NOVELTY - The method comprises supplying a flow of wastewater (102) comprising an organic pollutant to an anode of a solid polymer electrolyte electrolytic cell, providing a voltage of less than 3 volts across the electrolytic cell, operating the electrolytic cell at an operating temperature of 3-95 degrees C and a current density of less than 10 mA/cm2 for degrading the pollutant and for generating a hydrogen gas at a cathode of the electrolytic cell, and exhausting the generated hydrogen gas from the cathode. The anode comprises an anode catalyst layer. The cathode comprises a cathode catalyst layer.    USE - The method is useful for treating polluted wastewater.    ADVANTAGE - The method ensures energy efficient and safe treatment of the wastewater thus mineralizing the pollutants in water and reducing organic load and toxicity of the waste, where the pollutants include persistent organic pollutants, dioxins, nitrogen species, pharmaceuticals, pathogens, microorganisms and pesticides.    DETAILED DESCRIPTION - The method comprises supplying a flow of wastewater (102) comprising an organic pollutant to an anode of a solid polymer electrolyte electrolytic cell, providing a voltage of less than 3 volts across the electrolytic cell, operating the electrolytic cell at an operating temperature of 3-95 degrees C and a current density of less than 10 mA/cm2 for degrading the pollutant and for generating a hydrogen gas at a cathode of the electrolytic cell, and exhausting the generated hydrogen gas from the cathode. The anode comprises an anode catalyst layer. The cathode comprises a cathode catalyst layer. The cathode is liquid-electrolyte free. The electrolytic cell further comprises a solid polymer membrane electrolyte separating the anode and the cathode. The anode is positive with respect to the cathode. Spacing between the anode and the cathode is less than 30 mm. The anode comprises a fluid distribution layer, and a microporous sublayer that is positioned between the anode catalyst layer and the fluid distribution layer. The fluid distribution layer comprises niobium mesh and tungsten gauze. The cathode comprises a gas diffusion layer, and a microporous sublayer that is positioned between the cathode catalyst layer and the gas diffusion layer. The anode catalyst layer further comprises carbon or graphite particles having a surface area of greater than 280 m2/g, and tantalum, niobium or titanium carbide particles having a particle size of less than 45 microns. The method further comprises: recovering the exhausted generated hydrogen gas produced at the cathode and converting the hydrogen gas back into electricity; performing post treatment process for removing free chlorine, where the post treatment process comprises electrochemically reducing, adsorbing and decomposing chlorine by contacting a transition metal, reacting chlorine with a salt, a chemical reducing agent and organic matter, decomposing chlorine by contacting a redox filter, decomposing chlorine by light exposure, and decomposing chlorine by heating; preventing formation of chlorine, where the preventing step comprises controlling a pH of the wastewater (greater than 2), increasing an ionomer concentration at an anode fluid delivery layer, increasing the ionomer concentration at the anode catalyst layer, and incorporating materials that catalyze a decomposition of free chlorine into the anode; and performing cleaning step consisting of ion exchanging in-situ, purging the cathode with a cleaning solution and potentiostatic cleaning. An INDEPENDENT CLAIM is included for a system for treating wastewater.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a system for treating wastewater.    Wastewater (102)    Peristaltic pump (103)    Effluent tank (104)    Pressure gauge (105)    Valve. (106)