Investigation of effective factors on the ammonia removal efficiency in the wastewater treatment plants using the air stripping process

Removal of ammonia from wastewater in the treatment plants due to its dangerous and toxic effects on human health and biotic resources is essential. This study was aimed to investigate the effective operational parameters on the efficiency of the air stripping process, determine their priority and degree of effect on ammonia removal and compare the ammonia removal efficiency during the air stripping process in the municipal wastetewater treatment plants using synthetic and real wastewater.

In this study, the effect of each operating parameter on the ammonia removal efficiency including initial ammonia concentration, pH and temperature during the air stripping process for synthetic and real wastewater, respectively, based on standard methods (the Nesslerization method, preparation of standard solutions) using a spectrophotometer, pH meter and temperature module were evaluated.

The results of this study showed that the maximum of ARE for synthetic wastewater with Air to water ratio 80 and an initial ammonia concentration of 59. 6 mg /l, pH 12.05 and temperature 46.3°C was %91. Also, the results of the study on the ARE during the air stripping process showed that the maximum of ARE (%91) for real wastewater (primary sedimentation tank effluent (PST)) with Air to water ratio 80 and an initial ammonia concentration of 61.04 mg/l, pH 12.53 and temperature 45.9 ° C was obtained.

Based on the results of univariate regression model, initial ammonia concentration˃ temperature˃ pH have the greatest effect on the ammonia removal efficiency in synthetic wastewater and real wastewater, respectively. In the multivariate regression model, the effect of temperature and pH on the ammonia removal efficiency in synthetic and real wastewater is increasing and decreasing, respectively. Based on the findings of this study, the air stripping process can be successfully used to remove ammonia from wastewater in the municipal treatment plants, especially in the tropics.