Upgrading of a small overloaded activated sludge plant using a MBBR system

Area of Science:

• Environmental Engineering
• Wastewater Treatment Technologies
• Biofilm Systems

Background:

• Overloaded activated sludge municipal wastewater treatment plants (MWWTPs) face challenges in meeting treatment standards.
• Conventional systems often require significant infrastructure upgrades to handle increased loads.
• Fixed biomass systems offer potential advantages in space efficiency and operational flexibility.

Purpose of the Study:

• To evaluate the application of Moving Bed Biofilm Reactor (MBBR) technology for upgrading a full-scale overloaded activated sludge MWWTP.
• To assess the performance of MBBR in terms of hydraulic capacity, organic carbon removal, and nitrification.
• To validate pilot-scale findings at the full-scale plant.

Main Methods:

• Implementation of MBBR technology in an existing activated sludge reactor with minimal modifications.
• Pilot-scale experimentation to gather operational parameters.
• Integration of a lamellar settler to address secondary settler overload.
• Comparison of pilot-scale and full-scale plant performance data.

Main Results:

• Achieved a significant increase in treated flow rate, up to 60%.
• Demonstrated high removal efficiencies for organic carbon (88%) and nitrification (90%) at hydraulic retention times (HRTs) of 5.5-7 hours.
• Successfully overcame hydraulic overload in the secondary settler by incorporating a lamellar settler.
• Observed a strong correlation between pilot-scale and full-scale MBBR performance.

Conclusions:

• MBBR technology is a viable and effective solution for upgrading overloaded activated sludge MWWTPs.
• The system offers advantages in terms of increased capacity, high treatment efficiency, and ease of implementation.
• Pilot-scale studies provide reliable data for the successful design and operation of full-scale MBBR systems.