Article Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
pubs.acs.org/jced
Adsorptive Removal of Tetracycline on Graphene Oxide Loaded with Titanium Dioxide Composites and Photocatalytic Regeneration of the Adsorbents Jiahong Wang,* Ruihua Liu, and Xiaolong Yin School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China ABSTRACT: Graphene oxide loaded with titanium dioxide composites (GO-TiO2) was successfully prepared by hydrolysis of titanium tetrachloride in the presence of an aqueous dispersion of graphene oxide, and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and X-ray diffraction (XRD). Characterized results exhibited that TiO2 was successfully loaded on the surface of GO. Adsorptive removal of tetracycline (TC) by GO-TiO2 and photocatalytic regeneration of adsorbent was investigated. Adsorption isotherms of TC onto GO-TiO2 proved that the adsorption process was multilayered, and the adsorption capacity of GO-TiO2 for aqueous TC in the tested range was 99.46, 117.98, and 133.05 mg/g at 15, 25, and 35 °C, respectively. TC adsorption by GO-TiO2 followed the pseudo-second-order kinetic model. TC adsorption by GO-TiO2 was favored at lower pH and decreased with an increase of solution pH. Additionally, Ca2+ had a more powerful inhibiting effect on TC adsorption by GO-TiO2 than K+ and Na+. The regeneration experiment demonstrated that the TC saturated GO-TiO2 could be easily recovered and regenerated by the photolysis under UV irradiation and the regenerated GO-TiO2 still showed high adsorption affinity for TC in solution. interactions between the GO and contaminant molecules.11−13 Due to its outstanding properties, GO has already been investigated as an efficient adsorbent for organic pollutants in aqueous solution such as antibiotics,14 naphthol,15 phenol,16 and dye.17,18 However, the weakness of the adsorbents is the disposal and regeneration of the used adsorbents. At present, the main methods for regeneration of adsorbent are thermal treatment, wet oxidation,19 water washing by changing the pH, oxidative or reductive regeneration, solvent washing,20 ultrasonication,21 steam regeneration,22 microwave assisted regeneration,23−25 and so on. These processes had several drawbacks including complicated operation and low efficiency of the regenerated adsorbent. The photocatalytic regeneration of the adsorbent is an efficient and clean method for regeneration of adsorbent. Titanium dioxide has been proved as an efficient photocatalyst for degradation of organic pollutants.26 Under UV irradiation, the electrons are excited from the valence band to the conduction band, generating the electron/hole pairs, which are powerful for oxidation of organic compounds adsorbed on the surface. Photocatalytic degradation of TC by TiO2 has been found to be a promising way to deal with TC wastewater.27,28 Therefore, titanium dioxide coated graphene oxide composite
1. INTRODUCTION Tetracycline (TC), one of the most common antibiotics in practical application, is a kind of polycyclic and tetrastyroxylamide compound with antimicrobial properties. TC has a wide utilization in animal husbandry, in agriculture, and as fungistat in medical treatment. Superfluous tetracycline largely presents in aquatic and soil environments, which has caused extensive concern including dissemination of antibioticresistant genes among microorganisms and harm to the human body.1−4 Removal of tetracycline in aquatic and soil environments is necessary for human health. Various methods including chemical coagulation, advanced oxidation, adsorption, membrane separation, biodegradation, and so on5,6 were developed for the removal of aqueous TC. Among these, the adsorption technique has been widely applied to remove TC from aqueous solution because of its high efficiency, easy operation, and availability. Graphene, a honeycomb and one-atom-thick structured carbon material which is also a fundamental building block for buckyballs, carbon nanotubes, and graphite, has attracted a great deal of scientific interest in recent years.7−10 Graphene oxide (GO), a two-dimensional carbon nanomaterial, possesses an ultralarge specific surface area, abundant oxygen-containing groups (e.g., OH, COOH, CO, CH(O)CH), and excellent water dispersibility, which made it a good adsorbent for contaminant removal through the combination of electrostatic attraction, π−π stacking, and hydrogen bonding © XXXX American Chemical Society
Received: September 12, 2017 Accepted: December 27, 2017
A
DOI: 10.1021/acs.jced.7b00816 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
the adsorbents were collected on a JEM-2100F transmission electron microscope (Jeol, Japan). 2.4. Adsorption Studies. On the basis of the preliminary experiments, adsorption equilibrium was achieved within 180 min. For an adsorption isotherm, 20 mg of GO-TiO2 was placed in a reagent bottle, and then 40 mL of TC with a designed initial concentration of 5, 10, 20, 40, 60, 80, 100, and 120 mg/L was added, respectively. The initial pH was adjusted to 6 using HCl (0.1 mol/L) or NaOH (0.1 mol/L). The solution was placed in a concussion incubator and shaken for 180 min at 150 rpm under 15, 25, and 35 °C, after which the mixtures were filtered using a 0.45 μm acetate fiber filter, and the equilibrium concentrations of TC in the filtrates were determined by a UV−vis spectrometer with detecting wavelength at 360 nm. The equilibrium adsorption amount of TC was calculated according to eq 1
(GO-TiO2) would be an efficient adsorbent for the removal of aqueous TC and TC saturated adsorbent could be readily regenerated by photocatalytic degradation of TC. In this study, GO-TiO2 was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscope (TEM). The batch adsorption process was used to evaluate the maximum adsorption capacity of TC on GO-TiO2. The effect of solution chemistry conditions including solution pH and ionic strength on TC adsorption by GO-TiO2 was explored. Photocatalytic regeneration of TC on GO-TiO2 under UV irradiation and the reusing of regenerated GO-TiO2 were also discussed.
