| 开放系统下方解石对磷的去除 |
| 摘要点击 1599 全文点击 906 投稿时间：2015-05-19 修订日期：2015-07-12 |
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| 中文关键词 磷 方解石 吸附 动力学 等温吸附 |
| 英文关键词 phosphate calcite sorption kinetics isotherm |
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| 中文摘要 |
| 通过批量平衡法,研究开放系统条件下方解石对磷的去除特性. 结果表明:①方解石在开放系统中的预平衡过程,在24 h左右便能完成; ②动力学的结果表明,当初始浓度为0.5 mg ·L-1时,磷去除在前10 h内便完成很大部分,推测其去除行为主要由表面吸附进行; 当初始浓度为2.5 mg ·L-1时,磷去除主要是靠后期的磷沉淀方式来完成. ③当初始磷浓度≤2.5 mg ·L-1时,反应时间设为10 h,磷的去除过程可用Langmuir等温吸附模型来较好地拟合,推测在该条件下,表面吸附是磷去除过程中的主导作用方式. ④加入邻苯二甲酸的情况下,当初始磷浓度<2.5 mg ·L-1时,磷的去除率下降了一些,这是因为此时磷去除主要通过表面吸附完成,而邻苯二甲酸与磷共同竞争表面上的吸附位点; 当初始磷浓度>2.5 mg ·L-1时,磷的去除率增大了一些,这是因为邻苯二甲酸的加入促进了钙浓度的增加,从而促进磷通过钙以沉淀的形式去除. |
| 英文摘要 |
| Batch methods were deployed to study the removal of phosphate by calcite in an open-system. Results showed that:①The pre-equilibrium process of calcite in open system could be achieved within 24 hours ②The kinetic results showed that, at initial concentration of 0.5 mg ·L-1, the phosphate removal was almost completed within 10 hours of the first phase. The observation may be attributed to surface adsorption. At initial concentration of 2.5 mg ·L-1, the phosphate removal was mainly carried out by the precipitation of phosphate at later stage of the process; ③At initial concentration of ≤2.5 mg ·L-1, setting 10 h as reaction time, the phosphate removal process was described well by the Langmuir model. It is hypothesized that surface adsorption was the principal removal way of phosphate; ④With the addition of phthalate, at initial concentration of <2.5 mg ·L-1, the phosphate removal rate experienced a small decrease. That was because phosphate was mainly removed by surface adsorption, and thus, phthalate was a competitor to phosphate for the same adsorption site. The phosphate removal rate increased a little at initial concentration of >2.5 mg ·L-1, this was because the phosphate precipitation was reinforced by the increase of calcium concentration, which was caused by phthalate addition. |
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