Phytoremediation is an environmentally friendly, economical, and sustainable technique for restoring farmland. It can remove heavy metals and organic pollutants from the soil through the implementation of hyperaccumulator plants. In recent years, it has garnered significant interest from academic and industrial sectors. This article screened 368 research papers from the Web of Science core collection database related to farmland phytoremediation and conducted a bibliometric analysis of the domain based on CiteSpace. The paper intuitively demonstrates the most influential countries, the most productive institutions, the most contributing groups of authors, and the primary sources of farmland phytoremediation research domain. The findings additionally indicate that the research hotspots include: (1) mechanisms and principles of phytoremediation, (2) the improvement of restoration efficiency, (3) the economic, ecological, and sustainable development of phytoremediation. The exploration of plants with potential to accumulate heavy metals and produce large amounts of biomass is the research frontier within the field of farmland phytoremediation. Additionally, this bibliometric analysis can help scholars willing to work in this research field by concisely understanding the overall research field and frontiers. With the continuous improvement of phytoremediation and its combination with other remediation technologies, the future of farmland remediation will have a promising prospect.

Population growth has significantly increased energy and resource demands, driving research toward cost-effective technologies that repurpose waste into alternative energy forms such as biohydrogen. This review aims to comprehensively evaluate biohydrogen production via anaerobic digestion, addressing gaps in previous studies focusing on a single sustainable development goal or limited environmental benefits. The methodology used the Scopus database with specific keywords, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol to screen relevant articles, and bibliometric analysis to delineate research directions from 2002 to 2024. Findings indicate that research on biohydrogen production via anaerobic digestion has grown exponentially over the past two decades, with increasing emphasis on advanced techniques, innovative reactor configurations, and diverse microbial consortia. Emerging trends, including the integration of artificial intelligence for process optimization and comprehensive life cycle assessments, suggest promising avenues for large-scale implementation. Anaerobic digestion-based biohydrogen production supports several Sustainable Development Goals (SDGs), including the ones related to clean energy (SDG7), SDG 13 (climate action), and SDG 12 (waste management), among others. Recent advancements are synthesized to provide a clear roadmap for future research toward sustainable energy solutions.

Excessive chemical substances in agricultural drainage water have serious adverse effects on the ecological environment of the watershed into which they are discharged. Therefore, it has attracted widespread attention from scholars worldwide. In this paper, 282 scientific articles related to agricultural drainage water treatment are selected from the Web of Science Core Collection database, and CiteSpace was used to visualize and analyze the knowledge map of this field. The most productive authors, institutions, and countries in agricultural drainage water research are graphically presented in this paper. Developing countries are becoming the core force in this realm of inquiry. In addition, this paper explains the changes in research topics in this field over time and reveals current research hotspots, including “desalination”, “denitrification”, and “phosphorus removal”. Future research endeavors in using bioreactors and agricultural drainage water ditches for treating agricultural drainage water are implied to become a research focus in this field. This paper also emphasizes that future environmental protection research should increase case studies in developing countries and develop corresponding solutions based on the actual situation of agriculture in rural areas of developing countries.

The distribution of atmospheric CO₂ is not homogenous, primarily due to variations in the CO₂ budgets of regional terrestrial ecosystems. To formulate a comprehensive strategy to combat the increasing global CO₂ levels and associated warming, it is crucial to consider both the distribution of atmospheric CO₂ and the CO₂ budgets of ecosystems. This study focused on analyzing the relationship between regional atmospheric CO₂ and CO₂ budgets in China from 2010 to 2017. Initially, a robust estimation model of net ecosystem CO₂ exchange was developed to calculate CO₂ budgets using collected emission data. Subsequently, Pearson correlation, redundancy analysis, and geographically weighted regression techniques were employed to examine the link between atmospheric CO₂ levels, CO₂ budgets, and other meteorological factors at various spatial and temporal scales. The findings from the redundancy analysis and geographically weighted regression indicated that the atmospheric CO₂ content of each province could not be solely determined by the regional CO₂ budgets. However, a significant and positive correlation between atmospheric CO₂ levels and CO₂ budgets was observed in non-coastal provinces for a period of six months (R² ranging from 0.46 to 0.83). Consequently, it is essential to promote a balance between CO₂ emissions and the CO₂ uptake capacity of regional ecosystems. This balance would minimize positive CO₂ budgets and effectively mitigate the increase in atmospheric CO₂ levels.

The mining industry is a cornerstone of global energy security and industrial supply chains, yet its resilience to systemic disruptions such as COVID-19 has been critically overlooked. This disruption provided a rare opportunity to trace supply-chain impacts. Using an environmentally extended multi-regional input-output (EEMRIO) model integrated with a Criteria Importance Through Intercriteria Correlation (CRITIC) weighted approach. We compare pandemic trajectories with counterfactual no-pandemic trajectories: the no-pandemic model (calibrated on 2004–2018) projects 2019–2025, while the pandemic model (calibrated through 2023) projects 2023–2025, with 2023 serving as the observed baseline and transition year. Our findings reveal a transient reduction in mining water and carbon footprints, juxtaposed with stark economic contractions: mining value fell by 40% in China, 37% in India, and 13% in the United States. The weighted component among the water-carbon-value (WVC) analysis further uncovers a tripolar spatial pattern, categorizing countries into financial hubs with high value, such as Switzerland, carbon-locked exporters like Brunei, and water-stressed regions, including Cambodia. Despite absorbing substantial embodied environmental burdens, China maintained its position as the global value hub. These insights underscore the urgency of policies that enhance structural efficiency, decarbonize the power sector, and foster supply chain diversification to decouple economic value from environmental pressures while mitigating spatial inequalities.

Rapid urbanization and climate change have intensified environmental pressures and social inequalities, making the integration of urban resilience and sustainable development a critical global challenge, with Nature-based Solutions (NbS) emerging as a promising pathway; however, the knowledge structure, collaboration patterns, and evolutionary trends of NbS research remain fragmented and insufficiently understood. This study conducts a comprehensive bibliometric analysis of 1261 publications from the Web of Science Core Collection (2005–2025), employing tools including VOSviewer 1.6.20, CiteSpace 6.4.R1, and Bibliometrix 4.1.3 to map publication trends, collaboration networks, knowledge bases, and thematic evolution. The results reveal a rapid expansion of NbS research since 2013, characterized by strong interdisciplinarity and a multicentric yet uneven geographical distribution dominated by China, the United States, and Europe. Four major research clusters are identified, encompassing policy governance, environmental benefits, ecosystem services, and social equity, reflecting a shift from ecological performance to integrated socio-ecological frameworks. Additionally, thematic evolution indicates growing emphasis on governance mechanisms, public health, and environmental justice. Overall, NbS research is transitioning toward a multi-scale, multi-objective, and governance-oriented paradigm. These findings highlight the need for strengthened international collaboration, standardized evaluation frameworks, and inclusive policy design to enhance the effectiveness and global applicability of NbS in advancing urban sustainable development.