Plastic waste is everywhere and the tinier the plastic is the harder it is to deal with. These microplastics are proving to be very difficult to address which has sent researchers looking into all sort of solutions. One solution is already up and running in some places: sand filters in water systems. It turns out that some existing sand filtration systems can capture plastic nano particles.
The results are now in, and they include some reassuring findings. In areportpublished today in theJournal of Hazardous Materials, the researchers show that even if untreated water contained considerable quantities of nanoplastics, these particles were retained in sand filters very efficiently during water treatment. Both in laboratory tests and in a larger test facility located directly on the premises of the Zurich Water Works, the biologically active slow sand filter was the most effective at retaining nanoparticles – achieving an efficacy level in the region of 99.9%.
Aquifers feel there pressure of increasing populations and farms; as a result, cities around the world get drastically close to running out of water. The solution in some places may have been under our noses the entire time: fog. In Lima they already have a system in place to capture water from fog to supplement existing sources, and other coastal cities are paying attention. The coolest part of the fog catching technology is that it comes from ancient techniques using tees!
In 2009, German conservationists Kai Tiedemann and Anne Lummerich planted 800 she-oak trees in Peru to create a natural fog-catching system that aimed to replicate this ancient technique. During their research they found that trees with vertical, needle-like leaves work as an organic net to which drops of water adhere. They later went on to develop artificial nets that could also capture water.
Marzol has been studying “the hidden precipitation” in fog for nearly 25 years now, partly because modern meteorological instruments struggle to measure its relationship with precipitation. During the course of her research she has witnessed the social transformation that can occur in communities that collect fog water.
When it rains cities should hold all the water. In the 20th century that idea would have been laughed out of the room; today, we know better. Urban water management is vital to a healthy city, ecosystem, and flood mediation. The old idea of building giant channels of concrete to force water out of their natural areas (the best example of this is in L.A.) is thankfully being replaced with better ideas.
One of those better water management ideas is to just soak it all up. Make the city a sponge.
The second is through the flow, where instead of trying to channel water away quickly in straight lines, meandering rivers with vegetation or wetlands slow water down – just like in the creek that saved his life.
This has the added benefit of creating green spaces, parks and animal habitats, and purifying the surface run-off with plants removing polluting toxins and nutrients.
The third is the sink, where the water empties out to a river, lake or sea. Prof Yu advocates relinquishing this land and avoiding construction in low-lying areas. “You cannot fight the water, you have to let it go,” he says.
Water scarcity is a real problem in Mexico City, and due to existing gender inequality women bare the brunt of the costs of a lack of water. This manifests itself in everything from laundry to buying potable water, both are time consuming endeavours in places with water scarcity. Mexico City launched a program a few years ago to naturalize rain water collection while also enhancing their rain barrel water collection for homes. These changes combined have had a very positive impact on water usage and gender equality in the city.
The program helps install rainwater harvesting systems, which capture the rain that falls on roofs of houses. Water is stored in a cistern, which can then be used for domestic purposes. It can also be used as drinking water if given additional treatment. These systems can provide a family with water forbetween five to eight monthsof the year.
Byprioritizing householdsheaded by women, single mothers, indigenous people, older adults and people with disabilities, the program aims to improve equity across the board. To date, more than 13,000 female heads of household have benefited â€” comprising around 65% of installed rainwater harvesting systems.
For years engineers tried to prevent flooding, then they realized they can’t stop nature. Now instead of trying to stop it, we try to mitigate flooding by creating spaces that can absorb a lot of water (parks along rivers are an example of this). Still, these attempts don’t always work and with increasing instability in our climate it’s getting harder to deal with more extreme flooding instances. This is where a new startup, Floodmapp, fits in. They are using machine learning and AI to improve how we understand flooding instead of the traditional physics-driven modelling.
The companyâ€™s premise is simple: We have the tools to build real-time flooding models today, but we just have chosen not to take advantage of them. Water follows gravity, which means that if you know the topology of a place, you can predict where the water will flow to. The challenge has been that calculating second-order differential equations at high resolution remains computationally expensive.
Murphy and Prosser decided to eschew the traditional physics-based approach that has been popular in hydrology for decades for a completely data-based approach that takes advantage of widely available techniques in machine learning to make those calculations much more palatable. â€œWe do top down what used to be bottoms up,â€ Murphy said. â€œWe have really sort of broken the speed barrier.â€ That work led to the creation ofDASH, the startupâ€™s real-time flood model.