Study on the Adsorption and Regeneration of Chloroacetic Acid on Polyacrylamide Bentonite Composite

Abstract:

Aiming at the removal of chlorinated disinfection by-products in water and the difficulty of separation of powder bentonite from water, the polyacrylamide bentonite composite was prepared and used as absorbent. The mechanism of adsorption and regeneration was discussed. The adsorption of chloroacetic acid on polyacrylamide bentonite composite followed Langmuir isothermal and Pseudo second order kinetic equation, and the adsorption capacity was 63.01mg/g at optimal temperature 30°C. The sorption heat were at the range of 9~16kJ/mol and decreased with the increase of temperature. It was indicated the adsorption mainly belonged to chemical adsorption, and the proportion of physical adsorption increased with the temperature increase. The thermodynamic parameters were ΔH0=-5.226kJ/mol, ΔG0=-27.753kJ/mol. These showed the adsorption was spontaneous and exothermal process. The composites were characterized by XRD and FT-IR. It was found the acrylamide intercalated in interlayer of bentonite and polymerized, then interacted with bentonite by hydrogen bonds. The d001 increased and decreased with adsorption and regeneration, the chloroacetic acid was considered to intercalate in the interlayer of polyacrylamide bentonite composite. The hydrogen bonds may exist between chloroacetic acid and CH2 groups. The polyacrylamide bentonite composite adsorbed chloroacetic acid could be regenerated by NaOH solution.

• Periodical: Advanced Materials Research (Volume 629)
• Pages: 358-363
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.629.358
• Online since: December 2012
• Authors: Xue Qing Chen, Ji Lin Cao, Tian Shui Feng, Xin Ling You
• Keywords: Acrylamide, Adsorption, Bentonite, Chloroacetic Acid, Regeneration

References

[1] Chuang Y H, Wang G S, Tung H H. Chlorine residuals and haloacetic acid reduction in rapid sand filtration. Chemosphere., 2011, 85, 1146-1153.

DOI: 10.1016/j.chemosphere.2011.08.037

[2] Wang, K.P.; Qi, R.; Zhang, Y, Yang . M; Deng, R. S. Adsorption performance of haloacetic acids onto 5 GACs from water. Environ. Sci., 2005, 26, 96-99.

[3] Maria, J. F.; Julien, R.; Francois, X. A.; Maxime, R.; Jurg, K.; Wolfgang, G. Fate of N-nitrosodim- ethylamine，trihalomethane and haloacetic acid precursors in tertiary treatment including biofiltration. Water Res., 2011, 45, 5695-5704.

DOI: 10.1016/j.watres.2011.08.033

[4] Zhang. J.; Meng, Z. H.; Liu, H. L. Status and Development of Zero-Valent Iron For Reductive Dechlorination of Chlorinated Organics. Environ Prot. Sci., 2010, 36, 7-10.

[5] Bian, Z. Q.; Mao, Y. Y.; Tian, X. H.; Hong, Y.; Zhang, J. Reductive Dechlorination of Trichloroacetic Acid in Drinking Water by Zn/Cu Catalyzed Inner Electrolysis System. Environ. Sci ＆Tech., 2010, 33, 105-108.

[6] Chalatip, R.; Chawalit, R.; Nopawan, R. Removal of haloacetic acids by nanofiltration. J. Environ. Sci., 2009, 21, 96-100.

DOI: 10.1016/s1001-0742(09)60017-6

[7] Sangyoup, L.; Jaeweon, C. Comparison of ceramic and polymeric membranes for natural organic matter (NOM) removal. Desalination, 2004, 160, 223-232.

DOI: 10.1016/s0011-9164(04)90025-2

[8] Chen, X. Q.; Cao, J. L.; Hou. L. H.; Tan, Z. Y. Sorption of Pb2+ and chloroactic in solution on molding bentonite and molding Ti-pillared bentonite and their regeneration, " Chin. J. Environ. Eng., 2007, 1, 36-40.

[9] Cao, J. L.; Chen, X. Q.; Liu, X. W.; Tan, Z. Y; An, L. J; Zhang, K. Preparation and Application of Magnetic Bentonite Clean Water Reagent. Journal of Tianjin University., 2007, 40, 457-462.

[10] Cao, J. L.; Zhang, H. R.; Chen, X. Q.; Gao, C. H. The preparation of bentonite composite and its adsorption of fluorine in water. 2009, CN: 101564676.

[11] Xi, Y.J. The Absorption Model of Single-aperture and Multi-aperture Material. Journal of Qinghai University., 2001, 19, 30-35.

[12] Donat, R.; Akdogan, A.; Erdem, E.; Cetisli, H. Thermodynamics of Pb2+ and Ni2+ adsorption onto natural bentonite from aqueous solutions. J. Colloid Interface Sci., 2005, 286, 43-52.

DOI: 10.1016/j.jcis.2005.01.045

[13] Sang, S. B. The Removal of Haloacetic Acides in Water by Activated Carbon Fiber. Shanghai: Tongji University, (2008).