Soil erosion is an important driver of land and ecological degradation, with hydraulic erosion in particular leading to widespread impacts and damage. As an important concept and indicator for characterizing the potential and pathways of sediment production and transportation within watersheds or on slopes, sediment connectivity has gained global attention and thus been analysed since its proposal in 2003. Sediment connectivity has become an effective metric for analysing the sources, processes, and potentials of soil erosion and sediment yield (SY) in watersheds, and it has been considered a popular research topic in the field of soil erosion over the past decade. Considering the lack of up-to-date systematic reviews of conceptual connotations, characterization indicators for sediment connectivity, and quantitative relationships between these indicators and erosion and SY, a bibliometric analysis of sediment connectivity was conducted via the CiteSpace tool, which is based on the Web of Science (WOS), Scopus (Elsevier) and China National Knowledge Infrastructure (CNKI) databases. In this research, the current state, popular topics, and trends in relevant studies were identified, and the conceptual connotations, influencing factors, and indicator algorithms of sediment connectivity and their quantitative relationships with soil erosion and SY were summarized. Furthermore, the contents and directions to be strengthened and improved in the future were determined. The results indicated that over the past 21 years, sediment connectivity has been analysed in 123 countries or regions. Researches have focused primarily on related concepts, indicators, scales, and influencing factors. This concept has been widely applied in various practices such as soil and water resource regulation, land use optimization, and soil erosion control. In previous studies, several linear (SY = a center dot IC + b) and exponential (SY = a center dot eb center dot IC) increasing relationships between sediment connectivity indicators (such as the index of connectivity (IC)) and SY at the slope or watershed scale have been established, facilitating the development of research on prediction and attribution analysis for the identification of sediment sources and changes. There is a consensus on what sediment connectivity is to date, but a unified and complete system has not been yet formed for sediment connectivity and several of its derived concepts. The Index of Connectivity (IC), as the primary means for quantitatively characterizing the status and distribution of sediment connectivity, has led to the creation of more than 20 different algorithms, whereas the included parameters mainly reflect the internal factors influencing topography and land use/cover. The effects of climatic factors and human activities have not been fully considered in previous studies, which has led to relatively backwards researching on functional connectivity indicators. Hence, the classification systems and theoretical frameworks for a series of concepts must be further refined on the basis of sediment connectivity, such as the objective openness, scale dependence, comprehensive impact, and distribution heterogeneity. Moreover, the amount of research on the influences of external drivers and the coupled effects of different factors on indicators of sediment connectivity should be increased. Nevertheless, it is still necessary to explore certain aspects, such as the parameter combinations and normalization methods of the upslope and downslope components of the IC algorithm, and to continuously improve the explanation of the dynamic changes in sediment while considering both hydrological connections along flow paths and off-site impacts on underlying surface variations. Moreover, there is a need to increase the spatiotemporal scale of research on sediment connectivity, explore its feedback mechanisms and close quantitative relationships with soil erosion and SY, focus on the integrated application of different indicators (methods), and validate and results via multisource information to promote relevant applications. The obtained results provide valuable reference for the refinement of theories and methods for sediment connectivity and enhance its support of studies of soil erosion and SY in watersheds.

Numerous studies have been conducted to investigate the impact of microplastics on soil eco-system, yet little attention has been given to the specific effects of mulch microplastics and the leaching of plastic additives from mulch films. This review inspects the propensity of commonly used plastic additives in mulch films, such as Di(2ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and benzophenones (BPs), to migrate into soils and pose potential risks to soil biota. Further, we highlight the degradation of non-biodegradable plastic mulch films over time, which leads to an increase in the release of plastic additives and microplastics into agricultural soils. DEHP has been detected in high concentrations for example 25.2 mg/kg in agricultural soils, indicating a potential risk of uptake, translocation and accumulation in plants, ultimately altering soil physicochemical properties and affecting soil microflora and invertebrates. The review also explores how exposure to ultraviolet (UV) radiation and microbial activities accelerates the weathering of mulch films. Moreover, the resultant plastic additives and mulch microplastics can lead to genotoxicity and growth inhibition in earthworms (Eisenia fetida) and negatively impact the soil microbiome. Despite the significant implications, there has been a lack of comprehensive reviews comparing the effects of non-biodegradable mulch film additives on agricultural soil flora and fauna. Therefore, this review addresses the knowledge gaps providing a bibliometric analysis and eco-toxicological evaluation, discussing the challenges and future perspectives regarding mulch plastic additives and microplastics, thus offering a comprehensive understanding of their impact.

