With help from AVK, Mariagerfjord wastewater plant has been able to expand its capacity, cut costs and significantly reduce their environmental impact.
Looking at the population growth over the next 25 years, combined with a desire to greatly improve both the economic and environmental benefits of local wastewater treatment, Mariagerfjord Municipality has decided to build a new state-of-the-art wastewater treatment plant. With the supply of a wide variety of valves, AVK is proud to have been part of this newly established plant in the North of Jutland.
Today, the plant treats wastewater from approximately 75,000 population equivalents, but it is constructed to handle a wastewater amount equal to a population of 110,000, and to meet even stricter environmental legislation in future. The new plant is replacing 10 smaller plants, which in total have treated 5-6 million m3 of wastewater annually where only about 2 million m3 are from citizens and companies. The remaining wastewater is rainwater led into the wastewater sewers. An area that Mariagerfjord Water will optimise by making a 2-string pipeline where old 1-stringed network still exist and by replacing the combined sewers with separated sewers.
Significantly reducing sludge amounts
Centralising wastewater treatment in one large plant is a growing trend in Denmark. It makes it possible to treat the sludge and then stabilise it in an aerobe process in a digestion tank, where the organic material is transformed into methane and carbon dioxide. This, considerably, reduces sludge amounts making it a huge gain for the environment.
More specifically, a 2,000 m3 digestion tank reduces the amount of sludge, and makes it possible to produce bio gas that is transformed into energy used for heating and electricity. The digested sludge is dewatered in decanters and then transported in closed semitrailers, which is a cheap and “smell-safe” way to store the sludge. The cleaning process is so efficient that the discharge of organic materials, nitrogen, and phosphorus is significantly less than the total discharge of the 10 wastewater treatment plants it is replacing.