Enhanced Wastewater Remediation Using Mesoporous Activated Wheat Straw Biochars: A Dye Removal Perspective

Priyanka, Priyanka; Vashisht, Devika; Ibhadon, Alex O.; Mehta, Surinder K.; Taylor, Martin J.

Abstract

The escalating contamination of water bodies by synthetic dyes necessitates innovative and ecoconscious strategies for wastewater treatment. In this study, activated biochars BC-800 (1:0.25), BC-800 (1:0.5), and BC-800 (1:1) from wheat straw were synthesized. Here, ratios denote the mass relationship between wheat straw and potassium hydroxide; “800” represents the pyrolysis temperature. These activated biochars were rigorously characterized revealing the most efficient material, BC-800 (1:1), presenting a surface area of 2578.82 m2/g and average pore diameter of 5.51 nm. Across parallel batch experiments, it effectively extracted synthetic dyes (rhodamine B (RhB), methylene blue (MB), and methyl orange (MO)) from wastewater within 15–20 min, primarily through chemisorption pathways. Increased surface area and porosity resulted in a greater dispersion of adsorption sites including C═C linkages (π–π interactions) and H-bonding via surface carbonyl groups (C═O). To understand the adsorption mechanism, Langmuir, Freundlich, and Temkin isotherm models were employed to investigate the equilibrium adsorption behavior. Results show that BC-800 (1:1) followed the Freundlich isotherm (R2: 0.9659 for RhB, 0.9927 for MB, and 0.9979 for MO, respectively), showing dye molecules form multilayers on the surface of the biochar (π-stacking). Biochar recycling through chemical regeneration demonstrated sustained dye removal efficiency >90% for BC-800 (1:1) over multiple cycles.

Citation

Priyanka, P., Vashisht, D., Ibhadon, A. O., Mehta, S. K., & Taylor, M. J. (in press). Enhanced Wastewater Remediation Using Mesoporous Activated Wheat Straw Biochars: A Dye Removal Perspective. ACS Sustainable Resource Management, https://doi.org/10.1021/acssusresmgt.3c00109

• Journal Article Type: Article
• Acceptance Date: Jan 26, 2024
• Online Publication Date: Feb 13, 2024
• Deposit Date: Feb 15, 2024
• Publicly Available Date: Feb 16, 2024
• Journal: ACS Sustainable Resource Management
• Electronic ISSN: 2837-1445
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1021/acssusresmgt.3c00109
• Keywords: Adsorption; Animal feed; Dyes and pigments; Plant biology; Plant derived food
• Public URL: https://hull-repository.worktribe.com/output/4547747