Graphene and water treatment: introduction and market status

Salgenx, developer of saltwater flow battery technology, has announced the expansion of its development of graphene and hard carbon-coated sand. Originally designed for use in advanced battery systems, Salgenx is now exploring a wide array of new applications for this innovative material, ranging from smart infrastructure to environmental sustainability.

The Company says that "the unique combination of graphene and hard carbon in a sand aggregate has the potential to transform the construction industry". By enhancing the electrical conductivity, mechanical strength, and durability of concrete, Salgenx’s carbon-coated sand opens up new possibilities in building and infrastructure development.

Australia-based NematiQ has announced that after more than a decade of work, the NematiQ Graphene Oxide membrane has obtained WaterMark certification, solidifying its status as a safe product for water filtration. 

The Australian WaterMark Certification Scheme is a mandatory scheme for plumbing and drainage products of a certain type. Certification ensures products are fit for purpose and appropriately authorized for use in plumbing and drainage installations. The Australian Building Codes Board administers and manages the Scheme.

Researchers at the U.S. Army Engineer Research and Development Center (ERDC) are developing a water treatment system based on a mix of graphene oxide and a byproduct made from shrimp shells. Recently, ERDC's graphene research attracted the attention of NASA, leading to a collaboration with the agency to investigate the use of novel graphene materials as high-capacity absorbents for the removal of spacecraft water contaminants.

Graphene could significantly reduce the need for resupply and component sparing in space missions, potentially enabling crewed missions to deeper regions of space. Graphene-enhanced water treatment systems may one day be used to help extend future space missions and lead to safer intergalactic explorations.

Researchers from Peking University, Beijing Normal University and KU Leuven recently reported a novel method to substantially reinforce large-area graphene membranes. Their work provides a facile method to fabricate large-area graphene membranes and paves the road to practical application in the membrane separation field. 

Nanoporous graphene membranes are attractive for molecular separations, but it remains challenging to maintain sufficient mechanical strength during scalable fabrication and module development. In this work, the team drew inspiration from the composite structure of cell membranes and cell walls, and designed a large-area atomically thin nanoporous graphene membrane supported by a fiber-reinforced structure with strong interlamellar adhesion. It was found that factors like fracture stress, fracture strength, and tensile stiffness of the composite membranes can be enhanced compared with other graphene-based membranes of large scale.

Researchers from the Indian Institute of Technology Madras (IIT Madras) and Tel Aviv University in Israel, have developed a graphene oxide-doped silica aerogel adsorbent that can remove trace pollutants from wastewater.

This graphene-modified silica aerogel reportedly removes over 76% of trace pollutants (PPM level) in continuous flow conditions, offering a sustainable path for large-scale water purification. The research team is dedicated to enhancing these results for large-scale applications.

U.K.-based Evove, which develops graphene-enhanced membrane and filtering solutions, has announced it has completed a pilot demonstrating the use of its filter technology at a large AB InBev brewery in Johannesburg, South Africa. 

It was explained that making beer is a process that requires a lot of water: Just sterilizing the equipment in a brewery can mean using thousands of gallons of water every week. That’s especially problematic in a place like drought-prone Johannesburg, where a water shortages and leaky infrastructure mean that water can be in short supply. Normally, the hot, caustic water used to clean tanks and water lines at a brewery can’t be reused, and ends up in the sewer system. It’s filled with grain residues, sugars, and yeasts that can’t easily be filtered out. “With conventional filters, it just clogs up the filters right away,” says Andrew Walker, Evove’s chief marketing officer.

A team of researchers from Japan's Chiba University, led by Associate Professor Tomonori Ohba and including master’s students, Mr. Kai Haraguchi and Mr. Sogo Iwakami, has fabricated fullerene-pillared porous graphene (FPPG)—a carbon composite comprising nanocarbons—using a bottom-up approach with highly designable and controllable pore structures. 

Separation processes are essential in the purification and concentration of a target molecule during water purification, removal of pollutants, and heat pumping. To make the separation processes more energy efficient, improvement in the design of porous materials is necessary. Porous carbon materials offer a distinct advantage as they are composed of only one type of atom and have been well-used for separation processes. They have large pore volumes and surface areas, providing high performance in gas separation, water purification, and storage. However, pore structures generally have high heterogeneity with low designability, which poses various challenges, limiting the applicability of carbon materials in separation and storage.

Researchers from Qatar University (QU), Maimoona Mohamed and Nada Yahya Deyab, along with their supervisor Dr. Shabi Abbas Zaidi, have made progress in addressing the challenge of oil-water separation.

Their research focuses on developing a novel material for efficient oil recovery from oil-water mixtures. By modifying polyurethane (PU) sponges and cotton with reduced graphene oxide (rGO), they have achieved promising results in terms of hydrophobicity, oil-absorption efficacy, reusability, and cost-effectiveness, offering a promising solution to address the issue of water and soil pollution caused by oil spills.

An international team of researchers from the Max Plank Institute for Polymer Research of Mainz (Germany), the Catalan Institute of Nanoscience and Nanotechnology (ICN2, Spain) and the University of Manchester (England) has found that water can interact directly with the carbon’s electrons: a quantum phenomenon that is very unusual in fluid dynamics.

A liquid, such as water, is made up of small molecules that randomly move and constantly collide with each other. A solid, in contrast, is made of neatly arranged atoms that are surrounded by a cloud of electrons. The solid and the liquid worlds are assumed to interact only through collisions of the liquid molecules with the solid’s atoms: the liquid molecules do not “see” the solid’s electrons. Nevertheless, just over a year ago, a theoretical study proposed that at the water-carbon interface, the liquid’s molecules and the solid’s electrons push and pull on each other, slowing down the liquid flow: this new effect was called quantum friction. However, the theoretical proposal lacked experimental verification.

Directa Plus has announced the start of a pilot project for a novel concept in produced water treatment. The Company said the project would use its ‘Grafysorber’ technology, and was being conducted through its subsidiary Setcar. The showcase of the pioneering endeavor reportedly took place at Setcar's Braila location in Romania

Produced water refers to the water that is extracted alongside crude oil during the oil production process. Currently, the water is disposed of without undergoing any treatment, but stricter industry regulations are driving the need for effective treatment solutions. Directa Plus said it was aiming to address the challenge with its new development, which had the potential to tap into untapped markets within the company's environmental division.