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四环素类抗生素是一种广泛用于农业、动物抗菌治疗和人类医疗用途的抗生素[1]. 此类抗生素是两性分子,含有丰富的离子化官能团(羰基、苯酚、酮和氨基等),可与带电和极性很强的物质相互作用[2]. 四环素类抗生素在自然环境中普遍存在,其残留物会促进耐药微生物的进化,从而对人类健康造成潜在威胁[3-5]. 因此,水体中抗生素的去除方法引起了研究人员的广泛关注. 目前水体中四环素类抗生素的去除方法主要有化学氧化法、吸附法、光催化降解法、膜过滤法和生物降解法[6-7],其中吸附法被认为是最经济有效的方法之一[8].
氧化石墨烯(graphene oxide,GO)是一种具有许多独特物理和化学性质的新型二维材料. 与其他碳纳米材料(如碳纳米管和nC60)相比,具有大的表面积(理论值为2630 m2·g−1)[9-10]和丰富的含氧官能团[11]等特性,被广泛用于有机污染物(如抗生素、双酚A和多环芳烃等)的去除[12-14]. Gao等[8]发现,四环素在GO上的吸附主要归因于π-π相互作用和阳离子-π键作用. Zhang等[15]研究表明,GO吸附四环素的过程中π-π电子供体-受体效应与氢键作用同时存在. 目前有研究报道了不同的水化学条件(如pH和离子强度)会对四环素在GO上的吸附特征产生影响. 一般而言,四环素在GO上的吸附量随着离子强度(即Na+浓度)或pH的增加而降低[8]. 同时,前期研究表明二价金属阳离子(如Ca2+)可显著增强四环素类抗生素在碳材料(如碳纳米管和生物炭)上的吸附[16-17].但现阶段关于二价金属阳离子对GO吸附四环素类抗生素的影响机制尚未完全阐明. 此外,四环素类抗生素包含多种类型,如四环素(tetracycline,TC)、土霉素(oxytetracycline,OTC)、金霉素(chlorotetracycline,CTC)、强力霉素(doxycycline,DOC)以及甲烯土霉素(methacycline ,METC) 等[18].不同种类的抗生素在分子结构、疏水性和官能团等方面具有不同的特征,进而可能会影响其与GO的相互作用[8]. 然而,目前关于GO对不同类型抗生素吸附性能的研究还不够深入.
基于以上分析,本论文系统地研究了不同水化学条件下(pH、离子强度、Cu2+),3种常用四环素类抗生素(TC、OTC、CTC)在GO纳米颗粒上的吸附行为. 深入分析了GO纳米颗粒吸附四环素类抗生素的内在机理以及3种抗生素与GO相互作用产生差异的原因,期望为GO纳米材料应用于抗生素类污染修复提供理论依据.
氧化石墨烯纳米颗粒对抗生素类污染物吸附特征及影响因素
Factors controlling adsorption of tetracycline antibiotics onto graphene oxide nanoparticles
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摘要: 本文通过吸附动力学和吸附等温线探究了氧化石墨烯(GO)纳米颗粒对3种典型的四环素类抗生素(即四环素(TC)、土霉素(OTC)和金霉素(CTC))吸附特征. 结果表明,伪二级动力学模型可以很好的拟合吸附动力学的结果,吸附速率可能受化学吸附控制. 吸附等温线的结果显示GO对3种抗生素均有较高的吸附能力,且吸附能力依次为:CTC >OTC >TC. 这主要是由于四环素类抗生素可以通过π-π作用、阳离子-π键、疏水作用以及静电作用等机制与GO产生结合. 此外,四环素类抗生素在GO上的吸附行为与背景溶液的水化学条件(如pH、离子强度和二价金属离子)密切相关. 总体来讲,由于静电斥力的增强,抗生素在GO上的吸附量随着背景溶液pH值的升高或离子强度(NaCl)的增加而降低,这主要是由于静电引力和吸附点位的减少所致;二价阳离子(Cu2+)可以通过表面桥连作用,显著促进抗生素在GO上的吸附. 本研究结果清楚地表明抗生素本身的化学性质和背景溶液的水化学条件在GO去除抗生素的过程起着重要作用.Abstract: In this study, adsorption kinetics and adsorption isotherms were employed to investigate the adsorption of tetracycline antibiotics (tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC)) onto graphene oxide (GO) nanoparticles. The results of adsorption kinetics demonstrated that the data were fitted well by the pseudo-second-order kinetic models, which indicated that the adsorption rate was probably controlled by chemisorption. Meanwhile, the results obtained by the adsorption isotherm experiments showed that GO exhibited high adsorption capacity for all the three tetracycline antibiotics, and the adsorption capacity followed the order of CTC > OTC > TC. The main mechanisms involved in the adsorption behaviors were π–π interaction, cation–π bonding, hydrophobic effect, and electrostatic interaction. Furthermore, the adsorption characteristics were related to solution chemistry conditions such as pH, ionic strength and divalent metal ions. The adsorption capacities of tetracycline on GO decreased with the increasing pH or ionic strength (i.e., NaCl concentration), which was stemmed from the reduction in electrostatic attraction and the increased electrostatic repulsion between tetracycline antibiotics and GO. Additionally, the presence of divalent cations (i.e., Cu2+) could significantly promote the adsorption of tetracycline antibiotics due to the surface-bridging mechanism. Our observations indicate that properties of tetracycline antibiotics and solution chemistries play important roles in the removal of tetracycline antibiotics from aqueous solutions by GO nanoparticles.