2. EXPERIMENTAL SECTION 2.1. Materials. Tetracycline hydrochloride was purchased from Sigma Corp. Graphite powder and other chemical agents of AR grade were obtained from Xi’an LaKa Chemical Reagent Company. Deionized water was used for the experimental work. 2.2. Preparation of GO-TiO2. GO-TiO2 was prepared by two steps. First, graphene oxide was synthesized with the modified Hummers method by oxidation of graphite powder. Five grams of graphite and 120 mL of concentrated sulfuric acid were added in a flask of 500 mL, and stirred at 160 rpm in an ice bath ( 7.6, the electrostatic repulsion between anionic TC and negatively charged GO decreased TC adsorption on GO-TiO2. In addition, the electrostatic repulsive force also suppressed π−π attraction interaction between GO and TC, which also resulted in the decreased TC adsorption.42 The effect of coexisting cations on adsorption was presented in Figure 8. Cations including Na+, K+, and Ca2+ were
Figure 6. Adsorption kinetics of TC on graphene oxide at initial concentrations of 40, 60, and 80 mg/L.
t 1 1 = + t 2 qt qe k 2qe
(9)
where qe and qt (mg/g) are the adsorption capacity at equilibrium and time t and k1 (1/min) and k2 (g/mg·min) are the pseudo-first-order rate constant and the pseudo-secondorder rate constant, respectively. Fitting parameters of pseudo-second-order kinetics and pseudo-first-order kinetics were shown in Table 3. According to Table 3, the correlation coefficients (R2) of pseudo-secondorder kinetics were higher than those of pseudo-first-order kinetics, and TC adsorption capacities calculated from fitting results were approximately identical to those obtained from experimental data, indicating that TC adsorption on GO-TiO2 followed pseudo-second-order kinetics. The pseudo-secondorder rate constants were 3.29 × 10−3, 3.09 × 10−3, and 2.82 × 10−3 at initial concentrations of 40, 60, and 80 mg/g, respectively, reflecting that the adsorption rate was reduced with increasing initial concentration. This was probably because GO-TiO2 provided sufficient functional sites at low concentration and facilitated TC adsorption, while functional sites on the surface of the adsorbent were scarce in relatively high concentration, leading to suppressed TC adsorption on the adsorbent. 3.4. Effect of Solution pH and Ionic Strength. The effect of pH on TC adsorption by GO-TiO2 was illustrated in Figure 7. The molecular structure of TC and functional groups on the surface of GO played important roles in adsorption of TC by GO-TiO2. GO is negatively charged in tested pH (at pH 2−10) due to the oxygen-containing functional groups on its surface.40,41 When pH is less than 3, TC exists in cationic form, and the electrostatic attraction between positively charged TC cations and negatively charged GO of the adsorbent would be
Figure 8. Effect of ionic strength on TC adsorption by GO-TiO2.
