(755a) Stimulated Magnesium Ammonium Phosphate Crystallization for Simultaneous Nutrient N, P, Cr(VI) and Cd(II) Removal

Nutrient enrichment coupled with discharge of toxic heavy metals cause decline in environmental quality in receiving bodies of water. Discharge of heavy metals such as Cr(VI) and Cd(II) and polluting amounts of nitrogen and phosphorus endangers the assimilative capacity of water bodies and their ability to support life. As the swine industry grows to sustain the country, so does the generation of wastewater and with it, a substantial amount of pollution load to Philippine waters. In this study, operating parameters in the crystallization of magnesium ammonium phosphate (MAP) such as initial nutrient and heavy metal concentrations, pH, mixing and dosing schemes will be stimulated to promote crystal formation. Water quality parameters such as pH, ammonia-N, phosphate-P and concentrations of heavy metals Cr(VI) and Cd(II) are assessed before and after crystallization. Simulated swine digestate effluent is based on an averaged wastewater profile from Philippine swine farms. Changes in water quality parameters such as N, P and pH throughout the crystallization process shall provide metrics to assess removal and recovery of nutrients.