Release scenario

Observations

AgNP are released from consumer products and anti-microbial coatings and enter WWTP via the wastewater stream.

CeO₂ NPs are expected to be released from catalyst, chemical-mechanical planarization (CMP) and coating-/paint applications to the wastewater stream and enter WWTPs.

1. ENM release from the WWTP is mainly governed by the amount of total suspended solids released from the WWTP. Elimination efficiencies were >99%, regardless of the ENM type.
2. The size of the particles that were emitted through the effluent over the experiment duration was rather constant and comparable to the particle size of the initial material for CeO₂ (~30 nm), but Ag(₂S) particles showed considerable variations, possibly as a result of the sulfidation process already occurred in the activated sludge. 
3. In the digested sludge, Silver NP were sulfidized. Ce NP agglomerates detected in the digested sludge showed sizes ~50 nm to >100 nm. 
4. Ce in the digested sludge was occurring to 40% as a Ce(III) phase after 86 days.

Parameters 

Emitted to

1. Size distribution of NP emitted from the WWTP via the effluent
2. Removal efficiency of the WWTP for the different NP
3. Speciation of Ce in the sludge after the experimental period of 86d (assessed using XAS)

 Incineration

Pyrolysis

Surface water

Read more

Read also

Visit the NanoFASE Library.

Kägi et al. (2019) Fate of NanoParticles in Managed Waste Facilities
 

B. Vriens, A. Voegelin, S. J. Hug, R. Kaegi, L. H. Winkel, A. M. Buser and M. Berg, Quantification of Element Fluxes in Wastewaters: A Nationwide Survey in Switzerland, Environ. Sci. Technol., 2017, 51, 10943-10953.