Hydroxyapatite Mineralization-Driven Granulation Enables Rapid Start-Up and Stable Operation of the One-Stage Partial Nitritation/Anammox Process.

Hydroxyapatite mineralization-driven granulation accelerates startup and stabilizes nitrogen removal in one-stage PN/A systems, achieving 85.24% efficiency within 40 days.

• Why it matters: Rapid and stable operation of PN/A processes is hindered by biomass washout, limiting their practical application in wastewater treatment. Improving biomass retention is crucial for efficiency and long-term stability.
• What they did: A hydroxyapatite-based strategy was developed using Ca/P regulation to promote granulation, with reactor experiments testing different Ca/P ratios and analyzing microbial community dynamics over time.
• The result: The approach enabled quick startup, high nitrogen and phosphorus removal, and stable microbial enrichment, demonstrating an effective method for enhancing PN/A performance and wastewater treatment sustainability.