The Netherlands’ Wastewater Treatment Plants are Resource Factories
A key aspect of developing the circular water economy is extracting raw materials from wastewater. Read how the Netherlands’ wastewater treatment plants are resource factories.
In response to climate change, increasing resource scarcity, and environmental degradation, locations around the world are driving the transition towards the ‘circular economy’ that focuses on reducing material consumption, reusing materials, and recovering materials from waste.
In the context of water resources management, water utilities are beginning to promote the circular water economy that reduces water consumption, reuses and recycles water and wastewater, and recovers materials, including heat and minerals, from water and wastewater to not only mitigate greenhouse gas emissions but also enhance resilience to climate change.
The Netherlands’ resource factories
In the Netherlands, water authorities are government bodies responsible for flood protection, water management, and water quality. In addition to managing water quantity and water quality, the authorities aim to use as few raw materials as possible by taking into account the lifespan, renewability, and environmental impact of materials. Each year, the water authorities purchase goods and services worth around €2.5 billion, enabling them to make a significant contribution to the circular water economy.
Extracting raw materials from wastewater
Over the past few years, the water authorities have been exploring ways of recovering useful substances during the wastewater purification process and converting various sewage treatment plants into ‘energy and raw material factories’. These resource factories have already had various successes, including:
- Phosphorous: Phosphorous is a fertiliser, which is found in the form of phosphate in wastewater. It is recovered from water in the form of struvite. In 2019, five water authorities recovered 165 tonnes of phosphorous in the form of struvite
- Cellulose: Cellulose comes from toilet paper and can be recovered from materials sieved out of wastewater. The fibres can be made into paper or cardboard. In 2019, two water authorities recovered over 900 tonnes
- Kaumera: Kaumera is a new raw material extracted from sludge granules. It can be used as a binding and adhesive agent in the concrete industry or a water-repellent coating in agriculture and horticulture. In 2019, the world’s first Kaumera plant opened in Zutphen
- Biogas: Biogas from sewage sludge can be processed into high-quality green gas suitable for the public gas grid. One water authority will supply over 4.5 million cubic metres of green gas per annum to an energy utility. The green gas will then be purchased by the transport sector
The take-out
Wastewater, a source of resources not to be wasted.
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