Water authorities enter into partnership with sludge processing Slibverwerking Noord Oost Nederland B.V.
The Noorderzijlvest, Hunze en Aa’s, and Drents Overijsselse Delta water authorities have concluded a twenty-year agreement with Slibverwerking Noord Oost Nederland B.V. (a joint venture between GMB and EEW) for the final treatment of their sewage sludge, effective as of 2021. The search for a new partner became necessary due to expiring contracts. The water authorities have opted for the most sustainable solution, including energy recovery, reuse of raw materials, and environmental requirements regarding transportation.
Slibverwerking Noord Oost Nederland B.V.
Sewage sludge is a byproduct of wastewater treatment at wastewater treatment plants. After dewatering, this sludge forms sludge cake. In total, the three water authorities mentioned will supply 86,000 tons of sludge cake annually to Slibverwerking Noord Oost Nederland b.v. (SNON) for processing. SNON is a joint venture 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 and waste.
Sustainable processing method
To process sludge cake, a combustible mixture must be produced. To achieve this, part of the sludge cake is dried through biological sludge drying (composting) to produce bio-granules. The other portion is pre-dried. The bio-granulate and the pre-dried portion are then combined and incinerated in a mono-sludge incineration plant. This means that only sewage sludge is incinerated in the combustion chamber. The results include 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 capacity for the final treatment of sludge. For this reason, the three water authorities decided to offer the joint total volume on the market over a long period of time. This will enable the private sector to invest in new treatment capacity.
Processing dewatered sewage sludge
