Unlock the Secret: How Inlet COD Dictates MBBR Biofilm Carrier Pore Selection in Wastewater Treatment

Introduction

At Small Boss, we’re passionate about empowering wastewater professionals with cutting - edge knowledge. Today, we explore a pivotal question: How does inlet COD concentration influence the choice of MBBR biofilm carrier pore numbers?

MBBR Biofilm Carriers: The Backbone of Efficient Treatment

MBBR (Moving Bed Biofilm Reactor) technology bridges traditional activated sludge and biofilm methods, using suspended carriers to boost microbial activity. Key advantages include:

• Continuous biofilm renewal

• Reduced clogging risk

• Enhanced oxygen and mass transfer

Pore numbers (e.g., K1 - K5) define carrier performance, balancing surface area, hydraulic flow, and biofilm growth.

Inlet COD: The Hidden Driver of Design

COD measures organic pollution levels, dictating treatment complexity:

• High COD (Industrial Wastewater)

  Requires high - surface - area carriers (more pores) for microbial attachment.

  Demands balanced porosity to prevent clogging and maintain flow.

  
  

• Low COD (Municipal Wastewater)

  Benefits from low - pore carriers for cost - effective, energy - efficient operation.

The COD - Pore Connection: Three Key Factors

1. Treatment Performance
   High COD requires dense microbial populations—achieved through carriers with more pores and larger surface areas.

2. Hydraulic Efficiency
   Fewer pores = higher porosity = reduced flow resistance and clogging risk for high - COD systems.

3. Mass Transfer
   More pores improve mixing and pollutant diffusion, critical for both COD levels.