Equipment and method for removing a supernatant phase from a body of water in a polluted groundwater

An equipment for removing a non-aqueous supernatant phase from a body of water in a well, the equipment comprising:

• a first stilling tube comprising a perforated hollow cylindrical casing extending for a predefined length according to the longitudinal axis of symmetry of the first stilling tube, provided with an upper flange and a lower flange, the following components being installed inside the first stilling tube:
• a sliding rod having a predefined length greater than or equal to that of the first stilling tube, arranged with its longitudinal axis parallel to the axis of symmetry of the first stilling tube, integral with the upper flange and with the lower flange, a float provided in the upper part with a hydrophobic filter through which the supernatant phase is filtered to be removed, the float being slidably engaged on the sliding rod;
• a pumping device, located below the lower flange, for collecting the supernatant phase and sending it to the surface via a first recovery duct;
• a second flexible tube which fluidically connects the hydrophobic filter to the pumping device transferring by gravity the recovered supernatant phase through the hydrophobic filter;
• at least one first pressure sensor installed between the lower flange and the pumping device;
• at least one second phase sensor installed on the upper flange;
• and
• a support for hooking and suspending the equipment, integral with the sliding rod.