氧氟沙星在凹凸棒土上的吸附特征研究

发布时间：2018-03-29 09:01

本文选题：吸附　切入点：凹凸棒土　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：抗生素类药物污染已经成为越来越严重的环境问题,吸附是去除废水中氟喹诺酮类抗生素(FQs)药物的主要方法之一。本研究选取了我国储量丰富的粘土矿物凹凸棒土(ATP)作为吸附剂,来去除废水中的FQs药物。研究中以氧氟沙星(OFL)作为典型污染物,通过吸附批实验探究了阳离子、兼性和阴离子形态的OFL(分别表示为OFL+、OFL±和OFL-)在ATP上的吸附特征。在此基础上,研究了阳离子表面活性剂十六烷基三甲基溴化铵(HDTMA)与OFL在ATP上的竞争吸附。得出以下主要结论:(1)OFL+主要通过与ATP表面的Ca~(2+)和Mg~(2+)进行阳离子交换吸附于ATP上,当OFL+浓度升高时,ATP表面的Si-O-与OFL+的羧基间会产生氢键作用。(2)OFL±和OFL-均可与ATP表面的铁、铝氧化物发生络合。OFL-可与Ca~(2+)、Mg~(2+)生成络合物再以静电作用形式吸附于ATP上,但是OFL±只能与Mg~(2+)形成络合物再以静电作用吸附于ATP上。OFL±还可与ATP表面的Ca~(2+)进行阳离子交换。(3)HDTMA主要通过与OFL竞争Ca~(2+)和Mg~(2+)和覆盖ATP表面的点位来抑制OFL在ATP上的吸附。(4)OFL单独存在时在ATP上的吸附量随溶液初始pH的升高呈下降的趋势。当与HDTMA共存时,HDTMA会以其更强的疏水性而优先大量地吸附于ATP上使ATP的有机碳含量增加,使OFL以疏水作用吸附于ATP上,进而使OFL在ATP上的吸附几乎不受溶液初始pH的影响。(5)相对于背景阳离子为Na~+,背景阳离子为K+、Ca~(2+)和Mg~(2+)时,K+、Ca~(2+)和Mg~(2+)分别会与OFL竞争吸附点位阻碍OFL与ATP中的Ca~(2+)进行阳离子交换以及使[Mg~(2+)-OFL]+与OFL之间产生静电斥力来抑制OFL在ATP上的吸附,且抑制作用强度为Mg~(2+)Ca~(2+)≈K+。在背景溶液中阳离子浓度为0.01 M时,共存的0.5 CMC HDTMA会与OFL竞争可交换阳离子从而抑制OFL在ATP上的吸附,但这种抑制作用强弱不受背景阳离子种类的影响。
[Abstract]:The pollution of antibiotics has become an increasingly serious environmental problem. Adsorption is one of the main methods to remove fluoroquinolones (FQs) from wastewater. The adsorption characteristics of cation, facultative and anionic OFLs (expressed as OFL OFL 卤and OFL-OFL) on ATP were investigated by adsorption batch experiments. The competitive adsorption of cationic surfactant cetyltrimethylammonium bromide (HDTMA) with OFL on ATP was studied. When the concentration of OFL is increased, the hydrogen bond between Si-O- and OFL carboxyl group on the surface of OFL can be produced. The OFL- and OFL- can be complexed with the iron on ATP surface, and the aluminum oxide can form complex with Ca~(2 / Mg-O-) and adsorb on ATP in the form of electrostatic interaction. But OFL 卤can only form complex with Mg~(2) and then adsorb on ATP by electrostatic interaction. OFL 卤can exchange cationic ion with Ca~(2 on ATP surface, mainly by competing with OFL (Ca~(2) and Mg~(2) and covering ATP surface to restrain OFL in ATP. The adsorption amount on ATP decreases with the increase of the initial pH of the solution. When it coexists with HDTMA, it will increase the organic carbon content of ATP with its stronger hydrophobicity and preferentially adsorb on ATP. The adsorption of OFL on ATP was hydrophobic, and the adsorption of OFL on ATP was almost independent of the initial pH of the solution. Background: when the cations are K ~ (+) -CaO ~ (2)) and Mg~(2), K ~ (+) ~ (2) and Mg~(2 (~ (2))) can compete with OFL to block the cation exchange between OFL and Ca~(2 in ATP, and to induce electrostatic repulsion between [Mg~(2 ~ (-OFL)] and OFL to inhibit the adsorption of OFL on ATP, which can inhibit the adsorption of OFL on ATP. When the concentration of cations in the background solution is 0.01m, the coexisting 0.5 CMC HDTMA can compete with OFL to exchange cations, thus inhibiting the adsorption of OFL on ATP. However, the inhibition is not affected by the background cation species.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;O647.33

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