Ammonia removal form municipal wastewater by air stripping process: An experimental study
Arezoo Zangeneh, Sima Sabzalipour, Afshin Takdatsan, Reza Jalilzadeh Yengejeh, Morteza Abdullatif Khafaie
Abstract
This study was aimed to evaluate ammonia removal efficiency (ARE) in the air stripping process in different operating conditions for wastewater with a low concentration of ammonia such as municipal wastewater treatment plants (WWTPs) on the laboratory scale. The experiments were performed at different pH (9.7 ± 0.26, 10.93±0.16 and 11.94±0.32), temperature (34.25±0.44, 38.57±3.4 and 40.5 ± 7.68 in °C), initial concentration (26.98 -47.34, 19.49 -47.48 and 41–98 in mg/L) and air-water (G/L) ratio (60:1, 70:1 and 80:1). The results showed that ARE in the operating conditions (initial NH4+concentration 26.98 -98 mg/L, pH 9.4–12.38, temperature 34–45.8 °C and G/L 60:1–80:1) was increased from 6.6% to 98% with the range of 1 to 14 h. Based on the results, ARE with 1 standard deviation (SD) increase per unit of pH, temperature and initial NH4+concentration was 13.03%, 3.99% and 2.3%, respectively. Also, based on multivariate regression model at high and low G/L, temperature and pH had the most significant effect on ARE for a synthetic solution as well as a municipal WWTPs stream, respectively. ARE (91%) was obtained during the stripping process of synthetic and actual municipal wastewater.