Tailored Bombax ceiba-based activated carbons for enhanced rhodamine B removal: A sustainable approach to industrial effluent remediation

Abstract

Bombax ceiba wood waste-derived activated carbon (AC) provides a low-cost, sustainable, and efficient solution for rhodamine B (RhB) dye removal from industrial wastewater through eco-friendly adsorption techniques. This study reports the synthesis of ACs from B. ceiba wood dust using three different chemical activating agents - phosphoric acid, potassium hydroxide, and sodium carbonate - followed by carbonization at an optimized temperature determined through thermogravimetric (TG) analysis and differential scanning calorimetry. The optimal carbonization temperature was identified as 400°C. AC samples were prepared through a one-step chemical impregnation and carbonization process under nitrogen flow. Comprehensive characterization using X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller surface area analysis confirmed the formation of amorphous carbon structures with abundant oxygenated surface functional groups and porous architectures. Among the three samples, phosphoric acid-activated carbon (Bc-H) exhibited the highest surface area (1,451.2 m²/g) and a well-developed micro-mesoporous structure. Batch adsorption experiments showed that Bc-H achieved 99.9% RhB removal under optimized conditions (20 ppm initial dye concentration, pH 8.5, 0.03 g adsorbent, 10 min). Its superior performance is attributed to its large surface area and rich surface functionalities. Notably, Bc-H also outperformed commercial AC under identical conditions, demonstrating faster kinetics and higher removal efficiency. These findings underscore B. ceiba wood dust as a low-cost and sustainable precursor for high-performance AC production. The work contributes to waste biomass valorization and offers a scalable, eco-friendly solution for industrial wastewater treatment, particularly relevant to textile and dyeing effluents in resource-limited settings such as Nepal.

Keywords

Bombax ceiba / Activated carbon / Rhodamine B adsorption / Wastewater treatment / Chemical activation / Sustainable adsorbent

Funding

None.

Conflict of interest

The author declares no conflict of interest.

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