A team from the UAE is one of four winners of the second edition of the global FoodTech Challenge in Abu Dhabi.
The team from Dubai-based agritech company Revoltech uses electromagnetic fields to speed up the freezing process, which allows food to be preserved for up to 50 years.
Other companies sharing the win with Revoltech are:
Aguagrain — Creating a soil improver made from organic waste that can absorb 30 times its weight in water, supplying water and food to crops. It requires no fertilizers.
Sustainable Planet — Developing a plant-based protein that can be grown in salt water, with 20 times less water than other protein isolates require.
Orbisk — Using AI technology to quantify food waste to reduce food-waste cost, water waste and carbon emissions.
The Abu Dhabi Ministry of Climate Change and Environment started The FoodTech Challenge to encourage sustainable food production and address food waste.
The winners of the 2022 FoodTech Challenge will share a U.S.$2 million prize. The prize also includes start-up incentives, mentorship programs and grants. Close to 700 applicants from 79 countries applied for this year’s competition.
Others who have won the award have had success bringing their projects to life.
One of the winners from the first edition was Ryan Lefers of Saudi Arabia-based Red Sea Farms. Red Sea Farms builds sustainable technologies to grow food in such harsh environments as deserts.
For prospective participants in future FoodTech competitions, Lefers advises, “Carve out time to wholeheartedly invest in the process of the FoodTech Challenge because ultimately, it is an investment in your business. It is worth it to create a thoughtful application and to engage fully in all of the mentor sessions,” in an interview with FoodTech Challenge.
Global food insecurity is on the rise. The World Food Programme estimates 345.2 million people in the world will be food insecure in 2023 — double what it was in 2020.
Linda Zou is a UAE researcher who uses nanotechnology to develop new materials for cloud seeding, a weather-modification technology that improves the chances a cloud will produce rain. She talked to the KUST Review about her work and the future of cloud-seeding technology.
CREDIT: Khalifa University
Linda Zou
Linda Zou is a professor in the Khalifa University Department of Civil Infrastructure and Environmental Engineering and the head of the Nano and Water Laboratory. This interview has been edited for space and clarity.
QUESTION: Walk us through the basics of cloud-seeding technology and what should people who aren’t familiar with cloud seeding know.
ANSWER: The sun shines and water vapor rises up from the Earth’s surface, and these tiny water vapors will keep on rising and finally condense to become either rain or snow.
In the presence of small particles as nuclei, water vapor condenses, turning into small liquid droplets. And that droplet will hit another small droplet during the falling process, and then they form a larger droplet. The size grows and grows. When the drops reach the lower part of the atmosphere, they’re too big, too heavy, and they fall as rainfall. And unfortunately the availability of this sort of small seeding nuclei in the atmosphere is unpredictable. It could be naturally occurring particles such as volcano ashes, dust particles or pollens. But when you need it you can’t guarantee you’ll get it.
Cloud seeding is to spread artificial seeding materials by using aircraft, flying over the bottom of suitable clouds and releasing the seeding materials, and an updraft will carry them into the cloud, to start the condensation and turn the water vapor into water droplets artificially. And this is the cloud-seeding process.
Q: How important is it to the world to tap that atmospheric moisture?
A: The World Meteorological Organization (WMO) did a survey and reported more than 45 countries are practicing some sort of weather modification. Cloud seeding is one of the major (weather-modification) technologies. This implied the advancement in the cloud-seeding materials could have a wider impact to combat the water-shortage problem globally.
Q: Is cloud seeding used primarily in desert countries or are a broad range of countries practicing it?
A: (Cloud-seeding) is technology-driven; commonly you need aircraft fleets. Countries like the US, South Africa and some European countries are very active, particularly in agricultural protection, as well. (Countries may have) a different purpose: Russia is more interested in hail-suppression. China has dry regions. For many decades, the science behind this water-related process hasn’t had much innovation, UAE is driving innovation through its UAE Rain Enhancement Science Program.
CREDIT: Anas Albounni, KUST Review
AI and nowcasting
Cloud seeding can increase a region’s rainfall, but knowing when the conditions for cloud seeding are optimal can be difficult. Read more›››
Now, researchers who recently won a U.S.$1.5 million grant from the UAE’s National Center of Meteorology think they can help by tapping into artificial intelligence.
Luca Delle Monache, deputy director of the Center for Western Weather and Water Extremes (CW3E), Scripps Institute of Oceanography at the University of California, San Diego, in March received the three-year grant of the UAE Research Program for Rain Enhancement Science (UAEREP) for the project using a hybrid machine-learning framework for enhanced precipitation nowcasting.
Nowcasting in meteorology is describing the present or predicting the very near-future weather conditions. Khalifa University’s Ernesto Damiani, Linda Zou and Hussam Al Hamadi will gather data and create a prototype artificial intelligence system for data fusion and weather nowcasting for the project.
Alya Al Mazroui, UAEREP director, says the work will continue the organization’s role in advancing rain-enhancement technology, as well as “promoting the UAE’s status as a prominent hub for rain-enhancement research and helping the world tackle the challenges posed by the scarcity of potable water.” ‹‹‹ Read less
Q: That leads into the next question: What are some of the problems and limitations that your work is looking to solve?
