Application of struvite process for nutrient recovery from anaerobic digesters of livestock wastewater

Process of struvite (Mg4NH4PO4·6H2O) precipitation is a promising method for phosphorus recycling. The use of cheap magnesium ore for precipitation struvite as phosphate recovery has been examined. The optimal conditions for precipitation are pH 9.0 and Mg²⁺: NH₄ ⁺: PO₄ ^-3 molar ratio 1.1:30.7:1. Linear correlation of experimental data is in qualitative agreement with modelling calculation. Surface characterization analysis demonstrates that struvite is the dominant component of precipitate. Fertility value tests show that struvite precipitate could be available as slow-release fertilizer.