title: Flows of engineered nanomaterials through the recycling process in Switzerland.
abstract: The use of engineered nanomaterials (ENMs) in diverse applications has increased during the last years and this will likely continue in the near future. As the number of applications increase, more and more waste with nanomaterials will be generated. A portion of this waste will enter the recycling system, for example, in electronic products, textiles and construction materials. The fate of these materials during and after the waste management and recycling operations is poorly understood. The aim of this work is to model the flows of nano-TiO2, nano-ZnO, nano-Ag and CNT in the recycling system in Switzerland. The basis for this study is published information on the ENMs flows on the Swiss system. We developed a method to assess their flow after recycling. To incorporate the uncertainties inherent to the limited information available, we applied a probabilistic material flow analysis approach. The results show that the recycling processes does not result in significant further propagation of nanomaterials into new products. Instead, the largest proportion will flow as waste that can subsequently be properly handled in incineration plants or landfills. Smaller fractions of ENMs will be eliminated or end up in materials that are sent abroad to undergo further recovery processes. Only a reduced amount of ENMs will flow back to the productive process of the economy in a limited number of sectors. Overall, the results suggest that risk assessment during recycling should focus on occupational exposure, release of ENMs in landfills and incineration plants, and toxicity assessment in a small number of recycled inputs.
authors.affiliation: EMPA, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Caballero-Guzman
authors.affiliation: EMPA, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
authors.forename: Tianyin
authors.initials: T
authors.lastname: Sun
authors.affiliation: EMPA, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland. Electronic address: nowack@empa.ch.
authors.forename: Bernd
authors.initials: B
authors.lastname: Nowack
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D006801:Humans; D017745:Incineration; D053768:Metal Nanoparticles / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000032:analysis*; D016273:Occupational Exposure; D059027:Recycling; D018570:Risk Assessment; D013557:Switzerland; D064091:Waste Disposal Facilities; D018505:Waste Management
chemical_list: D004785:Environmental Pollutants; D037742:Nanotubes, Carbon
keywords: Engineered nanomaterials; Nanowaste; Probabilistic material flow modeling; Recycling; Waste management