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Key words:
- graphene oxide /
- tetracycline antibiotics /
- solution chemistry /
- adsorption.
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表 1 不同水化学条件下GO纳米颗粒对四环素类抗生素的吸附等温线参数
Table 1. Comparison of the pseudo-first-order and pseudo-second-order models for adsorption of TC antibiotics onto GO
抗生素
Antibiotics电解质溶液/(mmol·L−1)
Electrolyte solutionpH 伪一级动力学模型
Pseudo first order dynamics model伪二级动力学模型
Pseudo second order dynamics modelk1 / h−1 R2 k2 / g· (mg·h)−1 R2 TC 10 NaCl 5.0 0.0325 0.982 0.0223 0.993 OTC 10 NaCl 5.0 0.0655 0.961 0.0351 0.993 CTC 10 NaCl 5.0 0.0686 0.966 0.0465 0.992 表 2 不同水化学条件下GO纳米颗粒对四环素类抗生素的吸附等温线参数
Table 2. Sorption isotherm parameters of tetracycline antibiotics onto GO nanoparticles under different solution chemistry conditions
抗生素
Antibiotics电解质溶液/(mmol·L−1)
Electrolyte solutionpH Freundlich model Linear model KF/( mg1-n·Ln·g−1) n R2 Kd / (L·g−1) R2 TC 10 NaCl 5.0 17.3 0.596 0.949 5.43 0.921 OTC 10 NaCl 5.0 61.3 0.798 0.978 37.1 0.975 CTC 10 NaCl 5.0 158.9 0.882 0.988 110.9 0.987 TC 10 NaCl 7.0 9.05 0.696 0.966 3.69 0.932 TC 10 NaCl 9.0 4.81 0.738 0.945 2.45 0.928 OTC 10 NaCl 7.0 44.3 0.791 0.970 26.6 0.996 OTC 10 NaCl 9.0 19.5 0.975 0.980 18.7 0.969 CTC 10 NaCl 7.0 84.3 0.757 0.975 45.9 0.917 CTC 10 NaCl 9.0 37.5 0.906 0.947 31.2 0.988 TC 5 NaCl 5.0 18.1 0.695 0.965 7.46 0.924 TC 20 NaCl 5.0 2.40 0.859 0.959 1.64 0.923 OTC 5 NaCl 5.0 74.1 0.839 0.973 48.3 0.954 OTC 20 NaCl 5.0 43.7 0.845 0.987 29.9 0.995 CTC 5 NaCl 5.0 136.2 0.862 0.962 127.3 0.985 CTC 20 NaCl 5.0 98.3 0.763 0.980 59.2 0.975 TC 0.05 Cu2+ 5.0 63.6 0.575 0.969 21.3 0.956 TC 0.1 Cu2+ 5.0 98.3 0.706 0.968 54.1 0.981 OTC 0.05 Cu2+ 5.0 89.3 0.850 0.971 60.1 0.945 OTC 0.1 Cu2+ 5.0 133.7 0.955 0.966 118.3 0.972 CTC 0.05 Cu2+ 5.0 104.5 0.832 0.982 79.6 0.986 CTC 0.1 Cu2+ 5.0 137.8 0.901 0.989 111.6 0.985 表 3 不同水化学条件下GO悬浮液的特性
Table 3. Selected properties of GO suspensions under different solution chemistry conditions
背景溶液
Background solutionpH GO纳米离子的ζ−电位 / mV
ζ-Potential of GO nanoparticles平均粒径/ nm
Average particle size Zavea10 mmol·L−1 NaCl 5.0 −18.5 ± 1.3 267.9 ± 8.5 10 mmol·L−1 NaCl 7.0 −21.2 ± 1.1 258.5 ± 2.3 10 mmol·L−1 NaCl 9.0 −24.6 ± 2.5 241.3 ± 3.5 5 mmol·L−1 NaCl 5.0 −20.1 ± 1.6 222.8 ± 4.9 20 mmol·L−1 NaCl 5.0 −15.7 ± 2.1 325.9 ± 1.7 0.05 mmol·L−1 Cu2+ 5.0 −16.4 ± 1.8 278.6 ± 9.8 0.1 mmol·L−1 Cu2+ 5.0 −11.3 ± 2.5 356.7 ± 6.2 注:a基于DLS分析的GO纳米颗粒的流体动力学直径. Note: a is the hydrodynamic diameter of GO nanoparticles based on DLS analysis. -
[1] DAGHRIR R, DROGUI P. Tetracycline antibiotics in the environment: A review [J]. Environmental Chemistry Letters, 2013, 11(3): 209-227. doi: 10.1007/s10311-013-0404-8 [2] YU L L, CAO W, WU S C, et al. Removal of tetracycline from aqueous solution by MOF/graphite oxide pellets: Preparation, characteristic, adsorption performance and mechanism [J]. Ecotoxicology and Environmental Safety, 2018, 164: 289-296. doi: 10.1016/j.ecoenv.2018.07.110 [3] 杜实之. 环境中抗生素的残留、健康风险与治理技术综述 [J]. 环境科学与技术, 2021, 44(9): 37-48. DU S Z. Research progress on antibiotic pollution, health risks and treatment technology in environments [J]. Environmental Science & Technology, 2021, 44(9): 37-48(in Chinese).
