Despite the economic importance of farmed shrimp, a number of technical, environmental, economic and social problems have been widely reported in the international literature. This paper focuses on the environmental a...Despite the economic importance of farmed shrimp, a number of technical, environmental, economic and social problems have been widely reported in the international literature. This paper focuses on the environmental and socio-economic impacts of semi-intensive and intensive shrimp farming in the coastal region of Northeastern Brazil and the identification of options for sustainable production. In this Region, the total area dedicated to shrimp farming is approximately 18,500 ha, of which 5750 ha are located in Ceará State. The estuary of Jaguaribe river has the largest number of shrimp farms in the state of Ceará. Currently, the industry has 64 participating farms with a total area dedicated to shrimp farming of 2411.3 ha. In 2011, the total production was 13,110 tons of shrimp with an average yield of 6330 kg ha1.year-1 in a pond area of 2071.2 ha. This industry employs 2350 people that represent 23.2% of jobs generated in the two municipalities where the Jaguaribe river estuary is inserted. Compared with other countries, Brazil has reduced its exports due to high cost inputs for shrimp farming. However, the Brazilian shrimp industry has benefited from high domestic prices, despite the decreases in international price of shrimp. In 2011, the prices for size category ranged between U$ 4.67 - 6.04 for 80/100 (count of head-on shrimp), U$ 4.95 - 6.60 for 70/80 and U$ 5.展开更多
Starting from the historical evolution of China s regional coordinated development policy and practice,three stages of"enlightenment stage","development stage"and"maturity stage",as well ...Starting from the historical evolution of China s regional coordinated development policy and practice,three stages of"enlightenment stage","development stage"and"maturity stage",as well as the connotation,characteristics and content of implementing regional coordinated development strategy were analyzed.On this basis,from different aspects of industrial distribution,pollutant characteristics and regional environmental protection policy,the existing ecological and environmental protection problems in China s regional coordinated development in the new era were analyzed,and some suggestions for the next step were put forward.It is necessary to follow the"four ones"concept from the overall point of view,implement"three lines and one list"from the perspective of the width of the access red line,strengthen"joint prevention and control"from the perspective of the depth of regional regulation,deepen the"planning environmental impact assessment"from the perspective of the breadth of industrial distribution,and promote the"green-way model"from the perspective of ecological low carbon.展开更多
At the present stage, China's overall industrial structure is undergoing adjustment and improvement. Therefore, the concept of ecological green development has gradually stepped into people's vision. At presen...At the present stage, China's overall industrial structure is undergoing adjustment and improvement. Therefore, the concept of ecological green development has gradually stepped into people's vision. At present, people have begun to pay attention to environmental protection in the development process of chemical industry and construction industry in our country. However, some chemical enterprises still have serious environmental pollution problems, which directly affect the overall quality of economic development, thus bringing a new direction to the future development of environmental advisory services. Therefore, this paper analyzes the relevant definition and advantages of environmental advisory services in our country, and analyzes the problems existing in the development process of environmental advisory services in our country at this stage, and puts forward the corresponding countermeasures, hoping to truly promote the environment and make the future development of advisory services more long-term.展开更多
The buffer zone of a World Natural Heritage Site constitutes a critical element of the heritage site protection system.It not only functions as an ecological security barrier,but also significantly influences the visu...The buffer zone of a World Natural Heritage Site constitutes a critical element of the heritage site protection system.It not only functions as an ecological security barrier,but also significantly influences the visual integrity and aesthetic value of the core area’s landscape.Given the rapid development of transportation infrastructure,particularly the growing number of high-speed railways traversing ecologically sensitive regions,the scientific assessment of their impact on the landscape environment of heritage sites has emerged as a pivotal concern in heritage conservation and regional development.This study focused on the section of the Guiyang-Nanning High-Speed Railway that traverses the buffer zone of the Libo World Natural Heritage Site in Guizhou Province.Beginning with five primary indicators,including natural landscape and aesthetic value,geological geomorphology and Earth history value,biodiversity value,integrity and protection management,and impact on ecological environment,a visual landscape impact assessment system for high-speed railways was developed based on the analytic hierarchy process(AHP)and the fuzzy comprehensive evaluation method(FCE).Through expert scoring,hierarchical weight calculation,and fuzzy membership degree analysis,a