Rehabilitation aerating nitrifikation filters.

The nitrifcation basins (NIT) at Veas are an important part of the biological treatment plant. The nitri fixation is carried out by nitrifying bacteria that use air and live in small leca bullets in the pool. At the bottom of the pool there are 4,200 nozzles that distribute process water and 4400 oxazurdyser that blow air through the water/lecacules. It is important for an effective nitri fixation that the oxazurdys are open and intact and that the pipes that deliver air to the oxazurdys are in good condition. Veas has 8 water treatment process lines with 4 nitrifcation filters per line, 32 in total. There is a need for 20 of the NIT filters to be inspected and rehabilitated. See Annex 1 for further details.