The Mönchengladbach-Neuwerk sewage plant, operated by Niersverband, is located on the banks of the River Niers to the north-east of Neuwerk-Donk. The sewage plant site is about 22.5 hectares large. The plant treats the wastewater of more than 1.5 million residents living in the surrounding towns of Mönchengladbach, Korschenbroich, Willich, Viersen and Tönisvorst.
Sewage plant in Mönchen-Gladbach
On the one hand, our task was to drastically reduce crystallisation in the about 400m-long sludge pipe section between digestion and dewatering. On the other hand, we had to find a way to stop the frequently occurring disruptions in the dewatering centrifuges caused by crystal that entered the pipe and formed deposits.
In 2006 P.C.S. was first asked to plan and run a one-year-long test with half of the sludge volume generated by the plant using the MAP process.
At the end of the test phase in 2007 the customer asked us to build and install a large-scale turnkey plant. The special requirement was to technically cause the MAP to precipitate prior to separation in a way that it was possible to send it to sludge dewatering without it forming further deposits.
At the end of the one-year test phase P.C.S., as the general contractor, installed a sludge treatment plant to effectively precipitate MAP and discharge the crystals.
After six months of construction the large-scale application of this process, the concept of which was similar to the concept we had developed for Berliner Wasserbetriebe, was completed. We realised the actual MAP plant with a discharge rate of up to one tonne of MAP/day at the sludge dewatering location itself because it was the only place that offered sufficient space.
We named the process AirPrex® – and the results were highly satisfying:
The dewatering rate had significantly improved and phosphate concentrations in the entire sludge and wastewater system of the sewage plant had substantially declined.
Today, the plant consists of a pre-precipitation process in the area of the digesters and a post-precipitation process in the area of sludge dewatering.
The plant was built in:
Digested sludge treatment capacity:
- up to 1,500 m³/d (population equivalent: about 800,000)
Reduction of the phosphate concentrations in the sludge water:
- > 95%
Improvement of the sludge dewatering rate:
- plus 3.5% → a pay-back period of less than three years!
- up to 1 t/d