A membrane filter worked much better than expected
Translated by Maryse de Preter
A Drenthe-based water company in the city of Emmen has succeeded in removing medicine residues from surface water. With this (accidental) discovery, a new method may have been found to solve the problem of removing medical residues more widely.
The solution was found by chance, and the company does not know exactly how it works, but it does. The only thing that is certain is that carbon and oxygen play an important role in the purification process, as reported by the Dagblad van het Noorden.
NieuWater, founded by Waterleidingmaatschappij Drenthe and Water Board Vechstroom, purifies sewage water into pure water in its factory in Emmen. This water is then used as steam by the Nederlandse Aardolie Maatschappij (NAM) in its shale gas drilling in Schoonebeek.
The water is purified by using membranes, a type of microscopic filter that blocks everything, such as sludge and bacteria, at a molecular level. Bacteria rest on the outside of the sieves and are difficult to remove. “A solution has been devised without using chemicals. Namely, the installation of carbon filters for the sieves and the addition of oxygen,” explains Veendendaal.
According to the researchers, it is surprising that the filters appeared to do even more than just remove bacteria after installation. They also cut down medicine residues in the water: ” After measurements, more than 80 percent of these remains were found to be destroyed”, said Veendendaal
For now it remains a mystery how the process for the removal of drug residues works.
After researchers at Radboud University in Nijmegen raised the alarm last year about the sharply increased amount of drug residues in Dutch surface water, this invention is interesting. Not only for aquatic life, but also for the preparation of drinking water, the 140,000 kilograms of medicine residues that end up in surface water every year are disastrous both for the ecosystem, and for drug resistance in anitbodies.
Two PhD students from the research institute for water technology in Leeuwarden (Wetsus) are currently investigating the discovery.