Water Treatment Saves Operating Cost In The Paper And Pulp Industry

Berlin, Germany — Rising water prices and stricter regulations on the quality of waste water call for new solutions for companies needing water for their production. With the integration of the product range of US market leader USFilter, the Siemens Industrial Solutions and Services (I&S) Group now provides optimized solutions for the paper and pulp industry. At the heart of the process, the waste water produced is treated immediately for recirculation into the production subprocess. Products and systems provided by I&S´ "Water Technologies" division enable full integration of individual processes into the production chain, covering fresh water treatment, secondary treatment and sludge treatment. This integration minimizes fresh water consumption and reduces or avoids the quantities of waste water produced. It also reduces the burden on the environment and saves cost.

Water is specifically used as a medium in almost all sections of the paper and pulp making process. Water is of decisive importance to the quality of pulp and paper. The process water used in each individual stage of papermaking is loaded with diverse substances and needs to be treated and purified before reuse or discharge.

The production of one ton of chemical pulp and paper requires up to 45 m³ of fresh water. Simultaneously, each ton produces up to 40 m³ of waste water. This means that an average pulp mill requires 63 million litres of fresh water per day.

In a typical paper and pulp mill, the cost of fresh water and discharging waste water accounts for up to ten per cent of production costs. New legislation with stricter regulations on discharge into rivers and sewage plants, added to rising fresh water rates, continues to drive up operating costs. Treating process water and closing water circuits helps to bring these costs down.

Siemens has developed water treatment and water circuit management solutions for each stage in pulp and papermaking. Each subprocess is equipped with the specific solution it requires, be it membrane filters, microflotation, anaerobic reactors, coarse filters or packed suspended bed reactors. Closing the water circuit in each stage of production rather than treating waste water collectively at a central plant, as was the case previously, has helped to reduce the amount of waste water produced while requiring significantly less fresh water.

SOURCE: Siemens