[Biofilm formation in an external loop three phase fluidized bed reactor]

Area of Science:

• Environmental Engineering
• Biotechnology
• Water Treatment

Context:

• Biofilm formation is crucial for wastewater treatment processes.
• Fluidized bed reactors offer advantages in handling biomass.
• Controlling operational parameters is key to optimizing biofilm development.

Purpose:

• To investigate the impact of sludge addition, C/N ratio, and hydraulic residence time (HRT) on biofilm formation in a three-phase fluidized bed reactor.
• To determine optimal conditions for rapid and stable biofilm development.
• To understand the relationship between suspended and attached sludge under varying HRT.

Summary:

• The study found that a sludge addition of 2 g/L and a C/N ratio of 8-12 were optimal for biofilm formation in granular activated carbon (GAC) fluidized beds (0.125-0.5 mm diameter) at 20-30°C.
• High C/N ratios (≥14) led to filamentous bulking sludge.
• Biofilm increased with HRT from 1-3 hours, stabilized between 4-5 hours, and decreased beyond 5 hours, correlating with suspended sludge levels.

Impact:

• Provides critical data for optimizing the design and operation of fluidized bed reactors for enhanced wastewater treatment.
• Offers insights into managing sludge characteristics and preventing operational issues like filamentous bulking.
• Contributes to the development of more efficient and stable biological treatment systems.