There are four categories of membrane systems, defined by the size of material it can remove from liquid.

Microfiltration is the coarsest of the membrane filtration classes. Its applications are to separate small particles suspended in liquids. Microfiltration membranes are classified by pore diameter cut off (pdco) which is the diameter of the smallest particles that are retained by it, typically in the range of 0.1 to 10 micron.

Ultrafiltration is used for the separation of large macromolecules such as proteins and starches. Ultrafiltration membranes are classified by the molecular weight cut off (mwco) which is defined as the molecular weight of the smallest molecule, 90% of which is retained by the membrane. Ultrafiltration range spans from 1000 to 500,000 molecular weight cut off.

Nanofiltration membranes retain solute molecules ranging from 100 to 1,000 molecular weight. Nanofiltration membranes are classified by the molecular weight cut off like ultrafiltration membranes or by percentage sodium chloride rejection like reverse osmosis membranes.

Reverse osmosis involves the tightest membranes which are capable of separating even the smallest solute molecules. Reverse osmosis membranes are classified by percentage rejection of sodium chloride in an aqueous solution under specified conditions and ranges from 95 to 99.5%.

Amelins ChemEng^R Divisions offers a product line of ultrafiltration, nanofiltration, and reverse osmosis membrane separation technologies to meet tap, brackish and seawater requirements for a variety of small-to-larger municipal and industrial applications.

Some typical applications for Amelins membrane systems include:

Water Purification
Microbial removal; bacteria, pyrogens, giardia and cryptosporidium cysts
Trihalomethane precursor and pesticide removal
Potable from seawater
Sodium and organics reduction for beverages
Bottled water
Can and bottle rinsing
Rinse water for metal finishing operations
Spot-free car wash rinses
Laboratory and reagent grade water
Semiconductor chip rinsing
Distillation and deionization system pretreatment
Kidney dialysis
Medical device and packaging rinse water



Waste Treatment
Tertiary sewage water recovery
Heavy metals and plating salts concentration
BOD and COD concentration
Dewatering liquid for reduced disposal volume
Textile waste recovery for reuse
Pulp and paper water recovery for reuse
Commercial laundry water and heat reuse