comprehensive assessment was conducted on the landscape ecological quality,visual coordination,and aesthetic perception within the buffer zone following the construction of high-speed railways.The findings indicate that the construction of the Guiyang-Nanning High-Speed Railway generally harmonizes well with the landscape environment of the heritage site.The level of visual disturbance remains within an acceptable range and has not significantly damaged the overall aesthetic value or authenticity of the heritage site.Although the integrity of the landscape in certain local areas has experienced a slight decline due to the exposure of bridge and slope structures,the adverse effects have been effectively mitigated through engineering interventions such as vegetation restoration and color coordination.This study innovatively integrates the AHP with fuzzy mathematics methods to achieve a comprehensive evaluation that combines both qualitative and quantitative approaches.This integration provides a scientifically grounded analytical path and a practical technical framework for assessing the visual impact of linear infrastructure projects,such as high-speed railways,within the buffer zones of World Heritage Sites.The findings offer valuable insights for the protection of landscapes and the sustainable development of infrastructure in heritage sites.展开更多
Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we fir...Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we first examined PHCZs levels and profiles in sediment,lotus,and fish fromthe Ya-Er Lake(China)that has been under the influence of an obsolete chlor-alkali facility for forty years and discovered substantial PHCZs contamination.Among the PHCZs determined,3,6-dichlorocarbazole(36-CCZ)and 3-chlorocarbazole(3-CCZ)were the most frequently detected.Sediments frombackfilled land exhibited ∑_(11)PHCZs at median concentration of 973 ng/g(dry weight),suggesting the chlor-alkali industry as an important source.Even after 20 years of dredging treatment,the concentration of ∑_(11)PHCZs in the sediment of the oxidation ponds(median=41.1 ng/g)remained substantially higher than in other areas globally.Furthermore,the concentration of ∑_(11)PHCZs was found to be higher in surface sediments(median)at 66.7 ng/g if compared to middle(14.1 ng/g)and lower layers(18.2 ng/g),indicating the potential availability of PHCZs from surface sediments to aquatic plants and animals.Notably,this study detected PHCZs in both fish(26.3 ng/g lipid weight)and lotus(14.5 ng/g dry weight),with significant enrichment of 3-monobromocarbazole(3-BCZ)observed in both lotus root systems(bio-soil accumulation factor,BSAF_(root)=5.04)and fish muscle(BSAF_(fish)=3.04).展开更多
Approximately 40% of USA coal originates in an ecologically sensitive area of semi-arid shortgrass prairie in Wyoming. Before a surface coal mine can begin operation in the USA, it must secure a mining permit and comp...Approximately 40% of USA coal originates in an ecologically sensitive area of semi-arid shortgrass prairie in Wyoming. Before a surface coal mine can begin operation in the USA, it must secure a mining permit and comply with regulations and performance standards under the USA Surface Mining Control and Reclamation Act （SMCRA）, other federal environmental acts, and state programs. The Wyoming Department of Environmental Quality （WDEQ）/Land Quality Division （LQD） administers Wyoming＇s coal regulatory program. The permit application and bonding process for the largest surface coal mine permit in the USA, North Antelope Rochelle Mine （NARM） located in short grassland prairie in the northeast Wyoming, is discussed. The permit application process begins with the collection of baseline environ- mental data that characterizes premining conditions of the permit area. The permit application includes adjudication information, baseline information, mine and operation plans, and reclamation plans. Fulfillment of permit commitments and requirements of rules and regulations are inspected monthly by the LQD＇ s representative in the field. Before a mine permit is issued, the mine operator must submit a reclamation bond to secure the performance of reclamation obligations that is later revised annually. In Wyoming, four reclamation bond release phases indicate the completion of various stages of the reclamatikon process. NARM＇s specific bond release verification cirteria, performance standards, and field verificatoins of bond release phases are discussed. The Bond Release Geodatabase （a GIS/GPS approach） was developed for this mine to monitor progress in meeting criteria and performance standards for incremental bond release. The Bond Release Geodatabase significantly reduces the time needed to track bond release progress, reach agreement between operator and regulator, and improve the state inspector＇s ability to assess reclamation adequacy and progress.展开更多
ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we br...ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we briefly describe the ADMS dispersion models and give an overview of their use in China. And it describes in more detail the use of ADMS-Urban in Fushun in Liaoning province and in Jinan in Shangdong province respectively, for studies of urban air quality. Finally the conclusions are presented.展开更多