[4] 杨伟伟, 高晓红, 张鑫, 等. 四环素在矿化垃圾上的吸附特性及动态过程 [J]. 环境化学, 2022, 41(5): 1726-1735. doi: 10.7524/j.issn.0254-6108.2021122404 YANG W W, GAO X H, ZHANG X, et al. Research on the adsorption characteristics and dynamic process of tetracycline on aged refuse [J]. Environmental Chemistry, 2022, 41(5): 1726-1735(in Chinese). doi: 10.7524/j.issn.0254-6108.2021122404
[5] SONG C, SUN X F, XING S F, et al. Characterization of the interactions between tetracycline antibiotics and microbial extracellular polymeric substances with spectroscopic approaches [J]. Environmental Science and Pollution Research, 2014, 21(3): 1786-1795. doi: 10.1007/s11356-013-2070-6 [6] ACOSTA R, FIERRO V, MARTINEZ de YUSO A, et al. Tetracycline adsorption onto activated carbons produced by KOH activation of tyre pyrolysis char [J]. Chemosphere, 2016, 149: 168-176. doi: 10.1016/j.chemosphere.2016.01.093 [7] YE Z L, DENG Y J, LOU Y Y, et al. Adsorption behavior of tetracyclines by struvite particles in the process of phosphorus recovery from synthetic swine wastewater [J]. Chemical Engineering Journal, 2017, 313: 1633-1638. doi: 10.1016/j.cej.2016.11.062 [8] GAO Y, LI Y, ZHANG L, et al. Adsorption and removal of tetracycline antibiotics from aqueous solution by graphene oxide [J]. Journal of Colloid and Interface Science, 2012, 368(1): 540-546. doi: 10.1016/j.jcis.2011.11.015 [9] XIA T J, LIN Y X, GUO X T, et al. Co-transport of graphene oxide and titanium dioxide nanoparticles in saturated quartz sand: Influences of solution pH and metal ions [J]. Environmental Pollution, 2019, 251: 723-730. doi: 10.1016/j.envpol.2019.05.035 [10] ZHU Y W, MURALI S, CAI W W, et al. Graphene and graphene oxide: Synthesis, properties, and applications [J]. Advanced Materials, 2010, 22(35): 3906-3924. doi: 10.1002/adma.201001068 [11] DREYER D R, PARK S, BIELAWSKI C W, et al. The chemistry of graphene oxide [J]. Chemical Society Reviews, 2010, 39(1): 228-240. doi: 10.1039/B917103G [12] 李雯雯, 覃彩蝶, 林思劼. 氧化石墨烯复合气凝胶吸附油类污染应用的基础研究 [J]. 环境化学, 2022, 41(6): 1869-1879. doi: 10.7524/j.issn.0254-6108.2022010503 LI W W, QIN C D, LIN S J. Graphene oxide-polyurethane acrylate nanocomposite aerogel for oil absorption [J]. Environmental Chemistry, 2022, 41(6): 1869-1879(in Chinese). doi: 10.7524/j.issn.0254-6108.2022010503
[13] 韩春晓, 阮敏娜, 李忠平, 等. 基于三维石墨烯去除水体中四环素 [J]. 环境化学, 2022, 41(1): 386-394. doi: 10.7524/j.issn.0254-6108.2020091502 HAN C X, RUAN M N, LI Z P, et al. The removal of tetracycline in water based on 3D grapheme [J]. Environmental Chemistry, 2022, 41(1): 386-394(in Chinese). doi: 10.7524/j.issn.0254-6108.2020091502
[14] WANG J, CHEN Z M, CHEN B L. Adsorption of polycyclic aromatic hydrocarbons by graphene and graphene oxide nanosheets [J]. Environmental Science & Technology, 2014, 48(9): 4817-4825. [15] ZHANG X T, SHEN J C, ZHUO N, et al. Interactions between antibiotics and graphene-based materials in water: A comparative experimental and theoretical investigation [J]. ACS Applied Materials & Interfaces, 2016, 8(36): 24273-24280. [16] YU F, LI Y, HAN S, et al. Adsorptive removal of antibiotics from aqueous solution using carbon materials [J]. Chemosphere, 2016, 153: 365-385. doi: 10.1016/j.chemosphere.2016.03.083 [17] FANG J, WANG M H, SHEN B, et al. Distinguishable co-transport mechanisms of phenanthrene and oxytetracycline with oxidized-multiwalled carbon nanotubes through saturated soil and sediment columns: Vehicle and competition effects [J]. Water Research, 2017, 108: 271-279. doi: 10.1016/j.watres.2016.11.004 [18] MIYAZAKI T, YOMOTA C, OKADA S. Interaction between sodium hyaluronate and tetracyclines [J]. Yakugaku Zasshi, 1995, 115(1): 72-80. doi: 10.1248/yakushi1947.115.1_72 [19] YANG K J, CHEN B L, ZHU X Y, et al. Aggregation, adsorption, and morphological transformation of graphene oxide in aqueous solutions containing different metal cations [J]. Environmental Science & Technology, 2016, 50(20): 11066-11075. [20] CHOWDHURY I, DUCH M C, MANSUKHANI N D, et al. Colloidal properties and stability of graphene oxide nanomaterials in the aquatic environment [J]. Environmental Science & Technology, 2013, 47(12): 6288-6296. [21] CHENG D, LIAO P, YUAN S H. Effects of ionic strength and cationic type on humic acid facilitated transport of tetracycline in porous media [J]. Chemical Engineering Journal, 2016, 284: 389-394. doi: 10.1016/j.cej.2015.08.159 [22] ZHAO Y P, TAN Y Y, GUO Y, et al. Interactions of tetracycline with Cd (II), Cu (II) and Pb (II) and their cosorption behavior in soils [J]. Environmental Pollution, 2013, 180: 206-213. doi: 10.1016/j.envpol.2013.05.043 [23] KUL A R, KOYUNCU H. Adsorption of Pb(II) ions from aqueous solution by native and activated bentonite: Kinetic, equilibrium and thermodynamic study [J]. Journal of Hazardous Materials, 2010, 179(1/2/3): 332-339. [24] JI L L, CHEN W, BI J, et al. Adsorption of tetracycline on single-walled and multi-walled carbon nanotubes as affected by aqueous solution chemistry [J]. Environmental Toxicology and Chemistry, 2010, 29(12): 2713-2719. doi: 10.1002/etc.350 [25] SINGH V, CHAKRAVARTHI M H, SRIVASTAVA V C. Chemically modified biochar derived from effluent treatment plant sludge of a distillery for the removal of an emerging pollutant, tetracycline, from aqueous solution [J]. Biomass Conversion and Biorefinery, 2021, 11(6): 2735-2746. doi: 10.1007/s13399-020-00683-4 [26] TANIS E, HANNA K, EMMANUEL E. Experimental and modeling studies of sorption of tetracycline onto iron oxides-coated quartz [J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2008, 327(1/2/3): 57-63. [27] ZHANG L, WANG Y, JIN S W, et al. Adsorption isotherm, kinetic and mechanism of expanded graphite for sulfadiazine antibiotics removal from aqueous solutions [J]. Environmental Technology, 2017, 38(20): 2629-2638. doi: 10.1080/09593330.2016.1272637 [28] BALARAK D, MOSTAFAPOUR F. Batch equilibrium, kinetics and thermodynamics study of sulfamethoxazole antibiotics onto Azolla filiculoides as a novel biosorbent [J]. British Journal of Pharmaceutical Research, 2016, 13(2): 1-14. [29] MAHADEVI A S, SASTRY G N. Cation–π interaction: Its role and relevance in chemistry, biology, and material science [J]. Chemical Reviews, 2013, 113(3): 2100-2138. doi: 10.1021/cr300222d [30] PERREAULT F, FONSECA de FARIA A, ELIMELECH M. Environmental applications of graphene-based nanomaterials [J]. Chemical Society Reviews, 2015, 44(16): 