Electrodialytic Recovery of Ammonium and Phosphate Ions in Fertilizer Industry Wastewater by Using a Continuous-Flow Reactor

The wastewater stream generated from fertilizer industries generally contains high concentrations of ammonium and phosphate ions. This stream offers an opportunity for the electrodialytic process to treat and recover these concentrated nutrients before releasing them to the environment. Therefore, this study aims at evaluating the performance of a continuous-flow electrodialysis reactor for ionic recovery of ammonium and phosphate. The results show that the pH and phosphate mass loading affected the overall performance of the reactor. Magnesium was added to the recovered ammonium and phosphate with the lowest concentration of impurity ions. The molar ratio of magnesium:ammonium:phosphate at 2.5:13:1 produced 57.3% of struvite (by mass) and 42.7% of other precipitate products, i.e., most likely fluorapatite and MgF₂.