Filtration technologies

Ultrafiltration is a selective fractionation process utilizing pressures up to 145 psi (10 bar). It concentrates suspended solids and solutes of molecular weight greater than 1,000. The permeate contains low-molecular-weight organic solutes and salts. UF is widely used in the fractionation of milk and whey, and also finds application in protein fractionation.

Nanofiltration is a special process selected when RO and UF are not the ideal choice for separation. NF can perform separation applications that are not otherwise economically feasible, such as demineralization, color removal, and desalination. In concentration of organic solutes, suspended solids, and polyvalent ions, the permeate contains monovalent ions and low-molecular-weight organic solutions like alcohol.

Microfiltration is a low-pressure cross-flow membrane process for separating colloidal and suspended particles in the range of 0.05-10 microns. MF is used for fermentation broth clarification and biomass clarification and recovery.

Reverse osmosis is a high-pressure, energy-efficient technique for dewatering process streams, concentrating low-molecular-weight substances in solution, or purifying wastewater. It has the ability to concentrate all dissolved and suspended solids. The permeate contains a very low concentration of dissolved solids. RO is widely used in the desalination of seawater.