NOM content is a factor in the removal of micropollutants from surface water by NF.
Increase in NOM content results in an increase in MWCO of membrane.
At low NOM, NOM–micropollutant complex improves rejection.
At high NOM, sorption within the membrane matrix is superior over surface sorption.
Extent to which NOM–micropollutant formation and MWCO change occur determines rejection mechanism.