The Bohai Sea(BS)is the unique semi-closed inland sea of China,characterized by degraded water quality due to significant terrestrial pollution input.In order to improve its water quality,a dedicated action named“Uph...The Bohai Sea(BS)is the unique semi-closed inland sea of China,characterized by degraded water quality due to significant terrestrial pollution input.In order to improve its water quality,a dedicated action named“Uphill Battles for Integrated Bohai Sea Management”(UBIBSM,2018–2020)was implemented by the Chinese government.To evaluate the action effectiveness toward water quality improvement,variability of the satelliteobserved water transparency(Secchi disk depth,Z_(SD))was explored,with special emphasis on the nearshore waters(within 20 km from the coastline)prone to terrestrial influence.(1)Compared to the status before the action began(2011–2017),majority(87.3%)of the nearshore waters turned clear during the action implementation period(2018–2020),characterized by the elevated Z_(SD)by 11.6%±12.1%.(2)Nevertheless,the improvement was not spatially uniform,with higher Z_(SD)improvement in provinces of Hebei,Liaoning,and Shandong(13.2%±16.5%,13.2%±11.6%,10.8%±10.2%,respectively)followed by Tianjin(6.2%±4.7%).(3)Bayesian trend analysis found the abrupt Z_(SD)improvement in April 2018,which coincided with the initiation of UBIBSM,implying the water quality response to pollution control.More importantly,the independent statistics of land-based pollutant discharge also indicated that the significant reduction of terrestrial pollutant input during the UBIBSM action was the main driver of observed Z_(SD)improvement.(4)Compared with previous pollution control actions in the BS,UBIBSM was found to be the most successful one during the past 20 years,in terms of transparency improvement over nearshore waters.The presented results proved the UBIBSM-achieved remarkable water quality improvement,taking the advantage of long-term consistent and objective data record from satellite ocean color observation.展开更多
On the basis of on-the-spot investigation, the causes of urban black-odor water bodies and the problems existing in the treatment are analyzed, and the control techniques and management countermeasures for black-odor ...On the basis of on-the-spot investigation, the causes of urban black-odor water bodies and the problems existing in the treatment are analyzed, and the control techniques and management countermeasures for black-odor water bodies were put forward. The countermeasures include: treating from both the roots and the symptoms and combining multiple technologies; comprehensively managing and improve the monitoring systems; coordinating functions and implementing long-term management; opening information and innovating supervision platform; coordinating advance and promoting the construction of sponge city; diversified financing to form the market-oriented model of water pollution control.展开更多
In recent years, water pollution has become increasingly serious in China. Meanwhile, decrease of water bodies in quality, frequent pollution incidents, safety of drinking water and water shortage have become prominen...In recent years, water pollution has become increasingly serious in China. Meanwhile, decrease of water bodies in quality, frequent pollution incidents, safety of drinking water and water shortage have become prominent day by day. However, water pollution can not be controlled effectively. To clear underlying reasons for increasingly worsening water environment, the external effects of pollution behavior and fictitious property right of pollution control bodies were analyzed using property right theory, and then internal reasons for serious water pollution were discussed. Fi- nally, control measures of water pollution were put forward.展开更多
Water pollution control planning for the Taizi River watershed,a typical Chinese case study,is presented in this paper. Based on comprehensive analysis.water quality in the watershed was assessed and predicated;water ...Water pollution control planning for the Taizi River watershed,a typical Chinese case study,is presented in this paper. Based on comprehensive analysis.water quality in the watershed was assessed and predicated;water quality models for the river and reservoir were built;and function of water bodies and environmental assimilative capacity were determined ;and then the planning for industrial pollution sources and concentrated sewage treatment were made respectively.展开更多
The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water enviro...The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water environment. The reuse of wastewater could not only reduce the discharge of pollutants,but it could also increase the consumption of eco-environmental water. Therefore the reuse of wastewater is an important approach to improve the water environmental quality. Combined with the formulation process of Regulations of Beijing on Prevention and Control of Water Pollution,the current situations of prevention and control of water pollution in Beijing,the discharge of pollutant,water environmental quality,the population and economic development and water resources and so on were analyzed. And the bottlenecks that restricted the improvement of water environmental quality were found. And the necessity of solving the control of water pollution by reusing the wastewater and ensuring the consumption of eco-environmental water was analyzed from the perspective of the control of water pollution. And some legislative countermeasures were put forward,which provided new ideas for solving the problem of the prevention and control of water pollution and improving the water environmental quality. It was of important reference values for local governments( especially water-deficient regions) to make relative polices or plans of water pollution control and water environmental protection.展开更多
Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and co...Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and coastal waters in China, then makes a comprehensive analysis on future trends of water pollution in China. The authors hold that the economic power, technology level and management level have determinative influences on the current status and future trends of water pollution. At last, this paper discusses briefly the policies and measures for preventing and controlling water pollution in the light of the national conditions.展开更多
