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Lunda Ytbehandling combines the expertise of several generations with modern equipment. Among the company's latest investments is a continuous sand filter that has given the company margins for all limit values. The company was started in 1938 in a villa outside Stockholm. At that time, watch links were polished by hand. Today, Lunda Ytbehandling employs 25 people and has a turnover of approximately SEK 35 million per year.
Delivering to Ericsson
The company's specialty is surface treatment with silver, copper, nickel or tin (glossy or matt) and aluminum chromating (yellow or colorless). Not least because of the success of electronics companies, Lunda Surface Treatment is very busy. A large part of the work consists of surface treatment of the parts that together form Ericsson's base stations for the mobile phone network. “We now deliver a lot to Bofors and Ericsson,” says Jarmo Laaksonen. “Other major customers are Algon and ABB.”
Flocculation is stopped in the filter With three automatic machines and a tumbling line, the company naturally also has several cubic meters of water to purify. For the chromium-containing water, there is a closed system with ion exchangers. The cyanide-containing and acidic/alkaline waters are each treated separately before being fed to the flocculation tank. After flocculation, it flows on to the lamella sedimentation, where the sludge is pumped to the thickener and the water flows to the sand filter. “Most of the flocculation settles as sludge on the bottom and goes on into the filter press, but there is easy flocculation,” says Jarmo. Previously, this was a problem because the water went directly from the sedimentation to the municipality's sewage system. But now the stray flocculations are caught by the new sand filter.
"If you buy a sand filter, you want everything to work perfectly. With Toveko, it's fun to see the results."
Simple and reliable It was in the autumn of 1996 that Lunda Surface Treatment invested in a continuous filter from Organo Toveko. “When the lamella was overloaded earlier, the dirty water flowed out. But now the filter works like a policeman,” explains Jarmo. For Lunda Surface Treatment, it was important to find a filter that did not have to be cleaned but could work continuously. Another advantage was that the filter takes up so little space. Now it is positioned so that the water flows down to the sand bed under its own power instead of being pumped there. “This way we neither broke the flocks nor wasted pump energy,” notes Jarmo. “In addition, we did not have to expand. We just had to install the filter next to the old facility.” Suspected small silver discharge Even though the authorities are not imposing any additional requirements on water treatment at the moment, Jarmo believes it is important to be prepared. With the filter switched on, there are margins to take. Since last autumn, the values for emissions of copper, nickel and chromium have improved significantly. The silver values are almost too good. The company sometimes releases less than 0.01 mg of silver per liter of water, which is on the limit of what is possible to analyze. But there is an explanation. At Lunda Ytbehandling, the excess silver is not allowed to run off. Instead, it is recycled on plates in a so-called Retec, an electrolysis equipment for recycling precious metals. “When we shake off the plates, we get 98 percent pure silver back,” says Jarmo.
Far below the limit value At Lunda Surface Treatment, the quality of the water leaving the company is tested every hour. And when the water comes out of the Toveko filter, it contains unusually low levels of nickel and cyanides and has a pH value of 9.5. Jarmo is satisfied. “We are constantly trying to improve the values, out of pure self-preservation. And now it is fun to see the result.”
Toveko Cleaning System offers innovative solutions for water and sewage treatment as well as efficient energy production. Our customized systems handle everything from stormwater to industrial waste water, and we ensure a high degree of purification with advanced technology and carefully designed processes. With over 30 years of experience and leadership in continuous sand filtration, we strive to create a sustainable environment for future generations.
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