Simultaneous removal of ammonium and phosphate ions from wastewaters and characterization of the resulting product [articol]

Abstract

The compounds of ammonium and phosphate ions are major pollutants, which contribute to the stimulation of aquatic plants growth, microorganism development and eutrophication. This paper presents studies regarding the simultaneous removal of ammonium and phosphate ions from synthetic wastewaters through precipitation with magnesium sulfate. The laboratory research was carried out on four types of synthetic wastewaters with various initial concentrations of ammonium (0.08–1.6 g/L) and phosphate (0.4–8 g/L), at several Mg2+:NH4+:PO43- molar ratios (1:1:1 −2:1:1), and at various values of the pH of the reaction mass (6 − 11). The possibility of simultaneous removal of ammonium and phosphate ions from wastewaters was also studied on a micro-pilot installation, in the operating conditions established at laboratory scale. The resulting solid product (magnesium ammonium phosphate) was characterized in view of capitalize it as fertilizer, through: chemical analysis, thermal analysis and X-ray diffractometry.