stormwater in Paris megacity Robin TREILLES* 1 , Johnny GASPERI 1 , - PowerPoint PPT Presentation

Macro and microplastics in stormwater in Paris megacity Robin TREILLES* 1 , Johnny GASPERI 1 , Mohamed SAAD 1 , Alain RABIER 2 , Jérôme BRETON 2 , Vincent ROCHER 3 , Sabrina GUERIN 3 , Bruno TASSIN 1 1 Laboratoire Eau, Environnement, Systèmes Urbains ( LEESU ) 2 Direction des Services de l’Environnement et de l’Assainissement du Val -de-Marne ( DSEA ) 3 Service public de l’assainissement francilien ( SIAAP ) *robin.treilles@enpc.fr 1 µMED International conference on microplastic pollution September 15th/18th 2019

Introduction: plastics in urban waters Atmosphere ++ Sources Waste water Drinking water ++ Industrial Domestic Stormwater wastewater wastewater Water reservoir +++ Water treatment Combined Stormwater sewer Sludge WWTP retention Airborne overflows pond +++ emissions Agricultural fertilizer Effluents Industrial +++++ and domestic Environment * Combined network use ** Separative network 2 µMED International conference on microplastic pollution – September 15th/18th 2019

Introduction: plastics in urban waters Atmosphere ++ Sources Waste water Drinking water ++ Industrial Domestic Stormwater wastewater wastewater Water reservoir +++ Water treatment Plastic fluxes and Combined Stormwater contribution from sewer Sludge WWTP retention Airborne overflows stormwater ? pond +++ emissions Agricultural fertilizer Effluents Industrial +++++ and domestic Environment * Combined network use ** Separative network 3 µMED International conference on microplastic pollution – September 15th/18th 2019

Methods: sampling site Runoff water at the Sucy-en-Brie catchment outflow (DSEA Val de Marne) Microplastics are Macrowaste are collected from two grid refusals (6 collected during rain events . and 1 cm) once per month . Paris 12/03/18 Marne Flowrate (m 3 /s) Time 4 µMED International conference on microplastic pollution – September 15th/18th 2019

Characteristics of the Sucy-en-Brie catchment Macrowaste (> 1 cm) and microplastics (> 50 µm) Runoff water at the Sucy-en- Brie catchment outflow in stormwater of Sucy-en-Brie Runoff Surface Catchment Coefficient Land use Inhabitants (km 2 ) (%) Mainly a residential area with large Sucy-en- number of multi- 2.28 21 ~ 20 000 Brie occupancy family 1 km houses, limited commercial activities 5 µMED International conference on microplastic pollution – September 15th/18th 2019

Methods: macrowaste in stormwater of Sucy-en-Brie 3. Incubation at 40°C 1. Debris from the 2. Samples are 4. Debris are sorted runoff water are weighted during 10 days and classified collected from two grid refusals ( GR1 6 cm and GR2 1 cm ) 6 µMED International conference on microplastic pollution – September 15th/18th 2019

Methods: microplastics in stormwater of Sucy-en-Brie 80-100L of runoff water are collected upstream of the • grid refusals during rain events for microplastic analysis. This water is then filtered with a 80 µm net and • microplastics are analyzed. 0.6 12/03/18 Plankton net 0.4 Flowrate (m 3 /s) Samples 0.2 Collector Time 7 µMED International conference on microplastic pollution – September 15th/18th 2019

Methods: microplastics in stormwater of Sucy-en-Brie > 5 mm 1-5 mm 3 4 1 2 Sieving H 2 O 2 Digestion Density SDS separation Particles > 5 mm C = 3.5 g.L -1 C = 30% NaI ( ρ = 1.65 T = 40°C T = 40°C Particles > 1 mm g.cm -3 ) t = 24 h t = 48 h t = 24 h 300 rpm 300 rpm Particles < 1 mm Filtration on metal filter Ø=90 mm ; porosity 10 µm < 1 mm Filter after SDS + digestion Filter after density separation 8 µMED International conference on microplastic pollution – September 15th/18th 2019

