DynaDisc installation resolves urgent need to reduce discharge levels
Himmerfjärdsverket, a water treatment plant south of Stockholm, is currently undergoing renovation work, which is due to be completed in 2018. Before this, however, the plant needed to find a quick solution to enable it to meet new, more stringent standards that have already come into force.
The challenge
Himmerfjärdsverket is scheduled to be fully operational again in 2018. However, new and more stringent requirements meant that the plant was forced to take action so that it would be able to keep running and continue releasing its treated water into the sensitive environment of Himmerfjärden Bay. Several different options were explored, but only Nordic Water’s solution was considered satisfactory.
The solution
On three different occasions, we installed a total of six DynaDisc filters at the plant. DynaDisc is a rotating disc filter system that combines intelligent design and state-of-the-art technology. Thanks to its unique construction, the filter offers exceptional reliability over a long period.
Our DynaDisc filters replaced ten overhead filters that were already there. The DynaDisc filters are installed downstream from the biological treatment stages and settling tanks.
The result
The SS levels discharged have been reduced to < 5 mg/l (well below the target value of 10 mg/l). Doses of both PAC and polymers are added as required.
Technical data
Qmax: 6,000 m3/h
Speed: 5-9 m/h, depending on inflow
Mesh size: 10 microns
Inflow SS: 20-30 mg/l
Outflow SS: < 5 mg/l