[Experiment of simultaneous denitrifying phosphorus accumulation].

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Technologies
• Nutrient Removal Processes

Context:

• Denitrifying phosphorus accumulation (DNPA) is a crucial process for enhanced biological phosphorus removal in wastewater treatment.
• Sequencing Batch Reactors (SBRs) are widely used for nutrient removal due to their operational flexibility.
• Understanding the factors influencing DNPA is essential for optimizing wastewater treatment plant performance.

Purpose:

• To investigate the conditions favoring Denitrifying Phosphorus Accumulation (DNPA) in a Sequencing Batch Reactor (SBR) using synthetic wastewater.
• To identify the critical operational parameters, including anaerobic stage duration and nitrate concentration, that influence DNPA efficiency.
• To evaluate the impact of different operational sequences on phosphorus removal via DNPA.

Summary:

• Acclimatized sludge demonstrated significant DNPA when nitrate was introduced after an anaerobic phase, highlighting the necessity of the anaerobic stage.
• Optimal anaerobic duration was found to be 1 hour when acetate was the sole carbon source and no nitrate was present during the anaerobic stage.
• Increasing nitrate concentration from 5 mg/L to 20 mg/L in the anoxic phase significantly boosted DNPA, with concentrations above 20 mg/L showing no further improvement.
• DNPA persisted even with a subsequent aerobic stage, with shorter aerobic periods correlating to a higher proportion of phosphorus removal through DNPA.

Impact:

• Provides insights into optimizing SBR operation for enhanced biological phosphorus removal through DNPA.
• Identifies critical operational parameters (anaerobic time, nitrate concentration) for maximizing DNPA efficiency.
• Contributes to the development of more effective and sustainable wastewater treatment strategies for phosphorus management.