New technology cleans water with bacteria: here's everything you need to know

New York: Researchers, led by an original Indian, have developed a new technology capable of cleaning water twice as fast as commercially available ultrafiltration membranes. hope to countries like India where the quality of drinking water is a major problem. According to a team at Washington University in St. Louis, more than one in ten people in the world do not have access to basic drinking water and, by 2025, the half of the world's population will live in areas of water stress.

The team led by Srikanth Singamaneni, a professor at the university, has developed an ultrafiltration membrane based on graphene oxide and bacterial nanocellulose that they found extremely efficient, sustainable and respectful of the environment.

Membrane technology purifies water while preventing biological fouling, or the build-up of bacteria and other harmful microorganisms that reduce water flow. For the study, published in the journal Environmental Science and Technology, they used bacteria to build such filter membranes.

The bacterium Gluconacetobacter hansenii is a sweet substance that forms cellulose nanofibers when it is in water. The team then incorporated graphene oxide (GO) flakes into the bacterial nanocellulose during its growth, essentially retaining the membrane in the membrane to make it stable and durable. They exposed the membrane to the E. coli bacteria and then lit the surface of the membrane.

After being irradiated with light for only three minutes, E. coli bacteria died. The team determined that the membrane was heating up rapidly above the 70 degrees Celsius needed to break down the cell walls of E. coli bacteria.

While the bacteria were killed, the researchers had a virgin membrane containing high quality nanocellulose fibers, capable of filtering water twice as fast as commercially available ultrafiltration membranes. under high operating pressure.

When they did the same experiment on a bacterial nanocellulose membrane without reduced GO, the E. coli bacteria remained alive. Although researchers recognize that implementing this process in conventional reverse osmosis systems is challenging, they offer a spiral wound module system, similar to a towel roll.

It could be equipped with LEDs or a type of nanogenerator that exploits the mechanical energy flow of the fluid to produce light and heat, which would reduce the overall cost.

If the technique were to be developed on a large scale, it could benefit many developing countries where drinking water is scarce, the researchers noted.