3D Nanotech Breakthrough Offers Clean Water Purified by Sunlight

Everyone having access to safe, clean drinking water is one of the major challenges facing the world today.

Roughly half of the world’s population, according to the 2024 UN World Water Development Report, experiences severe water scarcity for at least part of the year. Water deficits have actually been linked to a 10% increase in global migration.

Low levels of wastewater treatment cause poor water quality in lower-income countries, whereas runoff from agriculture is a big problem in higher-income countries.

Meanwhile, the demand for clean drinking water continues to rise as the world population increases. Rapid population growth, urbanization, and increasing water needs from energy sectors, agriculture, and industry contribute to the rising demand for water.

However, data suggest that billions of people will lack access to safe water, sanitation, and hygiene in 2030. In 2022, 703 million people had no basic water service, while a much higher number, 2.2 billion, lacked safely managed drinking water.

Amidst this, water availability is becoming less predictable, while water scarcity is projected to surge with the rise of global temperatures due to climate change. Water resources are also at risk from pollution and waterborne diseases.

The Challenge of Untreated Wastewater

A vast majority of industrial waste, according to the United Nations, is disposed of in developing nations without being fully treated.

Meanwhile, only a small fraction of the world’s wastewater is adequately treated. According to the UN, the proposition of total wastewater receiving some level of treatment could only be calculated for 73 countries (42% of the world’s population), out og 107 countries (73% of the global population) that reported wastewater statistics for 2022.

Reporting on industrial wastewater treatment is extremely limited, with data only reported from 22 countries (8% of the world’s population), where a mere 38% of industrial wastewater has been reported to be treated. Moreover, just 27% of wastewater has been safely treated.

As for domestic (household) wastewater, 42% was not safely treated. The primary reason for this was the lack of an appropriate system for collecting greywater and blackwater.

Wastewater is water generated after the domestic, industrial, and commercial use of raw water, freshwater, or drinking water. It contains various substances that can be harmful to ecosystems and human health. 

Substances like heavy metals, organic and inorganic pollutants, pathogens, and industrial discharge, among others, introduced into water are not naturally decomposed, meaning they persist in the environment.

Then there are emerging contaminants, including detergents, industrial chemicals, pharmaceuticals, cyanotoxins, hormones, per- and poly-fluoroalkyl substances (PFAS), and nanomaterials, which are causing havoc.

Technological innovation can provide high-performance, low-cost treatment options to ensure sufficient clean, cheap water for all.

Some of these innovations in water purification include advanced membrane technologies such as reverse osmosis (RO), ultrafiltration (UF), and direct-contact membrane distillation (DCMD).

Solar-powered filters use solar energy to make clean water accessible in remote areas. Emerging technologies like electrocoagulation, microbial fuel cells, and advanced oxidation processes are also helping improve water quality.

Yet another technological innovation driving water purification is nanotechnology, which offers efficient removal of pollutants and germs. 

Nanotechnology For Effective Water Treatment

Conventional water disinfection methods are highly effective and, as such, widely utilized, but they have their own disadvantages. For instance, in chlorination, there is a risk of the formation of harmful disinfection by-products. Ultraviolet radiation, meanwhile, needs substantial energy inputs and has limited efficacy against the likes of tetracycline-resistant E. coli.

In a bid to improve water treatment processes, scientists have made technological advancements that have led to the use of nanotechnology in water purification for safe drinking.

Nanotechnology involves deliberate manipulation of matter at a really small scale, and it has the potential to play a key role in enabling integrated water management to increase the effectiveness of treatments and even expand water supplies by using unconventional water sources. 

To increase access to clean, safe drinking water, nanotechnology treats groundwater, surface water, and wastewater with innovative nanomaterials. Some of the advancements in nanotechnology used for wastewater treatment include magnetic nanoparticles, bioactive nanoparticles, nanofiltration, nano adsorbents, nanocatalysts, nanopowder, nano biocides, and nanofibers.

Scientists have popularly demonstrated the use of carbon nanotubes and nanocellulose for water filtration. These methods remove toxic heavy metals from water, prevent biological and chemical hazards from entering water, and adsorb contaminants from water streams. Even gold nanoparticles have been used to clear water of pollutants like pesticides and pharmaceuticals.

While nanotech offers promising solutions for clean drinking water, it faces potential health and environmental risks from nanomaterials and even bigger difficulties in large-scale production and cost, hence the limited implementation. 

