Wastewater purification system, that floats
Amsterdam’s newly built De Keuvel floating housing development has its own floating wastewater treatment facility, a world’s first. It depollutes wastewater for 550 households and is energy-neutral.
The Buiksloterham area in Amsterdam used to be a bustling shipping yard. Now it is redeveloped into a popular area to live. The new neighbourhood is earmarked as a circular area which includes a sustainable wastewater treatment facility. However, due to the steep land values, it was deemed too costly to build the structure on land. Fortunately Dutch water company Waternet came up with a scheme to solve the problem and save money – build it on water.
Waternet assigned Dutch-Frisian company Desah to build a floating water purification installation near the floating housing development. Its base is a concrete box containing wastewater recycling equipment.
The installation cleans 2 types of waste water:
- grey water – wastewater from showers, kitchen and washing machines
- black water – wastewater from toilets
Grey water is the easiest to treat because of the low percentage of waste materials. After the purification process, the water is drained into the nearby IJ river.
Black water on the other hand, takes more time to purify the mix of solid waste materials and cannot be returned to the water stream. It has its benefits though. The installation separates the organic material into nitrogen, phosphor and biogas. The Phosphor is a component in making fertilizer, which in turn can be applied to treat nearby football fields. Additionally, the biogas can be used to power the facility.
The installation processes, recycles and drains the wastewater nearby the housing complex making it more sustainable and economical to operate compared to a regular waste water treatment facility.
To make the overall treatment more efficient and to conserve water, the floating houses are fitted with waterless vacuum toilets, the type used on ships. These toilets use 85% less water compared to normal toilets. It also has the advantage of making it easier to process the solid waste materials making it less difficult to extract the nitrogen, biogas and phosphor components.
Desah started the onsite treatment project with 32 households and has installed similar purification devices in Canada and Sweden - which are built on land. The company optimized the technologies and used it in the Amsterdam-project - which contains 550 houses, built on water.
Sustainable Urban Delta
The inherent complexities and pressures associated with densely populated urban areas are second nature to the Dutch. Over many centuries, authorities, industries, knowledge institutes, and citizens have striven to develop integrated approaches and a holistic vision to enable sustainable development of the urban environment – the Sustainable Urban Delta.