TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Components: The process cell has a vertical cylindrical geometry and comprises a cathode constituting the external wall and a cylindrical anode installed in a central position coaxially with the cathode, and the inlet and outlet are capable of maintaining a high mass transport being respectively placed in correspondence of the lower and upper extremity of the cell with a horizontal and tangential orientation. The high mass transport is established by a spiral flow. The stainless steel cathode is further provided with a catalytic coating for hydrogen evolution. The anode is a titanium anode provided with a catalytic coating for oxygen evolution capable of working at a potential lower than 1.7 V/SHE.Preferred Process: The electrolytic reduction is protracted up to a final concentration of hexavalent chromium not exceeding 0.2 parts per million. The electrolytic reduction is arrested at a residual concentration of hexavalent chromium in the reduced solution higher than the value prescribed by the norms of disposal of industrial waters and is followed by a final treatment of the reduced solution comprising the addition of a chemical reductant. The final treatment is carried out in a reactor provided with a potentiometric element. The final treatment reduces the concentration of hexavalent chromium down to a value not exceeding 0.2 ppm. The potentiometric element detects the redox potential of the reduced solution. The addition is arrested when the potentiometric element detects a redox potential of 0 V/SHE. The reduced solution is further neutralized with precipitation of trivalent chromium hydroxide, and the chromium hydroxide is subsequently separated by filtration. The reduced solution is further evaporated with subsequent separation of trivalent chromium by crystallization as chromium sulfate.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The catalytic coating is a ruthenium metal coating, or iridium or tantalum mixed oxide. An additional porous coating of catalytically inert material is applied upon the catalytic coating. The additional porous coating comprises tantalum oxide. The chemical reductant is sodium sulfite, sodium bisulfite, ferrous salts, or iron powder.