The problem of water scarcity is more pressing than we can imagine. According to the data presented by the United Nations Environment Programme, close to 50 percent of the planet’s population, which translates to nearly 4 billion people, deal with water shortfalls at least one month of the year.
Next year, by 2025, 1.8 billion people are likely to face what the Food and Agriculture Organization (FAO) calls “absolute water scarcity.”
Tackling such a humongous and all-pervasive problem requires innovative solutions, solutions that use unexplored or underexplored resources.
For instance, combating the issue of water scarcity could have seawater turned into fresh water, which is one of the most effective solutions since the supply of seawater is abundant. It would be better if the process could be carried out using renewable energy, like solar power.
In the following segment, we delve deeper into research that has achieved a breakthrough in this area.
Energy-Efficient Device to Produce Drinking Water from Seawater
Turning seawater into fresh drinking water would require desalination. However, the current desalination systems that pump seawater through membranes to separate salt from water are not only energy-intensive but also suffer from salt accumulating on the device’s surface. Resultantly, the water flow gets obstructed, reducing efficiency. These salt depositions make these machines unfit for continuous operation and cost-intensive, requiring frequent maintenance work.
A team of University of Waterloo researchers have now come up with a solution inspired by the water cycle of nature, drawing heavily from the ways trees transport water from roots to leaves.
According to Dr. Michael Tam, a professor in Waterloo’s Department of Chemical Engineering:
“Our inspiration comes from observing how nature sustains itself and the way water evaporates and condenses in the environment.”
Since the mechanism draws inspiration from the natural water cycle, it hardly requires major maintenance.
The process involves an engineered solution that induces water to evaporate, transports it to the surface, and condenses it in a closed cycle. The outcome is effective prevention from salt accumulation and enhanced device longevity with uncompromised efficiency.
What adds to the benefits of the device is that it uses renewable energy, making the device energy-efficient. It runs on solar power and can convert close to 93% of the Sun into energy.
The efficiency is five times better compared to the current desalination systems available in the market, producing close to twenty liters of fresh water per square meter.
Interestingly, it is the same quantum of water that the WHO recommends for each person every day for basic drinking and hygiene.
To make the device efficiently use solar energy, the researchers used the base material Nickel (Ni). The nickel foam foundation was provided with a conductive polymer coating and thermoresponsive pollen particles. The composition made the material conducive for absorbing sunlight across the solar radiation spectrum.
For the upward movement of water, a thin layer of salt water was heated up and transported. It is similar to how water travels through natural tree capillaries. The evaporation of water leads to the remaining salt moving to the bottom of the device.
The simplicity of the solution makes it ready for greater adoption. Its portability ensures that it can be used in remote regions, especially in coastal and island nations.
While summarizing the gross benefits of the solution, Dr. Yuning Li, a professor in Waterloo’s Department of Chemical Engineering, said:
“This new device is not only efficient but also portable, making it ideal for use in remote regions where access to fresh water is limited.”
To elaborate on the potential benefits further, Dr Michael Tam said the following:
“If the test is proven successful, the technology can sustainably supply fresh water to coastal communities and advance UN Sustainable Development goals three, six, 10 and 12.”
While the above-mentioned research has raised much hope in the scientific community and people working towards sustainable freshwater solutions, other researchers have been at it, too.
In the coming segment, we discuss the development of a portable desalination unit that MIT researchers proposed in 2022.
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A Portable Desalination Unit to Generate Clear, Clean Drinking Water
In April 2022, MIT researchers developed a portable desalination unit that weighed less than 10 kilograms, about the size of a suitcase. It could run with less power than what was required to operate a cell phone charger. Available for purchase at US$50, like the device we discussed in our previous segment, this one, too, came free from the need for water passing through the filters. Instead, it used electrical power to remove particles from drinking water.
Ion Concentration Polarization Technique Making the Unit Filter-Free
The process, a result of the researchers’ decade-long work, involved applying an electrical field to membranes placed above and below a water channel. The membranes could repel positively or negatively charged particles, including salt molecules, bacteria and viruses, as water flew past them. The process could help get rid of both dissolved and suspended solids.
The researchers, in devising their solution, made prudent use of the best available techniques, including machine learning. Machine learning proved effective in finding the ideal combination of ICP and electrodialysis modules since the process involved six modules in total.
The researchers also kept in mind that devices like these, which would only prove effective if they got a lot of adopters, must be easy and simple to use. Therefore, it could be launched with only one button for automatic desalination and purification.
It could also notify the users when the salinity level and particle numbers came below a specific tolerable threshold. To make the reading of data simple and intuitive, the researchers offered a smartphone app capable of controlling the unit wirelessly and reporting all available data on power consumption and water salinity in real-time.
Funded, in part, by the DEVCOM Soldier Center, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS), the Experimental AI Postdoc Fellowship Program of Northeastern University, and the Roux AI Institute, the research provided satisfactory results.
The researchers took the solution out of the lab and tested it at Boston’s Carson Beach. The resulting water exceeded the World Health Organization quality guidelines by reducing the number of suspended solids by at least a factor of 10, while the prototype generated drinking water at a rate of 0.3 liters per hour, requiring only 20 watt-hours per liter.
Elaborating on the game-changing nature of the experiment, senior author Jongyoon Han, a professor of electrical engineering and computer science and of biological engineering and a member of the Research Laboratory of Electronics (RLE)., had the following to say:
“This is really the culmination of a 10-year journey that I and my group have been on. We worked for years on the physics behind individual desalination processes, but pushing all those advances into a box, building a system, and demonstrating it in the ocean, that was a really meaningful and rewarding experience for me.”
