18.01.2019 change 18.01.2019

Researchers at the University of Silesia developed membranes for removing heavy metal contaminants

Photo: Fotolia Photo: Fotolia

Researchers associated with the University of Silesia in Katowice have developed a method of production of special membranes from graphene oxide or its derivatives and cellulose that allow to remove trace amounts of heavy metals from aqueous solutions.

The invention has been covered by patent protection.

"The membranes we have obtained can be used both for the determination of metal ions and their removal from aqueous solutions We use membranes to determine the content of heavy metal: after passing the solution through the membrane, metal ions can be washed out and their content determined with atomic spectroscopy techniques" - head of the Analytical Laboratory of Spectroscopic Methods at the Institute of Chemistry, University of Silesia Prof. Rafał Sitko told PAP.

Previous solutions were based on the use of graphene. But the materials thus obtained exhibited much lower adsorption properties with respect to heavy metal ions. In addition, toxic compounds were needed for their production, which greatly complicated the production process.

With the solution proposed by scientists associated with the Institute of Chemistry of the University of Silesia, the production of membranes of graphene oxide or its derivatives and cellulose is less complicated, faster and cheaper, and allows to obtain homogeneous materials with good adsorption properties. They are durable and stable not only in an acidic and neutral environment, but also in an alkaline environment, which was extremely difficult to achieve until now. They can also be regenerated many times.

"We are not technologists, so it is difficult to speak about large-scale production of membranes. But their production process is simple and requires low-cost reagents. It comes down to obtaining a homogeneous suspension of graphene oxide and cellulose - preceded by dissolving cellulose and its precipitation in the presence of graphene oxide - and sedimentation through vacuum filtration. Graphene oxide necessary for the production of membranes is obtained from graphite by oxidation. This is a relatively simple process that requires low-cost reagents .The time consuming part is the purification of graphene oxide consisting of repeated washing and centrifugation. In laboratory conditions, the process is simple" - explained Prof. Sitko.

PhD student at the Institute of Chemistry, University of Gdansk, Marcin Musielak is the co-author of the method of production of membranes from graphene oxide or its derivatives and cellulose.

PAP - Science in Poland, Anna Gumułka

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