Patent DE-102009005011-A1 (DE)
Title: Electrochemical disinfection of drinking- and industrial water or for production of disinfectant concentrates from water with high hard contents using electrolysis cells with anodes, comprises flowing anode space by water to be treated
Inventor: THIELE WOLFGANG
IPC: C02F1/78
Filed: 2009-01-17
Abstract: The process for electrochemical disinfection of drinking- and industrial water (2) or for production of disinfectant concentrates from the water with high hard contents under using electrolysis cells (1) divided by separators with anodes coated by noble metal mixed oxides or endowed diamond and cathode made of a porous material, comprises flowing an anode space by water to be treated, tightly pressing a porous cathode to the separator by known measurements, and flowing a cathode space formed by the porous cathode with cathodically developed/supplied gas as continuous phase from top to bottom. The process for electrochemical disinfection of drinking- and industrial water (2) or for the production of disinfectant concentrates from the water with high hard contents under using electrolysis cells (1) divided by separators with anodes coated by noble metal mixed oxides or endowed diamond and cathode made of a porous material, comprises flowing an anode space by the water to be treated, tightly pressing a porous cathode to the separator by known measurements, flowing a cathode space formed by the porous cathode with cathodically developed or supplied gas as continuous phase from top to bottom, and dosing a diluted acid (5) from the top into the cathode space in a desired quantity and concentration such that a trickling film forms as continuous phase in the area of the cathode limiting at the separator and the aqueous solution emerging from the porous cathode together with the gas has an acid pH-value of = 3. The separators are cation exchange membranes or microporous flexible plastic diaphragms. The porous cathode is carbon fiber fleeces, knitted fabrics made of stainless steel or open-pore metal foams made of nickel or copper. The diluted acid is a hydrochloric acid with a concentration of 5-100 g/l. The gas-fluid flow emerging from the porous cathode is separated over a gas separator and the acid catholyte is separately discharged from anolytes. The gas-fluid flow is sucked into the water flow to be disinfected using an injector before entering into the anode space. The diluted acid from a supply container is fed from the top into the porous cathode in a less quantity and the downwardly emerging catholyte is fed back into the acid supply container by a gas elevator under using the cathodically developed or supplied gas. Electrode metal sheets made of valve metal are used as disinfectant for producing active chlorine and are coated with iridium/tantalum and/or ruthenium/titanium mixed oxides. For producing disinfectant concentrates with hypochlorous acid, 2-10 g/l sodium chloride is added to the water to be disinfected as active material. The disinfectant concentrate is subsequently diluted with untreated water or aqueous solution to be disinfected. For producing ozone, the diamond-coated anodes made of valve metal with perforated structure are used as disinfectant, are flowed through by the water to be disinfected, and are tightly pressed to the separator. The valve metal with perforated structure is niobium-expanded metal. The porous cathode is flowed through by oxygen and/or air or the ion exchange membrane is equipped with an active layer for oxygen reduction and is used as oxygen-consumption cathode. An independent claim is included for an electrolysis cell for disinfection of drinking- and industrial water with high hard contents.