discussed, and adsorption capacity exhibited a decreasing tendency as the concentration of cations increased. According
Table 3. Simulated Parameters of TC Adsorption on GO-TiO2 Using Pseudo-First-Order and Pseudo-Second-Order Kinetics at Initial Concentrations of 40, 60, and 80 mg/L pseudo-first-order kinetics
pseudo-second-order kinetics
C0 (mg/L)
qexp (mg/g)
k1 (1/min)
qe (mg/g)
R2
k2 [g/(mg·min)]
qe (mg/g)
R2
40 60 80
72.75 94.07 107.07
3.36 × 10−2 3.85 × 10−2 3.16 × 10−2
37.83 43.46 43.73
0.947 0.945 0.959
3.29 × 10−3 3.09 × 10−3 2.82 × 10−3
74.63 96.15 108.7
0.999 0.999 0.999
E
DOI: 10.1021/acs.jced.7b00816 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
to Figure 8, Ca2+ had a more powerful inhibiting effect than Na+ and K+ on TC adsorption, which was probably because Ca2+ caused a higher ionic strength and competed adsorption sites of GO-TiO2 with TC molecules. Moreover, increased ionic strength reduced the π−π attraction interaction between TC and GO-TiO2, which also resulted in the suppressed TC adsorption on GO-TiO2. The results revealed that the electrostatic interaction and π−π attraction interaction had made a major contribution to TC adsorption on GO-TiO2. 3.5. Photolytic Regeneration of Adsorbent. UV irradiation was used for photocatalytic desorption of GOTiO2. The adsorption behavior of TC on GO-TiO2 and photolytic regeneration of used adsorbent was analyzed by XPS technology. High resolution XPS spectra for C 1s spectra of GO-TiO 2 before and after TC adsorption and after regeneration were illustrated in Figure 9, and the relative
Figure 10. Adsorption amount of TC on regenerated GO-TiO2.
4. CONCLUSIONS In this study, GO-TiO2 composite was prepared and used as an adsorbent to eliminate TC from aqueous solution. The adsorption capacity for TC was because of π−π attraction interaction, hydrogen bond, and electrostatic interaction between TC molecules and GO-TiO2. The TC adsorption by GO-TiO2 was highly dependent on solution pH, and the optimum condition was found to be at pH 3. The presence of Ca2+ has more inhibiting effect than Na+ and K+. Adsorption isotherms of TC on the adsorbent can be fitted by the Sips model, and the adsorption process was proved spontaneous, endothermic, and entropy-driven. Adsorption kinetics was well fitted by the pseudo-second-order kinetics model. Tetracycline saturated adsorbent was regenerated by photocatalysis, and the regenerated adsorbent still possessed high adsorption capacity for TC.
Figure 9. C 1s of GO-TiO2 before, after TC adsorption and after regeneration.
■
AUTHOR INFORMATION
Corresponding Author
content of functional groups was tabulated in Table 4. According to Figure 9, the binding energies at 284.58, 286.06, and 288.56 eV were attributed to the CC, CO, and CO groups of GO-TiO2.43 The reduced content of the CC bond and increased content of CO and CO groups of GO-TiO2 after TC adsorption reflected that TC had been adsorbed on the surface of GO-TiO2.44 The content of CC, CO, and CO bonds recovered after photolytic degradation of TC under UV irradiation, which confirmed that TC saturated adsorbents can be efficiently degraded by photocatalytic regeneration. The adsorption capacity of regenerated GO-TiO2 was illustrated in Figure 10. From the results, the adsorption capacity of TC reduced from 108.32 to 101.20 mg/g after the first adsorption−regeneration cycle. After the fourth cycle, the adsorption capacity became 87.96 mg/g, 81.20% of the adsorption capacity of the initial virgin adsorbent, which demonstrated that TC saturated adsorbents could be efficiently regenerated by UV photolysis and the reused adsorbent still exhibited high adsorption affinity for TC in aqueous solution.
*E-mail:
[email protected]. Phone: 86-29-86168291. Fax: 86-29-86168291. ORCID
Jiahong Wang: 0000-0003-1786-879X Funding
This work was supported by National Science Foundation of China (21677092), Innovation Program of Scientific Research Group of Shaanxi Province (2014KCT-15), and the Scientific Research Program Funded by Shaanxi Provincial Education Department (15JK1095), Xi’an, China. Notes
The authors declare no competing financial interest.
■
REFERENCES
(1) Huang, X.; Liu, C.; Li, K.; Liu, F.; Liao, D.; Liu, L.; Zhu, G.; Liao, J. Occurrence and Distribution of Veterinary Antibiotics and Tetracycline Resistance Genes in Farmland Soils around Swine Feedlots in Fujian Province, China. Environ. Sci. Pollut. Res. 2013, 20, 9066−9074.
