A water purifier, including a housing, a piston cylinder, a base, and a dust cap. The housing includes a water inlet end and a water outlet end, and a composite filter material and an ultrafiltration membrane are disposed in the housing to constitute a filter element. The piston cylinder is sleeved on the housing. The upper end of the piston cylinder is provided with a suction nozzle. The base includes an upper part and a lower part. The upper part includes a lower bayonet and an upper bayonet. The lower part includes a multipurpose interface and a water inlet nozzle. The dust cap is disposed on the upper end and covers the suction nozzle. The central part of the dust cap protrudes downward to form a flexible sealing plug. The water inlet end of the housing is secured to the lower bayonet of the base.

A filtration system can include a loading member configured to receive a plurality of filtration members which can be sequentially moved from a non-active position in which a respective one of the plurality of filtration members is not in fluid communication with a sample flow path of the cell removal system, to an active position in which the respective filtration member is in fluid communication with the sample flow path, and to a discarded position in which the respective filtration member has been removed from fluid communication with the sample flow path.

A device for filtering liquids, including a filtration module and an ultrasound emission module, where the ultrasound emission module is fixed distant from the filtration module using a fixing means, and the ultrasound emission module is equipped coaxially along its axis with a weight or is equipped perpendicular to its axis with at least one weight, the filtration module and the ultrasound module equipped with its at least one weight going into resonance via the fixing means when the ultrasound emission module emits ultrasound.