We want to introduce you to Peter, who lives in Gicumbi District, Rwanda with his wife and two children. Every day he and his family need to travel two and a half miles round-trip to an unprotected spring to get water. Even though one of their children is only 4 years old, she travels with her family to the spring every morning.
“We wake up in the morning around four o’clock, because the first thing we do as the whole family is collect water. We have to use flashlights so that we can see the way.” said Peter on an interview.
The lack of safe water does not only make Peter’s children late for school, but it harming his family’s health too. Throughout the year, his family has gotten sick with water-related illnesses like diarrhea.
Peter and his family are not alone.
Water Scarcity
70% of the surface of our planet is covered with water. However, only 3% of the world’s water is freshwater. On top of this two-thirds of that is in frozen glaciers or otherwise unavailable for our use. Meaning that all humans have to rely on around 1% of all the water that is available on the planet. Even though we have this same amount of water, we have been using water in very inefficient ways. 72% of all water withdrawals are used by agriculture, 16% by municipalities for households and services, and 12% by industries.
This lack of water has caused 1.1 billion people worldwide to lack steady access to water, and 2.7 billion people find water scarce for at least one month of the year. According to the Global Water Institution, 700 million people worldwide could be displaced by intense water scarcity by 2030. If we can provide a cheap, steady flow of water, we alleviate these problems so we can have a better future. This is a huge problem!
Drinking-Water from the Ocean
Instead of relying on only 1% of the total water that is available, we can expand our total supply of water! What the 70% of seawater drinkable for humans?
Currently, there are many desalination attempts being created in order to turn salt water into fresh water. The common methods for desalination, Reverse Osmosis and Solar Desalination, are not sustainable for real-world deployment. These solutions require a ton of energy in order for it to function. This huge amount of energy makes this system really expensive to use on a large scale. For example, in order to treat an acre-foot of water with these methods would cost around $2,000.
Nure is taking a new approach to filtration, where instead of using Reverse Osmosis to allow for the filtration to occur, we are leveraging Glass — Fiber Membranes. Recent and promising research shows that these membranes will be more efficient and a cheaper alternative to current methods.
Ion Bombardment
In order to filter the salt from the water, the process of Ion Bombardment can be used. This method separates the salt and water molecules in the mixture of seawater. Water is one of the smallest molecules in the mixture of seawater, with everything being much bigger than simple water molecules. Filtering the small items through while stopping the big items can act as desalination.
Graphene Oxide Filters
In order to use the process of Ion Bombardment, Nure is using Graphene. This is material has uniform shaping in hexagon ties, which allows for selective tearing that can allow water to pass through while blocking larger items. This sounds like it can really help, but on a larger scale, it is not efficient. Getting the exact amount of holes is something that cannot be done on an industrial scale. Graphite Oxide can work instead. The oxidation of geo sheets (showed in the image above) leads to graphene oxide. We can use layers of Graphite Oxide so that water can be carried with capillary action, while the salt ions are blocked from entering.
Nure uses multiple layers of Graphite Oxides which we place on top of one another. The space between layers of the filter has to be just large enough to fit water in, but small enough to block salt ions and other larger ions. A range of distances can fit here, anywhere from 6.4 to 9.8 angstroms. The filter’s distance can erode over time, meaning that salt ions could manage to get through. To fix that, epoxy can be added to fix the distance between layers for a long time. This filtration system can get rid of up to 97% of salts!
Graphite Oxide Layers
In order to create the layers of Graphite Oxide, we have to utilize the process known as Hummer’s Method. This is a chemical process that can be used to create Graphite Oxide through the addition of potassium permanganate. The process works by following a four-step process shown below.
- 100 g of Graphene + 50g of Sodium Nitrate are in 2.3 liters of Sulfuric Acid, with a temperature of 66 degrees Celsius
- The solution is then cooled to 0 degrees celsius.
- 300 grams of Potassium Permanganate are added to the solution and then stirred
- Water is incrementally added until a mixture of 32 liters is created when it is then cleaned.
Creating Cheaper Graphene
Graphene Oxide filters are really effective, but the biggest problem in water filtration and desalination isn’t addressed, cost. The cost of graphene is not cheap, and therefore the filters will be expensive. Creating graphene in a cheap, non-toxic way becomes the main issue.
By utilizing a bottom-up approach that has been tested in labs, we can create graphene easily and cheaply. By heating any carbon-containing material up to 3000 Kelvin, we can isolate graphene cheaply. Energy consumption would be around 7.2 kilojoules/gram, meaning that it is very cost-effective.
Glass Fiber Membrane
Even by decreasing the cost of graphene by using the bottom-up approach, it is not sustainable to have the entire system use graphene. If we keep the core parts unchanged while replacing some parts of the filter, we would have a large difference in cost without downgrading the machine itself. Through fusing graphene and teflon nano-particles into commercial glass-fiber membranes, we can create the replacement material. Teflon binds both glass and graphene together, making a filter with customizable pore size.
About Nure
Nure has a wonderful and passionate team that is on a mission to solve water scarcity. We really believe in this problem because water scarcity is a huge challenge that people experience every day. Water is a human necessity but still, people don’t have access to it.
Our team is comprised up of Nivan Gujral and Aniket Majumder!
The Future
Even though Nure has solved the biggest barrier towards full deployment of the Graphene Oxide Filters, the work is not done. All of these features that make up the Nure filtration system are still used heavily in labs. Moving forward we will work towards pushing these technologies future so that they can be implemented in our filters.
This new process towards water filtration will allow families around the world to never have to worry about not having water. Water is not a tool that is necessary for people to live, it builds health, community, and much more. Using these new technologies, Nure’s goal is to provide a constant source of water for 1 billion people that are suffering as a result of a scarcity of water by 2031.