The Project - Waste Water Treatment Solutions in Pulp and Paper Industry

Thai Cardboard Co Ltd situated near Bangkok is a reputed manufacturer of Card board for printing and molded pulp products.


Production activities within the plant premises generates around 1.5 to 2 MLD effluent which is treated in a wastewater treatment plant comprising DAF followed by Micro Screens. The Primary treated effluent is then further treated biologically in a conventional activated sludge process.


  • DAF
  • Micro Screens
  • Activated Sludge
  • Secondary Clarifier
Waste Water Treatment Solutions in Pulp and Paper Industry
Fig 1 : Existing Treatment Unit


The existing activated sludge process was facing severe bulking problem having SVI values of 800-900 ml/g and also outlet COD was very high to the tune of 320 mg/lit which required to be controlled for meeting discharge limits. The excessive bulking had caused severe sludge floating and thus restricted the plant operation reducing the treatment capacity.

The Solution - Waste Water Treatment Solutions in Pulp and Paper Industry

  • In order to solve the clients specific issues related to sludge bulking , COD reduction and additional treatment capacity, trials were conducted at site with Levapor carriers.
  • After successful trial run of pilot plants, it was confirmed that addition of Levapor carriers certainly improves the COD reduction, sludge settling properties reducing bulking and also allows higher flow rates increasing plant treatment capacity.
Fig 2 : Results of the Pilot testing conducted at site.


  • After adding Levapor carriers in the existing activated sludge with little modification, within few weeks the plant had achieved remarkable improvement in the settling properties of sludge reducing bulking and also COD reduction improved drastically achieving COD < 100 ppm at the clarifier outlet. Due to better performance of the clarifier the unit was also able to treat higher flow rates through the biological process increasing the plant’s overall treatment capability.
Fig 3 : Results after full scale implementation


  • Higher flow rates to the tune of 2 MLD from same plant
  • COD < 100 ppm at the outlet of secondary clarifier
  • Reduction in sludge bulking and lower TSS carryover in the treated effluent
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.