FOR PROTECTION OF THE BALTIC SEA ENVIRONMENT

Concrete Ways of Reducing Microplastics in Stormwater and

Wastewater

Nils Höglund,

MSCG April 2017

Conclusions

• MPs in stormwater & wwtp effluents • MP amounts released by stormwater ≥ by wastewater

• MPs <300 µm abundant

• Large variations of MP conc. in wastewater

• Black particles in large concentrations – Tyre wear?

• End-of-pipe solutions important

• Constructed wetlands and stormwater ponds efficient barriers for MPs in water

Micro plastic…

4 Studied facilities –

constructed ponds and

wetlands

Sampling by pump: -20 µm filters -300 µm filters (one at the time)

Method

Complementary sampling - Filtration through 20 µm filters

Also, for verification - Simple melting test - FTIR spectroscopy

Visual analysis of filters

Results: measured occurrence

Results: Reduction after wetland/pond

Summary

Conclusions

• Study shows MPs content in stormwater & wwtp effluents o MP amounts released by stormwater ≥ by

wastewater

o MPs <300 µm abundant

o Large variations of MP conc. in wastewater

o Black particles in large concentrations – Tyre wear?

• End-of-pipe solutions important as well as upstream work

• Constructed wetlands and stormwater ponds efficient barriers for MPs, reducing also nutrients, pharmaceuticals