Membrane filtration is a technique which is used to separate particles from a liquid for the purpose of purifying it. This filtration method has a number of applications, ranging from treating wastewater to filtering milk used for cheese production, and there are several different approaches to membrane filtration. In all cases, the goal is to create a filtered solvent. A number of different types of systems are available from companies which specialize in filtration products, along with replacement membranes and other parts and equipment.

In membrane filtration, a solvent is passed through a semi-permeable membrane. The membrane's permeability is determined by the size of the pores in the membrane, and it will act as a barrier to particles which are larger than the pores, while the rest of the solvent can pass freely through the membrane. The result is a cleaned and filtered fluid on one side of the membrane, with the removed solute on the other side.

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