Research trends and hotspots of aquatic biofilms in freshwater environment during the last three decades: a critical review and bibliometric analysis

Freshwater periphytic biofilms (FPBs), existing widely in various aquatic environments, have attracted extensive attention for many years. In the present study, a bibliometric analysis based on Web of Science Core Collection (WoSCC) was used to understand the research progress, trends, and hot topics of FPBs qualitatively and quantitatively. The results indicated that publications on FPBs have increased from 1991 to 2020 rapidly, and researchers have focused more on the areas of environmental sciences, microbiology, and marine freshwater biology. The most influential countries were mainly the USA, Spain, France, and Germany. Cooperation network analysis reflected that the USA and its affiliated institutions played crucial roles in the research of FPB cooperation, but the collaboration between core author groups still fell short. Based on the analysis of top 20 high-cited FPB documents over the last 30 years, research hotspots mainly included micro-observation and assembly mechanisms of FPBs; interactions of FPBs and pollutants including heavy metals, antibiotic resistance genes, pathogens, organic pollutants, and nanoparticles; and the role of FPBs for biogeochemical cycling, especially nitrogen cycling. Additionally, future research directions were proposed. Overall, this study provides a comprehensive and systematic overview of FPBs, which is useful for research development and researchers who are interested in this area.