About the Dinxperlo Nereda WWTP - The Netherlands
Dinxperlo WWTP serves the town of Dinxperlo, which is situated in the East of the Netherlands, bordering Germany.
The plant processes around 570,000 litres of wastewater each hour, of which a third originates from Germany. The plant was built in 1970 and an upgrade was required, as the 40-year-old technology was too outmoded to meet current regulatory standards. More stringent effluent limits had been imposed and Waterschap Rijn en IJssel, the Dutch water authority which operates the plant, looked at the options available.
Following a year-long small-scale pilot trial, Royal HaskoningDHV was appointed to design and construct the Nereda plant, which was built while the existing WWTP remained fully operational. There are several exceptional features to Nereda technology, including the added value of the microorganisms. Unlike conventional treatments, where the purifying bacteria grow in flocs, the ones formed in the Nereda process grow in granules and sink. The whole process takes place in a single reactor tank, which has reduced building costs. The system also allows for a reduction in energy consumption and chemicals needed, as well as the plant’s overall footprint. At Dinxperlo an additional aspect of the design is the ‘Water Harmonica’, which revitalises the effluent flowing through different stages of biological habitats, before it is discharged to the surface water.
The project cost in excess of €2M and was fully operational by 2014. The plant now serves a population equivalent of 10,000. The plant’s daily average flow rate is 3,100 m³/day, with peak flow reaching 570 m³/h. Dinxperlo is unique, as during the process the purifying water undergoes further cleaning in an eco-water garden. Established in collaboration with the municipality of Aalten, the water garden is a former waste disposal site. The waste has been excavated, moved to the sides and covered with clean soil to construct a natural environment. Walking tracks have been established throughout this water park, so that the landscaped area can also be used for recreational purposes.