Biochar-coated aluminium electrodes for Cr, Mn and Fe removal in electrochemical treatment for polluted river water remediation

Biochar (a by-product of biomass pyrolysis) is developed as a renewable, low-cost, and promising carbon-based electrode for electrochemical remediation of Cr, Mn and Fe in polluted river water. The biochar - electrode were prepared with two types of tailored sieved size medium (2.0 mm) and fine (150 µm). The effect of the different sieved size on the electrochemical reactor was set at 60V of voltage supply, 6 cm inter-electrode distance within 105 minutes electrolysis operational time. The results indicated that the highest removal efficiency for Cr was achieved at 95% after 105 minutes followed by Mn at 99.9% in 65 minutes and Fe at 92.76% in 105 minutes. Interestingly, the electrode with larger sieved size showed the highest removal efficiency for all three elements. These results emphasize the importance of tailoring the porous structure of the biochar electrode material as a function of the specific size of adsorbate ions to improve the electrochemical water treatment performance for polluted river water.