Multistage filtratin device for the utilization of wastes and purification of waste water

A combined treatment of solid waste and waste water using a coal filter and a thermal reactor wherein the waste water is clarified in the coal filter and the solid waste, together with spent coal carrying impurities removed from the waste water in the coal filter, is subjected to thermal decomposition and pyrolysis in the thermal reactor to produce heat energy, a combustible gas rich in hydro carbons, and fresh filter coal which, after optional activation and/or pelletization, may be returned to the coal filter.