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.

Microplastic (MP) pollution is lately receiving increasing attention owing to its harmful impact on terrestrial ecosystems. In this microcosm study, we assessed the uptake and transfer of MPs in Solanum nigrum seedlings exposed to 50 mg L^–1 of 0.2-µm polystyrene (PS) beads for 30 d. Confocal laser scanning micrographs helped detect highly intense red fluorescence signals from PS-MP beads in S. nigrum root compared with the controls. Confocal images revealed that the PS beads were primarily distributed in the epidermis and xylem of roots and vascular systems of stems and leaves. Scanning electron microscopy showed that PS beads were scattered on the cell walls of the root xylem and leaf vascular system. Few PS beads were transferred from roots to stems and leaves via the vascular system following the transpiration stream. In conclusion, our findings showed that PS beads accumulated in S. nigrum roots and were transferred from the roots to the aerial parts.