| 茶叶基水合氧化铁吸附水体中Pb(Ⅱ)的性能 |
| 摘要点击 2281 全文点击 1417 投稿时间：2014-02-19 修订日期：2014-05-07 |
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| 中文关键词 水合氧化铁 铅 茶叶渣 吸附 应用 |
| 英文关键词 hydrated ferric oxide lead tea waste adsorption application |
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| 中文摘要 |
| 采用原位沉积技术将水合氧化铁（HFO）负载于废弃茶叶渣表面制备了复合材料茶叶基水合氧化铁（HFO-TW），研究了HFO-TW对水溶液中Pb（Ⅱ）的吸附特性，探讨了溶液pH值、时间、共存碱土离子、温度、Pb（Ⅱ）初始浓度等因素对Pb（Ⅱ）的吸附效果的影响. 结果表明酸性范围内，Pb（Ⅱ）的吸附量随溶液pH升高而增大；Pb（Ⅱ）的吸附速度较快，100 min内便可达吸附平衡，且动力学曲线较好地符合伪一级和伪二级动力学模型，拟合系数可达98.8%；在竞争离子Ca（Ⅱ）/Mg（Ⅱ）的浓度高于Pb（Ⅱ）50倍时，HFO-TW对Pb（Ⅱ）仍具有较强的吸附能力，Pb（Ⅱ）的吸附量仅分别下降12.1 mg ·g-1 和8.1 mg ·g-1；Pb（Ⅱ）的吸附过程较好地符合Langmuir等温模型，理论最大吸附容量为89.43 mg ·g-1，远高于未经改性的茶叶渣和其他生物吸附剂. 所有结果均证实HFO-TW在净化实际铅污染水体中有着较为广阔的应用潜力. |
| 英文摘要 |
| Hydrated ferric oxide was successfully impregnated onto tea waste by precipitation to obtain a new sorbent named HFO-TW,the adsorption characteristics of which toward Pb(Ⅱ) in aqueous solution was investigated by evaluating the effects of pH value, contact time, coexisting ion, temperature, and initial concentration of Pb(Ⅱ). The Pb(Ⅱ) sorption onto HFO-TW was pH-dependent, and the higher pH value was more helpful for Pb(Ⅱ) adsorption onto HFO-TW in the pH range of 2.5-7. Lead sorption speed was quick and could reach equilibrium within 100 min, and the kinetics curve could be fitted well by both pseudo-first and pseudo-second models. The related coefficient was 98.8%. HFO-TW exhibited highly selective lead retention and the adsorption capacity of Pb(Ⅱ) onto HFO-TW was declined by only 12.1 mg ·g-1 and 8.1 mg ·g-1 in the presence of competing Ca(Ⅱ), Mg(Ⅱ) at 50 times of the target ion. In addition, Pb(Ⅱ) sorption onto HFO-TW could be described satisfactorily by Langmuir model, and the maximal sorption capacity calculated by Langmuir equation was 89.43 mg ·g-1, which was much higher than the unmodified tea waste and other bio-sorbents. All the results validated that HFO-TW was a promising sorbent for removal of lead from waters. |
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