Enhanced nutrient removal MBR system with chemical addition for low effluent TP

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Bioreactor Systems

Background:

• Achieving ultra-low effluent total phosphorus (TP) concentrations is critical for preventing eutrophication.
• Conventional wastewater treatment often struggles to meet stringent TP discharge limits.
• Membrane bioreactors (MBRs) offer advanced wastewater treatment capabilities, but their application for combined biological and chemical phosphorus removal requires further investigation.

Purpose of the Study:

• To evaluate the performance of a membrane bioreactor (MBR) process for combined biological and chemical phosphorus (P) removal.
• To develop and validate a simulation model for predicting MBR performance and optimizing its design and operation.
• To assess the impact of chemical P removal on other biological treatment processes within the MBR.

Main Methods:

• Conducted a pilot-scale study of an MBR process with combined biological and chemical P removal.
• Utilized an activated sludge model integrated with a chemical precipitation model for simulation.
• Calibrated the simulation model using data from the pilot test to accurately represent system behavior.

Main Results:

• The pilot MBR system successfully achieved a very low effluent TP concentration of 0.025 mg P/L.
• The integrated simulation model accurately predicted effluent quality and mixed liquor suspended solids (MLSS) during the pilot study.
• Limited chemical addition for P removal did not negatively impact organic matter and nitrogen removal efficiencies.

Conclusions:

• The MBR process is effective for achieving ultra-low effluent TP concentrations through combined biological and chemical P removal.
• The developed simulation model accurately represents the pilot MBR process and can be used for optimization.
• Optimizing chemical addition control, especially under dynamic loading conditions, is crucial for sustained biological P removal and overall process efficiency.