New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groun...New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groundwater through various industrial activities.Over the past four decades,researchers have consistently focused on the remediation of TCM-contaminated soil and groundwater using microorganisms and iron-based materials,which hold significant potential for practical application.Understanding the remediation process and the factors influencing TCM degradation through these two methods is crucial for advancing both theoretical research and practical implementation.This review focuses on the degradation mechanisms of TCM in soil and groundwater by microorganisms and iron-based materials.It summarizes the active microorganisms and modified iron-based materials with high TCM degradation capabilities,discusses enhancement measures for both methods in the remediation process,and finally,outlines the challenges faced by these methods.The goal is to provide theoretical references for efficient remediation of TCM-contaminated soil and groundwater.展开更多
Mass movements are very common problems in the eastern Black Sea region of Turkey due to its climate conditions, geological, and geomorphological characteristics. High slope angle, weathering, dense rainfalls, and ant...Mass movements are very common problems in the eastern Black Sea region of Turkey due to its climate conditions, geological, and geomorphological characteristics. High slope angle, weathering, dense rainfalls, and anthropogenic impacts are generally reported as the most important triggering factors in the region. Following the portal slope excavations in the entrance section of Cankurtaran tunnel, located in the region, where the highly weathered andesitic tuff crops out, a circular toe failure occurred. The main target of the present study is to investigate the causes and occurrence mechanism of this failure and to determine the feasible remedial measures against it using finite element method(FEM) in four stages. These stages are slope stability analyses for pre-and postexcavation cases, and remediation design assessments for slope and tunnel. The results of the FEM-SSR analyses indicated that the insufficient initial support design and weathering of the andesitic tuffs are the main factors that caused the portal failure. After installing a rock retaining wall with jet grout columns and reinforced slope benching applications, the factor of safety increased from 0.83 to 2.80. In addition toslope stability evaluation, the Rock Mass Rating(RMR), Rock Mass Quality(Q) and New Austrian Tunneling Method(NATM) systems were also utilized as empirical methods to characterize the tunnel ground and to determine the tunnel support design. The performance of the suggested empirical support design, induced stress distributions and deformations were analyzed by means of numerical modelling. Finally, it was concluded that the recommended stabilization technique was essential for the dynamic long-term stability and prevents the effects of failure. Additionally, the FEM method gives useful and reasonably reliable results in evaluating the stability of cut slopes and tunnels excavated both in continuous and discontinuous rock masses.展开更多
Nuclear power plants are designed with stringent safety measures to prevent accidents and radioactive releases.However,major accidents like the Three Mile Island(1979),Chornobyl(1986),and Fukushima Daiichi(2011)have s...Nuclear power plants are designed with stringent safety measures to prevent accidents and radioactive releases.However,major accidents like the Three Mile Island(1979),Chornobyl(1986),and Fukushima Daiichi(2011)have sig-nificantly impacted human health,the environment,and public perception of nuclear energy.Even during normal operation,nuclear power plants release effluents that can have some impact on the environment.These effluents are carefully monitored and regulated to minimize their environmental impact.Radioactive releases have potential long-term consequences for human health and the environment.To mitigate the risks of accidents and the environmental impact of normal operation,continued focus on nuclear safety,rigorous regulatory oversight,and improved emergency response measures are crucial.The behavior and impact of radionuclides in the environment,models and methods for simulating the transport and deposition of radio-nuclides in the atmosphere and ocean,toxicokinetic and toxicodynamic studies to predict the potential impacts of radionuclide releases and support risk management decisions,and environmental monitoring and control technology of nuclides,et al are discussed.The article aims to provide an overview of the importance of environmental toxicology in radioactive risk as-sessment and management,discuss the unique challenges associated with monitoring and remediating radioactive releases,and suggest future research directions.展开更多
The widespread occurrence of acidic soils presents a major challenge for agriculture,as it hampers productivity via a combination of mineral toxicity,nutrient deficiency,and poor water uptake.Conventional remediation ...The widespread occurrence of acidic soils presents a major challenge for agriculture,as it hampers productivity via a combination of mineral toxicity,nutrient deficiency,and poor water uptake.Conventional remediation methods,such as amending the soil with lime,magnesium,or calcium,are expensive and not environmentally friendly.The most effective method to mitigate soil acidity is the cultivation of acid-tolerant cultivars.The ability of plants to tolerate acidic soils varies significantly,and a key factor influencing this tolerance is aluminum(Al)toxicity.Therefore,understanding the physiological,molecular,and genetic underpinnings of Al tolerance is essential for the successful breeding of acid-tolerant crops.Different tolerance mechanisms are regulated by various genes and quantitative trait loci in various plant species,and molecular markers have been developed to facilitate gene cloning and to support marker-assisted selection for breeding Al-tolerant cultivars.This study provides a comprehensive review of the current developments in understanding the physiological and molecular mechanisms underlying Al resistance.Through the application of genome-wide association methods,it is expected that new Al-resistant genes can be identified and utilized to cultivate Al-resistant varieties through intercrossing,backcrossing,and molecular marker-assisted selection,promoting the sustainable use of acidic soils.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.42177239 and 41991330)the“14th Five Year Plan”of Independent Deployment Project of Nanjing Institute of Soil Research,Chinese Academy of Sciences(No.ISSASIP2213)。
文摘New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groundwater through various industrial activities.Over the past four decades,researchers have consistently focused on the remediation of TCM-contaminated soil and groundwater using microorganisms and iron-based materials,which hold significant potential for practical application.Understanding the remediation process and the factors influencing TCM degradation through these two methods is crucial for advancing both theoretical research and practical implementation.This review focuses on the degradation mechanisms of TCM in soil and groundwater by microorganisms and iron-based materials.It summarizes the active microorganisms and modified iron-based materials with high TCM degradation capabilities,discusses enhancement measures for both methods in the remediation process,and finally,outlines the challenges faced by these methods.The goal is to provide theoretical references for efficient remediation of TCM-contaminated soil and groundwater.
