Characterization of Ammonia Removal from Municipal Wastewater Using Microwave Energy: Batch Experiment

Abstract

This study investigates the characteristics of ammonia removal from municipal wastewater using microwave radiation (MW). Synthetic and real wastewater samples were heated in batch reactors by MW radiation and ammonia removal efficiency was tested under variable conditions. The effects of initial ammonia concentration, pH, and radiation time on ammonia removal efficiency were investigated. Radiation time and pH showed significant influence on the removal of ammonia nitrogen with lower influence of the initial ammonia concentration. The highest ammonia removal efficiency achieved was 91.1 ±0.8% and 90.5 ±1.2% for synthetic and real wastewaters, respectively. The highest efficiency in both cases was achieved at a pH of 11 with 4 minutes of MW radiation. Comparing the results of this study with the work of others, it was found that ammonia removal efficiency from municipal wastewater that normally has low initial ammonia concentration is less than its removal efficiency from industrial wastewater that has initial ammonia concentrations in the range of 500-12000 mg NH3-N/L. It is concluded from this study that MW radiation is an effective method for the removal of ammonia nitrogen from municipal wastewater.