A: The kind of seeding material adopted around the world heavily depends on atmospheric relative humidity. That means the seeding material released is only activated or useful at very high relative humidity. So a lot of cases you release (the seeds), and if it isn’t very humid conditions, it’s not useful. So because I’m thinking on the science of the interactions between materials and atmospheric relative humidity, I can see that there’s room to improve.
Q: And your proposal is to change the seeding material?
A: Yes. I proposed three ideas: Each has been investigated and concept is realized. The first is to change the surface of the material to make it more reactive (so it can work) at a lower relative humidity. Instead of 75 percent or higher, now we can use it at 65 percent.
To achieve this, we used nanotechnology to engineer a material that is activated in much broader relative-humidity conditions. Because the structure is so porous, water will melt easily, forming larger droplets, increasing the probability that it will work.
Secondly, a bioinspired hydrophilic/hydrophobic pattern was created on the seeding material to enhance the interaction with water vapor; thirdly, a porous 3D nanocomposite was developed to promote ice nucleation and growth for cloud-seeding in cold clouds.
Q: Old-technology cloud-seeding materials might be harmful to the environment. That’s another problem you’re looking to solve?
A: There are different types of seeding material used. Various salt particles are used for warm clouds; their environmental effect is less of concern. But the one you hear about is mostly silver iodide, which is mostly for cold clouds – for ice- and snow-making. Over longer periods of application, silver iodide may pose some toxic effects. It is not used in my research project, as the design of novel seeding material is to steer away from potential harmful materials.
Q: Some of your materials are inspired by natural adaptations in biological organisms. What would you say is the value of looking to nature to solve problems?
A: Nature has evolved over millions of years. Every biological system that thrives today is the positive result of evolution. Modern analytical tools enable scientists to look at the details of biology at the biochemistry level and have more understanding on how they work. This newly gained knowledge helped us to mimic the biological mechanism in designing nanomaterials. Although we’re not able to replicate biological mechanisms, I can be inspired and learn from their principles.
Cloud-seeding materials are spread by airplanes but can also be released by balloons and drones. CREDIT: UAE Program for Rain Enhancement Science
Cloud seeding
and beyond
The United Arab Emirates’ rain-enhancement operations began in the 1990s and were developed in cooperation with such international organizations as the United States’ NASA and National Center for Atmospheric Research. Read more›››
According to the UAE Program for Rain Enhancement Science, the Emirates now have more than 60 networked weather stations, five specialized aircraft used for seeding and an integrated radar network.
Other benefits from cloud-seeding research include increased understanding of cloud microphysics; cloud dynamics and thermodynamics; the physical chain of events that lead to cloud formation and rainfall; and how cloud-condensation nuclei and ice nuclei interact with clouds.
Research impacts include improved cloud-seeding materials and delivery methods and helping meteorologists better nowcast and forecast the weather. ‹‹‹ Read less
Q: What would you say are the biggest challenges to seeding clouds?
A: One of the major problems is all cloud-seeding operations are carried out in the open atmosphere. All the conditions cannot be controlled as in a closed system.
Secondly, all clouds are different at a time and they’re also varied and unpredictable. These make the evaluation of cloud-seeding effects difficult. But we accept this unpredictability. And if the seeding materials become more and more efficient, the probability (of success) is higher for any given cloud conditions.
Q: Some of your work focuses on ice and snow instead of rain. How are these approaches different?
A: It’s different and it’s the same in some regions. Clouds that form at a few thousand meters above us are in sub-zero temperatures. Precipitation at that altitude will be ice. But when ice falls down to the earth, if it falls down in cold regions it will be snow. If it falls down to the warm regions such as UAE it will melt into rain.
So for clouds with sub-zero temperatures, different techniques have to be used. The sub-zero clouds’ conditions are different. The water vapors are oversaturated in some cold clouds, so their relative humidity is like more than 100 percent but they stay as supercooled water vapor. So at this stage if (the supercooled vapor meets) a suitable ice nuclei it will form ice crystals and grow rapidly as an ice explosion, as an avalanche of ice crystals.
So I also investigate to develop this type of ice nuclei. The ice nucleus is often silver iodide. Why? the possible theory behind is that its crystal structure is similar to the ice. So crystal grows on the other crystal due to their crystal framework lattice matching. So it’s very different from the droplets, a different mechanism.
And as we said with the silver iodide there are some problems but there aren’t many alternatives. So I designed an alternative material. This material can also help create artificial snow at ski resorts. It works well in cloud-chamber experiments.
Q: Can you describe that material?
A: The novel cloud-seeding material has a shell/core structure, it has a sodium chloride core, which is covered by a nanometer thickness of titania particles. This structure offers a synergistic effect on condensation at lower relative humidity and forms larger water droplets: Both are important to increase the probability of rainfall.
Q: Is this the sort of technology that would be used to control undesirable weather, like preventing hail?
A: Yes. That’s the case in some European countries, to protect agriculture industry from extreme weather attack, such as hail and frost.
Whether the precipitation falls as rain or snow depends on the air temperature. CREDIT: Shutterstock
Q: What impact would you say cloud-seeding will have on climate change?
