Fe/Mn/N Tri-Doped Sawdust-Derived Biochar Nano-Adsorbents: A Systematic Review on the Recent Progress in Heavy Metal Removal from Contaminated Water

Okwuolise Gift; Emereibeole Enos .I.; Anyanwu Jonathan .C.; Uche Cosmas .C.; Okorondu Justin .N.; Edo Friday. A.; Okwuolise Blessing .C.

doi:10.56201/ijgem.vol.12.no7.2026.pg211

Fe/Mn/N Tri-Doped Sawdust-Derived Biochar Nano-Adsorbents: A Systematic Review on the Recent Progress in Heavy Metal Removal from Contaminated Water

Okwuolise Gift, Emereibeole Enos .I., Anyanwu Jonathan .C., Uche Cosmas .C., Okorondu Justin .N., Edo Friday. A., Okwuolise Blessing .C.

Abstract

Heavy metal contamination of aquatic environments remains a major global environmental challenge due to rapid industrialization, mining, agricultural activities, and urban expansion. Toxic metals such as cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), copper (Cu), zinc (Zn), and mercury (Hg) are persistent, non-biodegradable, and bioaccumulative, posing significant ecological and public health risks. Conventional wastewater treatment technologies, including chemical precipitation, membrane filtration, ion exchange, and electrochemical methods, are constrained by high operational costs, sludge generation, membrane fouling, and limited efficiency in treating complex multi-metal systems. Consequently, adsorption has emerged as a sustainable and cost-effective alternative for heavy metal remediation. This review critically examines recent advances in Fe/Mn/N tri- doped sawdust-derived biocharnano-adsorbents for the removal of heavy metals from contaminated water systems. The review discusses the occurrence, sources, environmental impacts, and toxicity of heavy metals, as well as the principles and limitations of conventional treatment technologies. Particular emphasis is placed on the synthesis, physicochemical properties, characterization, and adsorption mechanisms of Fe/Mn/N tri- doped biochar, highlighting the synergistic roles of iron, manganese, and nitrogen in enhancing surface functionality, adsorption capacity, reaction kinetics, and selectivity. Recent developments in adsorption isotherms, kinetic and thermodynamic modelling, and advanced characterization techniques are also examined to provide insight into adsorption behaviour and mechanism. Furthermore, current research trends, empirical findings, existing knowledge gaps, and future perspectives for large-scale application are discussed. The review demonstrates that Fe/Mn/N tri-doped sawdust biochar represents a promising, environmentally friendly, and economically viable adsorbent capable of addressing the limitations of conventional treatment technologies. Future studies should prioritize pilot- scale investigations, regeneration and reusability assessments, and performance evaluation under real wastewater conditions to facilitate commercial implementation and support sustainable water resource management.

Keywords

Fe/Mn/N tri-doped biochar; sawdust-derived biochar; heavy metals; adsorption; nano-adsorbents; wastewater treatment; contaminated water; environmental remediation; adsorption kinetics; adsorption isot

References

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Fe/Mn/N Tri-Doped Sawdust-Derived Biochar Nano-Adsorbents: A Systematic Review on the Recent Progress in Heavy Metal Removal from Contaminated Water

Abstract

Keywords

References

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