If you happen to be in Singapore…Better yet, if you happen to be in Singapore and you’re reading this in the shower or while you’re brushing your teeth, you’re using water from a closed loop system. The national water provider treats waste water and—instead of releasing it out to sea or into a river—it reinjects it into the water supply.
Don’t look disgusted. Not all waste water is stuff you’ve flushed out of the toilet. There’s water from the sink and the shower that isn’t so dirty.
Singapore is a severely water-challenged country, with few of its own resources. By 2040 it’s going to be one of the countries most vulnerable to water supply disruptions. But thanks to their efforts to become self-sufficient, it’s years ahead of many other countries when it comes to treating water. Their work will pay off. By 2060, 85% of Singapore’s water demand will be covered by what is calls NEWater and desalinated water.
So this closed loop system doesn’t make added demands on the environment. It’s the kind of thing that will be developed in other cities around the world in your near future.
Water climate solutions from wastewater
I mentioned toilets. There you have the idea of biogas in the wastewater on an … individual level. There’s already—in your time—a German company working on a toilet that treats waste and cleans the water so that it can be used for gardening. This will be a very important technology in Africa, for use on the many small subsistence farms that have little access to water.
What else is floating into your future?
Well, wastewater actually carries a lot of energy within itself. Wastewater has five times as much energy contained within it as the energy required to clean it. In particular, wastewater contains a lot of organic material that can be used to produce methane. Collect that methane from the water, and you can produce a lot of heat and electricity.
But wastewater is an even more valuable source of thermal energy. Thermal energy, recovered through technologies such as heat exchangers and heat pumps, can be used for district heating/cooling, agricultural greenhouses, and so on.
This is because wastewater exhibits a relatively high temperature, as it comes from warm sources such as showers, dishwashers and washing machines.
That’s just one of the innovations you’ll be seeing more of in the next decade.
Nitrogen, phosphorous and water climate solutions
Not only water and energy can be extracted from wastewater, though. It also contains nutrients, most importantly phosphorus and nitrogen that need to be removed to not overload the aquatic environment.
You might not hear about it a lot, but in the right doses, phosphorus is an element essential to sustaining life on the planet. Why? Because it’s a necessary element to produce our food. Phosphorus, in its phosphate form, is needed to fertilise the soil. But we’re running out of it. Extractable phosphorus mineral resources are predicted to become scarce or even exhausted in the next 50 to 100 years. At the same time, we are wasting so much of it that it pollutes the waters, and is a leading cause of eutrophication.
Part of the how we solve this crisis though has already been invented. Technology to extract up to 85% of phosphorus already exists. We just need to improve the technology and start implementing it across the globe.
Nitrogen, on the other hand, is not going anywhere. There’s a bunch of it in the atmosphere. So we need to just remove it, not recover it. But the method you use to remove Nitrogen from wastewater results in the formation of nitrous oxide, which is a potent greenhouse gas. If you recover the nitrogen instead, you can reduce greenhouse gas emissions, and avoid the overloading of the aquatic environment with nutrients. That’s going to be important point of attention in treatment technology choices and operating conditions because water and wastewater utilities are responsible for up to 7% of all greenhouse gas emissions.
Digital water climate solutions
We already talked about digitalisation, which is going to be a key innovation in water management, and it’s going to have a big impact on our ability to deal with climate change. Because, with temperatures rising, water becomes more and more precious.
Think of how digitalisation is starting to work in a city or even a home. You ride your bike down a bike path and sensors turn on the lights ahead of you, instead of running lights all night in case someone rides that way. That’s just one feature of a smart city. Or maybe your home has a smart meter that tells you when demand for electricity is low and, therefore, when you can use it cheaply. If you don’t have a meter like that now, you will soon.
These kinds of digital “smart” features are coming to water systems too. They’ll improve the detection of leaks. They’ll figure out the optimal way to store water around the system to prepare for a rainstorm. That means digital flood protections, creating extra water storage space so that areas don’t become flooded.
The water sector evolves more slowly than others we talked about, because it uses big infrastructure that doesn’t have to be replaced for decades. But all these changes are coming.
Desalinated water climate solutions
Look at desalination—taking seawater and turning it into water for domestic, commercial and industrial use. It’s been around for three decades. Gradually it’s becoming cheaper and cleaner. Certainly it’s widespread. Almost all Malta’s water is desalinated. Most of Israel’s water, too. There’ll be more of it soon in places that don’t yet fully realise they have a water shortage.
Because water—not enough of it, or too much of it, causing flooding—is also an issue in places that have always seemed to have just the right amount of water, in the past. In 2021, flooding in Germany cost €35 billion. The solutions for these problems won’t all be digital. They won’t all be about big pipes. Water experts are looking at what they call “nature-based solutions”, too. That could mean changing infrastructure so that, for example, floodwater is guided into a field where it can seep away into the ground, instead of sitting in concrete pools that don’t drain fast enough and can overflow.
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