Japanese researchers have developed a method to clean oil-contaminated water at oil and natural gas development sites.

Schematic view of a mesoporous polymer. Image: National Institute for Materials Science


Large volumes of oil-contaminated water are generated at oil and natural gas development sites. Such sites need low-cost and efficient water treatment systems that can prevent this water from polluting the environment. Now, researchers at Japan’s National Institute for Materials Science (NIMS) have developed a method, published recently in Nature Communications, that harnesses engineering plastics widely used for industrial purposes to prepare a high-performance oil absorbent.

Previously, conventional technologies were unable to form, in a controlled manner, the nano-sized pores necessary to give polymer materials an oil-absorbent property. The NIMS researchers used cryogenic separation to separate a polymer and solvent from a polymer solution. The solvent was then used to form nanocrystals within engineering plastics. By removing the nanocrystals, they created a mesoporous polymer containing nanoscale pores connected in sequence. This new absorbent polymer can take the form of a sheet, pellet or fibre.

The polymer has a large surface area exceeding 300 square metres per gram, which allows it to efficiently absorb oil from water, say the researchers. They found that the new mesoporous material could absorb more than 260 mg of cresol per gram. Cresol is an organic compound found in oil-contaminated water. Moreover, at high temperatures, oil could be removed from the absorbent polymer, allowing it to be used repeatedly.

The researchers say their next focus will be confirming the on-site performance of the separation system using the new material.


For further information contact:

Sadaki Samitsu
Researcher, Separation Functional Materials Group
Polymer Materials Unit
National Institute for Materials Science
Email: samitsu.sadaki@nims.go.jp

Izumi Ichinose
Unit Director
Polymer Materials Unit
National Institute for Materials Science
Email: ichinose.izumi@nims.go.jp