Remediation of pollutants from wastewater using fungi: An updated review
TL;DR
This critical narrative review separates biosorption, bioaccumulation, redox transformation, biodegradation, decolorization, detoxification, biomineralization and mineralization, because these endpoints are too often reported as if they mean the same thing.
Abstract
Fungi can remove or alter metals, dyes, pesticides, hydrocarbons, pharmaceuticals and selected polymers, but the evidence is uneven across pollutant classes. This critical narrative review separates biosorption, bioaccumulation, redox transformation, biodegradation, decolorization, detoxification, biomineralization and mineralization, because these endpoints are too often reported as if they mean the same thing. The discussion of metals is arranged by contaminant and by fungal mechanism. Cell-wall sorption is well established for Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Cr species and U(VI). Living fungi can add intracellular sequestration, valence change, organic-acid-driven mobilization, and phosphate- or oxalate-associated precipitation. Those same processes may immobilize a metal or make it more mobile, so a lower dissolved concentration is not, by itself, evidence of lasting risk reduction. White-rot fungi, laccases and peroxidases can attack dye chromophores and transform some pharmaceuticals and pesticides. Real effluents complicate that picture: they may suppress growth, inhibit enzyme production, or show color loss without mineralization. Much of the field still rests on batch experiments in defined media. The stronger route to application links equalization, immobilized or pelletized fungal reactors, biomass separation, polishing, product analysis, toxicity testing and a clear residuals plan. Fungal remediation is therefore best treated as a mechanism-specific treatment platform. Its value has to be shown for a named contaminant, matrix, endpoint and operating scale, not inferred from fungal tolerance or laboratory removal alone.