Removing microplastics from wastewater Dr. Bruno BARILLON SUEZ - - PowerPoint PPT Presentation

Removing microplastics from wastewater Dr. Bruno BARILLON SUEZ - CIRSEE Workshop on emerging pollutants Brussels 24 October 2018

Global assessment Microplastic Emission Pathway Model Graphical Representation WWTPs are a pathway for microplastics (MP) release in marine environment But only part of the overall microplastics emissions go through WWTPs To what extent do WWTPs act as a barrier for MP release ? Source: EUNOMIA, final report, 2018 2 I Workshop on Emerging pollutants, Brussels

SUEZ commitment since 2013 Project ECOSEASTEM 2013-2015 5 campaigns on WWTPs  France, Italy  90,000 – 3,500,000 PE Mainly microfibers  Biological treatment (CAS, MBR) w/o primary treatment  Sampling: inlet /outlet Retention rates: 80 - 95 % Remaining key questions  Sampling protocols and analytical methods not standardized: what do we measure ?  Role of primary and secondary treatment in the microplastics removal ?  Need for an add-on treatment ? In which cases ?  Technology specifications ? 3 I Workshop on Emerging pollutants, Brussels

Project MICROPLASTIC SUEZ commitment since 2013 2015 - 2019 On-going collaborative MICROPLASTIC project Funding FUI (France) Simplified operational method for quantification  Protocol definition Partners Done  Evaluation as part of GWRC round-robin test Additional WWTP audits  3 WWTPs in France with new analytical protocol Done  Focus on unit processes: primary, secondary and tertiary Add-on treatment assessment  Pre-selection of technologies: e.g. sand filter, dissolved Air Flotation, To be done mechanical filter  Pilot implementation in France (2019)  Techno-economical assessment 4 I Workshop on Emerging pollutants, Brussels

Simplified operational method for MP quantification Protocol definition  Sampling:  Automatic samplers with glass bottles and Teflon pipes  Blanks for contamination assessment  Analysis:  Chemical pre-treatment: NaOH hydrolysis Analysis Sampling  Raw wastewater volume: 40 ml diluted with 160 ml Raw wastewater X45 deionized water  Treated wastewater: 200 ml  Filtration 2 µm on glass fibre  Visual counting with binocular magnifier 5 I Workshop on Emerging pollutants, Brussels

Sampling WWTP audits point Treatment lines Tertiary filtration 6 I Workshop on Emerging pollutants, Brussels

WWTP audits Microplastic removal MP / L  Variability in influent concentrations in the 2000 1735 range 200 – 1,500 MP/L  Higher concentrations compared to literature 1500 but sampling preparation with filtration @ 2µm 1000  Significant role of primary decantation : 80 500 210 185 % MP removal in average 50 12 5  MP removal inlet/outlet: 90 – 97 % when 0 WWTP 1 WWTP 2 WWTP 3 primary and/or tertiary treatment Inlet Outlet 7 I Workshop on Emerging pollutants, Brussels

Key questions Where are we ?  Sampling protocols and analytical methods not standardized: what do we measure ?  Development of an operational method for MP quantification by microscopy  Still, no standardized method in the literature  Role of primary and secondary treatment in the microplastics removal ?  ~ 80 % of MP are removed by primary decantation  Global MP removal > 90 % if biological treatment with primary and/or tertiary treatment or if Membrane Bioreactor (> 95 %)  Global MP removal > 80 % if biological treatment but without primary and/or tertiary treatment  Need for an add-on treatment ? In which cases ?  For WWTP without primary or tertiary treatment or WWTP not equipped with Membrane Bioreactor  Technology specifications ?  Next phase of the MICROPLASTIC project with pilot implementation 8 I Workshop on Emerging pollutants, Brussels

Key points to be addressed  SUEZ has been advocating for EU action to be taken and considers that combined action is required: at source , to prevent and reduce the presence of pollutants (micropollutants, microplastics ,…) in effluents, and at end of pipe with the deployment of treatment technologies  Contribution of stormwater drains should be assessed (as pathway for microplastics emissions from tyres, for instance)  Actions to be conducted / further investigated:  Assess mass balances of microplastics going through WWTPs (% COD)  Quantify microplastics in sludge  Assess the impact on the disposal routes for the sludge 9 I Workshop on Emerging pollutants, Brussels