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Ecotoxicological Effects of Transformed Silver and Titanium Dioxide Nanoparticles in the Effluent from a Lab-Scale Wastewater Treatment System

Ecotoxicological Effects of Transformed Silver and Titanium Dioxide Nanoparticles in the Effluent from a Lab-Scale Wastewater Treatment System

Category
Journal publication
Abstract
In this study, a lab-scale wastewater treatment plant (WWTP), simulating biological treatment, received 10 μg/L Ag and 100 μg/L TiO2 nanoparticles (NPs) for 5 weeks. NP partitioning was evaluated by size fractionation (>0.7 μm, 0.1−0.7 μm, 3 kDa-0.1 μm, < 3 kDa) using inductively coupled plasma mass spectrometry (ICP-MS), single particle ICP-MS and transmission electron microscopy. The ecotoxicological effects of the transformed NPs in the effluent were assessed using a battery of marine and freshwater bioassays (algae and crustaceans) and an in vitro gill cell line model (RTgill-W1). TiO2 aggregates were detected in the effluent, whereas Ag NPs (0.1−0.22 μg/L) were associated with S, Cu, Zn. Fractionation showed that >80% of Ag and Ti were associated with the effluent solids. Increased toxicity was observed during weeks 2−3 and the effects were species-dependent; with marine epibenthic copepods and algae being the most sensitive. Increased reactive oxygen species formation was observed in vitro followed by an increase in epithelial permeability. The effluent affected the gill epithelium integrity in vitro and impacted defense pathways (upregulation of multixenobiotic resistance genes). To our knowledge, this is the first study to combine a lab-scale activated sludge WWTP with extensive characterization techniques and ecotoxicological assays to study the effects of transformed NPs in the effluent.
Client
  • Norges forskningsråd / 238972
  • Norges forskningsråd / 197405
Language
English
Author(s)
Affiliation
  • Norwegian Institute of Water Research
  • SINTEF Industry / Sustainable Energy Technology
  • Norwegian Institute of Water Research
  • Norwegian Institute of Water Research
  • SINTEF Ocean / Miljø og nye ressurser
  • The University of Queensland
  • Norwegian Institute of Water Research
Year
2018
Published in
Environmental Science and Technology
ISSN
0013-936X
Volume
52
Issue
16
Page(s)
9431 - 9441