Hello everyone!
This week we talk about cultivating water, bacteria-based dyes, clean water from poop, and a laboratory that fits in your suitcase.
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Disclaimer - the views expressed herein are ours and ours alone.
Sunlight+Seawater = 140 litres of clean water in 30 minutes!
First up is something getting plenty of press this week - a team of researchers between China & Monash University in Australia have developed a new light responsive technology that can convert seawater into drinking water within 30 minutes. They use a metal-organic framework (MOF) to desalinate water. The researchers created a new MOF called PSP-MIL-53. MOFs in general are very porous materials – just a teaspoon of the material when compressed can be opened out to cover an area the size of a football field – and this new system could potentially be fitted to pipes and other water systems to produce clean drinking water.
This hollow framework of pores separates and absorbs salts and other impurities in the seawater, thereby releasing cleaned water. This particular MOF does so in 30 minutes under dark conditions. To add to its versatility, after just four minutes of exposure to sunlight, the material releases all of the salt ions it soaked up from the water, and is ready to be used again. The cleaned water has fewer than 500 parts per million (ppm) of total dissolved solid (TDS). The WHO suggests good-quality drinking water should have fewer than 600 ppm. of TDS
This system has produced 139.5 litres (nearly 37 gallons) of clean water for every kilogram (2.2 pounds) of MOF per day. That’s about 30 people hydrated for every kilo of the MOF. So in summary - it's cheap, it's stable, it's reusable, and it produces water that meets the WHO standards for desalination.
Bacteria-based Dyes for textiles
This is slightly tricky to wrap your head around. The dyeing industry uses more than 8,000 chemicals. Many, including sulfur, arsenic and formaldehyde, are harmful to wildlife and human health. A team of Cambridge University scientists, on seeing the textile industry pollution of water sources in Nepal, developed a new way to dye clothes that won't harm the planet. The technology they have developed eliminates the need for toxic chemicals, uses up to 90% less water and up to 40% less energy than the conventional dyeing process.
How is this dye made? While the dyes are inspired by "nature's blueprints", the technology doesn't derive pigments straight from plants or animals, like traditional natural dyeing methods. Instead, it copies nature's processes in a lab setting, by replicating the "DNA message" that codes for color in an organism. It then inserts the genetic information that directs the color-making process into a bacterial cell, which copies itself every 25 minutes. The bacteria are fed with sugar molasses and nitrogen -- by-products of the agricultural industry -- in a fermenting machine, where the cells multiply in number, each making more pigment. A bit like the fermentation process in beer production.
Researchers from Ethiopia and the United Kingdom are working on a portable laboratory that fits into a suitcase and tests water samples to identify waterborne hazards. This portable testing laboratory can screen millions of bacteria in water samples without the need to run multiple tests at a time.
To improve water quality, the water must first be tested. In Sub-Saharan Africa, the process has challenges, including transportation costs and absence of real-time data to aid decision-making. This suitcase will require roughly 20-30% of the cost of a conventional benchtop sequencing machine.
Human waste into clean water and fertilizer
A University of South Florida (USF) researcher has been working with NASA to design a compact machine that turns human waste into fertilizer, possibly giving space inhabitants the ability to grow fresh produce (remember that scene in the Martian movie with Matt Damon?). The Organic Processor Assembly (OPA) as it is known, is a closed system the size of a miniature fridge and automatically converts human waste into clean water, energy and fertilizer.
While the primary aim for the technology is to give astronauts a way to grow produce in space, the OPA technology is being tested as a means to sustainably recycle human waste water into potable water and fertilizer nutrients as well. The OPA system will be sent to NASA’s Kennedy Space Center next week to test its effectiveness under simulated space mission conditions.
Good News Corner
Returning this week is our good news corner with some pretty cool things happening around the world.
Venetians saving their lagoon? - While Venice continues to slowly sink into the sea, the locals are doing everything they can to restore the water body they are most proud of - the lagoon. In the past over 17,000 hectares (over half) of the lagoon used to be reed beds and salt marshes. Today, only 34 hectares remain. Also with the rivers and tributaries being diverted away from the lagoon, the water has grown increasingly salty.
Now via a project launched in 2017, a man-made canal diverts a freshwater flow from the Sile River into the lagoon. The canal allows the flow of water to be modulated according to the project's needs or high tides. Barriers made of biodegradable coconut fibres contain the fresh water in the target area and help the reeds develop. In total, the project aims to restore about 20 hectares of reeds. Baby steps yes, but steps in the right direction.
Water Cultivation - In the Quechua region of Peru, an NGO are following the practice of planting and harvesting water to aid the indigenous community of Quispillaccta. Started by two sisters Magdalena and Marcela Machaca who are both agricultural engineers, they build traditional reservoirs high in the mountains of Peru to ‘cultivate’ rainwater.
Since 1994, they have built more than 120 reservoirs, which ‘cultivate’ 15 million cubic meters of water per year. Their cultivation method is to build small stone and clay dikes that direct rain or glacial runoff into the subsoil and thereby recharging the aquifers. Hat-tip to the gang at Future Crunch for educating us about it.
Mines, water & geothermal heat in UK - Mines that are no longer functioning in the UK have since been flooded. Now this water is deep in the earth and is not really clean enough to drink. However, the depth of these mines translates to this flood water being heated by geothermal activity. So in the UK where they are looking into geothermal heating projects for residences, the convenience of consistent water flow and mine management makes projects less risky than conventional geothermal drilling.
Moreover, because mine shafts convey water more easily than the underground aquifers used in geothermal heating schemes, less boreholes need to be dug to supply the water. With proper planning, developers can set these up so water travels through miles of tunnels while covering very little distance above ground. Interesting use case for what is effectively wasted water and heat.
C’est Fini!
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