Suspended materials and macromolecules can be separated from a waste stream
using a membrane and pressure differential, called Ultrafiltration. This method
uses a lower pressure differential than reverse osmosis and doesn't rely on
overcoming osmotic effects. It is useful for dilute solutions of large
polymerized macromolecules where the separation is roughly proportional to the pore size
in the membrane selected.
Ultrafiltration membranes are commercially fabricated in sheet, capillary and tubular forms. The liquid to be filtered is forced into the assemblage and dilute permeate passes perpendicularly through the membrane while concentrate passes out the end of the media. This may prove useful for the recovery and recycle of suspended solids and macromolecules.
Excellent results have been achieved in textile finishing applications and other situations where neither entrained solids that could clog the filter nor dissolved ions that would pass through are present. Membrane life can also be affected by temperature, pH, and fouling.
