Microplastics in rivers - first findings of a new method
Microplastics are on the rise worldwide. Primary sources of microplastics include litter and car tyres. We now have a reliable method to measure microplastics in rivers at a specific location. In the last three years, pilot measurements have been taken in the River Rhine at Lobith, and in the Maas at Eijsden and Rotterdam.
Imagetitle:
Microplastics in rivers
First findings of a new method.
Christa Oversteeg
Microplastics are on the rise worldwide.
Primary sources of microplastics include litter and car tyres.
We now have a reliable method to measure microplastics in rivers at a specific location.
In the last three years, pilot measurements have been taken in the River Rhine at Lobith, and in the Maas at Eijsden and Rotterdam.
[Music]
Edwin Mets
We are now at the measuring station in Eijsden,
where the water quality is continually monitored.
We take measurements for a month at a time.
Thousands of litres of water flow through the measuring equipment.
We are interested in capturing the solid matter suspended in the water.
The suspended solids are captured in the trap, and because the
process is continuous, when we look at the sediment in the lab, we get a very accurate picture of
just how much microplastic is in the water.
It's more accurate than if we just took a one-off sample.
We take the traps to the government laboratory in Lelystad.
Once there, we extract the suspended solid matter from the trap.
In the lab, we can very accurately determine the concentration of microplastics in the surface water.
[Music]
Christa Oversteeg
Before we can determine how much microplastic is in a sample, we first have to dry the sample in stages.
We start by removing the water from the trap, but we use a filter to make sure we keep the
suspended plastics.
The sample is then freeze-dried.
And then we grind it into a highly homogeneous powder.
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Once the sample has been ground and dried, we start the analysis process.
To help with that, we have this device.
First, the sample is heated in a kiln, in the absence of oxygen.
The heating process causes substances in the sample, including microplastics, to separate into fragments.
We can then identify these fragments with this part of the device.
We compare the patterns and peaks of pure plastics and other reference materials with those in the sample.
This allows us to distinguish rubbers and plastics in the sample.
So we can measure exactly what type of plastic the sample contains.
And how much of each plastic there is.
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This measurement method gives us an accurate picture of how much microplastic there is in Dutch watercourses.
It also tells us what type of plastics we have found.
These are mainly polyethylene and car tyre rubbers.
If we repeat these measurements often enough, we will discover how microplastic concentrations increase and decrease over time.
In the longer term, this should enable us to see whether agreements reached with industry on limiting plastic emissions are having an impact.
These efforts help us learn more about microplastics, an environmental problem that we are doing more research on.
Final leader
More information?
Visit zwerfafval.rijkswaterstaat.nl/monitoring-zwerfafval-langs-rivieren
A production from the Ministry of Infrastructure and Water Management
2023
Microplastics are on the rise worldwide. Primary sources of microplastics include litter and car tyres. We now have a reliable method to measure microplastics in rivers at a specific location. In the last three years, pilot measurements have been taken in the River Rhine at Lobith, and in the Maas at Eijsden and Rotterdam.