A: I think this is a very important question. It is in the broader spectrum of climate-change strategies. If we got more water as rainfall through cloud-seeding, it would be cooling the weather and replenish the ground-water aquifer. There would be less demand for air-conditioning, less demand for desalinization. It has very positive effects.
Q: So what’s the next frontier? What’s the next exciting development?
A: The next frontier will be scaling up the production, making the seeding materials more available. Apart from airplane, the seeding materials can be released by other methods such as balloons, or drones. In addition, it can also migrate into surface-water-harvesting applications, like catching fog.
Q: Is there anything we haven’t covered that you want people to know?
A: The UAE Research Program for Rain Enhancement Science is appreciated because they provide us funding on my research project. I really wish that this will have a ripple effect. We need to transform the novel seeding materials into commercial-scale production and wider application. We have started working on that. I need government and industry support on this direction. If this becomes commercially technology, more countries and regions will benefit.
If you’re ever lost in a desert, finding a water supply is key to your survival. Understandably, this is difficult in a desert as there is neither enough rainfall nor open-water sources, such as rivers or lakes, to reliably support the people inhabiting these areas. What many desert regions do have, however, are coastlines with access to plenty of salty seawater.
Enter desalination.
Desalination is a brilliant way to make fresh water. Seventy percent of the world is covered with water, but only 1 percent of that is potable. The solution? Take the salt out of the sea.
In the United Arab Emirates, even the groundwater is saline, in some cases up to eight times as salty as the surrounding seawater. Although this brackish groundwater can be used in irrigating salt-tolerant plants like date palms, everything else needs that water to be desalinated.
IMAGE: Anas Albounni, KUST Review
A harsh legacy of waste
“Historically, water availability has always been considered fundamental for human civilizations to evolve and flourish, from the early Mesopotamian age to the current rapidly growing cities in the Middle East. Read more›››
“Over time, wasteful water use, mismanagement and significant environmental challenges have triggered severe depletion and degradation of the available freshwater resources, with adverse effects on human health, living conditions, and social and economic prosperity.”
Tom Pankratz, Global Water Intelligence‹‹‹ Read less
In many ways, the Middle East is on the cutting edge of sustainability because the governments there were forced to confront water scarcity from the get-go. The evolution of water conservation and sustainability in this region is a result of a multi-pronged approach, involving rethinking city planning, efficient water use and innovative solutions to providing clean water.
A PERFECT FIT
Desalination plants are found in abundance in the Middle East: The U.S. Geological Survey says 70 percent of the world’s desalination plants are located in this area, found mostly in Saudi Arabia, the UAE, Kuwait and Bahrain. This makes sense: These countries are water-strapped but oil-rich. An energy-intensive clean-water-production technique is a perfect fit.
This oil won’t last forever, though. And the world is already feeling the effects of global warming and climate change thanks to rampant use of fossil fuels in applications including desalinating water for desert populations. The solution? “Renewabilize” it. And luckily, the Middle East also has plenty of renewable energy to spare: sunshine.
The most popular method is reverse osmosis, where large quantities of seawater are pushed through a semipermeable membrane to remove the salt from the water. Think of this membrane as a very fine sieve that catches salt and other impurities.
Although this is an effective means to desalinate seawater, it is driven by very high hydraulic pressure and requires robust pumping and expensive pretreatment. In Saudi Arabia’s Eastern Region, for example, the seawater first needs to be filtered for oils, greases and jellyfish.
IMAGE: Shutterstock
What to do
with the brine?
Brine is a high-concentration solution of salt in water and is a byproduct of many industrial processes, including desalination. The simplest way to dispose of brine is to return it to the ocean, but high localized brine concentrations raise seawater salinity and alkalinity, creating an environmental risk. Read more›››
Another common way to dispose of brine is to use evaporation ponds, where the water is evaporated and the salt is collected for use in other processes. Unfortunately, neither method is a fully environmentally friendly approach, and untreated brine can be corrosive and toxic if disposed of improperly.
A collaborative work between King Abdullah University of Science and Technology, Saudi Arabia, and Khalifa University of Science and Technology, UAE, saw the design of a solar crystallizer that uses solar energy as the main energy source to heat and evaporate the brine. This follows the same concept as an evaporation pond, except the condensate from the evaporated brine is collected as fresh water.
This sounds like an obvious solution to reducing the water loss, but the amount of salt in the water can affect the performance of the materials in the crystallizer, so the team needed to design a new device in which the water-evaporation surface and the light-absorption surface are separated by an aluminum sheet with high thermal conductivity. The bottom and inner walls absorb the solar energy, while the outer wall performs the evaporation and crystallization parts of the process.
The research team says the high thermal conductivity of the aluminum separator conducts the heat generated at the bottom of the device to the walls for water evaporation, resulting in a “high solar-to-vapor performance.” They believe this is a simple but promising strategy to provide a low-cost and sustainable solution for treating industrial brine, especially in small- to medium-size applications.‹‹‹ Read less
SEAWATER: SEE WATER
Desalination is an energy-hungry process. According to Richard Muller, professor of physics at the University of California, Berkeley, it will always take one kilowatt hour or more of energy to desalinate a cubic meter of seawater.
