COMPARATIVE STUDY OF AGRICULTURAL WASTE MATERIALS (ORANGE PEEL AND MAIZE HUSK) FOR THE REMOVAL OF PATHOGENS IN DOMESTIC WASTEWATER

Abstract The discharge of untreated domestic wastewater poses a significant threat to public health and the environment, particularly in developing countries like Nigeria where conventional treatment methods are often cost-prohibitive. This study investigates the potential of using locally available agricultural waste materials—orange peel and maize husk—as low-cost adsorbents for the removal of pathogens from domestic wastewater. The research aimed to compare their effectiveness through a series of controlled laboratory-scale batch adsorption experiments. The adsorbents were prepared by washing, drying, and grinding, and were applied to wastewater samples at varying dosages (0.5–6 g/L) and contact times (0–60 minutes). The treatment efficiency was evaluated based on the reduction of total coliforms (using the Most Probable Number method) and key physicochemical parameters (COD, pH, Turbidity, TDS). The results revealed a stark contrast in performance. Orange peel demonstrated exceptional efficacy, achieving up to 94% removal of total coliforms and a 98% reduction in Chemical Oxygen Demand (COD) at an optimum dosage of 5 g/L over 60 minutes. This high efficiency is attributed to its bioactive compounds (e.g., D-Limonene, citric acid) which possess antimicrobial properties and acidify the wastewater, creating an inhospitable environment for pathogens. In contrast, maize husk, while effective in reducing COD by 92.5%, showed no significant reduction in pathogen concentration, as it lacks inherent antimicrobial agents and did not alter the wastewater pH. The study concludes that orange peel is a superior and multifunctional adsorbent for pathogen removal and organic pollution reduction compared to maize husk. It is recommended as a sustainable, low-cost, and readily available material for decentralized domestic wastewater treatment in rural and peri-urban communities. However, the associated increase in turbidity and TDS in the treated effluent suggests the need for a subsequent filtration step for optimal water quality. Keywords: Agricultural Waste, Orange Peel, Maize Husk, Wastewater Treatment, Pathogen Removal, Adsorption, Low-Cost Technology.