Research on sulfur oxides and nitric oxides released from coal-fired flue gas and vehicle exhaust: a bibliometric analysis

Research status and prospect of purification technology of sulfur-containing odor gas

Catalytic purification of sulphur-containing malodorous gases has attracted wide attention because of its advantages of high purification efficiency, low energy consumption and lack of secondary pollution. The selection of efficient catalysts is the key to the problem, while the preparation and optimisation of catalysts depend on the analysis of experimental results and in-depth mechanistic analysis. By analysing the published literature, bibliometric analysis can identify existing research hotspots, the areas of interest and predict development trends, which can help to identify hot catalysts in the catalytic purification of sulphur-containing odours and to investigate their catalytic purification mechanisms. Therefore, this paper uses bibliometric analysis, based on Web Of Science and CNKI databases, CiteSpace and VOS viewer software to collate and analyse the literature on the purification of sulphur-containing odour pollutants, to identify the current research hotspots, to summarise the progress of research on the catalytic purification of different types of sulphur-containing odours, and to analyse their reaction mechanisms and kinetics. On this basis, the research progress of catalytic purification of different kinds of sulfur odour is summarized, and the reaction mechanism and dynamics are summarized.

A Bibliometric Analysis: Current Perspectives and Potential Trends of Enzyme Thermostability from 1991-2022

Thermostability is considered a crucial parameter to evaluate the viability of enzymes in industrial applications. Over the past 31 years, many studies have been reported on the thermostability of enzymes. However, there is no systematic bibliometric analysis of publications on the thermostability of enzymes. In this study, 16,035 publications related to the thermostability of enzymes were searched and collected, showing an increasing annual trend. China contributed the most publications, while the United States had the highest citation count. International Journal of Biological Macromolecules is the most productive journal in the research field. Moreover, Chinese acad sci and Khosro Khajeh are the most active institutions and prolific authors in the field, respectively. Analysis of references with the strongest citation bursts and keyword co-occurrences, magnetic nanoparticles, metal-organic frameworks, molecular dynamics, and rational design are current hot spots and significant future research directions. This study is the first comprehensive bibliometric analysis summarizing trends and developments in enzyme thermostability research. Our findings could provide scholars with an understanding of the fundamental knowledge framework of the field and identify recent potential hotspots and research trends that could facilitate the discovery of collaboration opportunities.

An overview of air pollution research in Chile: Bibliometric analysis and scoping review, challenger and future directions

This study provides a comprehensive overview and bibliometric analysis of air pollution research in Chile from 1980 to 2022. The analysis reveals a significant increase in scientific production, a 9.2 annual growth rate, and an H-index of 60. The research spans 33 countries and is influenced by environmental sciences, meteorology, and atmospheric sciences journals. The top ten authors account for 33.49 % of all publications, with local institutions contributing more than 35 %. The University of Chile and the Pontifical Catholic University of Chile are significant contributors. The most cited articles focus on health impacts and various pollutant sources, emphasizing air pollution as a critical public health concern. The study also emphasizes environmental science, meteorology, and atmospheric science, focusing on topics such as air pollution and health, pollutants, models, sources and chemistry, and social sciences. The findings are affirmed through rigorous discussion and review, providing a roadmap for future research, guiding decision-making processes, and expanding the knowledge frontier in the field.

Exploring the last 50 years of Indian research on the impact of coal mining using bibliometric analysis with an overview of water-related impacts

This paper throws light on the bibliometric review of the impact of coal mining in India over the past 50 years, emphasizing environmental, especially water-related impacts. The data were refined from the Web of Science database and analyzed in a bibliometric map visualization software tool, VOSviewer, to grasp the research focus, status quo and analyze the trend and direction of the work being carried out in this area. The methodology was covered in three phases: search and document selection, software and data extraction, and analysis of results and trends. The study results indicated that (i) the publication has increased in the past two decades (2001-2021) with a steep increase in the period from 2010 to 2021 with 74.68% article types documents and a mere 7.74% review documents. (ii) In India, the significant contribution is made by the Indian Institute of Technology (Indian School of Mines), Dhanbad with Department of Science and Technology as a primary funding agency. (iii) The bibliometric map of co-occurrence of author keywords showed that keywords relating to the "pollution" (connected to air, water) from "Jharia coalfield" have highest occurrences in the relevant published works of literature and topics like "reclamation," "mine spoil," and application of approaches like "remote sensing and GIS" have lower linkage strengths in general. (iv) The result of the co-citation network study has marked the most significant authors and the highly cited sources of the database revealing Ghose M.K. and Singh A.K. as among the most cited authors with citations more than 150 in the field of our interest. (v) The trend of publication in the research area of Water Resources showed a significant increase after 2015. The keyword occurrence map reveals that water quality studies have been extensively studied, but quantifications of the coal mining-induced changes in water regimes at river basin scales are absent.

