In many parts of the world, water is taken for granted. Turn on a tap and it appears – clear, clean, trustworthy – whenever it’s needed. But this isn’t the case everywhere. Although decades of global efforts to ensure people have access to clean and safe water and sanitation have improved the situation somewhat, as of 2017, 2.2 billion people still lacked access to safely managed drinking water.
There is a global effort to improve access to clean water and sanitation through the UN Sustainable Development Goals – specifically Goal 6: Ensure availability and sustainable management of water and sanitation for all. This requires a multidisciplinary approach, bringing together social research and technological innovation.
It also requires an understanding of our relationship to water. This year’s World Water Day, on 22 March 2021, is on the theme of valuing water – it asks us to consider the value of water to us personally and share it on social media through #Water2me. Recognizing our different experiences helps us develop better ways to tackle the issue of access to water.
Water borrowing as a coping mechanism
For the first time, researchers have systematically studied an invisible practice that is ubiquitous around the world: water borrowing. When there is no direct water supply, or when that supply is unreliable, people often borrow water from other households. This provides them with water and its benefits in the short term, but relying on social constructs like these, especially without understanding them, will not help us tackle the larger structural issue of water access.
Professor Asher Rosinger at Penn State College of Health and Human Development and his colleagues studied water borrowing in communities with water problems across five continents. Prof. Rosinger said: “Many communities in low- and middle-income countries have to meet their water needs outside of formal institutional provisions of water. We wanted to understand how different factors related to institutional failures predict the adaptive coping strategy of water borrowing.”
Using data from the Household Water Insecurity Experiences (HWISE) study, the team looked at about 5,500 households at 21 sites in 19 low and middle income countries around the world to determine how prevalent water borrowing is. They found that it is a universal practice: every site had some level of water borrowing, with between 11 and 85 percent of households reporting that they borrowed water in the last month.
The research also revealed that the more water-related failures there are, the higher the probability of water borrowing being used as a coping mechanism. “We see that these household-to-household transfers of water are happening. But that doesn’t mean that institutions should shirk their responsibility to provide water,” Prof. Rosinger said.
“Clean water means health, and it means peace of mind. If you have access to clean water, it starts to move into the background; you don’t have to deal with the uncertainty that causes so much physical and mental stress. Institutions should try to focus on making sure they get clean water to people’s houses. Water borrowing may improve a community’s ability to cope with water problems, but it might also shift even greater burdens onto the most disadvantaged members of these communities.”
Explore the online coverage: https://dimensions.altmetric.com/details/89790923
New materials make water purification more efficient
In addition to understanding what is happening socially, technological innovation is needed to overcome the physical barriers to water access. 2.3 billion people are living in water-stressed countries, yet we are surrounded by water – 71 percent of the Earth’s surface is covered in it. Technology could be the answer to unlocking the value of that water.
In a paper in Nature Sustainability, Professor Chunlei Guo and his team at the University of Rochester unveiled a device that they concluded “has the potential to be used as part of the solution to the global water crisis due to its simplicity, durability, reusability, efficiency and compatibility with solar-thermal technology.”
As an optical physicist, Prof. Guo uses lasers to create new materials. With a standing grant from the Bill & Melinda Gates Foundation, his aim is to improve access to clean water. Over the years, Prof. Guo and his lab have created materials that almost seem magic: a super hydrophobic material that makes water droplets bounce off its surface, unsinkable metal, and a material that is highly absorbent of light at certain wavelengths.
They are now combining their innovations to harness sunlight and purify water. Prof. Guo explained: “We can turned a shiny piece of metal pitch black, making it highly absorptive. We can also turned metal into superwicking material, which means water sticks to the surface easily, or a superhydrophobic material, which makes the water roll off. In this device, we were able to combine the superabsorbent and superwicking effects of the transformed metal to purify water very efficiently.”
This is not the first device for water purification, but it improves on previous technologies in many ways. In the past, water was either heated in a vessel in an inefficient process, with only the very top layer able to evaporate, or collected in a sponge-like material, which can easily become clogged. This new device pulls a thin layer of water out of the reservoir across the superwicking surface, so it is evaporated much more efficiently. In fact, combined with the superabsorbent material, the device operates at more than 100 percent efficiency.
“It’s very different from the approaches people could come up previously, simply because there was no available material to do this,” Prof. Guo said. “We are excited to bring our technology into this particular sanitation application and to push it to the next level.”
The device shows promise – in the paper, Prof. Guo and the team show that it can purify contaminated water, including removing salt, to well within WHO and EPA standards for drinkable water. But the technology is still very new. The team is now working on further improving its efficiency, by adding an automatic system that tracks the position of the sun and moves the device to absorb the most energy possible.
“I think we have the technology with all the elements that can really tackle real-life problems,” Prof. Guo said. “But it’s still a material from the laboratory; we now need to scale it up to the industry level for it to be a practical solution.”
Engaging the public with research
Engaging the public with research that contributes to the Sustainable Development Goals is an important part of the process. Prof. Guo and his team have had global news coverage, blogs, social media and even Wikipedia entries, not just for this paper but for many studies in the past.
Explore the online coverage: https://dimensions.altmetric.com/details/85716719
Prof. Guo had some advice to share:
“We want to make our research relevant to the general public. From the scientific point of view, our research is very rigorous, but that alone doesn’t necessarily resonate well with the general public and the media. We have had opportunities to interact with the media quite a bit in the past. People are interested in learning how our work may one day impact their lives, even if they wouldn’t be into a physics lecture.”
Other research contributing to SDG6: clean water and sanitation
- Grand theft water and the calculus of compliance
- Electrostatically driven fog collection using space charge injection
- Children drinking private well water have higher blood lead than those with city water
- Trihalomethanes in Drinking Water and Bladder Cancer Burden in the European Union
- Geographies of insecure water access and the housing–water nexus in US cities
- Slum Health: Arresting COVID-19 and Improving Well-Being in Urban Informal Settlements
- The effects of drinking water service fragmentation on drought-related water security
- Water and sanitation for all in a pandemic
- Cumulative risk analysis of carcinogenic contaminants in United States drinking water
- Viscoelastic solid-repellent coatings for extreme water saving and global sanitation
- Sub-optimal household water access is associated with greater risk of intimate partner violence against women: evidence from Nepal