Efficient Adsorptive Removal of Humic Acid from Water Using Zeolitic Imidazole Framework-8 (ZIF-8)
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To develop an efficient adsorbent for humic acid, the present study represents the first attempt to investigate the capability of zeolitic imidazole frameworks to remove humic acid from water. Zeolitic imidazole framework-8 (ZIF-8) is particularly selected as a prototype ZIF to adsorb humic acid owing to its high stability in aqueous solutions. ZIF-8 was synthesized and characterized using scanning electronic microscopy (SEM), powder X-ray diffraction pattern (PXRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analyzer (TGA) and then used to adsorb humic acid under various conditions. The structure of ZIF-8 was found to remain intact after the exposure to humic acid in water. Factors affecting the adsorption were examined, including solid-to-liquid ratio, mixing time, temperature, pH, presence of salt, and surfactants. The adsorption capacity of ZIF-8 was found to be much higher than that of activated carbon, fly ash, zeolites, graphite, etc., showing its promising potential for removal of humic acid. The adsorption mechanism could be attributed to the electrostatic interaction between the positive surface of ZIF-8 and the acidic sites of humic acid, as well as the π–π stacking interaction between imidazole of ZIF-8 and benzene rings of humic acid. The humic acid adsorption to ZIF-8 could be enhanced in the acidic conditions, and the adsorption process remained highly stable in the solutions of a wide range of NaCl concentrations. ZIF-8 can be also regenerated by simple ethanol-washing process and reused for humic acid adsorption. These features enable ZIF-8 to be an efficient and stable adsorbent to remove humic acid from water.
KeywordsMetal organic frameworks Zeolitic imidazole framework ZIF-8 Humic acid Adsorption
The authors thank Ms. Resta Saphore for her assistance on the manuscript proofreading and editing.
- Adak, A., Pal, A., & Bandyopadhyay, M. (2005). Spectrophotometric determination of anionic surfactants in wastewater using acridine orange. Indian Journal of Chemical Technology, 12, 145–148.Google Scholar
- Arrhenius, S. A. (1889). Über die dissociationswärme und den einflusß der temperatur auf den dissociationsgrad der elektrolyte. Zeitschrift für Physikalische Chemie, 4, 96–116.Google Scholar
- Cravillon, J., Schroder, C. A., Bux, H., Rothkirch, A., Caro, J., & Wiebcke, M. (2012). Formate modulated solvothermal synthesis of ZIF-8 investigated using time-resolved in situ X-ray diffraction and scanning electron microscopy. CrystEngComm, 14(2), 492–498. doi: 10.1039/C1CE06002C.CrossRefGoogle Scholar
- Daifullah, A. A. M., Girgis, B. S., & Gad, H. M. H. (2004). A study of the factors affecting the removal of humic acid by activated carbon prepared from biomass material. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 235(1–3), 1–10. doi: 10.1016/j.colsurfa.2003.12.020.CrossRefGoogle Scholar
- Freundlich, H. M. F. (1906). Über die Adsorption in Lösungen. Zeitschrift für Physikalische Chemie, 57, 385–470.Google Scholar
- Gascon, J., Corma, A., Kapteijn, F., & Llabrés i Xamena, F. X. (2013). Metal organic framework catalysis: Quo vadis? ACS Catalysis, 361–378, doi: 10.1021/cs400959k.
- Horcajada, P., Chalati, T., Serre, C., Gillet, B., Sebrie, C., Baati, T., et al. (2010). Porous metal-organic-framework nanoscale carriers as a potential platform for drug delivery and imaging. Nat Mater, 9(2), 172–178, doi: 10.1038/nmat2608, http://www.nature.com/nmat/journal/v9/n2/abs/nmat2608.html#supplementary-information.
- Huat, B. B. K., Gue, S. S., & Ali, F. H. (2004). Tropical residual soils engineering. CRC Press, 377-403Google Scholar
- Lagergren, S. (1898). About the theory of so-called adsorption of soluble substances. Kungliga Svenska Vetenskapsakademiens. Handlingar, 24(4), 1–39.Google Scholar
- Lin, J., Zhan, Y., & Zhu, Z. (2011). Adsorption characteristics of copper (II) ions from aqueous solution onto humic acid-immobilized surfactant-modified zeolite. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 384(1–3), 9–16. doi: 10.1016/j.colsurfa.2011.02.044.CrossRefGoogle Scholar
- Ngah, W. S. W., & Musa, A. (1998). Adsorption of humic acid onto chitin and chitosan. Journal of Applied Polymer Science, 69(12), 2305–2310. doi: 10.1002/(SICI)1097-4628(19980919)69:12<2305::AID-APP1>3.0.CO;2-C.CrossRefGoogle Scholar
- Qiu, L.-G., Li, Z.-Q., Wu, Y., Wang, W., Xu, T., & Jiang, X. (2008). Facile synthesis of nanocrystals of a microporous metal-organic framework by an ultrasonic method and selective sensing of organoamines. Chemical Communications (31), 3642–3644, doi: 10.1039/B804126A.
- Rashed, M. N. (2013). Adsorption technique for the removal of organic pollutants from water and wastewater (organic pollutants—monitoring, risk and treatment).Google Scholar
- Temkin, M. I., & Pyzhev, V. (1940). Kinetics of ammonia synthesis on promoted iron catalyst. Acta Physicochimica U.R.S.S., 12, 327–356.Google Scholar
- Weber, W. J., & Morris, J. C. (1963). Kinetics of adsorption on carbon from solution. Journal of the Sanitary Engineering Division, 89(2), 31–60.Google Scholar
- Yoon, J. W., Jhung, S. H., Hwang, Y. K., Humphrey, S. M., Wood, P. T., & Chang, J. S. (2007). Gas-sorption selectivity of CUK-1: a porous coordination solid made of cobalt(II) and pyridine-2,4- dicarboxylic acid. Advanced Materials, 19(14), 1830–1834. doi: 10.1002/adma.200601983.CrossRefGoogle Scholar
- Yu, X., Zhang, G., Xie, C., Yu, Y., Cheng, T., & Zhou, Q. (2011). Equilibrium, kinetic, and thermodynamic studies of hazardous dye neutral red biosorption by spent corncob substrate. BioResources, 6(2), 936–949.Google Scholar