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The frequent detection of persistent per- and polyfluoroalkyl substances (PFAS) in organisms and environment coupled with surging evidence for potential detrimental impacts, have attracted widespread attention throughout the world. In order to reveal research hotspots and trends of technologies for PFAS removal, herein, we performed a data-driven analysis of 3975 papers and 436 patents from Web of Science Core Collection and Derwent Innovation Index databases up to 2023. The results showed that China and the USA led the way in the research of PFAS removal with outstanding contributions to publications. The progression generally transitioned from accidental discovery of decomposition, to experimentation with removal effects and mechanisms of existing methods, and finally to enhanced defluorination and mechanism-driven design approaches. The keywords co-occurrence network and technology classification together revealed the main knowledge framework, which was constructed and correlated through contaminants, substrates, materials, processes and properties. Moreover, adsorption was demonstrated to be the dominant removal process among the current studies. Subsequently, we concluded the principles, advances and drawbacks of enrichment and separation, biological methods, advanced oxidation and reduction processes. Further exploration indicated the hotspots such as alternatives and precursors for PFAS ("genx": 1.258, "f-53b": 0.337), degradable mineralization technologies ("photocatalytic degrad": 0.529, "hydrated electron": 0.374), environment-friendly remediation technologies ("phytoremedi": 0.939, "constructed wetland": 0.462) and combination with novel materials ("metal-organic framework": 1.115, "layered double hydroxid": 0.559) as well as computer science ("molecular dynamics simul": 0.559, "machine learn"). Furthermore, the future direction of technological innovation might lie in high-performance processes that minimize secondary pollution, the development of recyclable and renewable treatment agents, and collaborative control strategies for multiple pollutants. Overall, this study offers comprehensive and objective review for researchers and industry professionals in this field, enabling rapid access to knowledge guidance and insights into research frontiers. [Display omitted] [ABSTRACT FROM AUTHOR]

In order to reveal the status and trends of chemical treatment for wastewater, the patents analysis from both structured and unstructured data was performed in this study. 35,838 patents recorded in the Derwent Innovation Index database were adopted. The results showed that China was the country with the largest number of patents in the field, and the United States was the main exporter of international technology flows. Chemical processes combined with biological and physical processes was the mainstream, and ozonation and electrochemical treatment were the major single technologies. Technology evolution path generally showed the transition from biological process-combined chemical treatment to electrochemical treatment and finally to physical process-combined chemical treatment. Furthermore, future trends were revealed from both patents and papers. It demonstrated that efficient removal of ammonia nitrogen, green water treatment agents and resourcezation of wastewater were the key innovation directions, and technologies with regard to efficient use of energy (including photocatalytic technology and microbial fuel cell) were the main research hotspots. Overall, this study provided a comprehensive understanding for the research and application of chemical treatment for wastewater technologies. [Display omitted] • 35,838 patents on chemical treatment for wastewater were analyzed. • Patent analysis from both structured and unstructured data. • Chemical process combined with biological and physical processes was the mainstream. • Technology evolution path was elucidated in three stages. • Future trends were revealed from both patents and papers. [ABSTRACT FROM AUTHOR]