Flows of engineered nanomaterials through the recycling system in - PowerPoint PPT Presentation

Flows of engineered nanomaterials through the recycling system in Switzerland Alejandro Caballero-Guzman Tianyin Sun Bernd Nowack SUN Conference 2015 EMPA Venice, Italy St. Gallen, Switzerland March 9-11, 2015 1/30

I. Background and goal  Sun et al. (2014) estimated the ENM mass flows in Switzerland and the European Union  Pigment-TiO 2  Nano-TiO 2  Nano-Ag  Nano-ZnO  CNT  Fullerenes T. Y. Sun, F. Gottschalk, K. Hungerbuhler, B. Nowack, Comprehensive probabilistic modelling of environmental emissions of engineered nanomaterials. Environmental Pollution 185, 69 (2014). 2/30

I. Background and goal  Goal: Model and quantify the outflows from the recycling system in Switzerland.  ENMs considered:  Nano-Ag  Nano-TiO 2  Nano-ZnO  CNT T. Y. Sun, F. Gottschalk, K. Hungerbuhler, B. Nowack, Comprehensive probabilistic modelling of environmental emissions of engineered nanomaterials. Environmental Pollution 185, 69 (2014). 3/30

II. Method a) System definition. 1. Waste Landfill Export Incineration Plant LF EXP WIP ? ? ? Production- Recycling Manufacture- ? in Consumption REC PMC ? ? ? Eliminated Wastewater Cement Kiln ELIM WW CK 4/30

II. Method b) Input information analysis 1.  33 consumer products categories analyzed using public inventories 5/30

II. Method b) Input information analysis 1.  Nano-mass input to recycling (Tons per year in 2012), based on Sun et al. (2014) Percentile Percentile Mode 15 85 Nano-TiO 2 30 43 79 Nano-ZnO 3 5 18 CNT 2 3 5 Nano-Ag 0.3 0.4 0.5 6/30

II. Method Chacterization of the recycling system using flow diagrams 2. E-waste recycling process (example) Sources : Goodship and Stevels (2012) and info available in Internet, among others. 7/30

II. Method Calculate the transfer vectors 3. 8/30

II. Method Calculate the transfer vectors. 3. Step 1 Step 2 Step 3 Step 4 Result 0.70 (0.35,0.35) 𝑈𝐷 𝑋𝐽𝑄 , 𝑈𝐷 𝐹𝑌𝑄 Products with ENM in plastics (0.50, 0.50) Consumer (0.45,0.55) electronics Products with 𝑈𝐷 𝑋𝐽𝑄 , 𝑈𝐷 𝐹𝑌𝑄 0.30 (0.10,0.20) ENM in batteries (0.33, 0.66) Category Multiply by Sum the Split into product Assess TCs by transfer mass weighted subcategories subcategories vector distribution vectors 9/30

II. Method Stochastic flow calculation 4.  Probabilistic approach of MFA to incorporate uncertainty based on Gottschalk et al. (2010)  simulation using Monte Carlo-Markov Chain  TC’s used to define triangular distributions  Mode = TC point value  Lower bound = 50% of the TC  Upper bound = 150% of the TC  Distributions simulation using 100,000 random values F. Gottschalk, R. W. Scholz, B. Nowack, Probabilistic material flow modeling for assessing the environmental exposure to compounds: Methodology and an application to engineered nano-TiO2 10/30 particles. Environmental Modelling & Software 25, 320 (2010).

Model assumptions  Mass-based approach  ENM characteristics (size distribution, shape…) have no influence on final fate  ENM transformations considered: only elimination  Static model (all flows occur in one year) 11/30

III. Results (nano-TiO 2 case) Only «relevant» product categories selected (relevancy measured 1. by total nano-mass transferred to recycling; at least ≥ 95%) 12/30

III. Results (nano-TiO 2 case) Product types analysis 2. Composition a) Material fraction with ENM b) Consumer electronics Paints 13/30

III. Results (nano-TiO 2 case) Fate of the material fractions with ENM within the Swiss recycling 3. system. Sources: waste management statistics and regulations; discussions with experts. 14/30

III. Results (nano-TiO 2 case) Transfer vector assessment for the Consumer Electronics 4. subcategories. Sources: Distribution : inventory information and discussions with experts. TCs : waste statistics and regulation; literature based. 15/30