Now, researchers at Ohio State University are offering a new method for purifying drinking water: 3D nanotech blankets. 

Made from titanium dioxide (TiO₂) nanofibers, they harness sunlight to break down harmful pollutants in water and generate sustainable energy. They don’t generate toxic byproducts, and the team has the tools to scale them up commercially.

A New Method for Purifying Drinking Water

In the latest study, supported by the National Science Foundation, researchers have created a new material to purify water by removing hazardous pollutants.

The new material has been developed by combining two methods — soft chemistry gels and blend electrospinning.

In electrospinning, a fiber production method, electric force is applied to a solution to create nanofibers. This method is commonly used to prepare long, continuous nanofibers. The team developed thin fiber-like strips of titanium dioxide this way.

Titanium dioxide (TiO₂) is an inorganic compound typically used in gas sensors, solar cells, photocatalysis, and self-cleaning technologies.

While the compound is a great alternative source of energy, solar fuel systems using its nanoparticles are usually limited in power. This is because they can only undergo photocatalysis by absorbing non-visible ultraviolet (UV) light, resulting in low efficiency and requiring complex filtration systems that create challenges in their implementation. 

Moreover, the short lifetime of the photogenerated electrons and holes in TiO₂ nanoparticles obstructs their effective utilization, while the lack of an easily recoverable self-supported nanostructure remains a challenge.

Various studies have explored doping it with various metal ions such as Ag (Silver), Fe (Iron), Pd (Palladium), Pt (Platinum), Zn (Zinc), Mn (Manganese), B (Boron), and Zr (Zirconium) to overcome these limitations and boost titanium dioxide’s photocatalytic properties.

But it was copper (Cu) that showed promise. Adding this soft metal with very high thermal and electrical conductivity to the material changed things. This, however, required reducing the optical bandgap and increasing the surface area to volume ratio of Cu-doped titania to obtain the desirable photocatalytic activity, which gave rise to other problems. 

So, the researchers had to design a system that provides stable Cu-doped TiO2 nanoparticles with a high surface area-to-volume ratio through nanofiber-based processes.

Click here to learn how solar-powered desalination is solving water scarcity.

A Water Remediation & Power Generating Tool

The study, published in the journal Advanced Science¹, detailed the new resulting structures, which are called nano mats. These nano mats could absorb enough light energy to break down hazardous pollutants in air and water.

According to lead study author Pelagia-Iren Gouma, who is a professor of materials science and engineering at The Ohio State University:

“There hasn’t been an easy way to create something like a blanket that you can lay on water and start creating energy. But we are the only ones who have made these structures and the only ones to demonstrate that they actually work.”

What adding copper did to titanium dioxide was that it supercharged the process of destroying pollutants.

Under this process, when TiO₂ absorbs light, electrons are formed, which oxidize water and attack pollutants, which are destroyed until they become benign. 

To determine the new material’s high effectiveness, researchers characterized the updated properties of the nano mat. This helped them understand how it behaved and what exactly made it different from other self-cleaning nanoparticles.

Researchers found that when exposed to natural sunlight, these nano mats can be more successful at power generation than traditional solar cells.

“These nanomats can be used as a power generator, or as water remediation tools. In both ways, you have a catalyst with the highest efficiency reported to date.”

– Gouma

What’s more, these fiber mats are lightweight, easy to remove, and can float and work above any body of water. They are also reusable and can undergo multiple cleaning cycles. 

Given the high effectiveness of these nanomats, researchers see their usage in removing industrial pollutants from water in developing countries and turning contaminated rivers and lakes into sources of clean drinking water.

On top of it, the fact that this technology doesn’t generate any toxic byproducts makes nanomats environmentally friendly.

“It’s a safe material, it won’t hurt anything, and it’s as clean as it can be.” 

– Gouma

As for the commercialization of this efficient technology, for which the team has the appropriate tools, it depends on industries taking notice of it.

“We have the tools to make them in large quantities and translate them to various industries. The only limitation is that it needs someone to take advantage of these abundant resources.”

– Gouma

Overall, the team believes in the nano mats’ potential. They could be used to provide clean drinking water in water treatment plants, remote areas, and disaster relief efforts. Depending on further testing and scalability, commercial applications could emerge within 3 to 5 years.

The team believes that these nano mats could also be promising tools in many future photocatalytic applications. These include long-term sustainability efforts like solar-driven hydrogen production and environmental remediation.

