Activated sludge process for industrial wastewater treatment: a patent landscape analysis

The activated sludge process (ASP) is a widely used biological wastewater treatment method. The present patent landscape analysis examined the patent published on ‘Activated Sludge’ from Patentscope (World Intellectual Property Organisation database), Scopus Patents, Google Patents, and Lens. This analysis included around 355 patent records of International Patent Classification C02F class that related to ASP for water treatments from year 1916 to 2024. The legal status of patent application shows 56% of Patent Application in Process, 43% of Granted Patent, and 1% of Amended Application. The jurisdictional structure revealed that the Patent Office of USA was the top office where the highest number of patents were published, that is, 146, which was around 40% of total application published globally. The patent no. US 4056465 A identified as a largest patent family belonged to Air Prod & Chem which was based on non-bulking ASP. The potential inventor was identified as Fujino Kiyoharu who had eight patent records related to ASP. Furthermore, this article has listed key features of patent application at national and multi-national phase via Patent Cooperative Treaty. As per the authors’ knowledge, this is the first article that provides patent insight on ASP for industrial wastewater treatment.