| 载镧或铈生物炭吸附水体中As(Ⅴ)的作用机制 |
| 摘要点击 2437 全文点击 801 投稿时间：2017-09-25 修订日期：2017-10-25 |
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| 中文关键词 生物炭 镧 铈 五价砷 吸附 |
| 英文关键词 biochar lanthanum cerium As (Ⅴ) adsorption |
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| 中文摘要 |
| 本实验采用一步热解法制备载稀土元素镧和铈生物炭（La-BC、Ce-BC），并对其吸附As（Ⅴ）的机制进行讨论.吸附实验结果表明，相对于BC、Ce-BC，La-BC对As（Ⅴ）有较强的吸附能力，在pH=7时理论最大吸附量为20.1 mg·g-1.在pH为5~9范围内随pH升高吸附量降低，最高（pH=5）为39.1 mg·g-1，最低（pH=9）仅为17.6 mg·g-1，在酸性条件下吸附能力较强.根据SEM-EDS、FTIR、XPS分析，吸附机制为La-BC上C=O与La—O官能团参与吸附As（Ⅴ）并分别转化为C—O和La—OH.Ce-BC对As（Ⅴ）吸附能力较差，是由于Ce-BC上虽然存在C=O与Ce—O官能团，但无法参与吸附As（Ⅴ）. |
| 英文摘要 |
| Loaded lanthanum or cerium biochars were prepared by one step pyrolysis of La (NO3)3-laden or Ce (NO3)3-laden rice hulls and were employed for enhancing the adsorption of As (Ⅴ) from water. In contrast with BC and Ce-BC in this study, La-BC had better adsorption capacity in the acidic condition. The maximum adsorption capacity could reach 20.1 mg ·g-1. With increased pH, the adsorption capacity of La-BC was reduced. The highest adsorption capacity reached 39.1 mg ·g-1 (pH=5) and the lowest was 17.6 mg ·g-1 (pH=9). The resulting La-BC with As (Ⅴ) adsorption was characterized by SEM-EDS, FTIR, and XPS. There were two types of active adsorption sites for As (Ⅴ), oxygen-rich functional groups and lanthanum oxide. Although Ce-BC had oxygen-rich functional groups and cerium oxide, it was unable to participate in the adsorption of As (Ⅴ) from water. |