For now, the team is working on ways to further the material, which is completely novel. This new form of nanotechnology, Gouma said, is “really impressive and something that we are very excited about.”

Innovative Company

Xylem Inc. (XYL -2.11%) 

A global leader in water technology, Xylem develops innovative solutions for water purification and treatment, making it a strong candidate for integrating nanotech-based water purification systems.

The company offers products across a range of applications, including water, water pumps, treatment equipment, pumps, valves, and heat exchangers. It also provides analytical instrumentation for water testing and solutions for the intelligent use and conservation of critical water and energy resources.

When it comes to wastewater treatment, Xylem provides a biological process called aerobic treatment, which takes place in the presence of oxygen and converts organics into carbon dioxide and new biomass. Then there’s anaerobic wastewater treatment, which takes place in the absence of oxygen, where microorganisms break down organic wastes. It is usually used for the treatment of warm, high-strength industrial wastewater with a great quantity of biodegradable organic matter.

Xylem also offers a digital water management solution called Water One® that optimizes your water treatment system for greater efficiency.

The company’s disinfection systems are offered for municipal, industrial, and recreational water applications. They include analyzers and process controllers, chlorine dioxide generation equipment, gas feed systems, ozone systems, hypochlorite generation systems, ultraviolet disinfection systems, and more. 

Its high purity water systems, meanwhile, treat water through several steps to help you meet the quality standards for critical applications in lab, healthcare, pharmaceutical, and semiconductor industries.

Xylem’s filtration solutions meanwhile cover everything from regenerative media filters, disc filters, sand filters, high-efficiency microsand filters, and pressure filters to reverse osmosis membranes, screw pumps, UF systems, micro filtration, vapor phase odor control systems, and water softeners. This offers a wide range of options for recreational and industrial use as well as for swimming pools and tertiary wastewater treatment for municipalities. 

Now, Xylem is a $29.65 billion market cap company whose shares, as of writing, are trading at $122.02, up 5.17% YTD. It has an EPS (TTM) of 3.65, a P/E (TTM) ratio of 33.40, and an ROE (TTM) of 8.55%. The company pays a dividend yield of 1.31%.

As for company financials, for Q4 2024, it reported an increase of 7% in revenue to $2.3 billion, while orders were $2.2 billion. Earnings per share for the quarter were $1.34, up 22%, and came in at $1.18 on an adjusted basis, up 19%.

“The team delivered a strong fourth quarter to close a record-breaking year for Xylem. All segments delivered strong Q4 orders growth, giving us momentum coming into 2025 on resilient underlying demand.”

– CEO Matthew Pine

Net income during the quarter was $326 million, and adjusted net income was $287 million. Xylem increased its first-quarter dividend by 11% to $0.40 per share, which was paid to shareholders this month.

For the full-year 2024, the revenue was $8.6 billion, an increase of 16%. Earnings per share was $3.65, up 31% and $4.27 on an adjusted basis, up 13%.

For this entire year, Xylem’s outlook is revenue between $8.6 and $8.7 billion, and free cash flow margin is forecasted to be 9 to 10 percent.

The company is expecting its earnings per share for this year to be in the range of $4.50 to $4.70. According to Pine:

“Our 2025 guidance reflects the team’s commitment to our long-term framework as we continue to enable our customers to address the world’s greatest water challenges.” 

Latest on Xylem Inc.

Conclusion

The world is facing a water crisis with millions lacking access to safe drinking water and sanitation. This water scarcity is the result of a growing population, pollution, overexploitation, and climate change. The situation is projected to get even worse in the coming years, creating a need for cost-effective and more efficient solutions to tackle the issue.

Wastewater treatment is one such crucial strategy that can help mitigate water shortage by improving water quality, increasing access to water, reducing reliance on freshwater sources, and making water a more sustainable resource.

Nanotechnology has long promised to revolutionize water purification, but it has yet to gain widespread adoption. So, the development of 3D nanotech blankets marks a significant breakthrough. These blankets utilize sunlight to remove pollutants while generating sustainable energy.

The lightweight, reusable nature of these nano mats, combined with the lack of toxic byproducts, makes them an environmentally friendly alternative to conventional filtration methods. As industries take notice, this novel technology could redefine how we approach water treatment globally. A successful commercialization, meanwhile, will meet the clean, safe drinking water needs of hundreds of millions of people globally!

Click here for a list of top nanotechnology stocks.