NOVELTY - Degradation of sludge and/or solid components of organic origin present in wastewater, by subjecting sludge to anaerobic biologic fermentation process, transporting first biomass and first interstitial liquid phase to an aerobic fermentation tank and subjected to an aerobic fermentation in the presence of an oxygen containing gas, and separating the sludge into purified effluent and a second biomass.    USE - For degradation of sludge and/or solid components of organic origin present in wastewater.    ADVANTAGE - The inventive method provides a better use of the energy present in the sludge. It obtains an optimum processing of sludge, thus a minimum amount of residual sludge, in particular biomass is formed.    DETAILED DESCRIPTION - Degradation of sludge and/or solid components of organic origin present in wastewater comprises subjecting the sludge to an anaerobic biologic fermentation process, in which a first biomass with a first interstitial liquid phase is formed and methane gas is produced; transporting the first biomass and first interstitial liquid phase to an aerobic fermentation tank and subjected to an aerobic fermentation in the presence of an oxygen containing gas, during which the temperature is maintained between 25-70degreesC and a second biomass with an interstitial second effluent is formed; and conducting the second biomass and interstitial effluent towards a separator for separating the sludge into purified effluent and a second biomass.    An INDEPENDENT CLAIM is also included for a device for the degradation of sludge and/or solid components of organic origin present in waste water, comprising a supply (11) for supplying of the sludge and/or solid components of organic origin present in waste water (10) to an anaerobic fermentation tank (1) to partly ferment the sludge and/or organic components to biogas and a first biomass in a first liquid phase; a connection for transporting the first biomass, remaining sludge and first liquid phase to an aerobic fermentation tank (2) to subject the first biomass to an aerobic fermentation until carbon dioxide is formed, second interstitial effluent and a second biomass; and a connection for transporting the second biomass and second interstitial effluent from the aerobic fermentation tank to a separation device (4) for separating solid components and effluent (13) and a connection for returning the solid components to one or more of the anaerobic and aerobic fermentation tank.    DESCRIPTION OF DRAWING(S) - The figure shows the apparatus for degradation of sludge and/or solid components of organic origin present in wastewater.    Anaerobic fermentation tank (1)    Aerobic fermentation tank (2)    Separation device (4)    Waste water (10)    Supply (11)    Effluent (13)