Exposure and health: A progress update by evaluation and scientometric analysis

Several hands are now working worldwide to reduce exposure to air pollution, especially in developing nations. Future steps should be determined and classified as possible research solutions and gaps from the massive bulk of research output. Therefore, a scientometric approach has been applied using VOSviewer to show an accurate picture and trend in the mentioned area "Air pollution exposure and health," and its signify issues. According to the proposed study, complete 26,859 documents were retrieved from the database (ISI Web of Science) related to air pollution exposure and health effects during 2018-2022. The mapping analysis is been conducted on the country's collaboration, co-authorship, institutional collaboration, and co-occurrence of keywords. The data collected shows the information about published articles (upward trend) over the years. Based on the citations and publication database, countries like China and the USA play a prominent role in air pollution exposure and health-related research. The study clearly defines the 3 domains of research and 4 major themes that have been currently focused. The case studies related to pollution and its impact on climate and health, studies involving chemical characteristics and management practices, also Hazardous health effects, theme like association of air pollutants, chemical composition and characterization of aerosols, health impacts due to exposure and modelling and analytical approach have been the most researched topics in the past 5 years. The developing and developed countries might potentially change the research network and work structure in order to obtain advancement in the field of Air pollution and enhance measures on exposure and health. The following research attempts to provide insights to the researchers and health sectors by straightening out developments up to date and raveling the research gaps that are needed to be addressed regarding Air pollution health and exposure.

Exploring development and evolutionary trends in carbon offset research: a bibliometric perspective

This study proposes a bibliometric measure to visualize and analyze the research status and development trend of carbon offset based on 1,581 articles over the period 1900-2019. The main findings include (1) carbon offset research turned into a rapid growth after 2009; (2) environmental studies, environmental science, economics, and energy fuels are the top four research domains in publication; (3) Energy Policy, Ecological Economics and Science are the top three journals in terms of citation impact; (4) climate change, impact, emission, CO2 emission, and policy are shown to be the most frequently used keywords; (5) the top 10 cited articles cover the following five essential aspects: individual carbon offset behavior; forest and land carbon offset; transportation carbon offset; international trade carbon offset; and eco-system service-related carbon offset; (6) eight research hotspots were identified including forest carbon sequestration program, understanding carbon and uncertainty market, policy design, biomass development, Chinese province, increasing adoption, and ecosystem service commodification. These findings suggest that the carbon offset research has been evolved from the theoretical exploration at the early stage to a more diversified conversion of research outputs at the practical level in recent years. Interdisciplinary research towards individual and organizational carbon offset behaviors in a broader context of socio-economic development and cooperation among various agents is the emphasis and direction for future study.

Specification of complex-PAHs in coal fire sponges (CFS) by high-resolution mass spectrometry with electrospray ionization

Underground coal fires are considered an ecological disaster. While underground coal fires are prevalent in coal-producing areas throughout the world, they are most problematic in northern China. Previous studies have shown that underground coal fires stimulate the formation of cracks or gas outlets on the surface, as well as coal fire sponges (CFS) on the soil layer surface, which collect coal-fired pollutants. Herein, ultra-high-performance liquid chromatography (UHPLC) was used in conjunction with electrospray ionization (ESI) high-resolution mass spectrometry to analyze CFS samples collected from the No. 8 fire zone, located in Wuda coalfield, Inner Mongolia, China. The results show that CFS contain 233 oxy-substituted polycyclic aromatic hydrocarbons (O-PAHs), e.g., naphthaldehyde; 40 oxapolycyclic aromatic hydrocarbons (OPAHs), e.g., dibenzofuran; 40 alkyl-substituted polycyclic aromatic hydrocarbons (R-PAHs); and 11 parent polycyclic aromatic hydrocarbons (PPAHs). Thus, CFS are primarily composed of O-PAHs, which are 25 times and 5 times more prevalent than PPAHs and R-PAHs, respectively. As such, a high relative abundance of varied O-PAHs are discharged from underground coal fires, which is significantly different from what is released during industrial coal burning. Owing to their water solubility and condensability, the new facts disclosed in this paper may provide a new perspective for understanding complex organic pollutants from underground coal fires and their environmental impacts.

Adaptive monostable stochastic resonance for processing UV absorption spectrum of nitric oxide

When ultraviolet (UV) absorption spectroscopy technology is used for nitric oxide (NO) detection, the background noise will directly affect the accuracy of concentration inversion, especially in low concentrations. Traditional processing methods attempt to eliminate background noise, which damages the absorption spectrum characteristics. However, stochastic resonance (SR) can utilize the noise to extract a weak characteristic signal. This paper reports a monostable stochastic resonance (MSR) model for processing an UV NO absorption spectrum. By analyzing the characteristics of UV absorption spectrum of NO, the evaluation indexes were constructed, thereby an adaptive MSR method was designed for parameter optimization. The numerical simulation confirmed the absorbance peak can be amplified and spectral signal-to-noise ratio (SNR) can be in the stable range of the proposed method, when noise intensity increased. Finally, this experiment obtained a NO detection limit (3σ) of 1.456 ppm and the maximum relative deviation of concentration is 6.32% by this proposed method, which is satisfactory for processing of the UV NO absorption spectrum.