A systematic comparison of commercially produced struvite: Quantities, qualities and soil-maize phosphorus availability

Production of struvite (MgNH4PO4·6H2O) from waste streams is increasingly implemented to recover phosphorus (P), which listed as a critical raw material in the European Union (EU). To facilitate EU-wide trade P-containing secondary materials such struvite, EU issued revised fertilizer regulation 2019. A comprehensive overview supply and its quality presently missing. This study aimed: i) determine current production volumes, ii) evaluate all legislated physicochemical characteristics pathogen content against newly set regulatory limits, iii) compare not-regulated characteristics. It estimated that 2020, between 990 1250 ton P are recovered EU. Struvite 24 plants, accounting for 30% 80 installations worldwide was sampled. Three samples failed legal limits; one had <7% three exceeded organic carbon 3% dry weight (DW). Mineralogical analysis revealed six 80–90% DW, 13 >90% DW. All showed heavy metal below limits. Microbiological analyses indicated may exceed certain Differences morphology particle size distribution were observed sourced digestate (rod shaped; transparent; 82 mass% < 1 mm), dewatering liquor (spherical; opaque; 65 1–2 mm) effluent upflow anaerobic sludge blanket reactor processing potato wastewater 51 mm 34 > 2 mm). uniform soil-plant P-availability pattern 3.5–6.5 mg P/L soil/d over 28 days sampling period observed. No differences plant biomass yield In conclusion, results highlight suitability most enter market.