This paper makes comparisons between Chinese Environmental Impact Assessment (EIA) Guidelines for Air dispersion modelling and the advanced air dispersion model ADMS. Since 2001 the ADMS model has been the first and o...This paper makes comparisons between Chinese Environmental Impact Assessment (EIA) Guidelines for Air dispersion modelling and the advanced air dispersion model ADMS. Since 2001 the ADMS model has been the first and only foreign model that has been approved by the Appraisal Center for Environment and Engineering (ACEE) to be used in EIA projects in China (http://www.china-eia. com/inden_content/rjrz/ rjrz_ADMS/htm). In the paper the following sections provide brief descriptions of the main features of the Chinese Guidelines for Air Dispersion (Section 2) and ADMS (Section 3); Section 4 provides a comparison of the two modelling methods for some simple cases and conclusions and discussion are given in Section 5.展开更多
Greenhouse gases are known to play an important role in global warming.In this study,we determined the effects of selected soil and climate variables on nitrous oxide(N2O),methane(CH4),and carbon dioxide(CO2)emissions...Greenhouse gases are known to play an important role in global warming.In this study,we determined the effects of selected soil and climate variables on nitrous oxide(N2O),methane(CH4),and carbon dioxide(CO2)emissions from a tropical grassland fertilized with chicken slurry,swine slurry,cattle slurry,and cattle compost.Cumulative N2O emissions did not differ between treatments and varied from 29.26 to 32.85 mg N m^-2.Similarly,cumulative CH4 emissions were not significantly different among the treatments and ranged from 6.34 to 57.73 mg CH4 m^-2.Slurry and compost application induced CO2 emissions that were significantly different from those in the control treatment.The CH4 conversion factors measured were 0.21%,1.39%,4.39%,and 5.07%for cattle compost,chicken slurry,swine slurry,and cattle slurry,respectively,differing from the recommendations of the Intergovernmental Panel on Climate Change(IPCC).The fraction of added Nemitted as N2O was 0.39%,which was lower than the IPCC default value of 2%.Our findings suggest that N2O emissions could be mitigated by replacing synthetic fertilizer sources with either biofertilizer or compost.Our results indicate the following:N2O emission was mainly controlled by soil temperature,followed by soil moisture and then soil NH^"content;CH4 fluxes were mainly controlled by soil moisture and chamber headspace temperature;and CO2 fluxes were mainly controlled by chamber headspace temperature and soil moisture.展开更多
The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit ...The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit launched in a petrochemical plant was introduced and evaluated from both the practice and mechanism study. Practically, the PACT process showed excellent capability in pollutants removal, shock resistance, toxicity tolerance, and the COD and ammoniumN in effluent of PACT unit assisted by PAC was equal to 15.5 mg/L and 0.7 mg/L lower than that without PAC addition,respectively. The wet oxidation regeneration unit was quite efficient in supplying regenerated PAC, and, however, the hard calcium sulphate scale and the high pollutant concentration solution needed to be carefully controlled. Moreover, although the carbon balance showed that the adsorption capability of regenerated PAC was negligible, the biological tests proved that the regenerated PAC increased microbe activity up to 17% more than pure activated sludge system, which was almost compatible with the fresh activated carbon.展开更多
Sustainable reclamation practices for large surface coal mines in USA semiarid environment contribute to the quality of the environmental on a long term basis where environmental resources are protected for future gen...Sustainable reclamation practices for large surface coal mines in USA semiarid environment contribute to the quality of the environmental on a long term basis where environmental resources are protected for future generation.Land,after reclamation,must be suitable for the previous use of greatest economic or social values to the community area.In the semiarid climate of USA,non-developed land is mainly utilized for crops,grazing,and wildlife.Completion of various stages of the reclamation processes includes verifcation and approval of reclamation criteria and performance standards created by state agencies.The sustainable reclamation practices were investigated at the USA’s largest surface coal mine of the semiarid environment in Wyoming.These practices include building post-mining topography to the approximate original contour and reestablish a stable hydrologic system to drain surface water.All available spoil material is backflled and graded to achieve the post-mining topography which closely resembles the pre-mining topography.No overburden material or other coal waste material is left in stockpiles at the mine.Detailed planning until the end of mining,the knowledge of available volumes of suitable backfll material and soil is necessary for sustainable management practices.Diverse and permanent vegetation capable of stabilizing soil surfaces and capable of self-regeneration is established.Sustainable management of the reclamation efort is achieved by enforcement processes developed by the state and federal agencies.Monthly inspections of mining and reclamation operations and reviews of annual reports submitted by the operator help determine if the reclamation processes are occurring according to the permit plan.展开更多
