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Global characteristics and trends of research on industrial structure and carbon emissions: a bibliometric analysis
2020
Sun, Liwen | Wu, Linfei | Qi, Peixiao
The relationship between industrial structure and carbon emissions has been widely identified as a critical research topic by international organizations and academics. Using bibliometrics analysis, this study aimed at dissecting the global characteristics and trends of research on industrial structure and carbon emissions. Based on the 806 documents from 2004 to 2019 in Web of Science, this work was implemented from four aspects, including basic characteristics analysis, country/territory and institution analysis, category and journal analysis, and reference and keyword analysis. The results of this study showed rapid growth trends of research on industrial structure and carbon emissions from 2015 to 2019. The collaborations among countries and institutions were extensive worldwide with China, the USA, and the UK as the main participants. Furthermore, the corresponding research topics, research priorities, and research paths were summarized according to the references co-citation analysis and keywords cluster analysis, which from the perspective of the correlation between different types of industry with carbon emissions. Finally, the timezone view of the top 100 keywords indicated that the emerging trends in the research on industrial structure and carbon emissions were regional analysis, industrialization, and environmental efficiency, and prediction of carbon emissions peak and the spatial distribution in different types of industries were the hotspots in recent years. The findings provide a better understanding of global characteristics and trends that have emerged in this field, which can also offer reference for future research.
Показать больше [+] Меньше [-]Geochemical Characteristics and Influencing Factors of Groundwater Fe in Seawater Intrusion Area
2020
Wang, Hongmei | Chen, Qiao | Wei, Jiuchuan | Ji, Yuhan
To reveal the influencing process and mechanism of seawater intrusion on groundwater Fe in coastal zones, the local groundwater in Buzhuang Town, together with those in the neighboring area where no seawater intruded, was sampled and comparatively analyzed, and the static simulation experiments were also performed in laboratory. The local groundwater has Fe levels of 6.09–196.96 μg/L, with an average of 73.38 μg/L, but groundwater Fe levels from the neighboring area are 1.3–17.7 times of those in local groundwater. Such facts indicate the groundwater Fe levels decreased due to seawater intrusion. The groundwater Fe levels are significantly negatively correlated with pH, significantly positively correlated with Ca²⁺, Mg²⁺, and positively correlated with SO₄²⁻. The simulation experiments indicate leached Fe increases with a greater mixture of seawater, increasing concentrations of NaCl and CaCl₂, but decreases with increasing NaHCO₃ concentrations. Fe(OH)₂ and Fe(OH)₃ minerals are super-saturated because of the high pH and high OH⁻ concentration resulting from seawater intrusion. By this way, the dissolving ability of groundwater Fe is restricted. Therefore, pH is the key factor determining groundwater Fe levels in coastal zones. Another, the decreasing of Ca²⁺, Mg²⁺ in groundwater decreases Fe levels because of the co-precipitation and deactivation of groundwater Fe. Salt effect and NaHCO₃ contribute less to groundwater Fe levels because of the restriction of maximum Fe solubility by high OH⁻ and super-saturation of Fe-bearing minerals. The influencing model of groundwater Fe levels under the effect of seawater intrusion is forwarded.
Показать больше [+] Меньше [-]Natural and Human Factors Affect the Distribution of Soil Heavy Metal Pollution: a Review
2020
Zhang, Qiaochu | Wang, Chengchen
Summarized the heavy metal pollution caused by natural and human activities. The natural causes include the migration and redistribution of soil debris and the hydraulic migration of soil parent rock with high background value under the action of wind; human factors include mining, abandoned mining areas, fertilizer and pesticide application, and sewage irrigation. By examining the sources of heavy metals in soil, the temporal and spatial variation and source variation of heavy metal pollution can be summarized, and then find a reasonable way to intervene as early as possible from the origin to reduce the harm of this pollution to the soil. Finally, future research trends and key problems were indicated, which laid a theoretical foundation for further effective research. Graphical abstract
Показать больше [+] Меньше [-]Adsorption and Desorption Characteristics of Vanadium (V) on Coexisting Humic Acid and Silica
2020
Song, Qiao-yu | Liu, Meng | Lu, Juan | Liao, Yu-liang | Chen, Li | Yang, Jin-yan
Vanadium (V) has been progressively studied due to its potential toxicity in the environment as a trace metal. A coexistence system of humic acid (HA) and silica was employed to simulate the main organic and inorganic components of soil. The adsorption and desorption characteristics of V by the system and the effects of several environmental conditions were investigated. The adsorption data were well described by the Langmuir and Freundlich models, illustrating that the adsorption of V on HA + silica was a monolayer adsorption. The kinetic study indicated that the main adsorption controlling step was a chemical reaction. The thermodynamic study showed that the adsorption was exothermic and spontaneous. The adsorption-desorption process was strongly dependent on the solution pH and HA concentration, while temperature (4–75 °C) and ionic strength (< 1 mol L⁻¹) showed limited effect on overall adsorption performances. In general, the results revealed a considerable V fixation ability of HA-silica coexistence system. The mobility and bioavailability of V in soil was effectively reduced by coexisting HA and silica.