Table 4. Simulation Results of XPS C 1s Spectra of GO-TiO2 before and after TC Adsorption and after Regeneration before adsorption peaks C 1s
CC CO CO
after adsorption
after regeneration
BE (eV)
content (%)
BE (eV)
content (%)
BE (eV)
content (%)
284.61 286.14 288.57
78.92 12.54 8.54
284.57 286.08 288.57
76.63 14.42 8.95
284.74 286.29 288.71
78.66 12.76 8.58
F
DOI: 10.1021/acs.jced.7b00816 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
(2) Leavey-Roback, S. L.; Krasnerb, S. W.; Suffet, I. H. Veterinary Antibiotics Used in Animal Agriculture as NDMA Precursors. Chemosphere 2016, 164, 330−338. (3) Hao, R.; Xiao, X.; Zuo, X.; Nan, J.; Zhang, W. Efficient Adsorption and Visible-light Photocatalytic Degradation of Tetracycline Hydrochloride Using Mesoporous BiOI Microspheres. J. Hazard. Mater. 2012, 209-210, 137−145. (4) Yue, L.; Wang, S.; Shan, G.; Wu, W.; Qiang, L.; Zhu, L. Novel MWNTs−Bi2WO6 Composites with Enhanced Simulated Solar Photoactivity toward Adsorbed and Free Tetracycline in Water. Appl. Catal., B 2015, 176-177, 11−19. (5) Homem, V.; Santos, L. Degradation and Removal Methods of Antibiotics from Aqueous Matrices-A Review. J. Environ. Manage. 2011, 92, 2304−2347. (6) Ahmed, M. B.; Zhou, J. L.; Ngo, H. H.; Guo, W. Adsorptive Removal of Antibiotics from Water and Wastewater: Progress and Challenges. Sci. Total Environ. 2015, 532, 112−126. (7) Fowler, J. D.; Allen, M. J.; Tung, V. C.; Yang, Y.; Kaner, R. B.; Weiller, B. H. Practical Chemical Sensors from Chemically Derived Graphene. ACS Nano 2009, 3, 301−306. (8) Fan, Z.; Wang, K.; Jun, Y.; Tong, W.; Zhi, L.; Feng, J.; Ren, Y.; Song, L. Facile Synthesis of Graphene Nanosheets via Fe Reduction of Exfoliated Graphite Oxide. ACS Nano 2011, 5, 191−198. (9) Wang, Y.; Guan, C.; Wang, K.; Guo, C.; Li, C. Nitrogen, Hydrogen, Carbon Dioxide, and Water Vapor Sorption Properties of Three-Dimensional Graphene. J. Chem. Eng. Data 2011, 56, 642−645. (10) Li, X.; Wang, S.; Liu, Y.; Jiang, L.; Song, B.; Li, M.; Zeng, G.; Tan, X.; Cai, X.; Ding, Y. Adsorption of Cu(II), Pb(II), and Cd(II) Ions from Acidic Aqueous Solutions by Diethylenetriaminepentaacetic Acid-modified Magnetic Graphene Oxide. J. Chem. Eng. Data 2017, 62, 407−416. (11) Dreyer, D. R.; Park, S. J.; Bielawski, C. W.; Ruoff, R. S. The Chemistry of Graphene Oxide. Chem. Soc. Rev. 2010, 39, 228−240. (12) Dikin, D. A.; Stankovich, S.; Zimney, E. J.; Piner, R. D.; Dommett, G. H. B.; Evmenenko, G.; Nguyen, S. T.; Ruoff, R. S. Preparation and Characterization of Graphene Oxide Paper. Nature 2007, 448, 457−460. (13) Dong, Z.; Wang, D.; Liu, X.; Pei, X.; Chen, L.; Jin, J. BioInspired Uurface-Functionalization of Graphene Oxide for The Adsorption of Organic Dyes and Heavy Metal Ions with A Superhigh Capacity. J. Mater. Chem. A 2014, 2, 5034−5040. (14) Kyzas, G. Z.; Deliyanni, E. A.; Matis, K. A. Graphene Oxide and Its Application as an Adsorbent for Wastewater Treatment. J. Chem. Technol. Biotechnol. 