TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Method: The method possess a static substrate bio-film system, which is fully submerged in the fermentation broth in the reactors of the first and second process steps of the process that is composed of heaps of waste, residual substances, new plastics and/or natural substances, which results due to the production and the consumption of economic goods. Biofilms formed on the surface of the static substrate bio-film system in which defined consortia or starter cultures are fixed. The bacteria mineralize the liquid and/or gas pure materials or material mixtures loaded with organic and/or inorganic solid masses. The used substrate is different and/or of the same size, configuration, structure, surface finish, specific surface and material composition. The waste can be in an unordered and/or structured manner with the same and/or different discrete substrate modules with variable relationship of equivalent diameter to the height of 0.1-0.6 and variable relationship of equivalent diameter of the substrate element to the inside diameter of the reaction tank of 0.1-0.3, so that they are brought into one or more closed reaction tanks and/or in reaction tanks that are materially and energetically coupled among themselves, the defined static substrate pouring gives rise to a gap slope of 0.4-0.8 in the case of fluids and 0.6-0.95 in the case of gases and of a specific surface of less than or equal to 500 m2/m3 reactor volume on parts or the whole of the real or extrapolated surface of the substrate by the use of starter or microorganism suspensions such as a mixture of less-solid pig- and/or cattle liquid manure, where after approximately 20-40 days a stable substrate bio-film system with a bio film height of 0.8-1.8 mm is obtained. The active bio films are developed on the substrate material. The bio-films adapt themselves independently in a short span of 3-10 days to changing process and environment conditions and adapt to the added substrate systems and under same process and environment conditions they remain active for a period of more than 2-3 years and thus do not cause blocking. The pre-fermentation of the liquid sludge the optimal process and environmental conditions are carried out at 0-55degreesC and an average hydraulic retention time of more than 20 hours. During pre-fermentation, a waste gas with more than 90 vol.% and the rest 5 vol.% of carbon dioxide dissolved pre-fermentation broth is produced, thus the methane fermentation process takes place in a very stable manner without the need for tilting. The methane fermentation takes place at a pH of greater than 6.5, mesophilic temperatures and thermophilic range, at an average hydraulic retention times of the foul fermentation broth of more than 2 days. The chemical oxygen requirement value and total solid content is reduced to less than 85% in comparison to the starting value of the liquid sludge. The aerobic post-treatment of the foul fermentation broth takes place optimally at 0-55degreesC, with a continuous surplus aeration of more than 3 hours, at an average hydraulic retention times of the foul fermentation broth in the air-lift reactor of more than 3 hours. After a dwelling phase of more than an hour, the solid mass remaining in the foul fermentation broth is quickly sedimented due to gravitational effect. The volume of the dispersed sediment phase is reduced in relation to its initial volume in the liquid sludge to less than 25 vol.% and the chemical oxygen requirement in the clear phase is reduced to more than 90%. The volume of the fluid mud of solid content of the sediment phase is saturated up to the initial content of the liquid sludge with the help of a suitable standard filter unit and/or gravity-separator, thus reduces the volume of the sediment phase (retention phase) further up to lesser than 5 vol.% of the initial value in the liquid sludge and leads to the chemical oxygen requirement in the clear phase (permeate) of less than 10%. The four process steps are operated separately and/or parallely in stationary or mobile equipments or existing clarifiers. The individual process steps are coupled materially and energetically in such a manner that the primary material flow (pre-fermentation broth, foul fermentation broth and clear phase) intermittently, continuously and/or pseudo-continuously are reintroduced and/or led into a cycle in each step and is turned off for the purpose of disposal or recycling. The biogenic co-substrate (0.1-24 wt.%), which has the methanogenic substances in the form of free organic acids and/or pure carbon-hydrogen-oxygen compounds, is added to the liquid sludge or other suitable aqueous substrates that strongly support the growth of the consortia of anaerobic bacteria and possess a high solubility potential for carbon dioxide to give the formation of a fermentation broth mixture concentrated with methanogenic substances, which is metabolized by a consortia of anaerobic bacteria at higher putrid (foul) space load and methane-rich biogas is produced as a recycle product.