Показать больше [+] Меньше [-]Trends in the management of waste tyres and recent experimental approaches in the analysis of polycyclic aromatic hydrocarbons (PAHs) from rubber crumbs
2020
Sibeko, Motshabi Alinah | Adeniji, Abiodun Olagoke | Okoh, Omobola Oluranti | Hlangothi, Shanganyane Percy
The health and environmental consciousness of waste tires has increased tremendously over the years. This has motivated efforts to develop secondary applications that will utilize tire when they reach the end of their life cycle and limit their disposal in landfills. Among the applications of waste tires which are discussed in this review, the use of rubber crumbs in artificial turf fields has gained worldwide attention and is increasing annually. However, there are serious concerns regarding chemicals that are used in the manufacturing process of tires, which ultimately end up in rubber crumbs. Chemicals such as polycyclic aromatic hydrocarbons (PAH) and heavy metals which are found in rubber crumbs have been identified as harmful to human health and the environment. This review paper is intended to highlight some of the methods which have been used to manage waste tire; it also looks at chemicals/materials used in tire compounding which are identified as possible carcinogenic.
Показать больше [+] Меньше [-]Ecological risk assessment of arsenic, cadmium, copper, and lead contamination in soil in e-waste separating household area, Buriram province, Thailand
2020
Amphalop, Nisakorn | Suwantarat, Natcha | Prueksasit, Tassanee | Yachusri, Chokchai | Srithongouthai, Sarawut
This study aimed to determine the arsenic (As), copper (Cu), cadmium (Cd), and lead (Pb) concentrations in the soil at e-waste separating houses in Buriram province. Soil samples were collected from five e-waste separating and five non-separating houses in each of two neighboring communities and from six reference houses located approximately 4 km away from the e-waste community. At each selected house, the surface (0–15-cm depth) and the subsurface (15–30-cm depths) soils were taken to be digested by a microwave digester and then analyzed for the heavy metal contents by atomic absorption spectrophotometry. The As, Pb, and Cd levels in the e-waste separating sites ranged from < 0.012 to 1.380, 0.110 to 15.283, and < 0.014 to 0.284 mg/kg, respectively, which were not in excess of the Thai standard level for residential soil (As = 3.9, Pb = 400, and Cd = 37 mg/kg), while Cu ranged from 1.180 to 380.413 mg/kg and exceeded the intervention value (190 mg/kg) of contaminated soil at three sites from a total of ten sampling sites. The physical e-waste dismantling activity enhanced the As, Cd, and Cu contamination levels in the surface soils. Ecological risk assessment revealed that the risk posed by the heavy metals in soils was higher at the e-waste separating houses than those at the non-separating sites and was mainly attributed to the levels of Cu > As > Cd > Pb for the surface soils and Cd > Cu > As > Pb for the subsurface soil. The association of the heavy metal soil levels with e-waste activity showed that if the e-waste activities were continuously operated, the As and Cu levels in the surface soil were more likely to exceed those levels in the reference houses. A good procedure for e-waste dismantling is necessary to be developed and implemented to prevent soil contamination and other related environmental problems.
Показать больше [+] Меньше [-]A Bibliometric Description of Lignin Applicability for the Removal of Chemical Pollutants in Effluents
2020
Teles, Maria Nazaré Oliveira | Santos, Brenda Lohanny Passos | Silva, Daniel Pereira | Teixeira, José António | Ruzene, Denise Santos
Several industrial sectors produce tons of effluents daily containing a high amount of hazardous chemical pollutants that pose a major threat to the environment and human health. Current wastewater treatment methods, such as flocculation and activated carbon adsorption, have drawbacks linked to high material cost and too much energy consumption. Thus, the search for renewable, biodegradable, and efficient materials has been the object of research aimed at replacing the conventional materials used to cheapen processes and reduce environmental impacts. Lignin stands out in this context as it has low cost and high availability. Therefore, several scientific researches were developed to harness the potential of lignin, especially as adsorbent, for the removal of chemical agents from effluents. This paper presents a bibliometric review performed on the Scopus database, showing the evolution of studies related to the applicability of lignin in the removal of chemical pollutants in waters over the last five years. Data regarding annual publications, languages, journals, countries, institutions, keywords, and subjects were analyzed. The realized screening selected 130 articles that met the previously defined criteria. Results indicated a strong collaboration between countries and China’s substantial contribution to the documents. The analysis also has shown that lignin is mainly used as adsorbent material, sorbent, flocculant agent, and hydrogel and presents important results and information for future researchers on this topic.
