NOVELTY - Method for treating material mixture from wastes containing organically and biologically convertible material and materially and/or energetically recyclable fractions, comprises supplying the material mixture to a common process step (3) and intensively washing the partial retention of the material mixture of preferably soluble, organic material components and adhesive fine substance by at least partly reused process water.    USE - The method is useful for treating material mixture from wastes containing organically and biologically convertible material and materially and/or energetically recyclable fractions (claimed).    ADVANTAGE - The improved method effectively treats the material mixture from the wastes without any increased wear adjustment, and is economical.    DETAILED DESCRIPTION - Method for treating material mixture from wastes containing organically and biologically convertible material and materially and/or energetically recyclable fractions, comprises supplying the material mixture to a common process step (3) and intensively washing the partial retention of the material mixture of preferably soluble, organic material components and adhesive fine substance by at least partly reused process water; where the common process further comprises process steps (5, 6, 7, 8, 9, 63) in solid path and a water path, in which at the process steps (5, 6, 7, 9) the oxidation- and/or reduction potential of at least a part of the process water and/or material components in the process water is changed by mechanical, biological and/or physiochemical treatment and the reactivity changed process water is again at least partly supplied to at least one of the process steps (3, 4, 5, 6, 7, 8, 9, 63) and the microbial dissociation of the process water from the common process step takes place in a hydrolysis step (6) under the addition of oxidized and/or oxidizing process water (55) from the process step (9) or in at least a continuous or batch-wise aeration step.    An INDEPENDENT CLAIM is included for a plant for treating of material mixture from wastes containing organically, biologically convertible materials and materially and/or energetically recyclable fractions comprising washing device (11), where in the first process step (3), preferably soluble organic material components and adhering fine substance are washed from the material mixture by at least a partly reused process water and a process water treatment, where the process water discharge (53) is subjected to a biological and/or physiochemical treatment and at least a part of the process water discharge (55) is reusable as process water feed in the from of washing liquid (15).    DESCRIPTION OF DRAWING(S) - The drawing shows a device for treating material mixture from wastes:    First process step; (3)    Water processing step; (5)    Hydrolysis step; (6)    Fermentation process step and/or methanation process step; (7)    Washing device. (11)