The client, a leading Pulp and Paper mill in India enjoying the status of being largest Pulp and Paper premises of Asia for a long time, has a biological wastewater treatment process comprising MBBR as Pre treatment unit followed by Conventional activated sludge for the treatment of Pulping effluent. The plant has a capacity of 30-35 MLD. Existing MBBR has been filled with plastic BioChip MBBR media having 900 m2/m3 surface area. The MBBR is expected to achieve 50-60% COD reduction while remaining COD is to be reduced in the Activated sludge process downstream of MBBR.

upgradation of paper and pulp mill mbbr
Existing Pulping stream biological wastewater treatment plant


Due to inherent issues related to the production, the plant is continuously receiving varying qualitative and quantitative fluctuations of wastewater which is disturbing the process in the MBBR and reducing its COD reduction capability. Further, the production facilities are also undergoing continuous expansion for higher production which requires higher treatment capacity for the biological wastewater treatment plant.

Major Problems Faced:

  • Shock loads disturbing the process
  • Reduced COD reduction
  • Poor process recovery after the shock load disturbance


Due to presence of activated carbon and higher inner porosity with very high surface area, Levapor carriers offer much better protection against toxic shock loads.

Based on our previous experience, following solution was offered:

  • Transfer all existing plastic Bio Chip to MBBR2 making its filling ratio to 20%
  • Add Levapor carriers in MBBR1 at 10% filling ratio with 320 m3 media
Proposed Solution for the upgradation of existing MBBR


Over the past one year, the process has now stabilized much and the results are improved to as per the clients requirement achieving consistent COD reduction at the MBBR outlet.

Current Flow
800-1000 m3/hr
Inlet COD
800-1200 ppm
Outlet COD
360-540 ppm
COD reduction achieved
Author Bio

Amit Christian is a MSc graduate in Environment Science from Middlesex University, London, UK. He has been active in the field of water and wastewater treatment since 1998. He specializes in design, engineering, and management of various biological wastewater treatments such as Activated Sludge Process (ASP), Sequencing Batch Reactor (SBR), Moving Bed Bio Reactor (MBBR), Integrated Fixed Film Activated Sludge (IFAS). He has helped various Industrial and Municipal clients in troubleshooting , optimizing their biological wastewater treatment processes to achieve latest Stringent norms for Ammonia Removal.