Authors : Ashish Bhagat; Sunil Kumar Singh; K. Dharmalingam

Volume/Issue : Volume 10 - 2025, Issue 12 - December

Google Scholar : https://tinyurl.com/4tma2vpb

Scribd : https://tinyurl.com/mr3jxyxh

DOI : https://doi.org/10.38124/ijisrt/25dec1020

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : This study examines the efficiency of a biodegradable carboxymethyl cellulose (CMC)-citric acid hydrogel for adsorbing Methylene Blue (MB) from water. The hydrogel was created utilizing solution casting and thermal crosslinking with citric acid as a green crosslinker. Batch adsorption tests were carried out at MB concentrations of 5, 50, and 100 ppm, with equilibrium reached within 60 minutes and maximum removal efficiencies of 99.35%, 98.97%, and 92%, respectively. Adsorption increased under alkaline circumstances as carboxylate groups deprotonated more effectively. FTIR analysis revealed electrostatic and hydrogen-bonding interactions, while kinetic modeling yielded the best agreement with the pseudo-second-order model, showing chemisorption-controlled adsorption. The findings demonstrate the hydrogel's ability to remove dyes from wastewater in a sustainable manner.

Keywords : Carboxymethyl Cellulose; Citric Acid; Methylene Blue; Hydrogel Adsorption; pH-Responsive Behavior; Adsorption Kinetics.

References :

1. Robinson, T., McMullan, G., Marchant, R., & Nigam, P. (2001). Remediation of dyes in textile effluent: A critical review. Bioresource Technology, 77, 247–255.
2. Forgacs, E., Cserháti, T., & Oros, G. (2004). Removal of synthetic dyes from wastewaters: A review. Environment International, 30, 953–971.
3. Crini, G. (2006). Non-conventional low-cost adsorbents for dye removal: A review. Bioresource Technology, 97, 1061–1085.
4. Zollinger, H. (2003). Color Chemistry: Syntheses, Properties, and Applications of Organic Dyes and Pigments. 3rd ed., Wiley-VCH, Weinheim.
5. Malik, P. K. (2004). Dye removal from wastewater using activated carbon developed from sawdust: Adsorption equilibrium and kinetics. Journal of Hazardous Materials, 113, 81–88.
6. Gupta, V. K., & Suhas. (2009). Application of low-cost adsorbents for dye removal – A review. Journal of Environmental Management, 90, 2313–2342.
7. Wang, S., & Zhu, Z. H. (2007). Effects of acidic treatment of activated carbons on dye adsorption. Dyes and Pigments, 75, 306–314.
8. Crini, G., & Badot, P. M. (2008). Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions. Progress in Polymer Science, 33, 399–447.
9. Lim, A. P., & Aris, A. Z. (2014). A review on economically adsorbents on heavy metals removal in water and wastewater. Reviews in Environmental Science and Bio/Technology, 13, 163–181.
10. Habiba, U., Siddique, T. A., Joo, T. C., Salleh, A., Ang, B. C., & Afifi, A. M. (2017). Synthesis of chitosan/polyvinyl alcohol/zeolite composite for dye adsorption. Carbohydrate Polymers, 157, 1568–1576.
11. Liu, Y., Wang, Z., & Han, J. (2016). Preparation of citric-acid-crosslinked cellulose hydrogels for dye adsorption. Cellulose, 23, 255–268.
12. Yu, J., Wang, J., & Zhang, Y. (2018). Citric acid crosslinked cellulose-based hydrogels for adsorption of cationic dyes. International Journal of Biological Macromolecules, 117, 1129–1138.
13. Wang, J., & Guo, X. (2020). Adsorption kinetic models: Physical meanings, applications, and limitations. Journal of Hazardous Materials, 390, 122156.
14. Ho, Y. S., & McKay, G. (1999). Pseudo-second order model for sorption processes. Process Biochemistry, 34, 451–465.
15. Lagergren, S. (1898). About the theory of so-called adsorption of soluble substances. Kungliga Svenska Vetenskapsakademiens Handlingar, 24, 1–39.
16. Mittal, A., Kaur, D., Malviya, A., Mittal, J., & Gupta, V. K. (2009). Adsorption of hazardous dye crystal violet from wastewater by waste materials. Journal of Colloid and Interface Science, 337, 345–354.
17. Fan, L., Luo, C., Sun, M., Qiu, H., & Li, X. (2013). Synthesis of magnetic β-cyclodextrin–chitosan nanoparticles and application for dye adsorption. Colloids and Surfaces B: Biointerfaces, 103, 601–607.
18. Silverstein, R. M., Webster, F. X., & Kiemle, D. J. (2014). Spectrometric Identification of Organic Compounds. 8th ed., Wiley, New York.
19. Coates, J. (2000). Interpretation of infrared spectra, a practical approach. In Encyclopedia of Analytical Chemistry, Wiley, 10815–10837.
20. Banerjee, S., & Chattopadhyaya, M. C. (2017). Adsorption characteristics for the removal of a toxic dye from aqueous solutions by a low-cost agricultural by-product. Arabian Journal of Chemistry, 10, S1629–S1638.