But Corrado Sommariva, founder and CEO of the Middle-East-based Sustainable Water and Power Consultants, says the desalination sector has been experiencing a revolution in the past five years and believes the process can be powered by renewable energy, particularly solar.
The cost of desalination from reverse osmosis has fallen dramatically in recent years, with much of this decrease in price stemming from streamlining processes and cheaper electricity, he notes, and as solar power looks set to become the cheapest form of electricity, moving to a renewable-power supply seems inevitable.
Tom Pankratz, editor of the US Water Desalination Report, confirms: “Desalination is more energy-intensive than other water-treatment processes, so there’s a growing interest in using renewable energy to reduce a plant’s operating costs and its environmental footprint. In many places, especially in the Middle East where desalination is the primary source of water, renewable energy is often much less expensive – even with the abundance of fossil fuels in the region.
”In theory,” he says, “any form of renewable energy could power desalination, but solar power is generating the most attention. Helpfully, the arid regions that need desalination the most are also the ones blessed with abundant sunshine.
IMAGE: Anas Albounni, KUST Review
Solar stills:
A classic solution
Sometimes the old ways are the best ways. Read more›››
The oldest desalination technology is the solar still, a simple device that uses sunlight to purify water.
Salt water is placed in the still and an angled piece of glass or plastic is placed above. The sunshine evaporates the water, which then condenses on the surface above before running down the surface to collect in a separate trough.
The impurities and salt remain in the bottom of the still and the water in the trough is clean, pure drinking water.
If you do find yourself lost without a clean water supply, you can make a solar still from a sheet of plastic lining a hole in the ground, a mug to collect the clean water, and another plastic sheet on top anchored with a rock to create the angled surface.‹‹‹ Read less
“Solar farms are sprouting up in more and more areas in the Middle East, and their power generation gets priority to feed into the grid,” Sommariva says. “For at least six hours a day, power tariffs as low as 1 U.S. cent per kilowatt hour are available to utilities from photovoltaic plants as the amount of electricity being generated by these plants will shortly outstrip grid demand during certain hours of the day. Photovoltaic power offers the chance to both operate desalination plants as potable-water generators and grid-energy absorbers and buffers.”
A TOUGH BALANCE
The journey of electricity from the power plant to our homes and businesses is not always a smooth one. Grid operators are faced with the complex task of balancing the amount of electricity fed into the grid against the amount of electricity consumed to keep the power system stable. But as more intermittent renewable-energy sources of electricity, like solar and wind, are fed into the grid, this balancing act becomes even more challenging.
Pankratz notes that it’s no coincidence renewable-energy desalination plants are being implemented in Saudi Arabia and the UAE, where some of the largest solar photovoltaic power plants are also being built.
“For larger plants, it is often infeasible to locate a large wind- or solar-energy power plant near a coastal seawater desalination plant. In these cases, it is usually more practical and cost-effective to build the wind or power plant farther inland, and feed the energy into an electrical grid that can be distributed to the desalination plant and other facilities,” Pankratz says.
“This approach not only ensures that the desalination plant and energy plants are located where they are most cost-effective, but it also eliminates, or lessens, the need for large batteries to store the energy during the night or low-wind conditions.”
AN INGENIOUS BATTERY
Sommariva believes solar-power-driven desalination plants could also act as an electricity-storage system, using the excess electricity produced by photovoltaic plants, rather than continuously running fossil-fuel plants, to desalinate water. Connecting the desalination plant to the renewable-power grid could be the solution to two problems facing the region: renewable-energy storage and drinking-water shortage.
In theory, any form of renewable energy could power desalination, but solar power is generating the most attention.
– Tom Pankratz, editor of US Water Desalination Report
“If the industry could simply move away from the traditional concept of steady water generation mainly dictated by a lack of storage, we could imagine a desalination plant able to operate in a sustainable and flexible manner: producing when excess power is available in the grid from photovoltaic production and curtailing desalination when the grid is in peak mode,” Sommariva says.
Additionally, producing water when excess power is available from solar power and curtailing production when the grid is in peak mode does not require any dramatic changes to infrastructure, except an increase in storage capacity for the resultant potable water. As Sommariva points out, additional water-storage capacity is part of the strategic development in the region anyway.
“If the industry could simply move away from the traditional concept of steady water generation mainly dictated by a lack of storage, we could imagine a desalination plant able to operate in a sustainable and flexible manner: producing when excess power is available in the grid from photovoltaic production and curtailing desalination when the grid is in peak mode,” Sommariva says. Additionally, producing water when excess power is available from solar power and curtailing production when the grid is in peak mode does not require any dramatic changes to infrastructure, except an increase in storage capacity for the resultant potable water. As Sommariva points out, additional water-storage capacity is part of the strategic development in the region anyway.
CAPTION: Solar power-driven desalination plants could also act as an electricity-storage system. IMAGE: Anas Albounni, KUST Review
“It is necessary that policy makers start seeing desalination not only as a water producer but also a potential energy buffer and indirect storage system,” he says, adding that all of the desalination plants in the Gulf region and worldwide have the opportunity to smart retrofit and develop a net-zero-energy operational process.
