Fate of Engineered Nanoparticles in Wastewater Treatment Plant

Abstract

Losy projektowanych nanocząstek w oczyszczalni ściekówA nanomaterial has at least one dimension in the nanometre scale of approximately 1 to 100 nm. Because of their very small size, nanostructures have different physicochemical properties, compared to the same materials on the macro scale. Engineered nanoparticles (ENPs) are deliberately produced by man using many different materials, such as metals: Ag, Zn, Au, Ni, Fe, and Cu; metal oxides: TiO2, Fe3O4, SiO2, CeO2, and Al2O3; nonmetals: silica and quantum dots; carbon: nanotubes and fullerene as well as graphene. The nanoparticles are used in all industrial and medicine, pharmacy, cosmetics, agriculture, transport, energy. Fast-growing nanotechnology provides a wide spectrum of applications, but it also brings new and unknown risks to human and environment. In recent years, the environmental release of ENPs has been on the rise because of increase of NPs in commercial products. Moreover, the fate of NPs in wastewater treatment processes may play an important role in determining the pathway their environmental release. The nanoparticles in wastewater treatment plants will experience aggregation, sedimentation, transformation which may affect their concentration in effluents, but also in the sludge. The most laboratory studies focused on fate of nanoparticles in activated sludge process were carried out with SBR reactors with addition of Ag, ZnO, CeO2 and TiO2 nanoparticles. Bacteria in biological treatment processes are likely be exposed to nanoparticles that have undergone agglomeration and transformation. These nanoparticles could agglomerate or even get adsorbed to the extracellular polymers during primary and secondary treatment eventually ending up in wastewater sludge. Hence, the fate of engineered nanoparticles during wastewater treatment process should be investigated to help reduce the risk of their potential negative environmental effects. In the article reviews of the recent results in the literature concerning transformation of engineered nanoparticles during treatment process have been shown.

Micropollutants in treated wastewater

“…The definition of NP stating that it is any material with at least one dimension in the range of 1-100 nm is very broad. Therefore, many substances such as metals (Ag, Zn, Ni, Fe, Cu); metal oxides (TiO 2 , Fe 3 O 4 , SiO 2 , CeO 2 , and Al 2 O 3 ); non-metals (silica and quantum dots); forms of carbon (nanotubes, fullerene, graphene) exist in nanoscale (Madeła et al 2016). Therefore, even though concentration of nanoscale fragments noted in effluent was significantly high (550 ± 130 lg/L), the effluent content of specific nanoparticles is lower: 5.5 lg/L for Ag-NP, 19.1 lg/L for fullerene C 60 , 1.65 lg/L for fullerene C 70 , and 31.9021 lg/L for N-methylfulleropyrrolidine C 60 (Farré et al 2010;Yang et al 2012).…”