REMOVAL OF HEAVY METALS FROM OILFIELD PRODUCED WATER USING MAIZE HUSK -ACTIVATED CARBON AND CALCITE COMPOSITE ADSORBENT

Heavy metal pollution from oilfield-produced water is a significant environmental challenge due to its toxic effects on ecosystems and human health. This study explores the use of maize husk-activated carbon and calcite composite as an adsorbent to remove heavy metals, specifically lead (Pb) and zinc (Zn), from oilfield-produced water. The maize husks were carbonized, chemically activated with sulfuric acid, and combined with calcite to form a composite adsorbent. Both the adsorbent and the produced water were characterized to evaluate their physical and chemical properties, including salinity, pH, total dissolved solids, and heavy metal concentrations. Batch adsorption experiments were conducted under varying conditions to determine the effects of adsorbent dosage, contact time, and pH on the removal efficiency of Pb and Zn. The results demonstrated that the adsorption process was rapid, with significant removal occurring within the first 45 minutes and equilibrium achieved at 75 minutes. Increasing the adsorbent dosage improved the removal efficiency, with higher doses resulting in greater reductions in metal concentrations. Kinetic studies revealed that the adsorption process followed a pseudo-second-order model, indicating chemisorption as the primary mechanism. The findings highlight the potential of maize husk-activated carbon as a low-cost and eco-friendly alternative for treating wastewater, particularly in resource-limited settings. By utilizing agricultural waste and natural calcite, the study provides a sustainable approach to addressing the challenges of industrial wastewater management. The composite adsorbent demonstrated high efficacy in removing Pb and Zn, with minimal environmental impact compared to conventional methods. This research contributes to the growing body of knowledge on alternative adsorbents for water treatment, offering an innovative and practical solution for mitigating heavy metal pollution. The study underscores the importance of developing sustainable technologies to protect water resources and improve public health, especially in regions heavily impacted by industrial activities. Future work could focus on scaling up the process for industrial applications and exploring its effectiveness for other pollutants.