Application of modified bentonite for efficient water purification: A case of Cr(VI) adsorption

Document Type : Research Article

Authors

1 Faculty of Chemical Petroleum and Gas Engineering, Semnan University, Semnan, Iran

2 Department of Chemical Engineering, Faculty of Engineering, University of Garmsar, Garmsar, Iran

Abstract

This study explores the use of acid-activated bentonite as an efficient adsorbent for removing hexavalent chromium (Cr(VI)) from water. Acid activation enhances the surface area and adsorption capacity of bentonite, improving its water treatment efficiency. Various techniques, including BET, FT-IR, XRD, XRF, and SEM, were used to analyze structural and compositional changes after activation. Adsorption experiments showed that under optimal conditions - room temperature, 0.1 ppm Cr(VI), and 1 g of acid-activated bentonite - 100 % removal was achieved. The adsorption followed the Langmuir isotherm with a maximum capacity of 0.122 mg.g-1. Kinetic studies confirmed a pseudo-second-order reaction model (R² = 0.99), indicating a chemisorption mechanism. Thermodynamic analysis showed the process is spontaneous and exothermic, requiring no external energy input. Groundwater tests from the Forumad region (Semnan Province) compared raw and acid-modified bentonite, revealing a 92 % Cr(VI) removal efficiency with the modified form, reducing contamination to safe levels. These results highlight acid-activated bentonite as a cost-effective, eco-friendly adsorbent for water purification, demonstrating its real-world potential for ensuring safer drinking water.

Graphical Abstract

Application of modified bentonite for efficient water purification: A case of Cr(VI) adsorption

Highlights

  • Enhanced adsorption efficiency of acid-activated bentonite for Cr(VI) removal from water.
  • 100 % Cr(VI) removal under optimal conditions.
  • Fits Langmuir isotherm and pseudo-second order kinetics.
  • Spontaneous and exothermic processes, requiring no external energy.
  • 92 % Cr(VI) removal from groundwater in Iran’s Forumad region.

Keywords

Main Subjects

Copyright © 2024 The Author(s). Published by IROST.

