Sustainable biofiltrate-modified natural coal as a green and efficient adsorbent for lead removal from aqueous solution
Year: 2026
Type: article
Abstract: The increasing contamination of water resources by toxic heavy metals has created an urgent need for efficient, low-cost, and sustainable adsorbents for wastewater treatment. This study focuses on developing a highly efficient biofiltrate-modified coal(BFMC) for removing toxic lead ions (Pb(II)) from aqueous solutions. BFMC was synthesized by modifying natural coal (NC) with an alkaline-activated biofiltrate extracted from Solanum marginatum leaves. BFMC was characterized by using Fourier transform infrared spectroscopy and X-ray diffraction, confirming successful preparation. Operational parameters significantly govern adsorption performance onto BFMC. Solution pH determines surface charge and speciation, and optimal removal occurs at pH 5. The maximum uptake capacity was reached at 120 min, with optimal initial concentration and adsorbent dosage of 50 mg/L and 0.05 g, respectively. Equilibrium adsorption was analyzed using the Langmuir and Freundlich isotherm models, Langmuir model showing the best fit (R 2 = 0.999) and an adsorption capacity of 85.179 mg/g. Adsorption kinetics analysis showed the pseudo-second-order model fits best (R 2 = 0.999) compared to the pseudo-first-order model, indicating that the adsorption process is primarily governed by chemisorption. Thermodynamic properties indicated that the adsorption process was spontaneous and exothermic. Hence, the findings demonstrate that BFMC is a highly efficient and promising adsorbent for Pb(II) removal from aqueous solutions while also enabling the value-added utilization of surplus natural coal resources.
Source: Scientific Reports
Institutions: Wollo University, Kotebe University of Education
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7220962222