10.1021/acs.est.9b07840.s001 Benedikt Steinhoff Benedikt Steinhoff Julian Müller Julian Müller Darya Mozhayeva Darya Mozhayeva Bastian T. F. Spelz Bastian T. F. Spelz Carsten Engelhard Carsten Engelhard Benjamin Butz Benjamin Butz Holger Schönherr Holger Schönherr Investigation of the Fate of Silver and Titanium Dioxide Nanoparticles in Model Wastewater Effluents via Selected Area Electron Diffraction American Chemical Society 2020 titanium dioxide nanoparticles Model Wastewater Effluents ratio energy-dispersive X-ray analysis physicochemical transformation proc... area electron diffraction Ag 2 S-NPs investigation MNM Ag 2 S Selected Area Electron Diffraction cloud point extraction WWTP EDX SAED TiO 2 Titanium Dioxide Nanoparticles Ag-NP crystal structure analysis wastewater treatment plants nanomaterial 2020-06-30 11:41:30 Journal contribution https://acs.figshare.com/articles/journal_contribution/Investigation_of_the_Fate_of_Silver_and_Titanium_Dioxide_Nanoparticles_in_Model_Wastewater_Effluents_via_Selected_Area_Electron_Diffraction/12588197 The increasing use of manufactured nanomaterials (MNMs) and their inevitable release into the environment, especially via wastewater treatment plants (WWTPs), poses a potential threat for aquatic organisms. The characterization of MNMs with analytical tools to comprehend their fate and effect on the ecosystem is hence of great importance for environmental risk assessment. We herein report, for the first time, the investigation of physicochemical transformation processes during artificial wastewater treatment of silver (Ag-NPs) and titanium dioxide nanoparticles (TiO<sub>2</sub>-NPs) via selected area electron diffraction (SAED). TiO<sub>2</sub>-NPs with an anatase/rutile ratio of ∼80/20 were found to not undergo any physicochemical transformation, as shown via previous energy-dispersive X-ray analysis (EDX) elemental mapping and crystal structure analysis via SAED. In contrast, Ag-NPs were colocalized with substantial amounts of sulfur (Ag/S ratio of 1.9), indicating the formation of Ag<sub>2</sub>S. SAED ultimately proved the complete transformation of face-centered cubic (fcc) Ag-NPs into monoclinic Ag<sub>2</sub>S-NPs. The size distribution of both nanomaterials remained virtually unchanged. Our investigations show that cloud point extraction of NPs and their subsequent crystal structure analysis via SAED is another valuable approach toward the comprehensive investigation of wastewater-borne MNMs. However, the extraction procedure needs optimization for environmentally low NP concentrations.