增加至100 mmol/L时，吸附效率由0.030增加至0.13，而当本体溶液离子强度（支持电解质为二价阳离子Ca2+）由0.2 mmol/L增加至10 mmol/L时，吸附效率由0.030增加至1.0，更多的Nano-HAP胶体被滞留在多孔介质中，阻碍其迁移．该研究结果将有助于从机制上深入地了解纳米羟基磷灰石在土壤-地下水环境中的迁移行为及其归趋． |
| 英文摘要 |
| Quartz sand was selected as collector and saturated packed column was constructed to explore the effects of environmental factors (humic acid, pH and ionic strengths of the bulk solution) on the transport and fate of hydroxyapatite nanoparticles (Nano-HAP) through measuring ζ potentials and representative ci/c0 of Nano-HAP. It was suggested that ζ potentials of Nano-HAP colloids became more negative with increasing humic acid concentration and the change in solution composition from 0 to 10 mg/L humic acid yielded an increase in the ζ potentials of Nano-HAP colloids from -15 mV to -55 mV and a sharp decrease in α (attachment efficiency) from 1.0 to 0.012, meanwhile, the increase in bulk solution pH yielded a slight decrease in α which enhancing its transportation in saturated packed column. However, ζ potentials of Nano-HAP colloids became less negative as the ionic strength of bulk solution increased due to the compression of diffuse double layer and yielded an increase in α which greatly impeded its mobility during the pore-water solution, meanwhile, divalent cations have significantly stronger influence on the transport of Nano-HAP than monovalent cations of the bulk solution. The increase in the concentration of monovalent cation (Na+) from 1 to 100 mmol/L yielded an increase in α from 0.030 to 0.13, and divalent cations (Ca2+) from 0.2 to 10 mmol/L yielded a greatly increase in α from 0.030 to 1.0. It is important to note that the results could considerably contribute to gain insights in the transport and fate of Nano-HAP in natured and engineered porous media. |
