(EP639108-A1)      A feed mixt. for an anaerobic bioreactor is prepd. by feeding a liq. into a reactor to give a free liq. surface. A solid waste is fed to the reactor and introduced to the liq. at a point below its free surface.    Light and heavy rejectable materials are sepd. from the mixt. using an agitator in the reactor within the mixt. and by countercurrent washing directed towards the bottom of the reactor.    USE/ADVANTAGE -   The method prepares a feed material suitable for anaerobic biological treatment from solid municipal waste and municipal sewage sludge. Unsuitable materials, e.g. stone, glass, metal, plastic and cork, are removed rendering the mixture more suitable for feeding to the anaerobic reactor    (JP7507481-W)      A feed mixt. for an anaerobic bioreactor is prepd. by feeding a liq. into a reactor to give a free liq. surface. A solid waste is fed to the reactor and introduced to the liq. at a point below its free surface.    Light and heavy rejectable materials are sepd. from the mixt. using an agitator in the reactor within the mixt. and by countercurrent washing directed towards the bottom of the reactor.    USE/ADVANTAGE -   The method prepares a feed material suitable for anaerobic biological treatment from solid municipal waste and municipal sewage sludge. Unsuitable materials, e.g. stone, glass, metal, plastic and cork, are removed rendering the mixture more suitable for feeding to the anaerobic reactor.    (EP639108-B1)      A method for producing a feed mixture, advantageously suitable for an anaerobic bioreactor and containing liquid and solid materials, for the further treatment of waste materials, wherein the method includes at least the following steps: (a) into a feed mixture reactor (1), there is first fed liquid so that the free liquid surface (5) is located essentially above the solid material feed point (6) provided in the reactor (1), (b) from the solid waste material fed into the reactor (1) both light (10) and heavy (14) rejectable materials are separated by utilizing a rising current created by an agitator (7) installed in the feed mixture reactor (1), and by counter-current washing (14) of the heavy rejectable materials directed towards the bottom part of the reactor (1), (c) continue agitation until the feed mixture is homogeneous and remove the ready-made feed mixture.    (US5679263-A)      A method for producing a feed mixture, advantageously suitable to an anaerobic biorector and containing liquid and solid materials, for the further treatment of waste materials comprising at least the following steps:    a) into a feed mixture reactor, there is first fed liquid so that a free liquid surface is located essentially above a solid material feed point provided in the reactor,    b) the solid waste material fed into the feed mixture reactor is fed to below the free liquid surface of the reactor, and from the solid waste material there is separated both light and heavy rejectable materials by utilizing an agitator installed in the feed mixture reactor, and by countercurrent washing directed towards the bottom part of the reactor, wherein the waste material fed into the feed mixture reactor contains both solid waste material and sludgy waste material to be fed in after the removal of rejected materials.