<b>ADSORPTION POTENTIAL OF MODIFIED RICE BY-PRODUCTS IN REDUCING HEAVY METAL CONTAMINANTS IN MAIZE FLOUR MILL EFFLUENT</b>

Abstract

Environmental pollution from industrial effluent, particularly maize flour mills has contributed to heavy metal contamination with toxic substances accumulating in water and soil due to human activities, pose substantial environmental and health problems. This study examines the adsorption capability of biochar derived from rice by-products for removing heavy metals such as chromium (Cr), cadmium (Cd), and lead (Pb) from maize flour mill effluent. Biochar was produced through pyrolysis at 500°C and modified to enhance porosity and adsorption capacity. The physicochemical properties and heavy metal concentrations of wastewater samples were analyzed using Atomic Absorption Spectroscopy (AAS) before and after treatment. Batch adsorption experiments were performed with biochar doses of 5 g, 10 g, and 15 g to assess removal efficiency. The batch adsorption experiments demonstrated that biochar dosage significantly influenced heavy metal removal. At a dosage of 15 g, biochar achieved removal efficiencies of 59 % for Cr, 90 % for Cd, and 58 % for Pb. The high porosity (75.4 %) and the abundance of functional groups on the biochar surface were key factors contributing to its adsorption effectiveness. These findings show the potential of modified rice by-products as cost-effective, eco-friendly adsorbents for sustainable waste/wastewater management.