The mobile water treatment cartridge is connectable into a water treatment circuit and includes fluid connectors and power and data connection ports. The cartridge includes an outer shell having an upper opening that can be hermetically sealed by a lid, and an inner shell having an opening at the top and delimiting an internal volume of the cartridge, in which all the technical equipment for operation of the cartridge is placed. The inner shell is secured to at least one structure that can be inserted into the interior volume through the opening. There is a device for handling the cartridge secured to the outer shell and a device for rendering the cartridge mobile.