This paper provides a theoretical model to explain the causality between China's energy transition and capital deepening found by the empirical study.We prove that in the equilibrium,China's energy transition ...This paper provides a theoretical model to explain the causality between China's energy transition and capital deepening found by the empirical study.We prove that in the equilibrium,China's energy transition is endogenously determined by capital deepening due to the homogeneity of electricity and the monopolistic competition features of China's electricity market.Price effect,which is the effect of change in relative factor price,will affect energy transition only if the policy intervenes electricity price in terms of the primary sources from which it is generated.We propose that investment can promote energy transition by stimulating capital deepening which is biased to clean energy development.In this regard,our paper provides a new way of thinking for other developing countries to design an effective energy transition policy.展开更多
This study inventoried the floral diversity of a secondary forest in Tuba,Benguet,Philippines as affected by different intensities of human disturbance.This study is unique from other land use studies in Southeast Asi...This study inventoried the floral diversity of a secondary forest in Tuba,Benguet,Philippines as affected by different intensities of human disturbance.This study is unique from other land use studies in Southeast Asia in having conventional farms as the most disturbed land use while other sites have oil palm plantations.A total of 267 species belonging to 222 genera and 78 families was documented.Results showed that the level of human disturbance is the major factor affecting the floral diversity while the effect of elevation is secondary.The level of human disturbance is significantly associated with species richness,species composition,dominant species and biodiversity indices.Greater human disturbance,as in the case of conventional farms,results in lower species richness,predominantly weed composition,dominant weed species and lower biodiversity indices.On the other hand,lesser human disturbance(as in the case of secondary forest)leads to higher species richness,greater native species composition,dominance of indigenous species,and higher diversity indices.The most disturbed land use experienced the greatest loss of species richness,change in floristic composition and vegetation structure,as well as a shift from native to alien-dominated plant communities.These results showed that the effect of land use change is not limited to species richness but also to species composition,dominant species and biodiversity indices.Locally,the study is an important baseline data for biodiversity conservation of the Marcos Highway Watershed Forest Reserve.展开更多
Water resources of a country constitute one of its vital assets that significantly contribute to the socio-economic development and poverty eradication. However, this resource is unevenly distributed in both time and ...Water resources of a country constitute one of its vital assets that significantly contribute to the socio-economic development and poverty eradication. However, this resource is unevenly distributed in both time and space. The major source of water for these resources is direct rainfall, which is recently experiencing variability that threatens the distribution of resources and water availability in Uganda. The annual rainfall received in Uganda varies from 500 mm to 2800 mm, with an average of 1180 mm received in two main seasons. The spatial distribution of rainfall has resulted into a network of great rivers and lakes that possess big potential for development. These resources are being developed and depleted at a fast rate, a situation that requires assessment to establish present status of water resources in the country. The paper reviews the characteristics, availability, demand and importance of present day water resources in Uganda as well as describing the various issues, challenges and management of water resources of the country.展开更多
[Objective] The research aimed to study influence factors of phosphorus removal by chemical method in sewage treatment system. [ Method] In different reaction systems, removal effect of the phosphorus in sewage by dos...[Objective] The research aimed to study influence factors of phosphorus removal by chemical method in sewage treatment system. [ Method] In different reaction systems, removal effect of the phosphorus in sewage by dosing lime and influence of the constraint factor were stud- ied. [ Result] Lime precipitation method treating high-concentration phosphorus wastewater could not only decline cost of phosphorus removal by chemical method, but also reach better treatment effect under suitable stirring and precipitation conditions by controlling alkalinity and pH. Phosphor- us content of chemical sludge after treatment could reach 9% -12%, with higher recyclable value. E Conclusion] Lime method treating phosphorus- rich sewage was more economic than low-concentration phosphorus sewage, and had very great potential for recycling phosphorus.展开更多
The characteristics and distribution law of electromagnetic environment around substations with different levels of voltage were studied,and the main influencing factors were discussed. Meanwhile,a scheme for locating...The characteristics and distribution law of electromagnetic environment around substations with different levels of voltage were studied,and the main influencing factors were discussed. Meanwhile,a scheme for locating monitoring points suitable for an on-line monitoring system of electromagnetic environment was proposed.展开更多
Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysi...Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysical, geochemical, etc.) pattern. One such significant enigmatic feature is the preservation of extremely dense and heavy platinum group elements (PGEs): Pt, Pd, Rh, Ru, Ir, Os. Concentration of PGEs during this period could have taken place in two ways: 1) presence of particular matter capable of preserving PGEs near the earth's surface, 2) transportation of PGEs by magma flows from deep lithospheric (asthenospheric) layers (slabs) to the subsurface. Clearly, much of the dense and heavy PGEs did not sink through to the Earth’s mantle (core) at the time of the magma-ocean, and occur near Earth’s surface in abundances for formation of ore deposits with PGE concentrations found to be 2 - 3 orders of magnitude greater than those in their host media. Their enrichments are associated in numerous cases with such enigmatic phenomena as formation of anorthosites and anorthosite-bearing layered magmatic intrusions. PGE deposits and mineralization zones are also found in associations with chromitites, dunites and serpentinites. In this review, problems related to the initial concentration and preservation of PGEs, their association with anorthosites, and formation of layered intrusions are discussed in detail. The main aim of this article is analysis of the requirements—initial concentration and preservation of PGE and PGM (Platinum Group Minerals) during the early Earth evolution, as well as examination of the distribution behavior of some PGEs in different ore deposits and meteorites. It is supposed that meteoritic bombardment of Earth has played a significant role in formation of PGEs deposits. Some conclusions made in this article may be useful for developing and enhancing strategies of prospecting for PGEs deposits.展开更多
文摘Despite the economic importance of farmed shrimp, a number of technical, environmental, economic and social problems have been widely reported in the international literature. This paper focuses on the environmental and socio-economic impacts of semi-intensive and intensive shrimp farming in the coastal region of Northeastern Brazil and the identification of options for sustainable production. In this Region, the total area dedicated to shrimp farming is approximately 18,500 ha, of which 5750 ha are located in Ceará State. The estuary of Jaguaribe river has the largest number of shrimp farms in the state of Ceará. Currently, the industry has 64 participating farms with a total area dedicated to shrimp farming of 2411.3 ha. In 2011, the total production was 13,110 tons of shrimp with an average yield of 6330 kg ha1.year-1 in a pond area of 2071.2 ha. This industry employs 2350 people that represent 23.2% of jobs generated in the two municipalities where the Jaguaribe river estuary is inserted. Compared with other countries, Brazil has reduced its exports due to high cost inputs for shrimp farming. However, the Brazilian shrimp industry has benefited from high domestic prices, despite the decreases in international price of shrimp. In 2011, the prices for size category ranged between U$ 4.67 - 6.04 for 80/100 (count of head-on shrimp), U$ 4.95 - 6.60 for 70/80 and U$ 5.
基金Supported by Special Project for Prevention and Control of Air Pollution from Fixed Sources of Ministry of Ecology and Environment,China(2020A060).
文摘Starting from the historical evolution of China s regional coordinated development policy and practice,three stages of"enlightenment stage","development stage"and"maturity stage",as well as the connotation,characteristics and content of implementing regional coordinated development strategy were analyzed.On this basis,from different aspects of industrial distribution,pollutant characteristics and regional environmental protection policy,the existing ecological and environmental protection problems in China s regional coordinated development in the new era were analyzed,and some suggestions for the next step were put forward.It is necessary to follow the"four ones"concept from the overall point of view,implement"three lines and one list"from the perspective of the width of the access red line,strengthen"joint prevention and control"from the perspective of the depth of regional regulation,deepen the"planning environmental impact assessment"from the perspective of the breadth of industrial distribution,and promote the"green-way model"from the perspective of ecological low carbon.
文摘At the present stage, China's overall industrial structure is undergoing adjustment and improvement. Therefore, the concept of ecological green development has gradually stepped into people's vision. At present, people have begun to pay attention to environmental protection in the development process of chemical industry and construction industry in our country. However, some chemical enterprises still have serious environmental pollution problems, which directly affect the overall quality of economic development, thus bringing a new direction to the future development of environmental advisory services. Therefore, this paper analyzes the relevant definition and advantages of environmental advisory services in our country, and analyzes the problems existing in the development process of environmental advisory services in our country at this stage, and puts forward the corresponding countermeasures, hoping to truly promote the environment and make the future development of advisory services more long-term.
基金Sponsored by Guizhou Provincial Key Technology R&D Program“A Study on the Conservation Model with Technology and Sustainable Development Demonstration of the World Natural Heritages in Guizhou”(2202023 QKHZC)the China Overseas Expertise Introduction Project for Discipline Innovation(China 111 Project)(D17016).
