Preparation of Modified Attapulgite Adsorbent and Its Adsorption Mechanism for Aqueous Cr(Ⅵ)
WANG Jiahong1,2, CHEN Yao1,2, SUN Tongtong1,2
1 College of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an 710021,China 2 Shaanxi Key Laboratory of Green Preparation and Functionalization of Inorganic Materials, Xi'an 710021,China
Abstract: Tetraethylenepentamine modified attapulgite (TEPA-ATP) was prepared by grafting tetraethylenepentamine (TEPA) on the surface of attapulgite (ATP) by γ-(2,3-epoxypropylene oxide) propyltrimethoxysilane. The structure and surface properties of synthesized composites were characterized by Fourier-transformed infrared spectroscopy (FRIR), X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), Zeta potential (Zeta), X-ray photoelectron spectroscopy (XPS) and elemental analysis, and their adsorption capability for aqueous Cr(Ⅵ) was also conducted. Characterized results indicate that tetraethylenepentamine has been successfully loaded on the surface of attapulgite, and TEPA-ATP exhibits high adsorption capacity for aqueous Cr(Ⅵ). The adsorption isotherm can be fitted by Langmuir model, and the maximum adsorption capacity in tested range for TEPA-ATP was 270.8 mg/g. The adsorption kinetics can be well described by the pseudo-second-order kinetic model. Adsorption amount of Cr(Ⅵ) onto TEPA-ATP decreased with increasing pH. Cl- has little effect on the adsorption of Cr(Ⅵ) by TEPA-ATP, and PO43- can greatly reduce the Cr(Ⅵ) adsorption on TEPA-ATP. From the adsorption tests and XPS analysis, the adsorption coupled chemical reduction mechanism contributes to the enhanced Cr(Ⅵ) adsorption on TEPA-ATP.
1 Thevenon F, Graham N D, Chiaradia M, et al. Science of the Total Environment, 2011, 412(61), 239. 2 Pen-Mouratov S, Shukurov N, Steinberger Y. Environmental Pollution, 2008, 152(1), 172. 3 Shams K M, Tichy G, Sager M, et al. Water Air & Soil Pollution, 2009, 199(1-4), 123. 4 Zhang J D, Li S. Journal of Occupational & Environmental Medicine, 1997, 39(4), 315. 5 Pugh C T, Palmer T T, Carr P A. Journal of Chemical Health & Safety, 2008, 15(3), 25. 6 Almaguer-Busso G, Velasco-Martínez G, Carreño-Aguilera G, et al. Electrochemistry Communications, 2009, 11(6), 1097. 7 Xu G R, Wang J N, Li C J. Chemical Engineering Journal, 2012, 198-199(2), 310. 8 Pradhan D, Sukla L B, Sawyer M, et al. Journal of Industrial & Engineering Chemistry, 2017, 55, 1. 9 Yanan C, Dong A, Sainan S, et al. Materials, 2018, 11(2), 269. 10 Liu W, Yang L, Xu S, et al. RSC Advances, 2018, 8(27), 15087. 11 Yi Y, Lv J, Liu Y, et al. Journal of Molecular Liquids, 2017, 225, 28. 12 Wu X, Xiong X, Brunetti G, et al. RSC Advances, 2017, 7(85), 53932. 13 Tarasevich Y I, Trifonov M Y, Ostapenko V T, et al. Journal of Water Chemistry & Technology, 2016, 38(6), 327. 14 Franguelli F P, Tannous K, Coppi C C. Chemical Engineering Communications, DOI:10.1080/00986445.2018.1557154. 15 Liu Y, Chen H, Zhang J, et al. Journal of Composite Materials, 2013, 47(8), 969. 16 Xu W B, He P S. Polymer Engineering & Science, 2010, 41(11), 1903. 17 Kaygun A K, Eral M, Erenturk S A. Journal of Radioanalytical & Nuc-lear Chemistry, 2017, 311(2), 1459. 18 Liu W, Yang T, Xu J, et al. Environmental Progress & Sustainable Energy, 2015, 34(2), 437. 19 Xie H L, Huang X X. Journal of Chongqing University of Technology (Natural Science), 2019, 33(4), 88 (in Chinese). 谢焕玲,黄小雪.重庆理工大学学报(自然科学),2019,33(4),88. 20 Mu B, Wang A Q. Journal of Materials Chemistry A, 2015, 3(1), 281. 21 Shi Y, Zhang Q, Feng L, et al. Korean Journal of Chemical Engineering, 2014, 31(5), 821. 22 Peng G W, Ding D X, Xiao F Z, et al. Journal of Radioanalytical & Nuclear Chemistry, 2014, 301(3), 781. 23 Xu Z, Wei L, Xiong Z, et al. Desalination & Water Treatment, 2016, 57(15), 7054. 24 Pan Y, Cai P, Farmahini-Farahani M, et al. Applied Surface Science, 2016, 385, 333. 25 Mansri A, Benabadji K I, Desbrières J, et al. Desalination, 2009, 245(1), 95. 26 Peng W, Xie Z, Cheng G, et al. Journal of Hazardous Materials, 2015, 294, 9. 27 Gupta A, Jain R, Gupta D C. Reactive & Functional Polymers, 2015, 93, 22. 28 Liu Y, Jin X, Chen Z. Science of the Total Environment, 2018, 627, 470. 29 Chen Y, Xu H, Wang S, et al. RSC Advances, 2014, 4(34), 17805. 30 Ghosh A, Basu T, Manna B, et al. Journal of Environmental Chemical Engineering, 2015, 3(1), 565. 31 Wang D, Zhang G, Zhou L, et al. Langmuir, 2017, 33(28), 7007. 32 Xing Y Q, Chen X M, Wang D H. Environmental Science & Technology, 2007, 41(4), 1439.