Patent DE-102008004663-A1 (DE)
Title: Method for sanitization and germ reduction from biologically cleaned sewage, comprises conducting the sewage or sewage partial flow to a clarification plant through electrolysis cell and subsequently supplying to industrial water container
Inventor: WORCH ECKHARD
IPC: C02F1/467
Filed: 2008-01-11
Abstract: The method comprises conducting biologically cleaned sewage (14) such as domestic sewage and sewage partial flow such as yellow water or grey water by a clarification or biological step to a clarification plant for sanitization and germ reduction through electrochemical treatment in an electrolysis cell (10) with a reversed polarity unit arranged in a sanitization module (5) for a polarization change of electrodes (12, 13) arranged in the electrolysis cell and of a control (11), and subsequently supplying to an industrial water container or a main outfall. The method comprises conducting biologically cleaned sewage (14) such as domestic sewage and sewage partial flow such as yellow water or grey water by a clarification or biological step to a clarification plant for sanitization and germ reduction through electrochemical treatment in an electrolysis cell (10) with a reversed polarity unit arranged in a sanitization module (5) for a polarization change of electrodes (12, 13) arranged in the electrolysis cell and of a control (11), and subsequently supplying to an industrial water container or a main outfall. The predetermined work attitudes of the control are activated or changed to flow strength and volume flow in dependent upon the result of a measurement of conductivity and/or chloride content and total organic carbon content of sewage and a sewage volume to be estimated so that a minimum value required for the sanitization is kept at free chlorine in the electrochemical treatment of sewage. The conductivity and/or the chloride content through a flow sensor arranged above the electrolysis cell and the content of free chlorine through a flow sensor arranged below the electrolysis cell are measured on-line that are brought to respective determined values of measured-value processing unit, whose signal generator is connected with a storage programmable control. The flow strength of the electrolysis cell is controlled in automated operation of the sanitization module through the measured value of conductivity and/or the chloride content and the content of free chlorine. Suspended- and coarse materials of the biologically cleaned sewage and the sewage partial flow are eliminated through flow filters serially connected to electrolysis cell. Boron-doped diamond electrodes or mixed oxide electrodes are inserted in the electrolysis cell, which is operated with a current density of 10-250 mA/cm 2>. By a flow-guard that is connected with the storage programmable control, the guiding of the electrochemical sewage to be treated is observed and signals for deactivating of electrolysis cell are given by the flow-guard in the storage programmable control. By a temperature guard that is connected with the storage programmable control, the temperature in the electrolysis cell is observed and signals for deactivating of electrolysis cells are given during exceeding a default threshold value for the temperature. An independent claim is included for a device for sanitization and germ reduction from biologically cleaned sewage such as domestic sewage and sewage partial flow such as yellow water or grey water through electrochemical treatment in an electrolysis cell.