文摘The buffer zone of a World Natural Heritage Site constitutes a critical element of the heritage site protection system.It not only functions as an ecological security barrier,but also significantly influences the visual integrity and aesthetic value of the core area’s landscape.Given the rapid development of transportation infrastructure,particularly the growing number of high-speed railways traversing ecologically sensitive regions,the scientific assessment of their impact on the landscape environment of heritage sites has emerged as a pivotal concern in heritage conservation and regional development.This study focused on the section of the Guiyang-Nanning High-Speed Railway that traverses the buffer zone of the Libo World Natural Heritage Site in Guizhou Province.Beginning with five primary indicators,including natural landscape and aesthetic value,geological geomorphology and Earth history value,biodiversity value,integrity and protection management,and impact on ecological environment,a visual landscape impact assessment system for high-speed railways was developed based on the analytic hierarchy process(AHP)and the fuzzy comprehensive evaluation method(FCE).Through expert scoring,hierarchical weight calculation,and fuzzy membership degree analysis,a comprehensive assessment was conducted on the landscape ecological quality,visual coordination,and aesthetic perception within the buffer zone following the construction of high-speed railways.The findings indicate that the construction of the Guiyang-Nanning High-Speed Railway generally harmonizes well with the landscape environment of the heritage site.The level of visual disturbance remains within an acceptable range and has not significantly damaged the overall aesthetic value or authenticity of the heritage site.Although the integrity of the landscape in certain local areas has experienced a slight decline due to the exposure of bridge and slope structures,the adverse effects have been effectively mitigated through engineering interventions such as vegetation restoration and color coordination.This study innovatively integrates the AHP with fuzzy mathematics methods to achieve a comprehensive evaluation that combines both qualitative and quantitative approaches.This integration provides a scientifically grounded analytical path and a practical technical framework for assessing the visual impact of linear infrastructure projects,such as high-speed railways,within the buffer zones of World Heritage Sites.The findings offer valuable insights for the protection of landscapes and the sustainable development of infrastructure in heritage sites.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750400)the National Natural Science Foundation of China(Nos.22076201,21936007 and 22376204).
文摘Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we first examined PHCZs levels and profiles in sediment,lotus,and fish fromthe Ya-Er Lake(China)that has been under the influence of an obsolete chlor-alkali facility for forty years and discovered substantial PHCZs contamination.Among the PHCZs determined,3,6-dichlorocarbazole(36-CCZ)and 3-chlorocarbazole(3-CCZ)were the most frequently detected.Sediments frombackfilled land exhibited ∑_(11)PHCZs at median concentration of 973 ng/g(dry weight),suggesting the chlor-alkali industry as an important source.Even after 20 years of dredging treatment,the concentration of ∑_(11)PHCZs in the sediment of the oxidation ponds(median=41.1 ng/g)remained substantially higher than in other areas globally.Furthermore,the concentration of ∑_(11)PHCZs was found to be higher in surface sediments(median)at 66.7 ng/g if compared to middle(14.1 ng/g)and lower layers(18.2 ng/g),indicating the potential availability of PHCZs from surface sediments to aquatic plants and animals.Notably,this study detected PHCZs in both fish(26.3 ng/g lipid weight)and lotus(14.5 ng/g dry weight),with significant enrichment of 3-monobromocarbazole(3-BCZ)observed in both lotus root systems(bio-soil accumulation factor,BSAF_(root)=5.04)and fish muscle(BSAF_(fish)=3.04).
文摘Approximately 40% of USA coal originates in an ecologically sensitive area of semi-arid shortgrass prairie in Wyoming. Before a surface coal mine can begin operation in the USA, it must secure a mining permit and comply with regulations and performance standards under the USA Surface Mining Control and Reclamation Act （SMCRA）, other federal environmental acts, and state programs. The Wyoming Department of Environmental Quality （WDEQ）/Land Quality Division （LQD） administers Wyoming＇s coal regulatory program. The permit application and bonding process for the largest surface coal mine permit in the USA, North Antelope Rochelle Mine （NARM） located in short grassland prairie in the northeast Wyoming, is discussed. The permit application process begins with the collection of baseline environ- mental data that characterizes premining conditions of the permit area. The permit application includes adjudication information, baseline information, mine and operation plans, and reclamation plans. Fulfillment of permit commitments and requirements of rules and regulations are inspected monthly by the LQD＇ s representative in the field. Before a mine permit is issued, the mine operator must submit a reclamation bond to secure the performance of reclamation obligations that is later revised annually. In Wyoming, four reclamation bond release phases indicate the completion of various stages of the reclamatikon process. NARM＇s specific bond release verification cirteria, performance standards, and field verificatoins of bond release phases are discussed. The Bond Release Geodatabase （a GIS/GPS approach） was developed for this mine to monitor progress in meeting criteria and performance standards for incremental bond release. The Bond Release Geodatabase significantly reduces the time needed to track bond release progress, reach agreement between operator and regulator, and improve the state inspector＇s ability to assess reclamation adequacy and progress.
文摘ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we briefly describe the ADMS dispersion models and give an overview of their use in China. And it describes in more detail the use of ADMS-Urban in Fushun in Liaoning province and in Jinan in Shangdong province respectively, for studies of urban air quality. Finally the conclusions are presented.
文摘This paper makes comparisons between Chinese Environmental Impact Assessment (EIA) Guidelines for Air dispersion modelling and the advanced air dispersion model ADMS. Since 2001 the ADMS model has been the first and only foreign model that has been approved by the Appraisal Center for Environment and Engineering (ACEE) to be used in EIA projects in China (http://www.china-eia. com/inden_content/rjrz/ rjrz_ADMS/htm). In the paper the following sections provide brief descriptions of the main features of the Chinese Guidelines for Air Dispersion (Section 2) and ADMS (Section 3); Section 4 provides a comparison of the two modelling methods for some simple cases and conclusions and discussion are given in Section 5.