Показать больше [+] Меньше [-]Tidal groundwater flow and its potential effect on the hydrochemical characteristics in a mud-sand-layered aquifer in Daya Bay, China
2020
Feng, Xiaobo | Xiao, Kai | Li, Hailong
Tidal groundwater dynamics and hydrochemistry can play important roles in influencing nearshore ecological and environmental systems. However, the potential relationship between the groundwater dynamics and the hydrochemical characteristics was not well understood. In this study, we conducted an integrated investigation by field work and numerical simulations to explore the potential effect of tidal groundwater dynamics on hydrochemistry in an intertidal mudflat in Daya Bay, China. The time series of groundwater level were monitored over a spring-neap tidal cycle along a 200-m-long intertidal transect, which had a mud-sand-layered aquifer. The shallow groundwater samples were collected to analyze the spatial distributions of hydrochemical characteristics, including major ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄²⁻, HCO₃⁻, and Cl⁻), heavy metals (As and Cu), and short-lived radium isotopes (²²³Ra and ²²⁴Ra). The groundwater transport process along the transect was simulated for understanding the groundwater flow field and quantifying the groundwater-seawater exchange rates across the water-sediment interface. The integrated results indicated that the seawater-groundwater interactions play a great influence on the groundwater hydrochemistry. For example, the major ions showed various degrees of enrichment and loss, such as losses of SO₄²⁻ due to microbial sulfate reduction, and enrichment of HCO₃⁻, Ca²⁺, and Mg²⁺ under the water-rock interactions. Heavy metals were transported by groundwater and accumulated in the intertidal sediments. In addition, there was a negative correlation between short-lived radium isotope activities and oxidation-reduction potential. However, the relationship between seawater-groundwater exchange rates and the short-lived radium isotope activities was not significant.
Показать больше [+] Меньше [-]Changes in dissolved inorganic carbon in river water due to urbanization revealed by hydrochemistry and carbon isotope in the Pearl River Delta, China
2020
Xuan, Yingxue | Cao, Yingjie | Tang, Changyuan | Li, Miao
Under natural conditions, the dissolved inorganic carbon (DIC) in river water is dominantly derived from carbonate or silicate dissolution by carbonic acid. However, sulfuric and nitric acids produced by human activities provide additional acidity for chemical weathering, which would affect the DIC flux and change its isotopic composition. To identify the natural and anthropogenic impacts on DIC, the major ion concentrations and stable carbon isotopes of the DIC (δ¹³C-DIC) of river waters were measured in the Pearl River Delta (PRD) region, which is one of the most developed and populated areas in China. The mass balance calculations for DIC-apportionment showed that carbonate dissolution by carbonic acid was the dominant origin of DIC in the Beijiang (BJ) River (67%) and Xijiang (XJ) River (78%) and silicate dissolution by carbonic acid was the dominant origin of DIC in the Guangzhou (GZ) Channel (37%) and Dongjiang (DJ) River (50%), which was related to the lithology of the catchment. The contribution of carbonate dissolution by sulfuric and nitric acids, which represented the contribution of human activities to the total DIC concentrations in river water, showed high proportions in the GZ Channel and DJ River, with averages of 42% and 34%, respectively, which were associated with a high degree of urbanization. Evidence of hydrochemical parameters and δ¹³C-DIC signatures indicated that human activities had impacts on the DIC pool. Carbonate dissolution by sulfuric and nitric acids caused by human activities changed DIC apportionments rather than the DIC flux, and this part of DIC would ultimately become a source of CO₂ to the atmosphere on the geological timescale and affects the CO₂ budget. An increase in nutrient concentration due to increased sewage discharge in the urbanized area could promote phytoplankton photosynthesis, which could change the DIC pool and increase the δ¹³C-DIC value. This study quantitatively highlights the influence of human activities on DIC apportionment in river water, suggesting that anthropogenic impacts should be seriously considered when evaluating the evolution of DIC.
Показать больше [+] Меньше [-]Induction of fetal abnormalities and genotoxicity by molybdenum nanoparticles in pregnant female mice and fetuses
2020
Mohamed, Hanan RH | El-Atawy, Radwa H. | Ghoneim, Ahmed M. | El-Ghor, Akmal A.
Increasing the uses of molybdenum (Mo) nanoparticles in a wide range of applications including food, industry, and medicine, resulted in increased human exposure and necessitated the study of their toxic effects. However, almost no studies are available on their genotoxic effects, especially on pregnant females and their fetuses. Therefore, this study was undertaken to estimate the possible induction of genotoxicity and fetal abnormalities, especially fetal malformations and skeletal abnormalities by Mo nanoparticle administration in mice. Oral administration of Mo nanoparticles resulted in significant decreases in the maternal body weight, the number and length of fetuses as well as skeletal abnormalities mainly less ossification and less chondrification. Administration of Mo nanoparticles also caused DNA damage induction which elevated the expression levels of p53, the vital gene in maintaining the genomic stability and cell differentiation in both maternal and fetus tissues. Similarly, the expression levels of E-Cad and N-Cad genes that control skeleton development have also been increased in the tissues of female mice administered Mo nanoparticles and their fetuses. Thus, we concluded that oral administration of Mo nanoparticles induced genotoxic effects and fetal abnormalities that necessitated further studies on the possible toxic effects of Mo nanoparticles.
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