The application of modified carbon nanotubes (MCNTs) in the field of wastewater treatment has received much attention in recent years. To better understand the research progress and trends of MCNTs in wastewater treatment, this paper presents a bibliometric analysis of the scientific literature on the application of MCNTs in wastewater, highlight how it has evolved over the years, and identify the sectors for which the study could be beneficial. The CiteSpace software was used to perform the analysis of the data in which specific maps were used to represent the network of the relationships among countries, journals, organizations, authors, and keywords related to the investigated topic and subtopics. The results show that in the time frame of the study, most attention has been focused on the functional modification of carbon nanotubes, the study of their application in water treatment, and the study of the patterns and mechanisms of pollutant removal. The recycling of MCNTs and their environmental risks have not been sufficiently studied. In conclusion, the recycling and regeneration methods of MCNTs, as well as the potential ecological, environmental and health risks will be the focus of future research and more research should be invested.

In order to better grasp the development and trends of tannery wastewater (TWW) treatment research, this paper provides a review of the TWW treatment research dynamics based on the Web of Science (WoS) database and using CiteSpace software. The research dynamics, hot topics, evolutionary history and research trends in this field are revealed. The results showed that research related to TWW treatment has shown a high growth trend in the number of articles in recent years, and India was outstanding in terms of influence in this area. The keyword clustering analysis showed that the main research hotspots in the field of TWW treatment were biological treatment processes (phytoremediation, constructed wetlands, anaerobic treatment and biofilm reactors) and chemical treatment processes (coagulation and flocculation, and advanced oxidation processes). The analysis of new research frontiers showed that the bioremediation and the application of biofuel cells in TWW will become important research directions in the future.