Fast Multielement Quantification of Nanoparticles in Wastewater and Sludge Using Single-Particle ICP-MS
Yuxiong Huang, Arturo A. Keller, Pabel Cervantes‐Avilés, Jenny Nelson
Abstract
Quantitatively monitoring the presence of engineered, natural, or incidental nanoparticles (NPs) is essential to understand their potential environmental and ecotoxicological implications. In particular, a significant number of NPs may travel through wastewater treatment plants (WWTPs), as a conduit to their release to the environment, either in treated effluent or in wastewater sludge (biosolids). Here we developed a fast and simple protocol for full quantitative multielement analysis of metallic or metal-containing NPs in wastewater and sludge samples via single-particle ICP-MS. We employed centrifugation to separate NPs from wastewater sludge, with high recoveries (>84%) for Au and Ag NPs, which have rather high densities (19.3 and 10.5 g cm–3, respectively). In wastewater samples, particle mass concentrations ranged from <1 ng/L for Cd-based NPs to almost 100 μg/L for Mg particles. Particles from most elements detected in wastewater were <100 nm in size, although TiO2 in raw wastewater was around 250 nm in size, and Mg was >1500 nm in size, well beyond the nanoscale. The efficiency of removal of NPs throughout the WWTP was significantly dependent on the type of metal-containing particles and the influent concentration.