It is not enough to save water. You also have to reuse it

Treated wastewater can be used safely in gardening. Here the flowers are grown in Prague for wider use. 1 credit

Drinking water is becoming a scarce resource and one in four people in the world does not have access to a source of safe drinking water. Population growth and climate change are further exacerbating water shortages. That’s why we need to think innovatively and use our water resources smarter.

WIDER UPTAKE is a project that tests various ways to reuse in five different countries.

“The barriers that prevent are common to many countries, so our goal is to jointly identify the best solutions,” says Herman Helness, lead researcher and coordinator of the WIDER UPTAKE project.

And the issue here isn’t primarily a technology issue, he says. Barriers to water reuse are mainly rooted in existing regulations and the lack of business models.

For example, treated wastewater can be used to irrigate urban green spaces and agricultural land, and this is currently being tested in demonstration projects in Ghana, the Czech Republic and Italy.

“In order to use wastewater for large-scale irrigation, we first need to show that the water quality is good and that it does not contain any harmful substances,” says Helness.

Facts about the WIDER INTAKE

WIDER UPTAKE is a project that brings together researchers, water and sanitation companies and other companies from five countries. The aim is to identify the best way to exploit available water resources, limit emissions and discharges and develop sustainable business models. Various demonstration projects are underway to test circular business models, and the results will be used to compile a set of guidelines for smart water solutions. For more details, visit the site

The objectives of wastewater treatment plant operators and other participants in demonstration projects are:

  • Use treated wastewater to irrigate agricultural land and .
  • Recovering phosphorus and nitrogen from wastewater for use as fertilizer and for soil improvement (links to two articles).
  • Develop made from both cellulose fibers extracted from wastewater and calcite, which is a residual product from the purification of drinking water.
  • Making biochar from sewage sludge with the aim of replacing the charcoal currently used in the Ghanaian textile industry.

Green parks in Prague irrigated with wastewater

The Czech Republic also suffered from a lack of rain and for some time, and there is a great willingness to try new solutions.

Ongoing trials in Prague using wastewater to irrigate city parks are showing promising results. The first step is to demonstrate that it is both safe and profitable for the community.

Scientists at the city’s sewage treatment plant are testing various qualities of water for irrigating lawns, bushes and flower beds. They use untreated water from the river and three different qualities of water from the factory; treated, extra pure and polished. To date, tests have shown that all of these water types are good enough to irrigate plants and flower beds.

Credit: Jaroslav Pollert

The rules need to change

Technical solutions are in place and water quality has been found to be acceptable. The next challenge is to change the regulations so that an efficient business model can also be established.

It is currently prohibited to use wastewater for irrigation.

The EU has issued a separate directive governing the reuse of wastewater, but its application must be approved at the national level. The researchers thus held several meetings with the authorities, including the Mayor of Prague and the Czech Ministry of Agriculture.

Treated wastewater for urban agriculture in Ghana

Access to is also a major challenge in Ghana.

The country experienced a and urbanization since the 1950s, and shortages of treated water are a problem, especially in urban areas. However, there is no national strategy for water reuse, yet untreated wastewater is currently used to irrigate vegetable crops in urban areas.

Analyzes show that vegetables do not contain high values ​​of harmful substances, but many people are skeptical about eating vegetables that have been watered with sewage.

“An information campaign is going to be carried out to persuade people that vegetables produced from the use of treated wastewater would not be harmful to their health,” says Gordon Akon-Yamga, researcher at the Ghana Research Council scientific and industrial.

The long-term goal is to formulate public policies that encourage wastewater treatment plants to integrate water reuse into their design and ensure that farmers get better revenues to pay for wastewater. processed.

It will also be necessary to establish national standards for various forms of water reuse. Currently, Ghana applies the WHO standards for concentration limits of in water.

Unprofitable in Norway

So when are we going to start reusing wastewater in Norway?

“It is far from certain that this will be profitable in the near future,” says Herman Helness.

Wastewater decontamination is a very energy-intensive process. We still have large volumes of water here in Norway, and devoting resources to this will not be sustainable.

It is not enough to save water, it must also be reused

Urban farmers in Ghana use wastewater to irrigate their crops. Credit: Gordon Akon-Yamga

There is much more to be gained by improving the distribution network and preventing leaks of treated water from supply lines.

Other relevant water-saving initiatives include the use of gray water (from sinks, showers and washing machines) for toilet flushes.

The Norwegian pilot projects integrated within the framework of WIDER UPTAKE are thus looking into the recovery of other waste water resources, including phosphorus that can be used in fertilizers.

Defining what it is to be “water smart”

“Common to all the pilot projects integrated under WIDER UPTAKE is the need to show that the solutions are sustainable and ‘water-smart'”, says Helness.

Researchers are thus developing a method for measuring “water smartness” and durability.

“A water-smart society is one in which the true value of water is recognized and realised, and all available water sources are managed to avoid water scarcity and pollution, and closed loops and symbiosis are created to promote circular circulation, economy and optimum resource efficiency.”

“It’s possible to be sustainable without being water efficient, but not the other way around,” says Helness. “A smart water solution is sustainable and must also be financially profitable for the water industry,” he says.

The key here is to achieve better interaction between the water sector and the industries that plan to use water-derived resources.

To date, the demonstration projects integrated under WIDER UPTAKE have demonstrated that there is much to be gained from smarter water use.

UN Sustainable Development Goal 6: Clean Water and Sanitation

Clean water is perhaps the most important prerequisite for good health. Up to 1 in 4 people in the world do not have access to safe sources of drinking water. Even more do not have access to standard toilets or sanitation. Not only is it uncomfortable and degrading not to be able to go to the bathroom, but it is also very likely that the lack of opportunity to practice good hygiene increases the likelihood of the spread of infectious diseases.

There is enough fresh water in the world if we just manage it the right way. However, the economy and lack of infrastructure generally stand in the way of universal access. Moreover, in many places, population growth and climate change are exacerbating water shortages. It is therefore important to protect the sources of drinking water that we have and to invest in new water and sanitation facilities in regions that do not have them.

The objective related to water reuse is to extend international cooperation and capacity building support to developing countries in water and sanitation related activities and programs, including the collection water, desalination, water efficiency, treatment, recycling and reuse technologies by 2030.

Development of new wastewater treatment technology for semiconductor production

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