Evaluation of Ammonia-Nitrogen Removal by Ultrasonic Irradiation in Synthetic Solution Using Response Surface Methodology

摘要

The objective of this study was to evaluate the ability of ultrasonic irradiation to remove ammonia-nitrogen in synthetic solution by considering the factors including initial concentration, pH and irradiation time. Ultrasonic bath was used to provide a constant effective power, frequency and temperature of 150 W, 37 kHz and 60°C, respectively during sonication. It was revealed that the removal efficiency of ammonia-nitrogen improved at lower concentration with basic water environment and extended irradiation time. Based on this judgement, optimization is carried out by using response surface methodology (RSM) of Box Behnken design to develop a quadratic regression model in order to analyze the interactions between the three factors and their effects on the removal efficiency. Optimum removal achieved from the model was found to be 82.26% at 10 mg/L of initial concentration with pH of 11 and sonication for 30 minutes. Verification of the quadratic regression model is done by comparing with the experimental work conducted within the experimental domain.