Sludge treatment takes place using the KemiCond method on the island of Lidingö located north of Stockholm, Sweden. “Following process optimization, KemiCond has proven to function well and we’ve been very pleased with it here at Käppala. Any minor problems in the process seen at the beginning were eliminated by the introduction of the Bucher Drytech press,” says Project Leader
Håkan Wiktorsson from Kemira.
The basic idea behind KemiCond is to break down the water-retaining structures formed in sludge. In the Käppala process, sludge and the purifying agents − sulphuric acid and hydrogen peroxide – are added to the reactor in alternating steps. Once the reaction period is completed, the sludge is transferred to mechanical dewatering.
Clear benefits offered by the KemiCond method include reductions in the amount of sludge, polymer consumption and need to clean dewatering equipment as well as major reductions in odor. These have also helped make Käppala a better workplace environment.
In February 2011 the Käppala Association, formed by 11 municipalities using the services of the Käppala wastewater treatment plant, organized a seminar on increased efficiency in sludge treatment in cooperation with Kemira and Bucher Unipekt. The KemiCond project and the results obtained were presented by
Per Manhem, Managing Director of Käppala.
The audience consisted of consultants, journalists, environmental authorities and, of course, potential customers. “There was a lot of interest in the KemiCond process, which is likely to generate new cooperation in the future,” says Wiktorsson.
Text by Johanna Paasikangas-Tella
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