Chemical Functionalization of Banana Stem Biochar for Enhanced Methylene Blue Removal from Wastewater

Banana stem-derived biochar chemically modified with phosphoric acid exhibited excellent potential as a sustainable adsorbent for methylene blue removal from aqueous solution. FTIR, SEM, and XRD analyses confirmed successful surface functionalization, increased porosity, and the formation of an amorphous carbon structure favorable for adsorption. Batch adsorption studies demonstrated that solution pH, adsorbent dosage, and contact time significantly influenced dye removal efficiency. The highest removal efficiency of 86.43% was achieved at pH 6, an adsorbent dosage of 1.0 g L−1, and 80 min contact time. The enhanced adsorption performance was attributed to the combined effects of electrostatic attraction, π–π interactions, and increased surface active sites introduced through phosphoric acid activation. These findings indicate that chemically modified banana stem biochar is an eco-nomical, environmentally friendly, and promising adsorbent for the treatment of dye-contaminated wastewater and offers considerable potential for large-scale wastewater remediation.

[1]     J. F. Gudin˜o, U. Grandi, and C. Hidalgo, ‘Large language models (LLMs) as agents for augmented democracy’, Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, vol. 382, no. 2285, p. 20240100, 2024. [2]     A. K. Biswas and C. Tortajada, ‘Water crisis and water wars: myths and realities’, International Journal of Water Resources Development, vol. 35, no. 5. Taylor & Francis, pp. 727–731, 2019. [3]     A. du Plessis, ‘Persistent degradation: Global water quality challenges and required actions’, One Earth, vol. 5, no. 2, pp. 129–131, 2022. [4]     A. Abou-Shady, M. S. Siddique, and W. Yu, ‘A critical review of recent progress in global water reuse during 2019–2021 and perspectives to overcome future water crisis’, Environments, vol. 10, no. 9, p. 159, 2023. [5]     M. A. Medina Jr, ‘Global water crisis and climate change’, Journal of Hydrologic Engineering, vol. 15, no. 3, pp. 167–170, 2010. [6]     S. S. Abdullahi, R. E. A. Mohammad, A. H. Jagaba, H. Musa, and A. A.   Birniwa, ‘Natural, synthetic, and composite materials for industrial effluents treatment: a mini review on current practices’, vol. 9, p. 100570, 2024. [7]     S. Kato and Y. Kansha, ‘Comprehensive review of industrial wastewater treatment techniques’, Environmental Science and Pollution Research, vol. 31, no. 39, pp. 51064–51097, 2024. [8]     T. E. Oladimeji, M. Oyedemi, M. E. Emetere, O. Agboola, J. B. Adeoye, and O. A. Odunlami, ‘Review on the impact of heavy metals from industrial wastewater effluent and removal technologies’, Heliyon, vol. 10, no. 23, 2024. [9]     R. Al-Tohamy et al., ‘A critical review on the treatment of dye-containing wastewater: Ecotoxicological and health concerns of textile dyes and possible remediation approaches for environmental safety’, Ecotoxicology and environmental safety, vol. 231, p. 113160, 2022. [10]    T. Robinson, G. McMullan, R. Marchant, and P. Nigam, ‘Remediation of dyes in textile effluent: a critical review on current treatment technologies with a proposed alternative’, Bioresource technology, vol. 77, no. 3, pp. 247–255, 2001.