Ammonium removal using a vertically moving biofilm system

Area of Science:

• Environmental Engineering
• Microbiology
• Wastewater Treatment

Background:

• Ammonium-nitrogen (NH4-N) is a common pollutant in wastewater.
• Effective removal of NH4-N is crucial for environmental protection.
• Conventional methods can be energy-intensive or less efficient at lower temperatures.

Purpose of the Study:

• To investigate the efficiency and kinetics of NH4-N removal using a novel vertically moving biofilm system.
• To evaluate the system's performance at a low temperature (11°C).
• To assess the aeration efficiency of the vertically moving biofilm system.

Main Methods:

• Utilized a vertically moving biofilm system with high surface area plastic media.
• Biofilm modules were repeatedly moved vertically between air and wastewater.
• Monitored NH4-N removal efficiency, areal removal rates, and dissolved oxygen (DO) concentrations.
• Applied a zero-order empirical model to simulate ammonium removal kinetics.

Main Results:

• Achieved maximum NH4-N removal efficiency of 98.8% at 11°C.
• Observed areal NH4-N removal rates ranging from 0.68-1.94 g NH4-N m⁻² day⁻¹.
• Demonstrated that ammonium removal kinetics, post-carbonaceous oxidation, follow a zero-order model.
• Found the ammonium removal rate to be proportional to the square root of biofilm mass.
• Confirmed good aeration efficiency through DO concentration monitoring.

Conclusions:

• The vertically moving biofilm system is highly effective for NH4-N removal, even at low temperatures.
• The system offers predictable removal kinetics and efficient aeration.
• This technology presents a promising solution for sustainable wastewater treatment.