2014, 89, 196−205. (15) Wang, J.; Chen, B. Adsorption and Coadsorption of Organic Pollutants and A Heavy Metal by Graphene Oxide and Reduced Graphene Materials. Chem. Eng. J. 2015, 281, 379−388. (16) Fu, C.; Juang, R.; Huq, M. M.; Hsieh, C. Enhanced Adsorption and Photodegradation of Phenol in Aqueous Suspensions of Titania/ Graphene Oxide Composite Catalysts. J. Taiwan Inst. Chem. Eng. 2016, 67, 338−345. (17) Cheng, Z.; Liao, J.; He, B.; Zhang, F.; Zhang, F.; Huang, X.; Zhou, L. One-Step Fabrication of Graphene Oxide Enhanced Magnetic Composite Gel for Highly Efficient Dye Adsorption and Catalysis. ACS Sustainable Chem. Eng. 2015, 3, 1677−1685. (18) Fan, L.; Luo, C.; Sun, M.; Li, a.; Lu, G.; Qiu, M. Preparation of Novel Magnetic Chitosan/Graphene Oxide Composite as Effective Adsorbents toward Methylene Blue. Bioresour. Technol. 2012, 114, 703−706. (19) Shende, R. V.; Mahajani, V. V. Wet Oxidative Regeneration of Activated Carbon Loaded with Reactive Dye. Waste Manage. 2002, 22, 73−83. (20) Velu, S.; Watanabe, S.; Ma, X.; Song, C. Regenerable Adsorbents for the Adsorptive Desulfurization of Transportation Fuels for Fuel Cell Applications. Abstr Pap Am. Chem. Soc. 2003, 48, 526−528. (21) Rege, S. U.; Yang, R. T.; Cain, C. A. Desorption by Ultrasound: Phenol on Activated Carbon and Polymeric Resin. AIChE J. 1998, 44, 1519−1528.
(22) Shah, I. K.; Pre, P.; Alappat, B. J. Steam Regeneration of Adsorbents: An Experimental and Technical Review. Chem. Sci. Trans. 2013, 2, 1078−1088. (23) Ge, X.; Tian, F.; Wu, Z.; Yan, Y.; Giancarlo, C.; Wu, Z. Adsorption of Naphthalene from Aqueous Solution on Coal-based Activated Carbon Modified by Microwave Induction: Microwave Power Effects. Chem. Eng. Process. 2015, 91, 67−77. (24) Xiao, X.; Liu, D.; Yan, Y.; Wu, Z.; Wu, Z.; Giancarlo, C. Preparation of Activated Carbon from Xinjiang Region Coal by Microwave Activation and Its Application in Naphthalene, Phenanthrene, and Pyrene Adsorption. J. Taiwan Inst. Chem. Eng. 2015, 53, 160−167. (25) Wei, X.; Wu, Z.; Du, C.; Wu, Z.; Ye, B.; Giancarlo, C. Enhanced Adsorption of Atrazine on a Coal-based Activated Carbon Modified with Sodium Dodecyl Benzene Sulfonate under Microwave Heating. J. Taiwan Inst. Chem. Eng. 2017, 77, 257−262. (26) Tian, F.; Wu, Z.; Chen, Q.; Yan, Y.; Cravotto, G.; Wu, Z. Microwave-Induced Crystallization of AC/TiO2 for Improving the Performance of Rhodamine B Dye Degradation. Appl. Surf. Sci. 2015, 351, 104−112. (27) Wang, W.; Fang, J.; Shao, S.; Lai, M.; Lu, C. Compact and Uniform TiO2 @g-C3N4 Core-shell Quantum Heterojunction for Photocatalytic Degradation of Tetracycline Antibiotics. Appl. Catal., B 2017, 217, 57−64. (28) Martins, A. C.; Cazetta, A. L.; Pezoti, O.; Souza, J. R. B.; Zhang, T.; Pilau, E. J.; Asefa, T.; Almeida, V. C. Sol-gel Synthesis of new TiO2/activated Carbon Photocatalyst and Its Application for Degradation of Tetracycline. Ceram. Int. 2017, 43, 4411−4418. (29) Szabo, T.; Berkesi, O.; Dekany, I. Drift Study of DeuteriumExchanged Graphite Oxide. Carbon 2005, 43, 3186−3189. (30) Bissessur, R.; Scully, S. F. Intercalation of Solid Polymer Electrolytes into Graphite Oxide. Solid State Ionics 2007, 178, 877− 882. (31) Perera, S. D.; Mariano, R. G.; Vu, K.; Nour, N.; Seitz, O.; Chabal, Y.; Balkus, K. J. Hydrothermal Synthesis of Graphene-TiO2 Nanotube Composites with Enhanced Photocatalytic Activity. ACS Catal. 