Denitrifying phosphorus removal by anaerobic/anoxic sequencing batch reactor

Area of Science:

• Environmental Microbiology
• Water Treatment Engineering
• Biotechnology

Background:

• Biological phosphorus removal is crucial for wastewater treatment.
• Denitrifying phosphorus-removing bacteria (DPB) offer a sustainable alternative to conventional methods.
• Optimizing conditions for DPB is key to enhancing phosphorus removal efficiency.

Purpose of the Study:

• To verify denitrifying phosphorus removal in a laboratory-scale anaerobic/anoxic Sequencing Batch Reactor (A/A SBR).
• To investigate the growth and activity of DPB under specific anaerobic/anoxic conditions.
• To assess the impact of carbon and nitrate presence on phosphorus removal.

Main Methods:

• Operation of a laboratory-scale A/A SBR for 18 months.
• Enrichment and isolation of denitrifying phosphorus bacteria (DPB).
• Batch tests to evaluate the influence of carbon and nitrate on phosphorus removal.

Main Results:

• The A/A SBR system successfully enriched DPB capable of anoxic phosphate uptake using nitrate.
• Phosphorus removal efficiencies between 40-100% were achieved.
• Simultaneous anoxic phosphate uptake and denitrification were observed.
• The presence of both carbon and nitrate was found to be detrimental to denitrifying phosphorus removal.

Conclusions:

• The anaerobic/anoxic strategy is effective for enriching DPB and achieving significant phosphorus removal.
• DPB can utilize nitrate as an electron acceptor for phosphate uptake under anoxic conditions.
• Wastewater management strategies must consider the interplay between carbon sources and nitrate to optimize denitrifying phosphorus removal.