A Royal Task To Mastering Wastewater
Willem-Alexander, king of the Netherlands since April 2013, chose ‘water’ as his main diplomatic issue while still crown prince. For many years he presided over the UN’s Advisory Board on Water and Sanitation. Not really surprising. Solving water problems is historically Dutch and sanitation already a preoccupation in the Golden Age (17th century); Dutch housewives and maidservants were well-known for their cleanliness.
Image: ©Mediatheek Rijksoverheid / Hans Roggen Fotografie
Holland never relaxed its high standards when it came to water and sanitation. On the contrary. It continues to have the Dutch government’s full attention. Water and sanitation is big business in the Netherlands. It represents a sizeable percentage of the GDP with industry, business and universities heavily invested.
A prime example of Dutch innovation ‘Green Technology’ in this area can be seen in Sneek, an mid-sized town in the province Friesland, in the north of the Netherlands. As a follow-up to a small trial project, Sneek is replacing 280 older homes with new sustainable ones in the neighborhood ‘Noorderhoek’. These new houses will be equipped with effective new technologies to save water, and generate energy while purifying and processing raw waste materials to be used as fertilizers. These advanced technologies will make running a household more economic and will cut water and energy costs by an estimated 25 – 50 %.
Black and grey water reuse
The process is called ‘Decentralized sanitation and recycling’ (DeSaH). One of the basic components lies in separating so called black and grey domestic wastewater; the first is what comes from toilets and the latter is mostly wastewater from kitchens and bathrooms.
In the old houses all this wastewater was routinely flushed down the drain and into Sneek’s sewerage. It resulted in an expensive process needed to bring the contaminated residual flows up to the quality that could be discharged into the surface water, while nutrients are purified and made into valued fertilizer to be used in farming. The homes and the care center will also be fitted with other smart features, like a system for vacuum toilets and vacuum disposal of fruit and vegetable waste. A central fermenter converts this into biogas, renewable energy which is then used to heat the housing. Other advantages are the removal of nitrogen, phosphates and medications from wastewater and a reduction in the production of silt and CO2.
In the Netherlands there is already a large surplus of nutrients like phosphorus, nitrogen and potassium. They result as bare elements from the water purification and are essential ingredients in most fertilizers used in farming.
In emerging and developing countries, on the other hand, there’s a demand for quality fertilizers for their growing populations and expanding agricultural needs. Sustainability, on a world scale, is therefore helped by exporting purified raw materials like those that remain from the Noorderhoek project.
This project demonstrates that wastewater can be a provider of energy and resources. Wastewater treatment can provide energy rather than use energy
“Clean water and sanitation are not only about hygiene and disease, they’re about dignity, too. … everyone, and that means all the people in the world, has the right to a healthy life and a life with dignity. In other words: everyone has the right to sanitation.” ̶ King Willem Alexander