NOVELTY - A dissolved methane removal apparatus comprises a venturi aerator having a liquid inlet communicating with a conduit, a constricted throat portion, a liquid outlet and an air inlet at or adjacent the throat portion. The liquid outlet communicates with a liquid inlet of a degassing chamber having a liquid outlet at or adjacent its lower region.    USE - The invention is for separating and removing dissolved methane from a liquid (claimed) trade waste such as leachate from landfill sites. The leachate comprises a mixture of rainwater draining through the waste.    ADVANTAGE - The invention provides an inline methane removal system, allows trade effluent, such as leachate, to be pumped straight through the apparatus and into the sewerage system, avoids the need for large volume storage tanks while reducing the concentration of dissolved methane contained in the trade effluent (14 to less than 0.14 ppm), to meet the environmental requirements for trade effluent disposal into the sewerage system.    DETAILED DESCRIPTION - A dissolved methane removal apparatus comprises a conduit (1) for conducting liquid from a source, and a venturi aerator (3) having a liquid inlet communicating with the conduit, a constricted throat portion (4), a liquid outlet and an air inlet (5) at or adjacent the throat portion. The liquid outlet communicates with a liquid inlet of a degassing chamber (6) having a liquid outlet (8) at or adjacent its lower region. The liquid outlet of the chamber communicates with a second conduit for conducting the treated liquid to a sewer for disposal or to a further treatment stage. A gas outlet (7) is provided at or adjacent an upper region of the degassing chamber.    INDEPENDENT CLAIMS are also included for:    (1) an apparatus for removing dissolved methane from a liquid as claimed above but further comprising a second degassing chamber having a liquid outlet communicating with a liquid disposal point such as a sewer or a further treatment stage;    (2) a method of reducing the concentration of dissolved methane in trade effluent with reference to the accompanying drawings;    (3) an apparatus for removing dissolved methane from a liquid; and    (4) a method of reducing the concentration of dissolved methane in trade effluent with reference to the accompanying drawings.    DESCRIPTION OF DRAWING(S) - The figure is a schematic diagram of a dissolved methane removal apparatus.    Conduit (1)    Pump (2)    Venturi aerator (3)    Throat portion (4)    Air inlet (5)    Degassing chamber (6)    Gas outlet (7)    Liquid outlet (8)    Another pump (9)