The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 2025
Filed:
Nov. 24, 2020
Kemira Oyj, Helsinki, FI;
Sakari Halttunen, Espoo, FI;
Miia Niemelä, Helsinki, FI;
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Abstract
The invention relates to a method for treating wastewater in an activated sludge process, which comprises a biological treatment step followed by a sedimentation step for separation of sludge and treated effluent water. The method comprises directing a part of the treated effluent water as a backflow from the sedimentation step to the biological treatment step, the backflow having an original pH value; adjusting the backflow pH from the original pH value to a first pH value between the sedimentation step and the biological treatment step, and adding a coagulant and/or an oxidant to the backflow after the adjustment of the backflow pH to the first pH value and before backflow's entry to the biological treatment step.