Common Issues in MBBR Process And The Solutions

The Moving Bed Biofilm Reactor (MBBR) is an efficient wastewater treatment system, widely used in industrial, medical, and municipal areas. However, during long-term operation, it may encounter issues such as biofilm sloughing, media clumping, and instability, which can reduce its treatment efficiency. In this article, we will discuss the causes of these problems and how to resolve them.

Biofilm detachment from the surface of mbbr filter media surfaces is a common issue, often caused by excessive aeration, industrial discharge/stormwater inflow, or temperature fluctuations. This can increase solids in the clarifier and deteriorate effluent quality.

Solutions:
• Adjust the aeration rate
• Install a flow equalization tank
• Monitor temperature, extend Hydraulic Retention Time (HRT) in colder conditions

Insufficient aeration, over-/under-filling of media, or prolonged biofilm retention can lead to excessive growth, causing media clumping and reduced treatment efficiency.

Solutions:

• Enhance aeration to improve air circulation

• Maintain optimal filling rate (30-70%) to prevent overcrowding

The lack of anoxic/anaerobic zones for denitrification in MBBR systems may disrupt the organic balance, making nitrogen and phosphorus removal difficult.

Solutions:
• Use an MBBR-IFAS hybrid system to enhance nutrient removal
• Add chemical phosphorus/nitrogen removal filters
• Adjust influent and supplement carbon if needed

Excessive foam and filamentous bacteria overgrowth can disrupt MBBR operation, often due to high F/M (Food-to-Microorganism) ratios, fats/oils, or low Dissolved Oxygen (DO).

Solutions:

• Implement pretreatment to control fat/oil inflow

• Maintain DO levels between 2-4 mg/L

• Regularly remove foam

MBBR carriers may escape the reactor if the screen system fails or excessive turbulence occurs.

Solutions:
• Install metal screens with appropriate pore sizes
• Use durable HDPE MBBR media

Direct sunlight exposure or excessive organic accumulation can trigger algal blooms, interfering with treatment.

Solutions:

• Install shading devices

• Adjust nutrient ratios in water

• Apply algaecides for control

Issues in MBBR system operation are manageable through optimized aeration, proper media filling rates, and other corrective measures. If you have further questions, please contact us. We provide standard MBBR products with own factory, as well as customized solutions to enhance your system's efficiency.