5861-5896. doi: 10.1039/C5CS00021A [31] LI J Q, CHEN J Y, LU T T, et al. Effects of low-molecular weight organic acids on the transport of graphene oxide nanoparticles in saturated sand columns [J]. Science of the Total Environment, 2019, 666: 94-102. doi: 10.1016/j.scitotenv.2019.02.242 [32] COTE L J, KIM J, TUNG V C, et al. Graphene oxide as surfactant sheets [J]. Pure and Applied Chemistry, 2010, 83(1): 95-110. doi: 10.1351/PAC-CON-10-10-25 [33] ZHANG D, PAN B, WU M, et al. Adsorption of sulfamethoxazole on functionalized carbon nanotubes as affected by cations and anions [J]. Environmental Pollution, 2011, 159(10): 2616-2621. doi: 10.1016/j.envpol.2011.05.036 [34] YANG Q Q, CHEN G C, ZHANG J F, et al. Adsorption of sulfamethazine by multi-walled carbon nanotubes: Effects of aqueous solution chemistry [J]. RSC Advances, 2015, 5(32): 25541-25549. doi: 10.1039/C4RA15056B [35] ZHAO H, LIU X, CAO Z, et al. Adsorption behavior and mechanism of chloramphenicols, sulfonamides, and non-antibiotic pharmaceuticals on multi-walled carbon nanotubes [J]. Journal of Hazardous Materials, 2016, 310: 235-245. doi: 10.1016/j.jhazmat.2016.02.045 [36] LI J, ZHANG K N, ZHANG H. Adsorption of antibiotics on microplastics [J]. Environmental Pollution, 2018, 237: 460-467. doi: 10.1016/j.envpol.2018.02.050 [37] MA Y, ZHOU Q, ZHOU S C, et al. A bifunctional adsorbent with high surface area and cation exchange property for synergistic removal of tetracycline and Cu2+ [J]. Chemical Engineering Journal, 2014, 258: 26-33. doi: 10.1016/j.cej.2014.07.096 [38] GU C, KARTHIKEYAN K G, SIBLEY S D, et al. Complexation of the antibiotic tetracycline with humic acid [J]. Chemosphere, 2007, 66(8): 1494-1501. doi: 10.1016/j.chemosphere.2006.08.028 [39] KANG J, LIU H J, ZHENG Y M, et al. Systematic study of synergistic and antagonistic effects on adsorption of tetracycline and copper onto a chitosan [J]. Journal of Colloid and Interface Science, 2010, 344(1): 117-125. doi: 10.1016/j.jcis.2009.11.049 [40] GAO W, ALEMANY L B, CI L J, et al. New insights into the structure and reduction of graphite oxide [J]. Nature Chemistry, 2009, 1(5): 403-408. doi: 10.1038/nchem.281 [41] TAN P, SUN J, HU Y Y, et al. Adsorption of Cu2+, Cd2+ and Ni2+ from aqueous single metal solutions on graphene oxide membranes [J]. Journal of Hazardous Materials, 2015, 297: 251-260. doi: 10.1016/j.jhazmat.2015.04.068 [42] BARKAUSKAS J, STANKEVIČIENĖ I, DAKŠEVIČ J, et al. Interaction between graphite oxide and Congo red in aqueous media [J]. Carbon, 2011, 49(15): 5373-5381. doi: 10.1016/j.carbon.2011.08.004 [43] YANG S T, CHANG Y L, WANG H F, et al. Folding/aggregation of graphene oxide and its application in Cu2+ removal [J]. Journal of Colloid and Interface Science, 2010, 351(1): 122-127. doi: 10.1016/j.jcis.2010.07.042 [44] CHEN J Y, ZHU D Q, SUN C. Effect of heavy metals on the sorption of hydrophobic organic compounds to wood charcoal [J]. Environmental Science & Technology, 2007, 41(7): 2536-2541. [45] WANG J, CHEN B L. Adsorption and coadsorption of organic pollutants and a heavy metal by graphene oxide and reduced graphene materials [J]. Chemical Engineering Journal, 2015, 281: 379-388. doi: 10.1016/j.cej.2015.06.102