Adsorption Characteristics of Different Forms of Ofloxacin to Attapulgite

作者：Quan Yao; Bi Erping^*

来源：Chemical Journal of Chinese Universities, 2017, 38(4): 622-630.

DOI：10.7503/cjcu20160773

• Ofloxacin
• Attapulgite
• Cation exchange
• Surface complex
• Electrostatic interaction

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.

• 出版日期2017-4-10
• 单位中国地质大学（北京）