Phosphate Fixation and P Mineralogy on Natural and Ca-Modified Zeolites During Simultaneous Nutrient Removal

Abstract The recovery and recycling of nutrients (N&P) from wastewater are one the major topics to save primary energy resources, raise efficiency treatment plants, foster a future circular economy. In present study, removal ammonium (NH 4 + ) phosphate (PO 3− using natural Ca-treated zeolite is investigated in detail. Special emphasis put on simultaneous both species model solutions followed by elaborate mineralogical analyses (XRD, EPMA, FEG-SEM) for characterization order determine type, structure, crystal sizes CaP-phases precipitating zeolites surface. effectivity segregation chemical composition crystalline structure CaP-phase surface depend physico conditions particular pH, molar ratio Ca P (due modification), presence NH . Results experiments N&P revealed that pretreatment enhances increases obtainable P-loadings Ca–zeolites. Maximum 25 mg g −1 Ca–zeolite binary containing were obtained. Simultaneous precipitation does not significantly influence ion exchange type CaP-precipitates formed assumed be mainly brushite apatite.