开放系统下方解石对邻苯二甲酸的吸附 |
摘要点击 2996 全文点击 1265 投稿时间:2014-11-28 修订日期:2015-03-14 |
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中文关键词 邻苯二甲酸 方解石 吸附 动力学 离子强度 |
英文关键词 o-phthalate calcite adsorption kinetic ionic strength |
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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邻苯二甲酸的吸附特性. 结果表明:①邻苯二甲酸在方解石上的吸附3 h后渐趋平衡,一级动力学方程与二级动力学方程都能较好拟合吸附过程; ②当pH从7.7增加到9.7时,邻苯二甲酸的吸附率逐渐降低,溶液中HCO3-和CO32-的竞争效应及方解石表面的静电效应是其主导因素; ③邻苯二甲酸的吸附率随离子强度升高而减少,这是由于电解质的"盐效应"作用增大了竞争离子HCO3-和CO32-的浓度; ④与间、对苯二甲酸相比,邻苯二甲酸的吸附率明显较高,可能是由于邻苯二甲酸的两个羧基距离较近,容易在方解石表面形成环状的络合物结构. 通过研究邻苯二甲酸在方解石上的吸附特性,有助于了解二者的相互作用机制,为利用方解石去除环境中的邻苯二甲酸提供理论支持. |
英文摘要 |
The batch sorption methods were deployed to study the sorption of o-phthalate on calcite in open-system. Results show that: ① The o-phthalate sorption reached the equilibrium within 3 hours. Both pseudo first-order and pseudo second-order models described the kinetic characteristics well; ②The o-phthalate sorption rate decreased with pH (7.7-9.7). This phenomenon was due to the competition effect of HCO3- and CO32-, and the electrostatic effect on the surface; ③The o-phthalate sorption rate also decreased with the increase in ionic strength. This was due to the rise in concentration of HCO3-and CO32- induced by salt effect; ④Compared with m-phthalate and p-phthalate, o-phthalate sorption rate was much higher due to the proximity of its two carboxyl groups which easily formed a chelate ring of surface complex. By studying the factors that influence o-phthalate sorption onto calcite, the sorption mechanism can be well understood. This mechanism can be applied in the removal of o-phthalate from the environment. |
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