Graphene’s Potential Role in Water Treatment

Written by AOS Treatment Solutions on August 16, 2017
Graphene’s Potential Role in Water Treatment

Since graphene was first isolated in 2004, the hexagonal lattice of carbon atoms has been widely touted as a wonder material which may ultimately disrupt numerous industries. Despite the fact that the crystalline, nearly transparent material is a single-atom thick, it offers superior mechanical strength, a substantial surface area, excellent electron mobility and high thermal conductivity.

Due to its unique properties, graphene may positively impact the environment in important ways. Ultimately, graphene may offer profound improvements in hydrogen fuel production, energy storage and the removal of air contaminants like carbon dioxide.

Graphene and Wastewater

Researchers also focus on graphene’s potential in water purification, including desalination and wastewater treatment. Graphene-based water purification research is advancing in the UK, Australia and Israel, and at Texas’ own Rice University.

Graphene oxide is one form of the substance which attracts particular interest because it is hydrophobic. Also, researchers discovered that adding oxygen to graphene to produce graphene oxide makes it far easier for water to flow through the substance.

Because graphene oxide is a two-dimensional structure, it is possible to control filtration by stacking layers of the material to create ultra-thin membranes. Forester Daily News discussed how creating micropores in graphene oxide membranes allows rapid water permeation. Because physical separation of contaminants is involved, researchers believe the process will be eminently scalable.

Water Filtration Research in the UK

The UK’s University of Manchester is one of the world’s leading centers for graphene research. In fact, two researchers there won the 2010 Nobel Prize in Physics for their pioneering work with graphene. University of Manchester researchers “are currently looking at how graphene membranes can be used for water filtration.”

Already, they have developed graphene oxide membranes capable of separating organic solvents from water. They can even filter out helium, one of the most difficult gases to stop. There are hopes that graphene oxide membranes could filter out pharmaceuticals and pathogens more effectively than other types of membranes currently in use.

Australian Project Advances

In Australia, the government is funding the development of next-generation wastewater filtration ideas using graphene oxide. Research is driven by a shortage of freshwater that often impedes Australian industrial, food and energy markets.

The lead researcher for the project is Monash University’s Prof. Mainak Majumder. In 2016, he developed a technique for the scalable production of graphene filters. Majumder asserts that, “Graphene has special properties which could disrupt current commercial filtration techniques and significantly reduce the energy required to filter wastewater.”

Another Monash professor, Ana Deletic, says the goal is nothing less than to “modernise Australia’s current wastewater management from the traditional treatment approach to a low energy consumption, resource recovery approach.” The research team expects to deliver the first graphene oxide-based products within two to three years.

Effective Bacteria Removal

Another type of graphene is useful in treating bacteria in water. In a May 22, 2017, press release, Rice University detailed collaborative research with Israel’s Ben Gurion University which demonstrated that laser-induced graphene (LIG) can “zap” bacteria with impressive efficiency.

Researchers even produced a video showing Pseudomonas aeruginosa bacteria drawn to an LIG anode that killed them. Low-voltage current increases LIG’s antibacterial qualities. In an experiment, LIG electrodes carrying 2.5 volts killed 99.9 percent of the bacteria in a 10 percent secondary wastewater solution. Rice researcher James Tour says, “This form of graphene is extremely resistant to biofilm formation, which has promise for places like water-treatment plants . . .”

AOS Treatment Solutions is a water treatment consulting and chemical supply company which assists municipalities in their quest for safe and economical water treatment. We offer both standard and custom solutions in groundwater, wastewater and surface water treatment. Please feel free to contact us for more information.

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