基金This work was funded by the Sao Paulo Research Foundation(FAPESP),Brazil(Nos.2012/06718-8 and 2017/11274-5).
文摘Greenhouse gases are known to play an important role in global warming.In this study,we determined the effects of selected soil and climate variables on nitrous oxide(N2O),methane(CH4),and carbon dioxide(CO2)emissions from a tropical grassland fertilized with chicken slurry,swine slurry,cattle slurry,and cattle compost.Cumulative N2O emissions did not differ between treatments and varied from 29.26 to 32.85 mg N m^-2.Similarly,cumulative CH4 emissions were not significantly different among the treatments and ranged from 6.34 to 57.73 mg CH4 m^-2.Slurry and compost application induced CO2 emissions that were significantly different from those in the control treatment.The CH4 conversion factors measured were 0.21%,1.39%,4.39%,and 5.07%for cattle compost,chicken slurry,swine slurry,and cattle slurry,respectively,differing from the recommendations of the Intergovernmental Panel on Climate Change(IPCC).The fraction of added Nemitted as N2O was 0.39%,which was lower than the IPCC default value of 2%.Our findings suggest that N2O emissions could be mitigated by replacing synthetic fertilizer sources with either biofertilizer or compost.Our results indicate the following:N2O emission was mainly controlled by soil temperature,followed by soil moisture and then soil NH^"content;CH4 fluxes were mainly controlled by soil moisture and chamber headspace temperature;and CO2 fluxes were mainly controlled by chamber headspace temperature and soil moisture.
基金financially supported by SINOPEC (CLY15043)CRICC of ChemChina (2017-KZY03 and 2018-KZ-Y04)
文摘The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit launched in a petrochemical plant was introduced and evaluated from both the practice and mechanism study. Practically, the PACT process showed excellent capability in pollutants removal, shock resistance, toxicity tolerance, and the COD and ammoniumN in effluent of PACT unit assisted by PAC was equal to 15.5 mg/L and 0.7 mg/L lower than that without PAC addition,respectively. The wet oxidation regeneration unit was quite efficient in supplying regenerated PAC, and, however, the hard calcium sulphate scale and the high pollutant concentration solution needed to be carefully controlled. Moreover, although the carbon balance showed that the adsorption capability of regenerated PAC was negligible, the biological tests proved that the regenerated PAC increased microbe activity up to 17% more than pure activated sludge system, which was almost compatible with the fresh activated carbon.
文摘Sustainable reclamation practices for large surface coal mines in USA semiarid environment contribute to the quality of the environmental on a long term basis where environmental resources are protected for future generation.Land,after reclamation,must be suitable for the previous use of greatest economic or social values to the community area.In the semiarid climate of USA,non-developed land is mainly utilized for crops,grazing,and wildlife.Completion of various stages of the reclamation processes includes verifcation and approval of reclamation criteria and performance standards created by state agencies.The sustainable reclamation practices were investigated at the USA’s largest surface coal mine of the semiarid environment in Wyoming.These practices include building post-mining topography to the approximate original contour and reestablish a stable hydrologic system to drain surface water.All available spoil material is backflled and graded to achieve the post-mining topography which closely resembles the pre-mining topography.No overburden material or other coal waste material is left in stockpiles at the mine.Detailed planning until the end of mining,the knowledge of available volumes of suitable backfll material and soil is necessary for sustainable management practices.Diverse and permanent vegetation capable of stabilizing soil surfaces and capable of self-regeneration is established.Sustainable management of the reclamation efort is achieved by enforcement processes developed by the state and federal agencies.Monthly inspections of mining and reclamation operations and reviews of annual reports submitted by the operator help determine if the reclamation processes are occurring according to the permit plan.
文摘This paper provides a theoretical model to explain the causality between China's energy transition and capital deepening found by the empirical study.We prove that in the equilibrium,China's energy transition is endogenously determined by capital deepening due to the homogeneity of electricity and the monopolistic competition features of China's electricity market.Price effect,which is the effect of change in relative factor price,will affect energy transition only if the policy intervenes electricity price in terms of the primary sources from which it is generated.We propose that investment can promote energy transition by stimulating capital deepening which is biased to clean energy development.In this regard,our paper provides a new way of thinking for other developing countries to design an effective energy transition policy.
