When Nanotech Meets Water!

Rianna Kalra
3 min readMay 16, 2021

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So I just read about how we can purify water with nanotechnology and I think it is one of the coolest technologies EVER made in this world.

I had to make a project related to my favorite technology and obviously, I chose nanotech. Just in case you don’t know what it is, it's a technology for the study and application of extremely small things, at the nanoscale level, used in many industries in the world.

I decided to make a project on how nanotechnology can be used to purify water. I had two ways to approach this: nanosensors, and nano filters. Both ways are unique in their own ways and different in their own ways.

1. Nanosensors for Water Purification

What are nanosensors? — Nanosensors are platforms with a characteristic dimension, nanometer in scale, and work in much the same way as a sensor; they detect either minute particles or minuscule quantities of something.

How they are used for water purification? — After researching many hours each day, I found the exact type of nanosensor that is used for water purification. The name of the nanosensor is called a graphene-based sensor. Graphene is a two-dimensional material made of carbon atoms, often dubbed “miracle material” for its outstanding characteristics. It is 200 times stronger than steel at one atom thick, as well as the world’s most conductive material. Graphene and sensors are a natural combination.

The thing about graphene-based sensors, in fact, any sensor is that they only “sense” or detect any bacteria or chemicals in the water. They do not actually remove the bacteria, only detect. So, therefore, you would have to use a graphene-based sensor to detect the chemicals and use another nanosensor to remove them.

2. Nano filters for Water Purification

What are nano filters/nanofiltration? — A nano filter has a pore size of around 0.001 microns. Nanofiltration removes most organic molecules, nearly all viruses, most of the natural organic matter, and a range of salts. Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to separate ions; Ultrafiltration (UF) is a pressure-driven barrier to suspend solids, bacteria, viruses, endotoxins, and other pathogens to produce water with very high purity.

This is a diagram of a nano filter and how it collects the bacteria and lets the water molecules pass through. It shows the membranes needed and their use.

So basically, there are small thin sized nano scaled membranes that are to be piled up and stuck together to make the water purification process more effective. If used to filter water, the nanomembranes allow only water molecules to pass while blocking other molecules. Other molecules are the contaminants or bacteria in the water such as Chlorine or Legionella. The molecules settle on the solid in a thin layer that is then irradiated with electrons. The whole membrane, when it is fully made, works by allowing all the water molecules/particles to pass by, but blocking the bacterial chemicals or contaminants. These bacteria stick to the nanomembrane and are trapped as shown in the image above.

Usage in the World

We all know that access to clean water is very difficult for a percentage of people in this world. People in poverty have to walk miles to get clean water and if nano filters can be used around the world, just imagine how easier that would be. It can clean the water immediately and help so many people around the world! And this idea or scheme would solve this problem! 😉

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Rianna Kalra

15 y/o student @ TKS Innovate | nanotech & gene editing enthusiast | huge bollywood fan