Sawdust-Assisted Phytoremediation: Boosting White Mustard (

Heavy metal-contaminated soils are a common problem that negatively affect the entire trophic chain. Therefore, solutions are needed that remove heavy metals from the soil, or allow their immobilization in the soil, limiting availability to plants. This research verified whether sawdust added to soil, contaminated with heavy metal ions, supports phytoremediation (bioaccumulation of metals in the plant) or sorbs heavy metals in the soil (immobilization), thus limiting their availability to plants. In batch equilibrium studies, spruce, pine, and oak sawdust were characterized for their physicochemical and biosorption properties, demonstrating varying capacities for the removal of heavy metal ions (Cd-(II), Cr-(III), Cu-(II), Zn-(II)), primarily through surface complexation and ion-exchange related to functional groups (e.g., amino, carboxyl, and phenolic). Among the metal ions tested, the most effective sorption by sawdust occurred in the case of Cd-(II) ions. The bath equilibrium study was supported by modeling calculations and biosorbent analysis using ICP-OES, XRF, FTIR, and SEM-EDS techniques. However, in pot tests using Cd-contaminated soil, the addition of all types of sawdust did not significantly limit the bioaccumulation of cadmium in the above-ground biomass of white mustard (