The permeate flux steeply dropped to 2 1% of
the pure water permeation flux, right at the
beginning of the concentration experiment, but
the flux smoothly decreased for increasing volume
reducing factors up to 5, which is a very promising
finding. The high protein rejections observed
throughout the experiments (63-82%), clearly
points out that NF is technically suited to accomplish
the aimed goals, i.e. environmental pollution
abatement from the fish meal wastewaters, and
recycle of water and proteins therein into the process.
The initial membrane hydraulic permeability
could be restored, in between the experiments,
through a complete basic-acid washing cycle.