II. Method REMINDER a) System definition. 1. Waste Landfill Export Incineration Plant LF EXP WIP ? ? ? Production- Recycling Manufacture- ? in Consumption REC PMC ? ? ? Eliminated Wastewater Cement Kiln ELIM WW CK 16/30

III. Results (nano-TiO 2 case) Transfer vector assessment for the Consumer Electronics 4. subcategories. Sources: Distribution : inventory information and discussions with experts. TCs : waste statistics and regulation; literature based. 17/30

III. Results (nano-TiO 2 case) Transfer vector assessment for the Consumer Electronics 4. subcategories. Sources: Distribution : inventory information and discussions with experts. TCs : waste statistics and regulation; literature based. 18/30

III. Results (nano-TiO 2 case) Transfer vectors for the product categories with nano-TiO 2 : 5.  Final input for the simulation of the probability distributions. 19/30

III. Results (nano-TiO 2 case) ENM probabilistic flows in 2012 (tons/year). Mode values (in blue) 6. and percentiles 15 th and 85 th . WIP LF EXP (16,44) (8,23) (2,6) 23 13 3 REC PMC (30,79) (0.9,2.9) 43 1.3 WW CK ELIM (0.5,1.5) (0.5,1.5) 0 0.7 0.7 Note: Thickness and pattern of the green arrows reflect the magnitude regarding the 20/30 overall flow.

III. Results (nano-TiO 2 case) ENM probabilistic flows in 2012 (tons/year). Mode values (in blue) 6. and percentiles 15 th and 85 th . Waste Incineration WIP LF EXP • Plant (WIP): plastics, (16,44) (8,23) (2,6) 23 13 3 painted wood, ceramics Landfill (LF) : mineral • material with paint (e.g. REC PMC gypsum, plaster) (30,79) (0.9,2.9) 43 1.3 WW CK ELIM (0.5,1.5) (0.5,1.5) 0 0.7 0.7 Note: Thickness and pattern of the green arrows reflect the magnitude regarding the 21/30 overall flow.

III. Results (nano-TiO 2 case) ENM probabilistic flows in 2012 (tons/year). Mode values (in blue) 6. and percentiles 15 th and 85 th . Exported (EXP): plastics • WIP LF EXP (16,44) (8,23) (2,6) Production- • 23 13 3 Manufacture- Consumption (PMC): demolished concrete REC PMC (30,79) (0.9,2.9) Cement Kiln (CK): • 43 1.3 mineral residues or wood with paint WW CK ELIM (0.5,1.5) (0.5,1.5) 0 0.7 0.7 Note: Thickness and pattern of the green arrows reflect the magnitude regarding the 22/30 overall flow.

III. Results (nano-TiO 2 case) ENM probabilistic flows in 2012 (tons/year). Mode values (in blue) 6. and percentiles 15 th and 85 th . Waste water (WW): • WIP LF EXP releases during washing (16,44) (8,23) (2,6) processes applied 23 13 3 during recycling. REC PMC (30,79) (0.9,2.9) 43 1.3 WW CK ELIM (0.5,1.5) (0.5,1.5) 0 0.7 0.7 Note: Thickness and pattern of the green arrows reflect the magnitude regarding the 23/30 overall flow.

III. General Results 24/30

III. General Results 25/30

III. General Results 26/30

III. General Results 27/30

III. Total ENM outflow distribution (all ENMs) 28/30

IV. Conclusions  Main flows to waste incineration, landfills or exported.  No significant dissipation of ENM to new products (only to very small extent into plastics, concrete and cement).  ENM risk assessment during recycling should focus on occupational exposure and release to the environment.  Main uncertainties  ENM mass distribution between product subcategories  ENM release kinetics  Product knowledge 29/30

Thanks! MAIN REFERENCE Caballero-Guzman, A., T. Y. Sun and B. Nowack (2015) . "Flows of engineered  nanomaterials thorugh the recycling process in Switzerland." Waste Management. 36: 33-45. DOI: 10.1016/j.wasman.2014.11.006 ACKNOWLEGMENTS SUN project funding from the EU FP7/2007-2013  CONTACT INFORMATION alejandro.caballero@empa.ch  30/30