Microplastics analyses Visual analysis Caracterisation Stereomicroscope Spectroscopy FTIR-ATR Fraction 1-5 mm → Identification of → Nature of the polymer potential plastics Microspectroscopy FTIR 20 cm Stereomicroscope → Fragments and fibers Fraction <1 mm are counted → Concentrations are (after treatment) estimated 25 mm 10 cm 9 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: macrowaste in stormwater of Sucy-en-Brie Grid refusal 1 (mesh size = 6 cm) 10 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: macrowaste in stormwater of Sucy-en-Brie Grid refusal 1 (mesh size = 6 cm) 11 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: macrowaste in stormwater of Sucy-en-Brie Grid refusal 2 (mesh size = 1 cm) 12 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: macrowaste in stormwater of Sucy-en-Brie Nine waste categories correspond to more than 95 % of all the macrowaste of ➢ Sucy-en-Brie (% number of objects accumulated on grid refusals): GR1 (mesh size = 6 cm) GR2 (mesh size = 1 cm) 13 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: macrowaste in stormwater of Sucy-en-Brie Macrowaste fluxes after x days of ➢ accumulation on both grid refusals Runoff water of Sucy-en-Brie Plastic waste in stormwater of 16 ➢ 160 Macrowaste flux (mg/m3) days 140 Sucy-en-Brie ~ 10 to 100 mg/m 3 28 120 days 100 If applied to Paris megacity ➢ 25 80 28 28 days population: 12 to 40 tonnes of 9 24 60 days days 44 days days 21 macrowaste/year in stormwater. 40 days days 20 0 July and august correspond to ➢ the strongest values (recreational activities, storms ?) Sampling date 14 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: microplastics in stormwater of Sucy-en-Brie 06/11/18 12/03/18 Flowrate (m 3 /s) 1 2 3 4 5 1 2 3 4 5 Time Fragments 1-5 mm (MP/L) Fragments <1 mm (MP/L) Fibres <1 mm (MF/L) 15 µMED International conference on microplastic pollution – September 15th/18th 2019

Results: microplastics in stormwater of Sucy-en-Brie Characterisation ➢ 06/11/18 on µFTIR (first 12/03/18 results): Flowrate (m 3 /s) Polyethylene 48% Polystyrene 37% 1 2 3 4 5 1 2 3 4 5 Polypropylene 15% Time Fragments 1-5 mm (MP/L) Fragments <1 mm (MP/L) Fibres <1 mm (MF/L) 16 µMED International conference on microplastic pollution – September 15th/18th 2019

Conclusion  For macrowaste in stormwater:  Nine waste categories correspond to more than 95 % of all the macrowaste of Sucy-en-Brie.  Macrowaste flux ~ 10 to 100 mg/m 3 .  For microplastics :  Microplastic concentration ranges between 2 and 5 MP/L  Small decrease is observed over time.  More rain events will be studied. 17 µMED International conference on microplastic pollution – September 15th/18th 2019

Thank you for your attention! Source : www.leyton.com Any questions??? robin.treilles@enpc.fr 18 µMED International conference on microplastic pollution – September 15th/18th 2019

Results : microplastics in stormwater of Sucy-en-Brie Comparaison with other studies : ➢ 06/11/18 12/03/18 4,9.10 -1 - 22,9 MP/L 2 – 29 MP/L Grand Paris (Dris et al., 2018) Flowrate (m 3 /s) Danemark (Liu et al., 2019) Characterisation on µFTIR (fragments, first results) : ➢ 1 2 3 4 Polyethylene 48% Polystyrene 37% Polypropylene 15% 5 1 2 3 4 5 6,00 Time Concentration MP/L or MF/L 4,00 Fragments 1-5 mm (MP/L) 2,00 Fragments <1 mm (MP/L) 0,00 Fibres <1 mm (MF/L) 1 2 3 4 5 1 2 3 4 5 Rain event 2: 12/03/18 Rain event 1: 06/11/18 19 µMED International conference on microplastic pollution – September 15th/18th 2019