Ammonia and Chemical Oxygen Demand Removal from Sewage Wastewater using Composite Adsorbent-Based Activated Carbon

This study was conducted to determine the effectiveness of activated carbon composite adsorbent media in removing ammonia and chemical oxygen demand (COD) form sewage wastewater. This study was divided into four main parts, composite media characterization, optimum parameter determination, batch study of the adsorption and adsorption column study. Optimum parameters such as pH, contact time and adsorbent dosage were also investigated. In addition, adsorption isotherm studies, adsorption kinetics and adsorption column study were conducted as well. The results showed that optimum pH 5 for removal of ammonia while pH 6 for COD. The optimum percentage of ammonia removal for the contact time was in the 15 min with the removal of 71% and for the removal percentage of COD occurred in the 30 min with the removal of 51%. The optimum adsorbent dosage for ammonia removal is about 25 g/L while for removal of COD is 50 g/L. In the isothermal studies, Langmuir and Freundlich isotherm models were applied and the results showed that ammonia and COD adsorption isotherm was in compliance with the Freundlich isotherm model with R-2 = 0.9004 and R-2 = 0.9818. Kinetic studies showed the kinetic rates for adsorption of ammonia and COD were obtained for second order kinetic model and the coefficient of correlation was R-2 = 0.9985 and R-2 = 0.9998. This study showed that the kinetic adsorption of ammonia and COD was influenced by the chemical processes. Based on the results obtained from the study of the adsorption column, the effectiveness of activated carbon composite adsorbent media in removing ammonia and COD of sewage wastewater is shown by removal percentage achieving up to 90% for ammonia and 88% for COD. This research showed that activated carbon composite adsorbent media can be applied to treat sewage wastewater.