1. No category

Are waste water treatment plants (WWTPs)
transfer routes for microplastics to the
aquatic environment?
Kerstin Magnusson
IVL Swedish Environmental Research Institute
20 January 2015
FRAGMENTED BEACH LITTER
STORM WATER
Microlitter in the
aquatic environment
Where does it come from?
DUMPING FROM BOATS
WASTE WATER EFFLUENTS
INDUSTRIAL PLASTIC PELLETS
Kerstin Magnusson 20 januari 2015
Effluent water from waste water treatment plants
(WWTPs)
Kerstin Magnusson 20 januari 2015
Waste water was pumped or poured through filters
and the filter material analysed
with stereo microscope
Kerstin Magnusson 20 januari 2015
Size matters –
the mesh size of the filter affects
what particles are captured
In our studies of microlitter in waste water we have used
300 µm and 20 µm filters
Kerstin Magnusson 20 januari 2015
Microplastics in incoming water to WWTPs,
number of particles per hour
Particles >300 µm
Particles >20 µm
Different scales on the y-axis!
1.5·109
Kerstin Magnusson 20 januari 2015
Microplastics in effluent water from WWTPs,
number of particles per hour
Particles >300 µm
Particles >20 µm
Different scales on the y-axis!
60·106
Kerstin Magnusson 20 januari 2015
Most of the particles are retained in the
WWTP sludge
300 µm
20 µm
Henriksdal
98.9 %
90.3 %
Ryaverket
99.9 %
74.0 %
Långedalsverket
99.5 %
87.0 %
Data from three Swedish WWTPs
Kerstin Magnusson 20 januari 2015
The amount of particles coming out from
WWTPs on a weight bases
Number/h
g/h
Pe*
Henriksdal 300 µm filter
880 000
1100
750 000
Ryaverket 300 µm filter
106 000
11.2
740 000
Långevik 300 µm filter
13 600
0.15
12 000
Henriksdal 20 µm filter
27 000 000
2020
750 000
Ryaverket 20 µm filter
70 000 000
27.6
740 000
Långevik 20 µm filter
840 000
1.0
12 000
* Population equivalent
Kerstin Magnusson 20 januari 2015
Number of microplastics >300 µm per hour and size (pe)
NUMBER OF PARTICLES IN EFFLUENT
WATER
Mikroplast ≥300 µm
per hour and pe
Viikinmäki, Helsingfors; 800 000 pe
0.6
Henriksdal, Stockholm; 750 000 pe
1.2
Ryaverket, Göteborg; 740 000 pe
0.2
VEAS, Oslo; 290 000 pe
0.4
Reykjavik, 97 000 pe
600
Tönsberg; Norway 82 500 pe
3.9
Hyvinkää; Finland 40 500 pe
0.3
MOVAR, Fuglevik; Norway 33 300 pe
0.8
Långeviksverket, Lysekil; 12 500 pe
0.8
Data from Swedish, Finnish, Norwegian and Icelandic WWTPs
Kerstin Magnusson 20 januari 2015
Sampling of microplastic litter particles in
Långeviksverket and in the recipient water.
From Magusson & Norén, 2014
Screening of microplastic particles …
Microplastic particles in Långeviksverket and in the recipient water
Sampling point
ƩMicroplastics >300 µm
Influent water (number m-3)
15 000
Effluent water (number m-3)
8.3
Recipient20m (number m-3)
2.0
Recipient50m (number m-3)
1.3
Recipient200m (number m-3)
1.1
Recipient reference (number m-3)
0.5
Sludge, wet weight (number kg-1)
720
Sludge, dry weight (number kg-1)
17 000
Waste water
flow rate =
200-400 m3 h-1
From Magusson & Norén, 2014
Screening of microplastic particles …
Kerstin Magnusson 20 januari 2015
Examples of microplastics in WWTP effluent water
Particles from influent and effluent water from Långeviksverket.
A) Polypropene (lenght~1 mm);
B) Thermoset plastic based on aliphatic polyester resin (lenght 0.5 mm);
C) Polyethene (length ~0.3 mm).
