Meri Environmental Solutions Gmbh

Luis Domene Figuerola

George Troubounis

Henning Laubrock

Lucas Menke

The present invention relates to a method and to a device for continuous cleaning of process water circulating in a device for treating waste paper. The process water is supplied, from a unit of the device, to an anaerobic reactor comprising a gas separator, and the cleaned process water is returned back to a unit of the device, wherein this unit is selected from: a pulper; screening device; dewatering unit; oxidation/reduction unit; centrifugal screening device; fine screening device; paper-machine mould section; paper-machine press section; reject treatment unit; fibre recovery unit; and drying section; wherein the content of inorganic solids in the reactor is measured and, if this content exceeds a pre-set limit value, process water from the reactor is continuously fed to a solid-liquid separator for separation into a fraction that is depleted of inorganic solids and a fraction that is enriched with inorganic solids, wherein the fraction that is depleted of inorganic solids is returned to the anaerobic reactor and the fraction that is enriched with inorganic solids is conveyed away out of the device, until the content of inorganic solids in the process water is less than the limit value.

Method for continuous cleaning of process water in waste paper treatment with control of the content of inorganic solids

The present invention relates to a method for cleaning process water circulated in a paper recycling system, comprising a process water treatment step, which comprises at least one pre-acidification step and at least one anaerobic cleaning step, wherein at least some of the process water to be cleaned is subjected to hydrolysis and acidification in the at least one pre-acidification step and the process water thus treated is then brought into contact with anaerobic microorganisms in the at least one anaerobic cleaning step in order to break down impurities in the process water, wherein at least one saccharide-splitting enzyme is added to the process water before or during the pre-acidification step, and the pH of the process water is set to 8.0 or lower at least during the at least one pre-acidification step and during the at least one anaerobic cleaning step.

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Munich, Germany

Luis Domene Figuerola