Response Surface Methodology Optimization of Chemical Oxygen Demand Removal by Rice Husk Activated Carbon

Abstract

High Chemical Oxygen Demand (COD) levels in water indicate a vast amount of oxidizable matter that consumes a lot of dissolved oxygen in water. This results in adverse impacts on both aquatic ecosystems and human health. Wastewater from the fish cracker industry typically has high organic content and high COD value. In this study, rice husk was chosen as the raw material because of its abundance and economy. The optimum adsorption parameters such as flow rate, contact time, and initial COD concentration that affect adsorption by rice husk activated carbon were studied using Response Surface Methodology. The treatment was done in a continuous fixed-bed column. From the Box-Behnken design, it was determined that 68.09% removal percentage resulted from the best combination of 4.5 hours of contact time, 1 mL/min of flowrate, and 5% initial COD concentration. The SEM micrograph shows the adsorbent consists of a large number of pores before adsorption. Based on the study, rice husk activated carbon can be an alternative treatment for COD removal in wastewater. The use of activated carbon derived from agricultural waste materials can help reduce the waste produced, which will otherwise end up in the landfill.