Abstract: The subject of the invention is an apparatus, system and process for liquid separation by reverse osmosis, nano-, ultra- and micro-filtration under the joint action of the differential pressure built up on the either side of the membrane (22) located in the apparatus for membrane separation (1), continuous rotation of the body (15, 17, 18) in the immediate proximity to the selective layer of the said membrane, oscillation of the liquid flow, caused by the means (15, 17, 18) and induced vibration of the said membranes. The superposition of the said continuous rotary movements, liquid oscillations and membrane vibrations on each other result in the reduction of membrane clogging with the substances being retained.