What is Membrane Filtration?

Membrane filtration is a growing popular choice in the water treatment sphere. The process involves separating undesirable organic compounds or dissolved substances from water. Membrane filtration can be used in conjunction with other water treatment methods, or it may be the only treatment process. Learn about the principles of membrane filtration and the materials it can eradicate from a water source.

How Does It Work?

In this instance, a membrane is a semi-permeable material able to separate contaminants based on their size or chemical makeup. Depending on the type of membrane, the pore size of the material will vary, as each type is designed to filter different shapes and sizes of contaminants. Using reverse osmosis pressure, contaminated water is forced through the membrane, leaving all unwanted substances behind, producing clean, pure water.

Membrane Filtration Levels

Before selecting a membrane filtration system, determine what particles must be removed. Smaller molecules require tighter membranes with miniscule pores. Here are the different classifications of membranes available:

• Microfiltration: The pore size ranges from 0.1 to 1.0 micrometers and removes particle material including bacteria. Microfiltration is used to remove contagious pathogens from potable water supplies that are resistant to traditional chemical water treatments. It is a staple process of commercial beverage production, removing unwanted substances without compromising the flavor of the final product. It is also used in the petroleum refinery field and is the first step in dairy product processing, before pasteurization.
• Ultrafiltration: The pore size ranges from 0.001 to 0.1 micrometers and removes viruses and acids, in addition to the particles targeted by microfiltration. Ultrafiltration is also used to purify drinking water, normally as a precursor to reverse osmosis. It is used to concentrate whey in the dairy industry and used as an effective wastewater treatment. Ultrafiltration is used for blood dialysis and in laboratories for other blood treatments.
• Nanofiltration: The pore size ranges from 0.0001 to 0.001 micrometers, removing all of the materials previously targeted by microfiltration and ultrafiltration, with the addition of dissolved heavy metals and salt. Nanofiltration is used for water softening and in commercial beverage production, including the dairy industry. It is commonly used in the personal care products industry to create perfume and lotion.
• Reverse Osmosis: The most microscopic membrane filter pore size ranges from 0.001 and down, removing the smallest substances possible. Reverse osmosis has a wide range of functions, but the primary use is to purify drinking water and recycle wastewater for non-potable purposes. It is widely utilized in the food industry to create concentrated beverages and products such as protein powder and maple syrup.

Depending on the context of the industrial system, one or more of the filters may be installed as a step in a water treatment system.

Membrane filtration at all levels is a useful treatment for both commercial and industrial sectors. Contact Innovative Water Treatment for in-depth guidance on selecting the membrane filtration system to fit your business.