Ammonium Removal and Recovery from Industrial Wastewater Using Distillation Method

Abstract

:Industrial wastewater contains high ammonium concentration, leading to difficulties in the treatment process using conventional methods. This study used the heat distillation method following the alkalization of wastewater to remove and recover ammonium from the wastewater of an industrial plant. The influent wastewater has a pH 6.41 and a very high ammonium concentration (28000 mgN/L). The distillation system was designed to consist of heating, cooling, and recovery units. After alkalinization, the wastewater sample was boiled using an electric stove, the ammonia vapor passed through the cooler and condensed into liquid ammonia, and was recovered. The controlling factors for the removal efficiency including solution pH (7-12) and distillation time (0.5, 10, 15, 30, 60 and 90 min) were investigated. Experimental results show that the optimal conditions for ammonium treatment from wastewater are at pH 12 and distillation time of 30 min, corresponding to 100% of removal efficiency. In terms of liquid ammonia recovery, the ice cooling mode was more efficient than the tap water cooling and vacuum evaporating modes. Final ammonia concentration reached 215 mgN/L that has potential for industrial production.