高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (4): 622.doi: 10.7503/cjcu20160773

• 物理化学 • 上一篇    下一篇

不同形态的氧氟沙星在凹凸棒土上的吸附特征

全瑶, 毕二平()   

  1. 中国地质大学(北京)水资源与环境学院, 水资源与环境工程北京市重点实验室, 北京 100083
  • 收稿日期:2016-11-07 出版日期:2017-04-10 发布日期:2017-03-23
  • 作者简介:联系人简介: 毕二平, 男, 博士, 教授, 博士生导师, 主要从事污染水文地质与环境有机化学方面的研究. E-mail: bi@cugb.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 41472231)资助

Adsorption Characteristics of Different Forms of Ofloxacin to Attapulgite

QUAN Yao, BI Erping*()   

  1. School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environment Engineering,China University of Geosciences(Beijing), Beijing 100083, China
  • Received:2016-11-07 Online:2017-04-10 Published:2017-03-23
  • Contact: BI Erping E-mail:bi@cugb.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.41472231)

摘要:

通过控制反应体系的pH值, 探究了阳离子、 兼性和阴离子形态的氧氟沙星(OFL, 3种形态分别记为OFL+, OFL±和OFL-)在凹凸棒土(ATP)上的吸附特征. 实验结果表明, OFL+主要通过与ATP表面的Ca2+, Mg2+进行阳离子交换吸附于ATP上, 当其吸附量较高时, 会存在少量的氢键; OFL±和OFL-可与ATP表面的铁氧化物、 铝氧化物进行表面络合, 也可与溶液中从ATP中溶解出的Ca2+和Mg2+形成络合物, 再通过静电作用吸附于ATP上. 在中性至微碱性(pH=7.10~7.70)条件下, 由于Ca的电负性小于Mg, [Ca2+-OFL]+不能稳定地存在于溶液中, 使得OFL±与Ca2+进行阳离子交换而与Mg2+形成络合物, 再通过静电作用吸附于ATP上. 当OFL主要以OFL-形态存在于溶液中时(pH=9.00~10.00), Ca2+和Mg2+均可与OFL-形成络合物, 再通过静电作用吸附于ATP上.

关键词: 氧氟沙星, 凹凸棒土, 阳离子交换, 表面络合, 静电作用

Abstract:

By controlling the pH of reaction system, the adsorption characteristics of different forms of ofloxacin(i. e., OFL±, OFL+, and OFL-) to attapulgite(ATP) were investigated. The experimental results showed that exchanging with Ca2+ and Mg2+ on the surface of ATP was the main sorption mechanism for OFL+. When OFL+ adsorption quantity increased, there will be little amount of hydrogen bonding between OFL+ and ATP surface. OFL± and OFL- can form surface complexation with iron/aluminum oxide on the surface of ATP. Meanwhile, both OFL± and OFL- can form complexes with cations(Ca2+, Mg2+) dissolved from ATP and then adsorbed on ATP by electrostatic attraction. Because of the lower electronegativity of Ca than Mg, [Ca2+-OFL]+ cannot exist stably in neutral to weakly alkaline(e. g., pH=7.10—7.70) solution, which results in the situation that OFL± exchange with Ca2+ but form complexes with Mg2+ then adsorbed to ATP by electrostatic attraction. When OFL- was the main form in solution(pH=9.00—10.00), both Ca2+ and Mg2+ can form complexes with OFL- and then adsorbed to ATP by electrostatic attraction.

Key words: Ofloxacin, Attapulgite, Cation exchange, Surface complex, Electrostatic interaction

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