CONTINUED IMPROVEMENTS
The potential use of renewable energy for desalination is hardly a new idea. Reported since the mid-1990s, a few conventional water-treatment plants in the United States have integrated solar power for water treatment, including a Massachusetts plant in 2009.
IMAGE: Anas Albounni, KUST Review
Managing
the resources
Previous poor water management and unsustainable agriculture practices in the Middle East have exacerbated desertification, and water scarcity is becoming severe in countries including Jordan and Yemen. Read more›››
Agriculture, industry, urbanization and population growth are all fueling the demand for more water, while climate change decreases supply day by day.
As the UN Food and Agriculture Organization points out, for every 1 degree Celsius of global warming, 7 percent of the world could see 20 percent of renewable water resources dry up. More frequent and severe droughts, combined with crops needing more water in higher temperatures, will put further pressure on dwindling water supplies.
According to the Water Project, other concerns with the future of desalination plants in the Middle East focus on the improper dependency they will cause, instead of encouraging alternate forms of water and energy to be explored and conservation of fresh water.‹‹‹ Read less
New renewable-energy technologies are becoming available for desalination applications as well. For example, an Australian pilot project utilizing wave-power technology for seawater desalination using submerged buoys began operating in 2015.
Despite the challenges, many researchers are working to improve desalination so it can reach more people and address climate change without contributing to it. The Global Clean Water Desalination Alliance has set a goal for 20 percent of new desalination plants to be powered by renewables between 2020 and 2025. Currently, the global share of renewable energy used in desalination is just 1 percent.
Sommariva does point out that the main challenge in pivoting to renewable-energy-powered desalination is retiring or converting traditional thermal-desalination assets.
“These plants have a residual economic life of several decades,” he explains. “Not to mention they are substantially energy-intensive. But desalination is a technology that is fast developing.”
There haven’t been any major recent breakthroughs in the technology, he adds, but the process is seeing a steady rate of improvements that are fine-tuning the process for ever-increasing efficiency.
A GROWING APPROACH
Already, stakeholders in the desalination industry are beginning to turn to renewables.
Dubai Electricity and Water Authority is planning to power its desalination plants with solar power by 2030, pushing for increased efficiency and large-scale integration of renewable energy in its water-production processes.
CAPTION: The desalination triangle: When the oil runs out, can the sunlight step in to power the process? IMAGE: Anas Albounni, KUST Review
In Port August, Australia, one desalination plant uses solar power to provide potable water for its tomato farm. In fact, in Western Australia, all new desalination plants must use renewable energy.
“All of the large Australian seawater desalination plant operators have contracts with renewable energy providers who supply energy into the local grid in an amount equal to that required by the desalination plant, in a cost-offset arrangement,” Pankratz adds.
Both the King Abdullah Economic City and the King Abdulaziz City for Science and Technology in Saudi Arabia are supplied by solar-powered seawater desalination plants, taking water from the Red Sea. Also in the United Arab Emirates, one Masdar plant in Ghantoot produces desalinated water using a solar-powered solution. The company behind this plant, Mascara Renewable Water, is now developing similar projects in Mauritius, Cape Verde, South Africa, Morocco and Vanuatu.
OTHER PROJECTS
There have also been several small-scale trials across the Middle East, Spain and India bringing together concentrated solar power and seawater desalination. Pankratzs says there are on-going research projects looking into using other forms of renewable energy too, including those from wave power, geothermal and biomass sources, and even from the energy contained within salinity, chemical and pressure gradients.
“There is absolutely a real future for this, and it’s happening now,” he says. “Renewable-powered desalination is proving itself in plants in the GCC and around the world. It’s happening on a local scale too, with hundreds of small, renewable-energy desalination plants under construction in island communities and off-grid locations in developing countries such as Kenya, Madagascar, Mozambique and Nigeria.”
As the planet faces an uncertain water future, desalination will continue pumping out freshwater for thirsty cities. And as renewables become increasingly mainstream and technology prices continue to fall, renewable energy will become an economically viable option as well as the environmentally friendly solution.
It’s not all bad though.
Renewable-powered desalination is proving itself in plants in the GCC and around the world.
– Tom Pankratz
Desalination can provide sufficient quantities of water as and when needed, which can significantly enhance the water security of a nation, while also supporting regional stabilities by evading any conflict over water resources. This also means there are a plethora of opportunities for society to benefit from desalination technologies.
Local employment opportunities during the construction and operation of desalination plants are one such benefit, but easy access to cheap water also means more work and education opportunities for women, who otherwise typically bear the often expensive, time-consuming and physically taxing burden of collecting and carrying water in the poorest communities.
COVID-19 was not the first pandemic to force changes in how we live: Communicable diseases have transformed urban planning before.
The Black Death outbreak in 14th century Europe saw narrow public squares transformed into larger public spaces better integrated with nature. The cholera outbreak in 19th century London prompted improvements to water-management infrastructure. And during the Spanish flu, residents eschewed cramped public transport in favor of walking in uncrowded streets.
Many of the practices in architectural and urban design prevalent now have evolved from similar measures taken throughout history to safeguard the health, hygiene and comfort of city dwellers. Now, researchers are turning their attention to suburbia.
Cities have to learn how to balance the competing demands of social distancing, preserving the economy and promoting people’s well-being.
