Removal efficiency

Removal efficiency is defined as the fraction of NP mass that is removed by the activated sludge process or, the fraction of NP mass that will remain in the digested sludge. It can be described by the following equation:

Where R% is the removal efficiency in percent, min is the NP mass entering the WWTP and mEF the mass of NP leaving the WWTP via the effluent.


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Visit the NanoFASE Library to read summaries:

NanoFASE Report D5.3 Report on the behaviour of ENM in reactors

R. Kaegi, A. Voegelin, B. Sinnet, S. Zuleeg, H. Hagendorfer, M. Burkhardt and H. Siegrist (2011) Behavior of Metallic Silver Nanoparticles in a Pilot Wastewater Treatment Plant, Environ. Sci. Technol. 45, 3902-3908. doi: 10.1021/es1041892



Ralf Kägi

EAWAG, Switzerland