Synthesis of a novel magnetic biochar composite enhanced with polyaniline for high-performance adsorption of heavy metals: focus on Hg( ii ) and Cu( ii )

, respectively. The electrochemical measurements of square wave anodic stripping voltammetry (SWASV) were employed to determine residual metal ion concentrations after adsorption. Calibration curves were constructed by varying the concentration of each ion, both individually (with the other held constant) and simultaneously (with both ions present in the same solution), to evaluate the electrode's performance in mixed-ion systems. The PANI-modified PMBS biochar demonstrates significant potential for wastewater treatment and is suitable for a broader range of separation applications.