Process for treating and purifying waste water to produce potable water, electrical energy and thermal energy, comprising the following steps in order: (a) introducing waste water into at least one separator of coarse elements; (b) extracting clarified water after passage through at least one concentrator unit connected via a conduit to said at least one coarse element separator; (c) conveying the clarified water successively into at least one heat exchanger (31A,31 B,31 C) then into at least one filtering stage (22A,22B) before remineralization by at least one remineralizer, said at least one heat exchanger (31A, 31 B, 31 C) being connected via a conduit to said at least one filtering stage (22A,22B) that itself is connected via a conduit to said at least one remineralizer: (d) producing potable water after remineralization by said at least one remineralizer; (e) capturing the thermal energy recovered from the clarified water after it has passed through said at least one heat exchanger (31A, 31 B, 31 C) connected to at least one heat pump (32A,32B), and producing potable water derived from step d) concomitantly and simultaneously, and (f) producing electrical energy and thermal energy by a mini co-generator unit receiving biogas produced by at least one anaerobic reactor supplied with a flow of concentrated effluent derived from said at least one concentrator unit, characterized in that said anaerobic reactor is heated by at least one heating fluid loop forming a closed circuit, said anaerobic reactor reactor being connected to said heat pump (32A,32B) by said heating fluid loop in which there circulates the thermal energy derived from step e), said heating fluid loop taking up thermal energy at said at least one heat pump (32A,32B) and releasing said thermal energy inside said at least one anaerobic reactor, said at least one heat pump (32A,32B) itself being connected to said at least one heat exchanger (31A,31 B,31 C) via at least one loop of heat exchange fluid (33A,33B,33C), (g) ensuring multi-objective management via at least one controller and at least one computer. (a) introducing waste water into at least one separator of coarse elements; (b) extracting clarified water after passage through at least one concentrator unit connected via a conduit to said at least one coarse element separator; (c) conveying the clarified water successively into at least one heat exchanger (31A,31 B,31 C) then into at least one filtering stage (22A,22B) before remineralization by at least one remineralizer, said at least one heat exchanger (31A, 31 B, 31 C) being connected via a conduit to said at least one filtering stage (22A,22B) that itself is connected via a conduit to said at least one remineralizer: (d) producing potable water after remineralization by said at least one remineralizer; (e) capturing the thermal energy recovered from the clarified water after it has passed through said at least one heat exchanger (31A, 31 B, 31 C) connected to at least one heat pump (32A,32B), and producing potable water derived from step d) concomitantly and simultaneously, and (f) producing electrical energy and thermal energy by a mini co-generator unit receiving biogas produced by at least one anaerobic reactor supplied with a flow of concentrated effluent derived from said at least one concentrator unit, characterized in that said anaerobic reactor is heated by at least one heating fluid loop forming a closed circuit, said anaerobic reactor reactor being connected to said heat pump (32A,32B) by said heating fluid loop in which there circulates the thermal energy derived from step e), said heating fluid loop taking up thermal energy at said at least one heat pump (32A,32B) and releasing said thermal energy inside said at least one anaerobic reactor, said at least one heat pump (32A,32B) itself being connected to said at least one heat exchanger (31A,31 B,31 C) via at least one loop of heat exchange fluid (33A,33B,33C), (g) ensuring multi-objective management via at least one controller and at least one computer.