– Khaled Alawadi
The team from Khalifa University says accessibility and walkability are crucial aspects for pandemic-proofing neighborhoods. The findings, published in Sustainable Cities and Society, suggest suburbs can provide better pedestrian accessibility with the right combination of structure and design.
Future pandemics may bring more lockdowns, says Khaled Alawadi, associate professor in the KU Department of Civil Infrastructure and Environmental Engineering, and open spaces will be vital.
“Cities have to learn how to balance the competing demands of social distancing, preserving the economy and promoting people’s well-being. … We argue that suburban design in the post-pandemic era should facilitate a balanced density level that is higher than the suburban norm but lower than that of traditional compact cities.”
A heavy Western influence
Despite the vast majority of the population continuing to reside in suburbs, retrofitting efforts to promote walkability and transit-oriented development are mostly limited to city centers. In GCC countries and the UAE in particular, suburbanization is the dominant development trend: suburbs occupy more than 50 percent of Abu Dhabi’s urbanized land and 40 percent of Dubai’s urban area.
Because suburbs are likely to continue to be the primary features of urban development, the researchers argue that suburban design should be rethought, instead of vilified, discarded or ignored. Their work integrates morphological mapping, urban-network analysis and forgotten urban-form elements such as alleys into designing future suburban areas. They focused on neighborhoods in Abu Dhabi and Dubai, examining the structural and physical layouts of both cities that resemble neighborhood typologies common in Western cities.
The grids and fragmented layouts that comprise the diverse set of neighborhoods in Abu Dhabi and Dubai are the same applied in city planning around the world.
– Khaled Alawadi
“Both cities have a history of inviting and hiring consulting firms and foreign architects who were all trained in Western countries,” Alawadi says. “The grids and fragmented layouts that comprise the diverse set of neighborhoods in Abu Dhabi and Dubai are the same applied in city planning around the world.”
The need to rethink suburban design stemmed from the need to confront climate change, long before the emergence of the novel coronavirus. Suburbs have been harshly criticized for their social, economic and environmental impact, and in terms of physical planning ideals, one of the key criticisms is low pedestrian accessibility.
Detached, single-family housing — the primary form of the suburban landscape all over the world — has either been glorified as the icon of the American dream of vilified as a deplorable built environment, but the KU team argues suburbia should not be visualized as sprawling low-density settlements only.
“The potential to design suburbs in various forms and levels of density cannot be overlooked,” Alawadi says. “For example, new suburbs can be designed to feature interconnected street systems rather than fragmented and broken street networks. Accessibility plays a vital role in good urban form. Residents are more likely to walk or cycle when their local area is more accessible and the distance between origins and destinations is shorter.”
Increasing accessibility
Accessibility and mobility go hand in hand: Mobility can be defined simply as how far you can go in a given amount of time, whereas accessibility is how easily one can get there. Research shows that, at neighborhood scale, accessibility has a significant influence on urban living, spatial equity, public health and walkability.
Comparing Abu Dhabi with Dubai, the researchers found that Dubai is more accessible overall but particularly when its network of alleys is considered. This suggests that better accessibility can be achieved by linking street networks with alleys between buildings.
“Walking within neighborhoods for recreational, fitness and utilitarian purposes is indispensable in a post-pandemic world,” Alawadi says. “The COVID-19 pandemic revived old debates in urban planning but there is an almost unanimous consensus regarding the need for walkable neighborhoods in post-pandemic cities. People want easy access to outdoor spaces, public parks and other destinations to meet their daily needs. Redesigned suburbs with more suitable infrastructure for local accessibility have the potential to serve as a viable housing option for the post-pandemic world.”
On a desert planet in a galaxy far, far away, the land is hot, dry and devoid of any large bodies of surface water. It is a parched world, desolate in that way only a planet illuminated by a pair of binary stars can be. Fantastical, yes; a pop-culture icon, also yes.
Listen to the Deep Dive
But there are two reasons to start with a description of Tatooine, the desert planet that appears in the Star Wars franchise: The technology seen here has become a reality, and we can test it in the real-world places that inspired the fictional landscape.
We’re talking moisture farming.
The moisture vaporators, also known as vapor spires in the Star Wars lingo, are devices used on Tatooine moisture farms to capture water from the atmosphere. Tall and slender, they were stationed at ground level and used refrigerated condensers to pull water from the air around them. Captured water was then pumped or gravity-directed into a storage cistern. These devices could collect 1.5 liters of water every day, even when the relative humidity of the air was only 1.5 percent. An amazing idea, and now becoming real as new technologies and materials emerge to harvest previously untappable water from the atmosphere.
The basic concept is simple. If you take an ice-cold glass of water outside on a hot day, you’ll quickly notice water droplets forming on the outside of the glass. If you cool warm, humid air, it loses its capacity to maintain its water content and you can produce and collect condensation, whether it’s on the outside of your glass or in a moisture vaporator straight out of science-fiction.
Rather than waiting for the rain, bring the rain to you
When clean drinking water comes out of the tap at home, it’s easy to think that it will always be plentiful, but fresh water is actually incredibly rare. Only 3 percent of the world’s water is potable, and two-thirds of that is stored away, frozen in glaciers, or otherwise unavailable for our use.
