Presented by IWMI's Josiane Nikiema (Research Group Leader – Circular Economy and Water Pollution) at OECD Workshop on Microplastics from Tyre Wear: Knowledge, Mitigation Measures, and Policy Options on May 20, 2020.

1. Capture of Tyre and Road Wear Particles
From Wastewater and Stormwater
Josiane Nikiema, PhD
Research Group Leader – Circular Economy and Water Pollution
International Water Management Institute
Email: j.nikiema@cgiar.org
Phone: +233-302 784 752/ 753

2. Report:
Water pollution by plastics and microplastics: a
review of technical solutions from source to sea
Josiane Nikiema, Javier Mateo-Sagasta, Zipporah
Asiedu, Dalia Saad and Birguy Lamizana
Tentatively available from September 2020

3. CAPTURE OF TYRE AND ROAD WEAR
PARTICLES IN URBAN WASTEWATER
Industries
Institutions
Households
Sewers
Treatment plant
Industries
Stormwater
Institutions
Combined sewers
Treatment plant
Households
Environment
StormwaterDrains
Treatment

4. IMPACT OF SHAPE AND SIZE OF MICROLITER
DURING CONVENTIONAL TREATMENT
0% 20% 40% 60% 80% 100%
Influent
Screening
Chemical and biological treatment
Effluent
Fibers Fragments Flakes Films Beads
0% 20% 40% 60% 80% 100%
Influent
Screening
Chemical and biological treatment
Effluent
> 0.300mm
0.1-0.3mm
0.02-0.1mm
Talvitie et al. 2017

5. Preliminary & primary stage Secondary treatment stage Tertiary treatment stage
Process Cost
in developing
countriesa
 Investment cost: USD 3-40
per capita (2013)
 O&M cost: USD 0.1-2 per
capita (2013)
 Investment: USD 10-150 per
capita
 O&M cost: USD 0.2-8 per
capita
-
Typical Costs
for the full
process in the
USAb,c
Not available as treatment at
this level is insufficient to meet
the quality standards for
treated WW
 Investment cost per m3/d is:
o Between USD 399-9,246 with
average of USD 3,308 (2017)b.
o Between USD1,300 and USD
11,900 per m3/d (2014)c.
 O&M cost per m3/d is USD 29-
1,321, with average of USD
437 (2017)b.
 Investment cost per m3/d
is between USD 984-
144,224 with an average
of USD 57,534 (2017) b
 Operation cost per m3/d
is between USD 76-
21,804 with an average of
USD 6,168 (2017) b
COST OF WASTEWATER TREATMENT
Wetlands in the USA (tertiary treatment)
 Total cost is USD 379-11,016 with average of USD3,441 (2017) b
References: aDrechsel et al. 2015; b Hunter et al. 2018; c Guo et al. 2014.

6. CAPTURE OF TYRE AND ROAD WEAR PARTICLES
IN URBAN STORMWATER
• In many developing countries of Africa or Asia,
it is estimated that up to 80% of the plastic
waste is poorly managed.
• In Africa and Asia, stormwater management to
prevent floods is a critical issue.
• Stormwater in urban areas is often collected
and channeled through separate drains, in
which solid waste could accumulate, or which
may also serve to collect grey water.

7. TREATMENT OF RUNOFF IN MANY DEVELOPING COUNTRIES
1. Conventional: In artificial basins called storm water retention ponds.
• How is the sludge managed?
2. Wetlands could capture and remove wide range of pollutants :
• Purification process involves vegetation, soils, and microbial assemblages through uptake
by microbes and plants as well as filtration.
• Not yet studied widely for MPs removal.
Wetland Örsundsbro Alhagen
Area (ha) 0.8 28
Mean flow (m3/d) 667 5,100
Theoretical residence time (d) 3.5 86
Reduction of MPs with 20 – 30 µm (%) 99.7 99.8
Reduction of MPs with > 300 µm (%) 100 100
Coalition Clean Baltic 2017

8. CONCLUSION
We need to embed stormwater
management and pollution control into a
financially viable model, to ensure
sustainability.

9. Josiane Nikiema, PhD
j.nikiema@cgiar.org