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Super clean whitewater replaces fresh water

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Super clean whitewater replaces fresh water

September 05, 2011 - 16:00
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BRUSSELS, Sept. 6, 2011 (RISI) -In China, the motivation is high to minimize water usage in paper mills, meeting stricter governmental regulations, combined with the focus to reduce costs through more efficient water and energy consumption. Many paper mills are actively pursuing plans to significantly reduce fresh water use and to return water to rivers cleaner than it arrived.

One proven approach, the PETAXTMfine filtration system from Kadant, is gaining popularity as a way to better manage water resources, including continuously circulating whitewater, and simultaneous capture of fibers and colloidal material. Management is assured of reduced costs for incoming and outgoing water, also making a positive contribution toward the national goal of minimizing industrial water usage. Independent of the water treatment system, the compact PETAX fine filtration system helps deliver consistently higher paper machine efficiency and runnability.

A wide range of paper, board, and tissue makers across Asia have chosen the PETAX to reduce water usage and save money. A paper and board producer in Thailand has now installed four units and has ordered another three.

With savings of 2,000 m3/day of fresh water, PETAX filters allow for whitewater reuse significantly reducing effluent load as well as providing recovery of fiber and heat from whitewater

Same water source for industry and communities

Usually a mill's water comes from the same rivers as fresh water for municipalities and farming. In addition to increasingly higher fresh water usage costs, fees continue to rise for effluent discharge. In 2010 the Chinese government mandated increased recycling of industrial water, and has offered incentives to achieve desired results faster.

Though national conservation policies have helped to limit increases, water use nevertheless climbed to a record 599 billion m3in 2010. Over the next decade, according to government projections, China's water use will reach 620 to 630 billion m3/yr , and an announcement earlier this year by the government indicates water use could reach as high as 670 billion m3/yr over the next decade.

Motivated by a desire for sustainable growth, cost savings, and the need to meet new governmental standards, more and more mills are progressively closing water loops and reducing fresh water consumption.

According to Tim Tian, team leader of water efficiency projects at Kadant Johnson's Wuxi facility, "China is moving quickly toward water saving systems, making more paper with less water, and recycling water without any linkage to wastewater treatment systems. Our PETAX system stands alone as an economical self-contained unit, whether there's a wastewater treatment system or not. In addition, our wide range of other products, including gravity strainers, multiple barrel pressure filters and shower systems, contribute to greater sustainability and smooth operation of mill equipment."

The system is capable of processing up to 240 m3/hr of white water with suspended solids in the range of 100-2000 mg/L. The recycled whitewater generated by this system can be reused for a wide range of functions, and does not clog equipment, such as shower nozzles.

As industry and human populations increasingly draw from limited fresh water resources, tapping into whitewater is proving to achieve profitability and environmental performance

To be continued ... Read Part IIhere.

Martin Koepenick has written about the pulp and paper industry for more than 2 years visiting mills around the