文摘Mass movements are very common problems in the eastern Black Sea region of Turkey due to its climate conditions, geological, and geomorphological characteristics. High slope angle, weathering, dense rainfalls, and anthropogenic impacts are generally reported as the most important triggering factors in the region. Following the portal slope excavations in the entrance section of Cankurtaran tunnel, located in the region, where the highly weathered andesitic tuff crops out, a circular toe failure occurred. The main target of the present study is to investigate the causes and occurrence mechanism of this failure and to determine the feasible remedial measures against it using finite element method(FEM) in four stages. These stages are slope stability analyses for pre-and postexcavation cases, and remediation design assessments for slope and tunnel. The results of the FEM-SSR analyses indicated that the insufficient initial support design and weathering of the andesitic tuffs are the main factors that caused the portal failure. After installing a rock retaining wall with jet grout columns and reinforced slope benching applications, the factor of safety increased from 0.83 to 2.80. In addition toslope stability evaluation, the Rock Mass Rating(RMR), Rock Mass Quality(Q) and New Austrian Tunneling Method(NATM) systems were also utilized as empirical methods to characterize the tunnel ground and to determine the tunnel support design. The performance of the suggested empirical support design, induced stress distributions and deformations were analyzed by means of numerical modelling. Finally, it was concluded that the recommended stabilization technique was essential for the dynamic long-term stability and prevents the effects of failure. Additionally, the FEM method gives useful and reasonably reliable results in evaluating the stability of cut slopes and tunnels excavated both in continuous and discontinuous rock masses.
基金supported by the National Natural Science Foundation of China(22125602,U2067215,22341601,and 22076078)the National Key R&D Program of China(2022YFC3701402)the Fundamental Research Funds for the Central Universities(021114380168).
文摘Nuclear power plants are designed with stringent safety measures to prevent accidents and radioactive releases.However,major accidents like the Three Mile Island(1979),Chornobyl(1986),and Fukushima Daiichi(2011)have sig-nificantly impacted human health,the environment,and public perception of nuclear energy.Even during normal operation,nuclear power plants release effluents that can have some impact on the environment.These effluents are carefully monitored and regulated to minimize their environmental impact.Radioactive releases have potential long-term consequences for human health and the environment.To mitigate the risks of accidents and the environmental impact of normal operation,continued focus on nuclear safety,rigorous regulatory oversight,and improved emergency response measures are crucial.The behavior and impact of radionuclides in the environment,models and methods for simulating the transport and deposition of radio-nuclides in the atmosphere and ocean,toxicokinetic and toxicodynamic studies to predict the potential impacts of radionuclide releases and support risk management decisions,and environmental monitoring and control technology of nuclides,et al are discussed.The article aims to provide an overview of the importance of environmental toxicology in radioactive risk as-sessment and management,discuss the unique challenges associated with monitoring and remediating radioactive releases,and suggest future research directions.
基金financially supported by the Key project of National Natural Science Foundation of China(42230711).
文摘The widespread occurrence of acidic soils presents a major challenge for agriculture,as it hampers productivity via a combination of mineral toxicity,nutrient deficiency,and poor water uptake.Conventional remediation methods,such as amending the soil with lime,magnesium,or calcium,are expensive and not environmentally friendly.The most effective method to mitigate soil acidity is the cultivation of acid-tolerant cultivars.The ability of plants to tolerate acidic soils varies significantly,and a key factor influencing this tolerance is aluminum(Al)toxicity.Therefore,understanding the physiological,molecular,and genetic underpinnings of Al tolerance is essential for the successful breeding of acid-tolerant crops.Different tolerance mechanisms are regulated by various genes and quantitative trait loci in various plant species,and molecular markers have been developed to facilitate gene cloning and to support marker-assisted selection for breeding Al-tolerant cultivars.This study provides a comprehensive review of the current developments in understanding the physiological and molecular mechanisms underlying Al resistance.Through the application of genome-wide association methods,it is expected that new Al-resistant genes can be identified and utilized to cultivate Al-resistant varieties through intercrossing,backcrossing,and molecular marker-assisted selection,promoting the sustainable use of acidic soils.
