For some time now, Gunnar Gerdts has worked together with experts from regional authorities, municipal water treatment and wastewater treatment plants. The reason: the works of Gerdts and other researchers show that wastewater and sewage sludge from treatment facilities contain large amounts of microplastics. “We still don’t have guidelines or threshold values for microplastics in wastewater, but it’s conceivable that in the future, filtering microplastics out of wastewater will become mandatory,” says Gerdts.
The discussion concerning microplastic coincides with the debate about a fourth filtration step for treatment plants: for some time now, there have been discussions about introducing additional filtering technologies to remove antibiotics, pharmaceutical residues and other substances from wastewater, as this cannot be achieved with conventional systems. “This offers a good opportunity to not only filter out the pharmaceutical substances, but also plastics,” explains Gerdts. “Nevertheless, the currently available data are hardly sufficient. We need a cross-cutting system analysis of the problem, which isn’t limited to the filtering processes used at treatment plants. Moreover, we still know far too little about the amounts of microplastic in rivers.”