Black carbon is a short-lived climate warming agent and serves as a crucial factor influencing the climate. Numerous models, observations, and laboratory studies have been conducted to quantify black carbon's direct or indirect impacts on the climate. Here, we applied bibliometric analysis to identify research trends and key topics on black carbon in the climate field. Based on the Web of Science (WOS) Core Collection database, a total of 4903 documents spanning the period from 2000 to 2023 were retrieved and screened, focusing on the topic of black carbon in the climate field, resulting in the Black-Carbon Climate Local (BCL) dataset. Our study examines the influence and trends of major countries, institutions, and authors in this field. The results show that China and the United States hold leading positions in terms of the number of publications. Based on keyword networks, the BCL dataset is segmented into six distinct research directions, and representative keywords of each direction include biomass burning, radiative forcing, air pollution, aerosol optical depth, optical properties, and biochar. This study helps to identify the current research status and trends of black carbon in the climate, highlighting main research directions and emerging topics.

In the chemical industry and in the manufacturing sector, the adsorption properties of porous materials have been proven to be of great interest for the removal of impurities from liquid and gas media. While it is acknowledged that significant progress and literature production have been developed in this field, there have been adsorption studies that failed to further advance our knowledge in generating a better understanding of the prevailing sorption types and dominant adsorption processes. Therefore, this review study has focused on porous materials, their sorption types and their adsorption properties, further investigating the adsorption properties of porous materials at either solid-gas and solid-liquid interfaces, underscoring both the properties of the materials, the characterization and the correlation between the porosity and the adsorption capacity, as well as the emergent interactions between the adsorbent and adsorbate molecules, including the adsorption mechanisms, the types of sorption and the kinetic and thermodynamic information conveyed.

In recent years, interest in Nanoplastics and Microplastics (NM) has increased both in scientific research and in the initiatives of environmental protection organizations. This points to their increasing importance and impact on scientific research and ecological conservation efforts. NMs are detected in natural water resources, air, and soil, depending on factors such as population density, industrial activities, and waste management policies. Due to the small size of NMs, they are more rapidly penetrated and transported. For this reason, the observation of NMs becomes very important due to the inclusion of easily transported NMs in biological processes and the increased damage to the environment. Considering the crucial role of NMs in almost every discipline, the motivation of this study is to investigate the current productivity level as well as the existing research trends in this area globally, and to forecast future research activity for specific countries. Bibliometric analysis was conducted for articles that were drawn from the Web of Science (WoS), published in 2021, 2022, and 2023. The extrapolation method was used to estimate potential future capacity trends for defined countries. A total of 6373 documents were produced worldwide on NMs during 2021-early 2023. China was the most active country, Science of the Total Environment was the leading journal, and the Chinese Academy of Sciences was the most productive institution. China was also the first one regarding total citations, while the USA and Italy were second and third. Portugal, Slovenia, and Cyprus formed the top three regarding the total number of documents and citations, after the adjustment for population level. Additionally, predictions depicted that China would preserve its uppermost role in this area in the upcoming 5 years. This study presents a comprehensive synthesis of the latest trends in productivity within this field. Global collaborative efforts, expanding research personnel, and improving the trend of research grants coupled with steady governmental policies, collectively will contribute to enhancing both the productivity levels and widespread dissemination of publications in this subject area. Hence, because of its topicality, this work could also be named as informative for upcoming and ongoing bibliometric studies.

Cracking behavior can reduce soil hydraulic and mechanical properties and is a preferential pathway for water flow and pollutant transportation, resulting in polluted environment, such as application to landfill liners and capping. Recently, researchers have advocated the use of waste materials for clay mixtures using various measurement and analysis methods. Therefore, this study aims to conduct a bibliometric analysis of the scientific literature published between 2002 and 2021 obtained from Scopus to quantitatively identify research trends, key research areas, and future research paths in this field on desiccation and crack behavior using waste materials as landfill liners. The VOS viewer software was used to analyze 41 articles in which the paper selection process was filtered. The results showed that the fly ash mixture's application as a landfill liner could reduce cracking significantly. Furthermore, fractal analysis and X-ray computed tomography measurements have proven to be good candidates for measuring cracks because they are the most accurate for calculating the crack value. Waste materials such as fly ash can be applied as landfill liners with other materials, such as bentonite and coconut coir fibers. This study is beneficial for improving the design and selecting the appropriate materials for landfill liners.