2012, 2, 949−956. (32) Rong, X. S.; Qiu, F. X.; Zhang, C.; Fu, L.; Wang, Y. Y.; Yang, D. Y. Preparation, Characterization and Photocatalytic Application of TiO2−graphene Photocatalyst under Visible Light Irradiation. Ceram. Int. 2015, 41, 2502−2511. (33) Zhang, L. L.; Liu, J. Q.; Tang, C.; Lv, J. S.; Zhong, H.; Zhao, Y. J.; Wang, X. Palygorskite and SnO2−TiO2 for The Photodegradation of Phenol. Appl. Clay Sci. 2011, 51, 68−73. (34) Zhang, X.; Li, H.; Cui, X.; Lin, Y. Graphene/TiO2 Nanocomposites: Synthesis, Characterization and Application in Hydrogen Evolution from Water Photocatalytic Splitting. J. Mater. Chem. 2010, 20, 2801−2806. (35) Chandra, V.; Kim, K. S. Highly Selective Adsorption of Hg2+ by A Polypyrrole-Reduced Graphene Oxide Composite. Chem. Commun. 2011, 47, 3942−3944. (36) Tanzifi, M.; Mohammad Tavakkoli, Y.; Asieh Dehghani, K.; Seyyed Hossein, H.; Martin, O.; A.K, B.; Shilpi, A.; Vinod Kumar, G.; Atefeh, K. Adsorption of Amido Black 10B from Aqueous Solution Using Polyaniline/SiO2 Nanocomposite: Experimental Investigation and Artificial Neural Network Modeling. J. Colloid Interface Sci. 2018, 510, 246−261. (37) Yan, B.; Catherine Hui, N.; Jian, W. Kinetics, Electron-DonorAcceptor Interactions, and Site Energy Distribution Analyses of Norfloxacin Adsorption on Pretreated Barley Straw. Chem. Eng. J. 2017, 330, 1211−1221. (38) Liu, Y. Is The Free Energy Change of Adsorption Correctly Calculated? J. Chem. Eng. Data 2009, 54, 1981−1985. (39) Reina, A.; Jia, X.; Ho, J.; Nezich, D.; Son, H. B.; Bulovic, V.; Dresselhaus, M. S.; Kong, J. Large Area, Few-Layer Graphene Films on Arbitrary Substrates by Chemical Vapor Deposition. Nano Lett. 2009, 9, 30−35. (40) González, J. A.; Villanueva, M. E.; Piehl, L. L.; Copello, G. J. Development of a Chitin/Graphene Oxide Hybrid Composite for The G
DOI: 10.1021/acs.jced.7b00816 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
Removal of Pollutant Dyes: Adsorption and Desorption Study. Chem. Eng. J. 2015, 280, 41−48. (41) He, Y.; Wu, F.; Sun, X.; Li, R.; Guo, Y.; Li, C.; Zhang, L.; Xing, F.; Wang, W.; Gao, J. Factors That Affect Pickering Emulsions Stabilized by Graphene Oxide. ACS Appl. Mater. Interfaces 2013, 5, 4843−4855. (42) Gao, Y.; Li, Y.; Zhang, L.; Huang, H.; Hu, J.; Shah, S. M.; Su, X. Adsorption and Removal of Tetracycline Antibiotics from Aqueous Solution by Graphene Oxide. J. Colloid Interface Sci. 2012, 368, 540− 546. (43) Li, X.; Cao, W.; Liu, Y.; Zeng, G.; Zeng, W.; Qin, L.; Li, T. Property Variation of Magnetic Mesoporous Carbon Modified by Aminated Hollow Magnetic Nanospheres: Synthesis, Characterization, and Sorption. ACS Sustainable Chem. Eng. 2017, 5, 179−188. (44) Song, W.; Yang, T.; Wang, X.; Sun, Y.; Ai, Y.; Sheng, G.; Hayat, T. Experimental and Theoretical Evidence for Competitive Interactions of Tetracycline and Sulfamethazine with Reduced Graphene Oxides. Environ. Sci.: Nano 2016, 3, 1318−1326.
H
DOI: 10.1021/acs.jced.7b00816 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
