title: Monte Carlo simulations of the transformation and removal of Ag, TiO2, and ZnO nanoparticles in wastewater treatment and land application of biosolids.
abstract: The use of nano-enabled materials in industry and consumer products is increasing rapidly and with it, the more imperative it becomes to understand the consequences of such materials entering the environment during production, use or disposal. The novel properties of engineered nanomaterials (ENMs) that make them desirable for commercial applications also present the possibility of impacting aquatic and terrestrial environments in ways that may differ from materials in bulk format. Modeling techniques are needed to proactively predict the environmental fate and transport of nanomaterials. A model for nanoparticle (NP) separation and transformation in water treatment was parameterized for three metal and metal-oxide NPs. Functional assays to determine NP specific distribution and transformation were used to parameterize the model and obtain environmentally relevant concentrations of NPs and transformation byproducts leaving WWTPs in effluent and biosolids. All three NPs were predicted to associate >90% with the solid phase indicating significant accumulation in the biosolids. High rates of transformation for ZnO and Ag NPs resulted in ~97% transformation of the NPs that enter the plant despite differences in transformation rate in aerobic versus anaerobic environments. Due to high insolubility and negligible redox transformation, the only process predicted to impact TiO2 NP fate and transport in WWTPs was distribution between the solid and liquid phases. Subsequent investigation of ZnO NP species fate and transport when land applied in biosolids indicated that steady state concentrations of ZnO phases would likely be achieved after approximately 150days under loading conditions of biosolids typical in current practice.
authors.affiliation: Department of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, NC 27708-0287, USA; CEREGE, CNRS, Aix-Marseille Université, UMR 7330, 13545 Aix en Provence, France; Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham, NC 27708-0287 USA; International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Barton
authors.affiliation: CEREGE, CNRS, Aix-Marseille Université, UMR 7330, 13545 Aix en Provence, France; International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France.
authors.forename: Melanie
authors.initials: M
authors.lastname: Auffan
authors.affiliation: Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Durenkamp
authors.affiliation: Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: McGrath
authors.affiliation: CEREGE, CNRS, Aix-Marseille Université, UMR 7330, 13545 Aix en Provence, France; International Consortium for the Environmental Implications of Nanotechnology (iCEINT), Aix en Provence, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Bottero
authors.affiliation: Department of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, NC 27708-0287, USA; Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham, NC 27708-0287 USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Wiesner
mesh_terms: D000383:Agriculture / Q000379:methods; D053768:Metal Nanoparticles / Q000032:analysis*; D008956:Models, Chemical; D009010:Monte Carlo Method; D012834:Silver / Q000032:analysis*; D014025:Titanium / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000379:methods* / Q000706:statistics & numerical data; D062065:Wastewater / Q000737:chemistry*; D015034:Zinc Oxide / Q000032:analysis*
chemical_list: D012834:Silver; D014025:Titanium; D062065:Wastewater; D015034:Zinc Oxide; C009495:titanium dioxide
keywords: Exposure; Monte Carlo modeling; Nanoparticles; Wastewater treatment