Application Case Study (Pulp/Paper Operations)
The pulp and paper industry has traditionally been a consumer of large amounts of fresh water and power. Recently, increased focus has been given to the optimized efficiency of paper mills and to the environmental sustainability footprint of the industry. Therefore, water resource management has become a more critical factor facing the industry. Several reasons include a need for operating and maintenance cost savings, water resource shortages, and environmental regulations.
These reasons, have increased the trend of conserving fresh water in the paper industry through the increased use of specialized water reuse systems.
Reusing water in a paper mill can be very beneficial to the operations of a paper company. Adding water reuse system processes to recycle this waste water resource requires an overall understanding of processes, chemistry and water quality conditions, not only in the paper industry in general, but also of the particular paper mill/facility itself.
A mid-size pulp and paper company producing tissue/paper towel wanted to reuse their washing waste water to reduce cost of water usage and maintain environment compliance. The levels of BOD, COD, TSS, and turbidity were required to be reduced to allow for reuse.
- Raw BOD levels: 1689 mg/l
- Raw COD levels: 2646 mg/l
- Turbidity: 80-120 NTU
- TSS: 205 mg/l
Genesis Water Technologies provided process consulting/design as well as building and supplying the specified pilot system solution in association with a local partner.
The system included screen filtration, specialized electrocoagulation, followed by dissolved air flotation without chemical polymer introduction to separate solids. This was accomplished via batch process.
The system solution was installed by a local project management/contracting firm with technical assistance provided by Genesis Water Technologies, Inc.
The optimal removal percentage efficiency results are listed below:
- Treated BOD levels: 90% reduction
- Treated COD levels: 84% reduction
- Treated Turbidity: 92% reduction
- TSS: 99% reduction
Power consumption of specialized Electrocoagulation system - .62 – 1.16 kw / m3 (264 US gallons of treated water.)
The sludge production was minimized with a higher solids content that was easy to dewater, therefore, reducing associated disposal costs.
The system has operated successfully within the water quality parameters set by the client to allow reuse of their wash water in the production of their paper products.