How is Nanotechnology Used for Water Purification?

Water and wastewater management companies always look for newer, more efficient ways to treat water. One of the most intriguing developments in water and wastewater treatment over the last 20 years is nanotechnology and water purification. 

While most large water and wastewater management operations haven’t implemented nanotech, it’s shown promise on smaller levels and could deliver clean water more efficiently than ever. Let’s take a look into how researchers of nanotechnology have tested water purification.

What is Nanotechnology?

You’ve probably heard of nanotech at some point in your life. It became a huge talking point in the technology industry in the mid-2000s. Nanobots, or microscopic robots, became popular plot points in science fiction films, TV and books. Audiences worldwide developed a fascination with the concept of these minuscule bots and how they could help or harm our world.

In more realistic terms, nanotechnology is the application of tiny machines applied across all science fields. Renowned physicist Richard Feynman introduced the concept at an American Physical Society meeting in 1959. While the term “nanotech” wasn’t coined until the 1980s, Feynman described the same idea of controlling matter down to a molecular level. 

How Can Nanotech Be Applied to Water Purification?

One application for nanotechnology is how it can separate microbes, chemicals and other pollutants from water to deliver clean drinking water to everyone without labor-intensive processes. Here are three examples of how researchers attempted to remove contaminants from water with nanotechnology.

Carbon Nanotubes for Water Purification

One of the most-discussed forms of water purification nanotech is the carbon nanotube (CNT). Japanese scientist, Iijima Sumio, discovered the carbon nanotube in 1991 while investigating the material extracted from solids that grew on the tips of carbon electrodes.

In terms of water filtration, the carbon nanotube structure allows water molecules to pass through the tube’s pores while attracting microbes to the carbon surface. Manufacturers can form CNTs into sheets or spirals that pull water through the honeycomb-like structures to remove pollutants. This formation prevents biological and chemical hazards from entering the water stream.

A National Informal STEM Education Network (NISE) presentation demonstrated the promising applications of CNTs on water filtration. This presentation also addressed the question of how to clear biofouling from a filter. The conductivity of the nanotube allows for electricity to pass through its structure, which can destroy harmful microorganisms on the surface of the CNT. This strategy was later expanded on by Nagoya University researchers as they used CNTs to remove toxic heavy metals from water.

Nanocellulose Applications for Water Purification

Another popular type of nanotech used for filtration is nanocellulose. This material is usually derived from the disintegration of naturally occurring polymers or bacterial action. It is similar to CNTs in form and function but differs in its manufacturing process. The cellulose nanocrystals and nanofibrils (CNC and CNF) are the rod-like nanoparticles that selectively adsorb contaminants from water streams. The shape of the fibrils and the less rigid structure of nanocellulose lends itself to being an excellent filter that could work in small and large water filtration systems. 

Golden Nanoparticles for Water Purification 

In a recent study conducted by a collective of research groups, scientists found that gold nanoparticles are useful for water purification. These nanorods could conduct heat in a localized fashion and destroy pollutants, like pharmaceuticals and anti-pesticides, in a more efficient way than heating the entire volume of water. The researchers discovered that if they evenly distributed these particles, the nanorods could be effective. They then applied a silica coating to part of the nanorods that kept them from clumping, which resulted in even dispersal. 

The Downside of Nanomaterials for Water Purification

With all of the upside potential of nanotech, it’s easy to think, “why hasn’t it been used yet?” In the mid-2000s, nanotechnology saw a spike in interest for all sorts of applications. The US government invested billions of dollars into what they thought would be the next revolutionary technology. As years passed, funding for various nanotech projects dried up as its promise didn’t deliver the expected results.

One nanotechnology filtration company showed why it was so difficult to keep a foothold in the market. They developed several devices that could instantly filter water from the least desirable of water sources. Using CNTs, it filtered water to a drinkable level in minimal time. This invention was revolutionary as it made clean water accessible to virtually anyone. The problem wasn’t that they had a dysfunctional product, but that they couldn’t find a sustainable market that was cost-effective.

Nanotechnology for water purification remains too expensive to implement cost-effectively, especially for large scale water and wastewater treatment plants. While nanotech research continues, the feasibility of its implementation has slowed. As researchers find new applications, there is still a possibility for nanotech to be used for large scale water purification in the future.

Are you looking for an excellent water and wastewater management team that uses the most effective and modern methods to keep your operations within EPA regulations? Contact Alliance Water Resources today to see how our team of experts can improve your water and wastewater operations.