We rely on water to live. However, we don’t always know what it takes to make it clean — or how much of the world struggles to find drinkable water.
As scarcity becomes a greater issue around the world, the water treatment industry — expected to be worth more than $38 billion by 2025 — is looking for new solutions. Here, nanotechnology — hyper-small scale tech on the scale of individual molecules — is breaking new ground and transforming how this liquid is filtered and purified.
The Growing Need for Clean Water
By 2020, about two-thirds of all people in the world are expected to live in water-scarce conditions. Other estimates show the trend isn’t likely to reverse and that by the middle of the century, vast populations could have difficulty accessing clean water.
New filtration methods could change this.
The most common methods of water treatment — filtering, reverse osmosis, and micro- or ultra-filtration — are effective, but require high amounts of energy. In some cases, they even need large quantities of chemical treatment agents. These chemicals have to be produced in areas with industrial infrastructure and transported to rural regions — which is not always easy or possible. Cheap and portable solutions that can filter even small amounts of water don’t always provide the high level of filtration needed to remove particles like dust and sediment or viruses and bacteria.
A lack of purification technology also leaves those without clean water vulnerable to the health effects of drinking toxic chemicals and microplastics, which can be present in places where drinkable water is the most scarce.
These populations are some of the most vulnerable — and the most in need of cost-effective and portable solutions. Nanotechnology could be the answer.
Water Purification at the Molecular Level
Water can be polluted in many different ways — through sediment, salt, chemicals, bacteria and heavy metals. Each of these pollutants can be of many sizes, and they can be separate from or totally mixed with the water. Not every filtration method provides complete purification.
New nanotech solutions are portable and provide high levels of filtration. There are several different types of nanotechnology that are being used or currently experimented with as water filters.
One of the most popular types of nanotechnology, carbon nanotubes, are cylindrical molecules made up of carbon atoms joined together in a single layer. The nanotubes look like miniature lattices or pieces of wire mesh, and are effective at filtering all sorts of things, including water. Effectively, these nanotubes are filters with openings that are molecule-sized. A nanotube will let water molecules pass through, but no pollutants.
Some nanotechnologies use ancient materials. Zeolite, for example, is a naturally occuring mineral that some scientists have taken an interest in due to how well it acts as an adsorbent in water. It can capture large, possibly dangerous molecules.
Many other nanotech possibilities are being developed — like magnetic nanoparticles used to extract chemicals, like dye, from water. The magnetization allows nanoparticles to be safely separated from the drinking water once used.
Traditional water purification systems require a certain amount of water to work. Because nanotech purification systems work at the nano-level, they should be applicable to even small amounts of water. This will be especially useful in the rural or difficult-to-access areas most likely to be affected by scarcity.
Many of these new nanotechnologies can also be incorporated into existing water filtration systems.
What Water Purification Will Look Like in the Future
More of the world is water-stressed, a trend that’s expected to continue in the future. New purification and filtration solutions are needed, and nanotechnology is a possibility that excites many in the water treatment industry.
The cost of materials and manufacture, however, may prevent nanotechnology from being used right away. This technology is still in its infancy. Large-scale fabrication of nanotech — especially carbon nanotubes — is both possible and already implemented in some industries. This technology is more expensive and less tested than other, more traditional solutions, but it holds promise.