Mikroplast - var är vi och vart vill vi?

Jes Vo l le r tsenP r o f e s s o r i M i l j ø t e k n o l o g i S e k t i o n f o r Va n d o g M i l j ø , I n s t i t u t f o r B y g g e r i o g A n l æ gA a l b o r g U n i v e r s i t e t

The societal awareness: Searches on Googlesearches on the term ”microplastics”

Orbmedia– bottled water ‘study’

Scientific study onmicroplastics in table salt

Plastic pollution

The use of plastics potentially leads to:

Impacts on nature and humans

Visual nuisances Physical damages on animals

Toxic effects on animals and ecosystems

Toxic effectson humans?

What do we know regarding impacts?

Uptake and occurrence in the food chain

Microplastics exposes marine organisms and ecosystems at all levels

Fishes

Cephalopods

Holothurians

Marine mammals

Molluscs, crustaceans,

annelidsFishes

Planktonicorganisms

Are there effects atenvironmentally realistic concentrations?

Human are exposed to microplastics, for example by indoor airMeasured in 3 student flats

90%

6%

4%

ProteinCelluloseTOT MP

• Protein is for example skin and hair• Cellulose is for example cotton• TOT MP are all types of microplastics

94%

3%3%

90%

8%2%

85%

6%9%

Differences between the 3 flats

Composition of organic material in the breathed air

Grey: Natural materialColored: Plastics

What do we know regarding fate?

Plastic is indestructible Plastic is degraded

Degradation

Common assumption Reality

Degradation in the natural and technical environment:

BiologicalPhysical-chemical

Nanoplastics? Complete mineralization?

25 years in the storage at the Danish War Museum

4 months at a Danish beach (Blåvandshug)

Degradation depends on the environment

Degradation in reality

What do we know regarding sources?

How well do wastewater treatment plants remove microplastics?10 Danish treatment plants

Plas

t [m

ikro

gram

per

lite

r]

0

200

400

600

800

1000

1200

1400

Plas

t [m

ikro

gram

per

lite

r]

0

200

400

600

800

1000

1200

1400

Inlet Outlet

Around 99% of all microplastic is retained

Where does the microplastics go?

Mikroplaster i kretsloppetSmå plastpartiklar, så kallad mikroplast, …

Sampling at Sjölunda Reningsverk

Results at Sjölunda Reningsverk

More than 99% of the microplastics were removed from the incoming wastewater

Total discharge of microplastics was calculated to 0.15 g/(PE year)

40% of the microplastics in the incoming wastewater was recovered in the anaerobically digested sludge

Fältförsök Petersborg – sampling

A Without sludgeB Sludge. 4 ton TS per hectare per 4:year (1981, 1985, 1989, 1993,

1997, 2001, 2005, 2009, 2013, 2017)C Sludge. 12 ton TS per hectare per 4:year (same years as B)

0 Without mineral fertilizer1 NPK in relation to growth. ½ N-dosing, 1/1 PK-dosing2 NPK in relation to growth. 1/1 N-dosing, 1/1 PK-dosing

Fältförsök Petersborg – mass results

Fältförsök Petersborg – polymer types

AlkydPolyesterPolyetylen (PE) Polypropylen (PP)Polyamid (PA)Polyvinylklorid (PVC)Polyuretan (PU) Polystyren (PS)

Biogödsel(anonymous biogas plant – only one sample from one plant)

6 mg plastic per kg TS AlkydPolyesterPolyetylen (PE) Polypropylen (PP)Polyamid (PA)Polyvinylklorid (PVC)Polyuretan (PU) Polystyren (PS) Significantly less than the wastewater treatment plant

sludge, however, only one grab sample was analyzed

Main conclusions

• The treatment plant is highly effective in retaining microplastics

• Data indicate that some plastic might ‘disappear’ during the treatment

• Sludge as fertilizer seems not to cause an elevated microplastic concentration

• Data indicate that some plastic might ‘disappear’ over time

• Solid waste possibly holds less microplastics compared to sludge

Mikroplast - var är vi och vart vill vi?