From Magusson & Norén, 2014
Screening of microplastic particles …
Kerstin Magnusson 20 januari 2015
Microplastics and other B
kinds of microlitter.
A: from waste water
B & C:from field samples
A
C
Kerstin Magnusson 20 januari 2015
Many companies have decided to phase out
the use of microplastics in their products
Kerstin Magnusson 20 januari 2015
What are the microplastic concentrations in lakes?
Most field samples are from a marine environment,
but there are some studies from freshwater bodies
Kerstin Magnusson 20 januari 2015
Mikroplast >500µm in the river Danube
Input from Danube to the Black Sea was estimated to be
4.2 ton of microplastic per day.
The dominating category was industrial pellets.
Fig. 1. Categories of drifting plastic items in the River Danube.
From Lechner et al. 2014
Kerstin Magnusson 20 januari 2015
Microlitter in beach sediment at Lake Garda, Italy
Imhof et al 2013
At the most contaminated shore(particles <5mm):
1108 ± 983 microplastic particles/m²
Suspected origin:
• Plastic fragments from water sport equipment, plastic toys,
packaging materials, fishing equiment
• Plastic fragments from land fills
• Plastic fibres from sewage effluent
Kerstin Magnusson 20 januari 2015
What negative effects can
microplastic have?
Kerstin Magnusson 20 januari 2015
Toxic effect 1: Plastics can be harmful in themselves
Bisphenol A, a building block in polycarbonate
plastic and epoxy has estrogen-like properties
POLYCARBONATE
Bisfenol A
Bisfenol A
Bisfenol A
Kerstin Magnusson 20 januari 2015
Toxic effect 1: Plastics can be harmful in themselves
Styrene, the building block in polystyrene,
is strongly suspected to be carcinogenic
Kerstin Magnusson 20 januari 2015
Toxic effect 2: Plastic contain harmful additives
which may leak into the environment
Some examples:
• Flame retardants (e.g. brominated diphyl ethers)
• Softeners (phthalates)
• Heat stabiliser in PVC (TBT)
Kerstin Magnusson 20 januari 2015
Toxic effect 3: Other organic pollutants may adsorb
to microplastic particles
Phthalate
PBDE
PBDE
Phthalate
Phthalate
Microplastic
Microplastic
Nonylphenol
Phthalate Phthalate
PBDE
Nonylphenol
Nonylphenol
Nonylphenol
PBDE
Phthalate
PBDE
Microplastic
Phthalate
Phthalate
Nonylphenol
PBDE
PBDE
PBDE
Microplastic
Phthalate
Microplastics may act as vectors for pollutants to aquatic animals
Kerstin Magnusson 20 januari 2015
Microlitter in wastewater as carriers of particle bound pollutants
MICROLITTER PARTICLES
&
ORGANIC POLLUTANTS
e.g.. PHTHALATES, NONYLPHENOL
TO WWTP
Vattnets roll i vårt hushåll. Illustration: Ulf Swerin
PLASTIC FIBER
PLASTIC PARTICLES
Kerstin Magnusson 20 januari 2015
FRAGMENTED BEACH LITTER
STORM WATER
So, how important are
the WWTPs as entrance
routes for microlitter in
water bodies?
DUMPING FROM BOATS
Still limited knowledge on the
relative importance of different
origines
WASTE WATER EFFLUENTS
INDUSTRIAL PLASTIC PELLETS
Kerstin Magnusson 20 januari 2015
Are there reasons to believe that
aquatic microlitter/microplastics is a
threat to drinking water in Sweden?
As the situation is right now; probably not!
Kerstin Magnusson 20 januari 2015
Plastic generally has a long half-life,
for some plastic materials many decades.
If microplastics are added to the
environment at a higher rate than they
are degraded, concentrations will
increase.
Kerstin Magnusson 20 januari 2015
Filter-feeding animals like blue mussels or
sediment eating animals like many polychaetes are
particularly at risk
Plastic particles
Photo: K. Norén
Photo. A.Johansson, 2011
Kerstin Magnusson 20 januari 2015