COLOGNE – Heraeus Precious Metals, headquartered in Hanau, Germany, is introducing a new antimicrobial technology that is being applied to nonwoven media for water filtration called AGXX.
It is based on reactive oxygen reactions and microelectric field effects caused by the electrochemical interaction between two precious metals.
In the presence of atmospheric humidity, oxygen is converted into reactive oxygen species that react with and kill microorganisms. In addition, the microelectric field present interferes with important cell membrane functions and accelerates the killing of microorganisms. Unlike conventional technologies, the mechanism of action is based on a catalytic reaction rather than the release of substances such as metal ions.
Heraeus, which has annual sales of approaching €30 billion and is one of the top ten family-owned companies in Germany, has high expectations for AGXX, particularly as a replacement for silver-based antimicrobial technologies.
Many current antimicrobials based on silver are not in step with the latest European Union legislation on biocides and face the prospect of being banned from the market.
“AGXX is not based on the release of any metals or harmful compounds and to date, has shown antimicrobial efficacy against over 130 microorganisms,” explained Dr Marie-Lena Harwardt, the company’s co-head of antimicrobials at the recent Filtech conference in Cologne. “These include bacteria, viruses, algae and fungi as well as silver-resistant E.coli strains, MRSA and CoV2 viruses.”
The technology initially used inorganic carrier powders, such as activated coal, aluminum oxide or other carrier materials that are well suited for incorporation into nonwoven filters and foams, as well as in coatings and individual fibres.
It has also been successfully applied to various types of activated carbon granules and pellets for easy incorporation into activated carbon-based water filters.
“AGXX carbon granules have shown excellent antimicrobial efficacy in laboratory water filtration tests and samples are now being tested in wastewater treatment and purification systems for swimming pools,” Harwardt said. “With the spread of multi-resistant germs and the dwindling supply of effective antibiotics and approved biocides, it is more important than ever to protect filters from bacterial growth and improve water quality through innovative antimicrobial technologies.”