基金the funding support from Hedcor,Inc.,a subsidiary of Aboitiz Power that operates run-of-river scheme of electricity generation in the Philippines,as part of their environment protection programco-funded by SEARCA(Southeast Asian Regional Center for Graduate Study and Research in Agriculture)through the Seed Fund for Research and Training。
文摘This study inventoried the floral diversity of a secondary forest in Tuba,Benguet,Philippines as affected by different intensities of human disturbance.This study is unique from other land use studies in Southeast Asia in having conventional farms as the most disturbed land use while other sites have oil palm plantations.A total of 267 species belonging to 222 genera and 78 families was documented.Results showed that the level of human disturbance is the major factor affecting the floral diversity while the effect of elevation is secondary.The level of human disturbance is significantly associated with species richness,species composition,dominant species and biodiversity indices.Greater human disturbance,as in the case of conventional farms,results in lower species richness,predominantly weed composition,dominant weed species and lower biodiversity indices.On the other hand,lesser human disturbance(as in the case of secondary forest)leads to higher species richness,greater native species composition,dominance of indigenous species,and higher diversity indices.The most disturbed land use experienced the greatest loss of species richness,change in floristic composition and vegetation structure,as well as a shift from native to alien-dominated plant communities.These results showed that the effect of land use change is not limited to species richness but also to species composition,dominant species and biodiversity indices.Locally,the study is an important baseline data for biodiversity conservation of the Marcos Highway Watershed Forest Reserve.
文摘Water resources of a country constitute one of its vital assets that significantly contribute to the socio-economic development and poverty eradication. However, this resource is unevenly distributed in both time and space. The major source of water for these resources is direct rainfall, which is recently experiencing variability that threatens the distribution of resources and water availability in Uganda. The annual rainfall received in Uganda varies from 500 mm to 2800 mm, with an average of 1180 mm received in two main seasons. The spatial distribution of rainfall has resulted into a network of great rivers and lakes that possess big potential for development. These resources are being developed and depleted at a fast rate, a situation that requires assessment to establish present status of water resources in the country. The paper reviews the characteristics, availability, demand and importance of present day water resources in Uganda as well as describing the various issues, challenges and management of water resources of the country.
文摘[Objective] The research aimed to study influence factors of phosphorus removal by chemical method in sewage treatment system. [ Method] In different reaction systems, removal effect of the phosphorus in sewage by dosing lime and influence of the constraint factor were stud- ied. [ Result] Lime precipitation method treating high-concentration phosphorus wastewater could not only decline cost of phosphorus removal by chemical method, but also reach better treatment effect under suitable stirring and precipitation conditions by controlling alkalinity and pH. Phosphor- us content of chemical sludge after treatment could reach 9% -12%, with higher recyclable value. E Conclusion] Lime method treating phosphorus- rich sewage was more economic than low-concentration phosphorus sewage, and had very great potential for recycling phosphorus.
基金Supported by the Open Project of Jiangsu Key Laboratory of Environmental Engineering(ZX2017005)
文摘The characteristics and distribution law of electromagnetic environment around substations with different levels of voltage were studied,and the main influencing factors were discussed. Meanwhile,a scheme for locating monitoring points suitable for an on-line monitoring system of electromagnetic environment was proposed.
文摘Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysical, geochemical, etc.) pattern. One such significant enigmatic feature is the preservation of extremely dense and heavy platinum group elements (PGEs): Pt, Pd, Rh, Ru, Ir, Os. Concentration of PGEs during this period could have taken place in two ways: 1) presence of particular matter capable of preserving PGEs near the earth's surface, 2) transportation of PGEs by magma flows from deep lithospheric (asthenospheric) layers (slabs) to the subsurface. Clearly, much of the dense and heavy PGEs did not sink through to the Earth’s mantle (core) at the time of the magma-ocean, and occur near Earth’s surface in abundances for formation of ore deposits with PGE concentrations found to be 2 - 3 orders of magnitude greater than those in their host media. Their enrichments are associated in numerous cases with such enigmatic phenomena as formation of anorthosites and anorthosite-bearing layered magmatic intrusions. PGE deposits and mineralization zones are also found in associations with chromitites, dunites and serpentinites. In this review, problems related to the initial concentration and preservation of PGEs, their association with anorthosites, and formation of layered intrusions are discussed in detail. The main aim of this article is analysis of the requirements—initial concentration and preservation of PGE and PGM (Platinum Group Minerals) during the early Earth evolution, as well as examination of the distribution behavior of some PGEs in different ore deposits and meteorites. It is supposed that meteoritic bombardment of Earth has played a significant role in formation of PGEs deposits. Some conclusions made in this article may be useful for developing and enhancing strategies of prospecting for PGEs deposits.