References

  1. Zhang, , Yang, M., Lan, J., Huang, Y., Zhang, J., Huang, S., Yang, Y., & Ru, J. (2023). Water Quality Degradation Due to Heavy Metal Contamination: Health Impacts and Eco-Friendly Approaches for Heavy Metal Remediation. Toxics, 11(10), 828. https://doi.org/10.3390/toxics11100828
  2. Beck, M., McHale, M. R. & Hess, G. R. (2016). Beyond Impervious: Urban Land-Cover Pattern Variation and Implications for Watershed Management. Environmental Management, 58, 15-30. https://doi.org/10.1007/s00267-016-0700-8
  3. Soltani, P., Zakeri, M., Samimi, A., & Agah, A.(2025). Green Synthesis of ZIF-8 Nanoparticles for the Simultaneous Removal of Cd(II) and Sb(III) from Contaminated Advances in Environmental Technology, 11(1), 75-90. https://doi.org/10.22104/aet.2024.6938.1901
  4. Samimi, , Zakeri, M., Alobaid, F., & Aghel, B. (2023). A Brief Review of Recent Results in Arsenic Adsorption Process from Aquatic Environments by Metal-Organic Frameworks: Classification Based on Kinetics, Isotherms and Thermodynamics Behaviors. Nanomaterials, 13(1), 60. https://doi.org/10.3390/nano13010060
  5. Atieh, A., Bakather, O. Y., Tawabini, B. S., Bukhari, A. A., Khaled, M., Alharthi, M., Fettouhi, M., Abuilaiwi, F. A. (2010). Removal of Chromium (III) from Water by Using Modified and Non-Modified Carbon Nanotubes. Journal of Nanomaterials, 2010, 232378. https://doi.org/10.1155/2010/232378
  6. Ariffin, , Al-Bakri Abdullah, M. M., Arif Zainol, M. R. R. M., Murshed, M. F., Zain, H., Faris, M. A., & Bayuaji, R. (2017). Review on Adsorption of Heavy Metal in Wastewater by Using Geopolymer. MATEC Web of Conferences, 97, 01023. https://doi.org/10.1051/matecconf/20179701023
  7. Sundaram, S. & Raghavan, P. S. (2011). Chromium-VI Reagents: Synthetic Applications. Springer Berlin. https://doi.org/10.1007/978-3-642-20817-1
  8. Sharma, P., Singh, S. P., Parakh, S. K., & Tong, Y. W.(2022). Health hazards of Hexavalent Chromium (Cr (VI)) and Its Microbial Reduction. Bioengineered, 13(3), 4923-4938. https://doi.org/10.1080/21655979.2022.2037273
  9. Altun, T. (2020). Preparation and Application of Glutaraldehyde Cross-Linked Chitosan-Coated Bentonite Clay Capsules: Chromium(VI) Removal from Aqueous Solution. Journal of the Chilean Chemical Society, 65(2), 4790-4797. https://dx.doi.org/10.4067/S0717-97072020000204790
  10. Sara, A., Ahmed, M. A., & Firas Habeb, A. (2020). Adsorption of Heavy Metals on Bentonite and Modified Bentonite Clay, Factors, Kinetic and Thermodynamic Studies/A Review. Algerian Journal of Materials Chemistry, 3(2), 90-106. https://asjp.cerist.dz/en/article/142159
  11. Gamoudi, S., & Srasra, E. (2017). Characterization of Tunisian Clay Suitable for Pharmaceutical and Cosmetic Applications. Applied Clay Science, 146, 162-166. https://doi.org/10.1016/j.clay.2017.05.036
  12. Balarak, , Yari, A. R., Kord Mostafapour, F., Mahdavi, Y., & Joghataei, A. (2016). Agricultural Waste as Adsorbent for Removal of Chromium (VI) from Aqueous Solution. (2016). Agricultural Waste as Adsorbent for Removal of Chromium (VI) from Aqueous Solution. Archives of Hygiene Sciences, 5(4), 310-318. https://dor.isc.ac/dor/20.1001.1.22519203.2016.5.4.11.6
  13. Moradi, , Dehpahlavan, A., Rezaei, Kalantary, R., Ameri, A., Farzadkia, M., & Izanloo, H. (2015). Application of Modified Bentonite Using Sulfuric Acid for the Removal of Hexavalent Chromium from Aqueous Solutions. Environmental Health Engineering and Management Journal, 2(3), 99-106. http://ehemj.com/article-1-93-en.html
  14. Panda, K., Mishra, B. G., Mishra, D. K., & Singh, R. K. (2010). Effect of Sulfuric Acid Treatment on the Physicochemical Characteristics of Kaolin Clay. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 363(1-3), 98-104. https://doi.org/10.1016/j.colsurfa.2010.04.022
  15. Ashour, A., & Tony, M. A. (2020). Eco-Friendly Removal of Hexavalent Chromium from Aqueous Solution Using Natural Clay Mineral: Activation and Modification Effects. SN Applied Sciences, 2, 2042. https://doi.org/10.1007/s42452-020-03873-x
  16. Thakur, A. K., Kumar, R., Chaudhari, P., & Shankar, R.(2021). Removal of Heavy Metals Using Bentonite Clay and Inorganic In M. P. Shah (Eds.), Removal of Emerging Contaminants Through Microbial Processes (pp. 47-69). Springer. https://doi.org/10.1007/978-981-15-5901-3_3
  17. Belibağlı, , Çiftci, B. N., & Uysal, Y. U. (2020). Chromium (Cr(VI)) Removal from Water with Bentonite Magnetite Nanocomposite Using Response Surface Methodology (RSM). Sigma Journal of Engineering and Natural Sciences, 38(3), 1217-1233. https://dergipark.org.tr/en/download/article-file/2018147
  18. Bakatula, N., Richard, D., Neculita, C. M., & Zagury, G. J. (2018). Determination of Point of Zero Charge of Natural Materials. Environmental Science and Pollution Research International, 25, 7823-7833. https://doi.org/10.1007/s11356-017-1115-7
  19. Chang, Y. S., Au, P. I., Mubarak, N. M., Khalid, M., Jagadish, , Walvekar, R, & Abdullah, E. C. (2020). Adsorption of Cu(II) and Ni(II) Ions from Wastewater onto Bentonite and Bentonite/GO Composite. Environmental Science and Pollution Research, 27, 33270-33296. https://doi.org/10.1007/s11356-020-09423-7
  20. Maged, , Kharbish, S., Ismael, I. S., & Bhatnagar, A. (2020). Characterization of Activated Bentonite Clay Mineral and the Mechanisms Underlying Its Sorption for Ciprofloxacin from Aqueous Solution. Environmental Science and Pollution Research, 27, 32980-32997. https://doi.org/10.1007/s11356-020-09267-1
  21. Adisu, , Balakrishnan, S., & Tibebe, H. (2022). Synthesis and Characterization of Fe3O4-Bentonite Nanocomposite Adsorbent for Cr(VI) Removal from Water Solution. International Journal of Chemical Engineering, 2022, 4441718. https://doi.org/10.1155/2022/4441718
  22. Najafpoor, A. A., Soleimani, G., Ehrampoush, M. H., Ghaneian, M. T., Rahmanpour Salmani, E., & Dolatabadi Takabi, (2014). Study on the Adsorption Isotherms of Chromium(VI) by Means of Carbon Nanotubes from Aqueous Solutions. Environmental Health Engineering and Management Journal, 1(1), 1-5. http://ehemj.com/article-1-40-en.html
  23. Taher, T., Palapa, N. R., Mohadi, R., & Lesbani, A. (2019). Adsorption Behavior of Cr(VI) from Aqueous Solution by Fe-Pillared Acid-Activated Indonesian Bentonite. AIP Conference Proceedings, 2194(1), 020124. https://doi.org/10.1063/1.5139856
  24. Taheri, , Khajenoori, M., Shiri-Yekta, Z., & Zahakifar, F. (2023). Application of Plantain Leaves as a Bio-Adsorbent for Biosorption of U(VI) Ions from Wastewater. Radiochimica Acta, 111(7), 513-524. https://doi.org/10.1515/ract-2022-0109
  25. Garg, K., Kaur, M. P., Garg, V. K., & Sud, D. (2007). Removal of Hexavalent Chromium from Aqueous Solution by Agricultural Waste Biomass. Journal of Hazardous Materials, 140(1-2), 60-68. https://doi.org/10.1016/j.jhazmat.2006.06.056
  26. Malook, , & Ihsan-ul-Haque (2019). Investigation of Aqueous Cr(VI) Adsorption Characteristics of Orange Peels Powder. Protection of Metals and Physical Chemistry of Surfaces, 55(1), 34-40. https://doi.org/10.1134/S2070205119010155
  27. Lia, G., Zhang, J., Liu, J., Chen, S., & Li, H. (2020). Investigation of the Adsorption Characteristics of Cr(VI) onto Fly Ash, Pine Nut Shells, and Modified Bentonite. Desalination and Water Treatment, 181, 389-402. https://doi.org/10.5004/dwt.2020.25909
Journal of Particle Science and Technology
Volume 10, Issue 2
December 2024
Pages 117-128

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History

  • Receive Date: 16 March 2025
  • Revise Date: 20 April 2025
  • Accept Date: 08 May 2025

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