A mixed method assessment of research productivity on microplastics in various compartments in the environment

Microplastic distribution and pollution as emerging contaminants have become a leading environmental issue globally, owing to their ecological and health implications on biota and humans. Although several bibliometric studies have been reported on microplastics, they are mostly restricted to selected environmental media. As a result, the present study aimed at assessing the literature growth trend of microplastics-related research and their distribution in the environment using a bibliometric approach. The Web of Science Core Collection was explored to retrieve published articles on microplastics from 2006 to 2021, and the data were analysed using the Biblioshiny package of RStudio. This study also highlighted filtration, separation, coagulation, membrane technology, flotation, bionanomaterials, bubble barrier devices, and sedimentation as MP remediation techniques. In the present study, a total of 1118 documents were collected from the literature search; the documents/author and authors/document were 0.308 and 3.25, respectively. A significant growth rate of 65.36% was recorded with notable progress between 2018 and 2021. China, the USA, Germany, the UK, and Italy recorded the highest number of publications within the period under consideration. A collaboration index of 3.32 was also relatively high, with the Netherlands, Malaysia, Iran, France, and Mexico having the highest MCP ratios, respectively. It is anticipated that findings from this study will help the policymakers in addressing issues concerning microplastic pollution assist the researchers in identifying areas to concentrate their studies, and where to seek collaboration in their future research plans.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13762-023-04916-7.

Research hotspots and trends of comprehensive utilization of phosphogypsum: Bibliometric analysis

Phosphogypsum is a by-product of the phosphate fertilizer industry. It is generally treated by stacking, which not only causes environmental pollution, but also wastes resources. Therefore, the harmless, comprehensive, and high-value utilization of phosphogypsum has attracted more and more scholars around the world. From the perspective of bibliometrics, this paper systematically and comprehensively describes the research progress, trends and hot spots of phosphogypsum resource utilization. This article is based on a scientific network database, and a total of 1067 articles from 1985 to 2020 were collected. Then, use VOSViewer software to perform co-occurrence, co-citation analysis and cluster analysis. The visual analysis results demonstrate that the research on the resource utilization of phosphogypsum shows the characteristics of rapid growth. The active countries are mainly China, Brazil, Spain and the United States. Four of the top 10 active organizations are from China. It systematically expounds the changes in research hotspots in this field at different stages and possible future research hotspots. Including the gradual attention to the preparation of phosphogypsum building materials, phosphogypsum adsorption materials, and radioactive elements in phosphogypsum; the extraction of rare earth elements from phosphogypsum; the use of phosphogypsum to prepare fertilizer or soil improvement. Research shows that phosphogypsum can be reasonably designed, transformed, and used in different fields.However, the radioactivity contained in phosphogypsum should be paid attention to because it has an impact on humans and the environment. We believe that this research provides a comprehensive and systematic overview for future research on phosphogypsum resource utilization.

Micro-Nano Plastic in the Aquatic Environment: Methodological Problems and Challenges

Microplastic research has become a buzz word. It is seen as one of the most pressing issues of Anthropocene contamination. There is certainly no doubt about the ubiquitous presence of microplastic (MP) in almost all environmental matrices. However, the validity of considering them as a vector for contaminants needs some reconsideration, there are other more potent pathways. Their effect on marine biota also calls for some realistic experiments with environmental concentrations of MP and nanoplastic (NP). It has been observed that in most published literature, polymer characterization is performed. Is it necessary to do, or will merely finding and confirming the particle as plastic suffice for environmental research? Harmonization of protocols is necessary, and there is likely a need for some inter-laboratory comparison exercises in order to produce comparable data and reliable assessments across regions. Samples collected from the same area using different techniques show an order of magnitude difference in MP concentration. The issue of nanoplastic is more contentious; are we technologically ready to identify NP in environmental samples?