Background: In 2012, Pan Pac invested $20m to install a state-of-the-art Wastewater Treatment Plant (WWTP) that biologically treats wastewater produced in our Pulpmill.
Purpose: Our WWTP is especially designed to remove the organic compounds in wastewater generated from the pulping process. If we didn’t do this, the wastewater would have an adverse effect on the marine environment in which it is discharged.
Summary: Since operation began, our WWTP has been under constant improvement to provide stable operation and maximum treatment benefits. These have included:
- Additional cooling of the incoming wastewater by the installation of two large cooling towers. This promotes a stable process for healthy bacterial growth.
- AS basin membrane replacement to a tubular membrane lift out system providing improved mixing and oxygen delivery.
- MBBR media replacement and volume increase (what the microorganisms live on).
- Automation projects to improve the operability of the plant (i.e., additional instrumentation and control systems).
The three stages of our biological treatment process
1. Dissolved Air Flotation
We use air to froth the water and then skim the surface foam which holds natural oils and wood fibres. This material is collected and burned in our two boilers that provide steam for other processes.
2. Biological Consumption
We then use naturally occurring microorganisms to consume wood resins and nutrients in the water. This interaction often causes water discolouration due to natural pigments in the microorganisms.
3. Water Clarification
The biologically treated water is processed through a clarifier which allows the microorganisms to be separated for incineration. The remaining water is discharged via the pipeline.
This project is aligned with Sustainable Development Goal 6 – Clean Water and Sanitation.