IMAGE: AI; KUST Review
Do not eat this packet
Almost everyone has bought something and found a packet of silica gel beads placed inside to absorb moisture while items are waiting to make their way to the customer. Read more›››
Silica is commercially available, inexpensive and a highly effective desiccant.
Silica can also be also used in water production via the conventional condensation approach.
Silica gel is one of the most commonly used materials in moisture harvesting, and Lisa Klein, professor of materials science and engineering at Rutgers University, has investigated using patterns on silica gel to facilitate water-droplet formation.
She conducted a series of experiments to condense water vapor on the hydrophilic pattern of silica gels. Although the pattern was hydrophilic, the gel itself was hydrophobic so the water droplets slide down the surface and collect in a container rather than absorb into the gel. This represents another potential area of investigation for harvesting water from the atmosphere. ‹‹‹ Read less
As a result, more than 1 billion people worldwide lack access to clean water year-round. Global warming may be melting those glaciers, but as humans continue to pump carbon dioxide into the atmosphere, weather and water patterns will change, combining to make less water available for people around the world. By 2025, predicts the World Wildlife Fund, two-thirds of the world’s population may be facing water shortages.
Technologies such as filtration, desalination and solar purification have been developed to use seawater or wastewater. However, because they depend on terrestrial water sources, these technologies are feasible only in coastal areas. Atmospheric water, however, is present everywhere, and the global water cycle enables a sustainable supply of water to the air, providing a resource equivalent to about 10 percent of all the fresh waterin lakes on Earth.
At 100 percent humidity, the air at 40 degrees Celsius contains about 51 milliliters of water per cubic meter of air. For the same humidity at 10 degrees Celsius, the air contains only 9.3 milliliters. Bring that 40-degree air down to 10 degrees and you should be able to extract that water difference. Scale that up and you could produce an awful lot of water on one of those sticky, hot Arabian Peninsula days.
Technologies already exist to catch fog or collect dew that condenses overnight, but pulling water directly from the air, without consuming lots of electricity, is still under development. Still, Ruzhu Wang, professor at Shanghai Jiao Tong University, says atmospheric water harvesting is accessible everywhere and can be easily co-operated with a renewable energy source for local needs.
The problem, Wang writes in Joule, is that there are few commercial water-harvesting systems available.
But when those systems do become available?
“In general, any viable atmospheric water-harvesting technology must satisfy five primary criteria: It should be efficient, cheap, scalable, wide-band and stable enough to operate for a whole year or at least a monsoon season,” Wang writes.
None of the existing commercial atmospheric-water generators meets all five criteria. Wang says this is mainly due to the energy inefficiency of the process.
So, the ideal moisture harvester has a high water uptake, low-energy demand for water release, fast water capture/release cycling, high cycling stability and a low cost — a tall order but one that could be achieved with advances in material science.
Large-scale moisture farming is science-fiction today. But it may someday bring clean water to desert cities. CREDIT: AI; KUST Review
Living in a material world
Atmospheric water harvesting based on moisture harvesters captures vapor from the air via adsorption, where water molecules adhere to the surface of a material through chemical or physical interactions.
Researchers are looking at materials such as hydrogels and zeolites, as well as porous materials similar to this AI-generated image. IMAGE: AI; KUST Review
For chemical adsorption, the surface needs to adsorb water through strong chemical bonding; releasing the water requires a large energy supply.
Physical adsorption needs pores in the surface, where water molecules can pool and collect. Energy is still required to release the water, but at a significantly lower rate than chemical adsorption.
Porous materials capture the water from the atmosphere, but said pores need to be perfect; you can’t just place a sponge in the desert and expect water to collect.
Enter the metal-organic framework (MOF): a network of metal and organic materials that can easily trap water vapor, which is then released using energy captured from the sun.
Water load of options
But MOFs aren’t the only material vying for a slice of the water-harvesting pie: hydrogels and zeolites have also entered the ring.MOFs work great in areas with lower humidity, but they have a finite number of pores. Fill those, and your harvesting device stalls until they can be emptied.
CREDIT: AI; KUST Review
Combining the two: Fog and moisture farming
The United Arab Emirates has all the necessary ingredients for fog as dry desert conditions exist next to the warm seas of the Arabian Gulf, with moist air carried inland by the afternoon sea breeze cooled by the night desert surface. Read more›››
Tendrils of fog snake their way through the dunes in the early morning and could be captured by the fog-farming technologies already available. At the same time, the humidity that plagues the region during the hot months makes atmospheric-water generation viable.
Combining both approaches could reduce dependency on desalination and provide clean water for the many farms found far out in the desert.‹‹‹ Read less
Hydrogels, on the other hand, can expand to hold more water. The soft, pliable and thin material that makes up more than 90 percent of contact lenses prescribed in the United States is a hydrogel: a water-swollen polymeric material that maintains a 3D structure.
The 3D network of hydrophilic polymers can swell in water while maintaining its structure and is tunable, dynamic, biodegradable and, most importantly, capable of encapsulating huge amounts of water.
Let’s just use hydrogels, then. Well, they’re not the best in low-humidity areas — they like it muggy outside.
