Sh. El Rafie, S. Hawash and M. S. Shalaby
The process of struvite precipitation and removal of NH4 +-N from industrial waste streams were studied by laboratory experimental work. Struvite, the slow release fertilizer was prepared by addition of magnesium and phosphate sources with calculated stoichiometric ratio to optimize reagent dosage and makes the precipitation more efficient. Liquid bittern (LB) was added as low cost magnesium source, containing 73% magnesium. Three industrial effluents from the fertilizer factory, proved to be cost –effective forstruvite production. The ammonia removal ratio was 80% from the nitric acid stream, 57% from the ammonium nitrate stream, and 54.2% from the ammonium sulfate stream. The yield of struvite was 1.15 g/L, 1 g/L, 0.79 g/L and 0.5 g/L recovered from ammonium sulfate stream, nitric acid stream, ammonium nitrate stream and mixed stream respectively. Struvite formation was later verified by analyzing the morphology and composition employing scanning electron microscope (SEM) and Xray Diffraction (XRD), respectively. A preliminary techno – economic evaluation for struvite production predicted from both pilot scale and industrial scale was studied and supported recoveredstruvite for potential use as a renewable fertilizer
