#205 - Singapore, Rice & Shrimp, Micellar UF, Sulfates, Leakbots and more...
Water Water Everywhere...
Hey Readers,
If you read the news, it says that when you boil water, that removes 90% of the microplastics, which by itself is amazing! - However if you’re like us, you are now asking, where do the microplastics go?
Let us know what you think is the answer in the comments section.
With that said - let’s get into the innovations & news from the world of water this week.
Leak detection by measuring temperature
First the landscape - typical leak detection systems work on either moisture detection systems or in pipe flow detectors. Moisture detectors sense moisture in the walls/ places they shouldn’t be but do not know about leaks that are happening behind walls or underground etc. The in-pipe systems are more efficient/ accurate at finding these leaks, but are more expensive and need professional installation to fit in pipes and make them leak-proof as well. This innovator from the UK, looked into the crowded field of leak detection/ monitoring and assessed a gap that they could address.
They built a Leakbot that can be clipped to the water main by the buyer and there it assesses the leaks by measuring the ambient temperature of the pipe and comparing it to the temperature of the water coming in the pipe. The temperature differential is a good proxy for leaks, and given that this sensor can detect 0.3 degree shift in temperature, it will find small leaks as well. By connecting to their app (naturally) over the home wifi, the device alerts homeowners about these leaks on their phone and the company will even go so far as alerting the closest available plumber to come over and help fix the leak!
Disaster relief water purifier in a suitcase
This Filipino inventor solved for a very pertinent problem in the Philippines. He built a portable water purification system that can be enclosed in a waterproof carrying case and powered by a 12-volt car battery. Given the available infrastructure post-natural disaster, this technology can be easily transported to remote areas without access to electricity. The system filters out contaminants like chemicals, heavy metals, and suspended solids, and removes turbidity, which makes the water clearer. They say that the water purification procedure involves sterilization with ozone and UV radiation, which disinfects any leftover impurities. This portable water purifier can treat up to 200 liters of water per hour, depending on the turbidity of the source water.
Micellar ultrafiltration to treat contaminated groundwater
Intensive agriculture uses a good amount of fertilizer, and the excess ends up in the groundwater. This in turn has resulted in a whole world of innovation around nitrate removal from groundwater, so it can be safe to drink/ use. Current methods of removing nitrate from groundwater like reverse osmosis, electrodialysis, ion exchange, have high energy demand and produce large amounts of brine. Moreover, the water treated by reverse osmosis and nanofiltration lacks important minerals such as magnesium and calcium, which are essential to human health. By way of an example, 10% of the wells in the Coastal Aquifer region of Israel have nitrate levels exceeding the standard for drinking water and have been closed as a result.
So naturally the solution we’re talking about is from the Ben-Gurion University in Israel. Their solution? - Micellar-enhanced ultrafiltration (MEUF). MEUF is a low-energy, high-flux membrane process where cationic surfactants (chemicals that help bring contaminants to the surface by bonding with them) are added to the contaminated water. The nitrate ions associate with the positively charged micelles—which are larger than the membrane pores, so when they flow against the membrane they can be removed by ultrafiltration (UF). The only drawback of this system is that the membranes get clogged up with these micelle surfactant contaminants so these smart folks developed a method of incorporating porous zeolitic imidazole framework (ZIF-L) nanoparticles into the membrane that give it antifouling properties. Now to take this system from lab environment to commercialization.
Removing Sulfates from our waterways
Scientists from the University of Queensland, Australia and Xiamen University, China have developed a new method to measure and remove sulfate from water. Sulfate is a very common ion, but in the environment, too much sulfate can pollute drinking water and accelerate the corrosion of pipes. The presence of sulfate also causes problems when immobilising radioactive wastes.
So to solve for these problems, the team of researchers developed a molecule that measures and traps sulfate in water with a high degree of selectivity. The trans-continental team has designed a cage-like molecule to trap the sulfate ions. What’s more, this ‘molecular trap’ can be prepared inexpensively from off-the-shelf chemicals.
Due to the volume and breadth of the industrial use of heavy metals and chemical dyes, they too end up in our waterways. To combat these inorganic/chemical compounds, researchers have leaned on bio-based materials, derived from living organisms, due to their non-toxic nature and relative abundance. This group of researchers working across the US, Australia and Bangladesh came up with a solution that most Coastal nations will like the taste of - the leftovers from making a shrimp fried rice.
More specifically rice husk and shrimp shells - they extract amorphous silica from the rice husk and chitosan from the shrimp shells. Which are then combined to produce nano-chitosan-coated silica (NCCS). To ensure the stability of the nanoparticles, silica was freeze-dried after being coated with nano-chitosan. They then tested this NCCS against a variety of dyes and heavy metals. What separates this NCCP from regular chitosan nanoparticles (CNPs) is that NCCS showed the best stability in a variety of situations. Their next steps are to work on ways for post-treatment of adsorbents after contaminant removal to enhance reuse potential.
Singapore Shining - case study
To end off this week, we wanted to share how Singapore is tackling their specific water challenges. As a densely populated city-state with no natural water resources, Singapore has faced significant challenges in securing a reliable water supply. Their solution trident? - Technology, Diplomacy, and Community Involvement.
On the technology front, their water management system includes real-time data monitoring, rainwater catchment, recycling, desalination, and sewage recycling. They then diversified their water supply sources, relying on desalinated water, reclaimed water, and imported water. These techniques (desalination, rainwater harvesting, wastewater treatment and water reclamation) also helped in creating water independence for Singapore. And finally, citizens are encouraged to play an active role in water conservation, contributing to the country's water security. This sense of shared responsibility has helped Singapore successfully implement water management initiatives and achieve water security goals.
Why did we want to talk about this? - We see this as a model coming to big cities around you in the near future.
That is it from us this Friday, until next week
Peace!