Is tap water recycled wastewater

Wastewater treatment

"New Water": drinking water from wastewater

The Singapore water company is a pioneer in wastewater technology. The company extracts high-purity drinking water from municipal wastewater. This is technically possible today, but there is still a lack of acceptance among the population.

For this reason, guided tours are offered in Singapore that explain to visitors how the new technology works and why it is necessary in view of the increasing scarcity of water.

The suppliers advertise the water with a positive-sounding name: "New Water". Around 30 percent of the water requirement is now covered by recycled wastewater.

Filter and disinfect wastewater

Wastewater technology is on the threshold that scientists call a paradigm shift. The future lies in reusing water.

This is technically possible thanks to membrane technology. The polluted water is filtered and pressed through a series of membranes with extremely fine pores. Most of the unwanted substances, including bacteria, are filtered out in this way.

To turn wastewater into drinking water, it must also be treated with ultraviolet light. The so-called UV disinfection reduces the number of germs in the water many times over.

Recycle wastewater

So far, the principle of water supply in industrialized countries has been based on the principle of throwing away. Precious drinking water is removed and disposed of in the sewage treatment plant after use. This means that although it is fed back into the water cycle by discharging it into a mostly flowing body of water, it is not used further directly.

Scientists warn that in view of climate change and the increasing world population, this supply system is no longer up to date. As is common in the garbage system today, in the future the wastewater would also have to be separated according to its use. Then wastewater can be treated as a resource and be of great use.

Recycle wastewater and ingredients

Research is faced with the task of developing a sewage system that enables the sustainable use of water as a resource. The goal is to reuse not only the water, but also the ingredients in the wastewater. Wastewater is divided into gray water, yellow water, brown water and black water.

Gray water is the water that was used to wash the body and clothes. Yellow water is mixed with urine and brown water with feces. Black water is the name given to all wastewater that flows into the sewer system. Separating this wastewater makes sense because each can be used for itself.

Yellow water becomes fertilizer, brown water can be used to generate energy and gray water can be very easily converted into water that can be used, for example, for watering flowers and washing again.

Water recycling in Germany

In Germany, the installation of gray water systems in residential buildings or hotels is becoming more and more common. However, this is only recommended if the system is included in the planning for the construction of the house. Subsequent installation is very expensive.

The gray water - i.e. the water that occurs when showering, bathing or washing hands - is separated from the rest of the wastewater. In a water recycling plant, gray water is treated so that it can be reused for cleaning and watering and for flushing toilets.

Such systems should always be installed by specialists. Since the existing water supply system in Germany works well and water recycling is only profitable in new buildings, there will not be any significant separation of wastewater here in the foreseeable future. However, German companies sell water recycling systems to other regions of the world.