The declining freshwater reserves across the globe at an alarming rate has put staggering pressure on the availability of clean potable water. With this, the demand for smart clean water solutions in various parts of the world has become intense, all the more. In a key advance made in the current nanofiltration technology, a number of scientists, led by the Institute of Carbon Science and Technology at Shinshu University and Penn State Materials Research Institute, have developed a scalable graphene-based hybrid membrane water filtration technology. The device uses graphene-based membrane to desalinate water, including highly polluting industrial dyes. The nanofiltration technology will provide clean water fit for irrigation, and possibly for human consumption in the coming years.
The details of the work was published online on August 28, 2017 in the journal Nature Nanotechnology and is peer-reviewed.
Few-Layered Graphene Membrane Makes for Inexpensive, Scalable Filtration Technology
The robust hybrid membrane could be the first step toward making a practically feasible, cost-effective, scalable, and remarkably efficient water clean solutions, claim the team of researchers. The technology will be useful in a variety of applications, primarily for wastewater treatment, pharmaceutical, and food industries.
The desalination devise mainly uses spray-on technology to make the hybrid membrane consisting of a mixture of graphene oxide and few-layered graphene. The polysulfone, along with polyvinyl alcohol, acts as adhesive to inhibit water solubility of graphene. The graphene oxide-few-layered graphene membrane helps in filtering out salt and dyes—to as much as 85% and 96% respectively–enables intensive water flow, and is immune to notably high pressures.
Unique Properties of 2-D Graphene Does the Trick
The team of investigators utilized the various unique properties of two-dimensional graphene, such as the high mechanical strength, notably high salt rejection, and being impervious to chlorine. The chlorine is widely used in the current water filtration technologies for biofouling of membranes, but their efficacy is constrained by gradual degradation of membranes it causes. Through these factors make graphene membranes highly suitable, researchers in the device have overcome the problems that naturally surface when these are scaled to industrial purposes.
This work was supported by the Center of Innovation Program and scientists from the Japan Science and Technology Agency.