While university researchers are heavily engaged in this noble pursuit, there are several companies that have taken up the job of desalinating water. Their contribution is equally crucial as large-scale adoption requires scaled-up solutions that work at a commercial scale. In the following segments, we look into a couple of such companies.
#1. Consolidated Water Co. Ltd. (NASDAQ: CWCO)
The company has its engineering services ready to empower its clients with the complete design-build of Sea Water Reverse Osmosis desalination systems. The company caters to the entire service cycle that involves installation, expansion, or retrofit.
The company, listed and traded on Nasdaq, carries out the management, engineering, and construction services for desalination through DesalCo, recognized by suppliers as an Original Equipment Manufacturer (OEM) of reverse osmosis seawater desalination plants for the Company.
Technologically, the company recognizes two principal methods for desalinating:
(i) Thermal distillation
(ii) Membrane separation.
The company prefers the latter due to its lower energy costs. The company deploys reverse Osmosis membrane separation for brackish and seawater desalination. It is a fluid separation process where the saline water is pressurized, and freshwater is separated from the saline by passing through a semipermeable membrane that rejects the salts.
The Seawater Reverse Osmosis plant of Consolidated Water is based out of Nassau, New Providence, the Commonwealth of the Bahamas. Commissioned in July 2006, the plant has an operating capacity to deal with 12 million US gallons of water per day.
In 2023, the company completed the acquisition of the remaining 39% ownership of PERC Water Corporation (“PERC”) to become the 100% owner of this subsidiary, which designs, constructs, operates, and manages water infrastructure facilities in the Southwest U.S.
In the same year, PERC was awarded a new $204 million contract to design, construct, and operate a new desalination facility in Honolulu, Hawaii.
The company’s retail operations in the Cayman Islands produce potable water at three seawater reverse osmosis desalination plants in Grand Cayman located at its Abel Castillo Water Works (“ACWW”) and West Bay sites.
The current aggregate production capacity of the two plants located at ACWW is 3.0 million gallons of water per day. The production capacity of the West Bay plant is 1,000,000 gallons of water per day.
In 2023, the company earned a revenue of US$180.2 million, a significant jump from its 2022 revenue of US$94.1 million. 2023 saw the company register record net income and earnings per share from continuing operations of $30.7 million and $1.93, respectively. The price of the company’s common stock reached an all-time high of US$38.29 in November 2023.
#2. Veolia
The company sees desalination as a key solution to fight water scarcity. It claims to have built hundreds of desalination plants and systems all over the world, producing freshwater for both municipal and industrial needs. The company’s most recent flagship projects included the Al Dur 2 plant in Bahrain, the Rabigh 3 plant in Saudi Arabia, and the Umm Al Quwain IWP plant in UAE.
Since 2007, the company has been responsible for building and operating the seawater reverse osmosis plant of Sur, together with the Oman Power and Water Procurement Company (OPWP). The facility provides drinking water to more than 600,000 people. Veolia also builds desalination facilities for industrial needs.
Veolia’s proprietary Barrel technology is a safe, compact, and digital RO desalination system whose plug-and-play approach helps secure a fast-track schedule while its embedded digital sensors ensure efficient remote monitoring.
Veolia, apart from its direct desalination solutions, also helps its clients with a combination of digital tools and expertise that makes processes smarter, safer, and more sustainable.
Its installed base services portfolio offers customized water treatment services tailored to the exact needs of the client. The mobile water services of Veolia deal in rental assets that support and assist the client’s site operations for temporary and longer-term water treatment needs. Finally, under its water treatment chemical programs wing, the company offers water hygiene and HYDREX chemical solutions that help enhance the performance of utility and water treatment equipment.
Veolia (OTC: VEOVY) shares trade on the over-the-counter (OTC) market. In the first half of 2024, the company registered a revenue of 22.141 Billion Euros, a slight decline from the H1 2023 revenue of 22.755 Billion Euros. Out of this 22.141 Billion, nearly 8.8 Billion Euros came from the business division that caters to water needs. The other two pertain to waste and energy.
The Growing Importance of Desalination
A significant volume of water comes from desalination already. According to the data presented by the International Desalination Association, the cumulative contracted desalination capacity has now surpassed 100 million m3/d and nearly 60% of desalination is devoted to human consumption. According to estimates, some 300 million people rely on this process for their daily water usage. Countries like Kuwait produce almost 100% of their freshwater use through desalination.
However, desalination projects are not yet distributed uniformly worldwide. The Middle East and North American regions cumulatively account for more than 70% of the world’s desalination capacity. Out of this 70%, the Middle East alone accounts for more than 53%.
Data also suggests that there were more than 21,000 seawater desalination plants in 2022, with a daily global production of 99 million m3/day of desalinated water. However, this production volume also results in more than 150 million m3/day of brine byproduct. Brine is the slightly concentrated seawater rejected by the Desalination plants to the sea. The salt content of the brine is roughly 60g/l for seawater at 40g/l, while the temperature of the brine reject is slightly higher than that of the seawater – a few degrees Celsius.
Future research will have to invest time and resources in finding ways that are more environmentally friendly. The use of solar power in running these plants helps reduce the carbon footprint of these facilities significantly. However future research must ensure that nearly all the seawater input gets converted into fresh drinking water. This will ensure that there is no harmful rejection coming out as a by-product.
Successful transportation and distribution mechanisms will ensure that this water goes beyond the nations located on the seashore and reaches arid, dry regions with no significant drinking water source nearby.
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