Although they may not be suited to the deserts of the Middle East, there are plenty of places with high humidity that are also water-stressed. Lima, Peru, is one such place.
Just south of Lima is the village of Bujama. Despite being in an area where air humidity reaches 98 percent, Bujama is almost a desert, and its people live in tough conditions with little access to clean water.
Researchers from the University of Engineering and Technology in Lima installed panels in advertising billboards that trap the humidity and transform it into drinking water for the people on the ground. These panels comprise filters and condensers and produced 96 liters of water a day in 2013.
People here may already have one solution to water scarcity, but that doesn’t mean hydrogels couldn’t also work in Bujama.
Zeolites are often considered “molecular sieves” as they can selectively sort molecules based primarily on a size-exclusive process. They are easy to manufacture and have a large internal surface area full of pores to adsorb the tiny quantities of water held in desert air — another contender for the low-humidity application.
Water is running out and we know that desalination is not the solution. It’s not just drinking water, it’s all the water used in industry, in agriculture.
– Michael Rutman, co-CEO of Watergen
Desert countries especially would benefit from atmospheric water harvesting. CREDIT: AI; KUST Review
The zeolite can collect water vapor overnight, and heat from the sun can then be used to extract the water for use. However, compared to MOFs and hydrogels, the water capacity of zeolites is relatively low, and releasing the water requires a high energy consumption that, even when supplied by solar power, make zeolites a less efficient option.
In areas where water scarcity is a problem — and climate change is putting more areas at risk — it’s important to consider different technologies and approaches.
Condensing the problem
The billboard in Bujama is just one example of the condenser approach. Michael Rutman is co-CEO of Watergen, a company creating drinking water from air. Based in Israel, “which has a very similar climate to the UAE,” Watergen uses a system involving food-grade polymer condensers and filters to draw water out of the air around us.
“Adsorption can only generate so much water,” Rutman explains. “It also requires a much larger resource footprint than condensation, and much more energy. Metal-organic frameworks that don’t need quite so much energy input to draw the water out are under development, but the metal part of a MOF should also be a concern.”
Atmospheric water is everywhere. The trick is finding energy- and cost-efficient ways to tap it. IMAGE: AI; KUST Review
Rutman points out that an air conditioning unit does much the same thing as a Watergen condensing system: pull warm air out of the environment and cool it, producing water as a by-product. However, the heat exchanger material in an AC unit is usually made of metal, and that metal leeches into the resulting water.
“That’s why you don’t drink from your AC,” Rutman says, laughing. “An AC unit produces tons of water, but that water is contaminated with heavy metals. The Watergen systems use food-grade polymers in the heat-exchanger technology, so the water produced is immediately potable, but we also add minerals to further improve the quality.”
Watergen didn’t set out to save the world from its water problem; the company started by trying to make dehumidifiers more efficient and less power-hungry.
It was Michael Mirilashvili, an Israeli-Georgian businessman, who declared they were wasting this technology. Now president of Watergen, Mirilashvili realized these highly efficient polymers could be used to solve the world’s biggest problem and spent the past five years pivoting the company to producing water from the air for everyone.
Their system works, too. It works in areas of high humidity, such as Colombia and South Africa, but it also works in the driest of places, like Arizona in the U.S., where the average relative humidity is 38.5 percent.
Rutman says he believes mass use of atmospheric water generation is the future.
“Water is running out and we know that desalination is not the solution. It’s not just drinking water, it’s all the water used in industry, in agriculture. It can take 160 liters of water to make a pair of jeans, and 60 liters for a loaf of bread. All this water can be replaced by water produced from the air. I believe we’re less than ten years away from this point. Our pilot technology works, and it’ll work everywhere.”
Perhaps a tabletop box like this will some day supply drinking water for an average home. CREDIT: AI; KUST Review
Speaking of everywhere, we should also start thinking about portability.
Conventional water supply starts with a large centralized plant that distributes water to the population, but if a device were small enough to incorporate into a home, gaps in water supply could be plugged.
Make them even smaller and they could travel to all sorts of now-uninhabitable regions: the middle of the desert, the polar extremes, Mars?
Back down to Earth
Understandably, research institutes in the Middle East are particularly invested in this new type of technology. Many of the projects showing promise in the U.S. were funded by Saudi Arabia’s King Abdulaziz City for Science and Technology, including projects designed by Omar Yaghi, pioneer in the MOF space, and his teams.
Similar technology is behind an industry-funded project at Masdar City, a hub for sustainability research and innovation in the MENA, with whom Khalifa University does research.
“As freshwater scarcity is becoming a global challenge, a promising route to overcoming water shortage is to extract water from air with innovative atmospheric water production (AWG) technologies,” says Samuel Mao, director of Masdar Institute at Khalifa University. “KU’s research team at Masdar Institute is performing comprehensive assessment of different AWG approaches, and developing advanced technologies to enable water extraction from air with better energy efficiency and lower cost.”
Almost half of all people on Earth live in water-threatened conditions, with demand growing drastically, while supply remains constant, according to the World Health Organization.
The United Nations recognizes that access to clean water and sanitation is at the core of sustainable development, and ensuring access requires innovation. Atmospheric water generation could be the solution, and it’s already here.
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