摘要
本文以化学合成的纤铁矿为研究对象,探讨典型氟喹诺酮类抗生素氧氟沙星(OFL)在纤铁矿上的吸附动力学､热力学过程及其环境影响因素.结果表明,纤铁矿对OFL的吸附过程更符合伪二级动力学模型(R^(2)=0.991)和Freundlich模型(R^(2)=0.996),平衡吸附量(Q_(e))为1.99mg/g,且该吸附为自发放热过程.纤铁矿对OFL的吸附有很强的pH值依赖性,主要取决于不同pH值条件下纤铁矿的带电性和OFL离子的存在形态;同时,离子强度的增加会减弱纤铁矿与OFL之间的静电斥力,从而使吸附量增加.富里酸(FA)对OFL在纤铁矿上的吸附具有促进作用;两种离子对OFL的竞争吸附有着不同的影响,其中Ca^(2+)抑制OFL的吸附,而NO_(3)^(-)则无明显影响.扫描电镜(SEM)和傅里叶变换红外光谱(FTIR)表明,OFL在纤铁矿上的吸附机制以羧基参与的双齿螯合配位或双桥配位作用为主.
In this paper,the kinetics and thermodynamic process of adsorption of typical fluoroquinolone antibiotic of ofloxacin(OFL)on lepidocrocite and its environmental influencing factors were investigated by chemically synthesized lepidocrocite.The results showed that,the adsorption process of OFL on lepidocrocite was more fitted with the pseudo-second-order kinetic model(R^(2)=0.991)and the Freundlich model(R^(2)=0.996).The equilibrium adsorption capacities(Q_(e))was 1.99mg/g and the reaction is spontaneous and exothermic.The adsorption of OFL by lepidocrocite is strongly pH dependent,which mainly depends on the charged nature of lepidocrocite and the existence form of OFL ions under different pH conditions;the increase of ionic strength will weaken the electrostatic repulsion between lepidocrocite and OFL,which will lead to an increase of adsorption.The adsorption of OFL on lepidocrocite was promoted by fulvic acid(FA);The two coexisting ions have different effects on the competitive adsorption of OFL.Ca^(2+)inhibits the adsorption of OFL,while NO_(3)^(-)has no significant effect.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)showed that the adsorption mechanism of OFL adsorption on lepidocrocite was dominated by bidentate chelate coordination or double-bridge coordination with the participation of carboxyl groups.
作者
甘翠
李玉琼
张天伦
童蕾
GAN Cui;LI Yu-qiong;ZHANG Tian-lun;TONG Lei(School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430078,China;State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution,Wuhan 430078,China;Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science,Wuhan 430078,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第6期2881-2888,共8页
China Environmental Science
基金
国家自然科学基金资助项目(41830862,42277068)。
