Water boards enter into partnership with Slibverwerking Noord Oost Nederland B.V.
The Noorderzijlvest, Hunze en Aa’s, and Drents Overijsselse Delta water authorities have signed a 20-year agreement with Slibverwerking Noord Oost Nederland B.V. (GMB/EEW consortium) for the final processing of their sewage sludge as of 2021. The search for a new partner became necessary due to expiring contracts. The water authorities opted for the most sustainablesolution possible, including energy recovery, reuse of raw materials, and environmental requirements with regard to transport.
Sludge Processing North East Netherlands B.V.
Sewage sludge is a residual product from the purification of sewage water in treatment plants. After dewatering this sludge, sludge cake is produced. In total, the three water boards mentioned above will supply 86,000 tons of sludge cake per year to Slibverwerking Noord Oost Nederland b.v. (SNON) for processing. SNON is a collaboration between GMB BioEnergie Zutphen B.V. (GMB) and EEW Energy from Waste Delfzijl B.V. (EEW). Both parties have many years of experience in the final processing of sludge/waste.
Sustainable processing method
To process sludge cake, a combustible mixture must be obtained. To this end, part of the sludge cake is dried by biological sludge drying (composting) to produce bio-granulate. The other part is pre-dried. The bio-granulate and the pre-dried part are then combined and incinerated in a mono-sludge incineration plant. This means that only sewage sludge is incinerated in the incinerator. This results in, among other things, the production of energy (in the form of steam) and the possibility of recovering phosphate. In addition, this processing method saves 3.5 million m3 of natural gas per year.
Processing capacity
Nationwide, there is insufficient processing capacity for the final treatment of sludge. That is why the three water boards have decided to jointly market the total quantity over a long period of time. This will enable the business community to invest in new processing capacity.
Processing of dewatered sewage sludge