For the evaluation of construction quality and the verification of the design of water conservancy and hydropower engineering projects, and especially for the control of dam safety operation behavior, safety monitorin...For the evaluation of construction quality and the verification of the design of water conservancy and hydropower engineering projects, and especially for the control of dam safety operation behavior, safety monitoring sensors are employed in a majority of engineering projects. These sensors are used to monitor the project during the dam construction and operation periods, and play an important role in reservoir safety operation and producing benefits. With the changing of operating environments and run-time of projects, there are some factors affecting the operation and management of projects, such as a certain amount of damaged sensors and instability of the measured data. Therefore, it is urgent to evaluate existing safety monitoring sensors in water conservancy and hydropower engineering projects. However, there are neither standards nor evaluation guidelines at present. Based on engineering practice, this study examined some key techniques for the evaluation of safety monitoring sensors, including the evaluation process of the safety monitoring system, on-site detection methods of two typical pieces of equipment, the differential resistor sensor and vibrating wire sensor, the on-site detection methods of communication cable faults, and a validity test of the sensor measured data. These key techniques were applied in the Xiaolangdi Water Control Project and Xiaoxi Hydropower Project. The results show that the measured data of a majority of sensors are reliable and reasonable, and can reasonably reflect the structural change behavior in the project operating process, indicating that the availabilities of the safety monitoring sensors of the two projects are high展开更多
To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were anal...To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were analyzed on the basis of analyzing the development and protection process of foreign water sources.The results show that for the comprehensive control of water sources,it is needed to pay attention to the accurate grasp of the current environmental quality of water sources and carefully analyze the problems in the ecological environment of water sources.Besides,it is necessary to ensure the water quality and quantity of sources,focus on the implementation of environmental remediation and ecological restoration,implement regional protection of water sources,and combine engineering and non-engineering measures to take comprehensive control of environmental problems.展开更多
We established a hydrodynamic model to simulate the pollutant transport and decay process in the case of a pollution incident in the sections of the Yangtze and the Jialing passing through the city area of Chongqing. ...We established a hydrodynamic model to simulate the pollutant transport and decay process in the case of a pollution incident in the sections of the Yangtze and the Jialing passing through the city area of Chongqing. The Boussinesq assumptions and the Navier-Stokes equations of incompressible fluid were applied to setting up the pollutant diffusion equations and the equations for the decay process. E. coli was taken as the example pollutant, and chloride dosage, light, temperature and ultraviolet intensity were considered in the equations for bacterial decay process. The calculated values of the fluid velocities in the two rivers agree well with corresponding measured results, indicating an ideal accuracy of the model. In simulation, the concentration of E. coli in water was assumed to be zero before the accident. The upriver boundary velocity was ?1.35 m/s for the Jialing flow and 1.75 m/s for the Yangtze flow, and the downriver boundary was water depth set at 0. Simulation results show that the bacteria are transported downstream along the riverbank. A long and narrow pollutant belt develops at 12 h after the start of the accident ascribed to the quick longitudinal transfer. After the pollution sources are cut off, the pollutant concentration decreases slowly, mostly by advection and diffusion, suggesting inadequate self-purification ability of the rivers and the necessity of effective decontaminating measures in the case of a pollution incident. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body of the Three Gorges Reservoir.展开更多
Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with comp...Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with complex terrain and variable climate,as the research subject.Based on Google Earth Engine,we used Landsat data and the Open-surface Water Detection Method with Enhanced Impurity Control method to monitor the spatiotemporal dynamics of surface water area in Gansu Province from 1985 to 2022,and quantitatively analyzed the main causes of regional differences in surface water area.The findings revealed that surface water area in Gansu Province expanded by 406.88 km2 from 1985 to 2022.Seasonal surface water area exhibited significant fluctuations,while permanent surface water area showed a steady increase.Notably,terrestrial water storage exhibited a trend of first decreasing and then increasing,correlated with the dynamics of surface water area.Climate change and human activities jointly affected surface hydrological processes,with the impact of climate change being slightly higher than that of human activities.Spatially,climate change affected the'source'of surface water to a greater extent,while human activities tended to affect the'destination'of surface water.Challenges of surface water resources faced by inland arid and semi-arid areas like Gansu Province are multifaceted.Therefore,we summarized the surface hydrology patterns typical in inland arid and semi-arid areas and tailored surface water'supply-demand'balance strategies.The study not only sheds light on the dynamics of surface water area in Gansu Province,but also offers valuable insights for ecological protection and surface water resource management in inland arid and semi-arid areas facing water scarcity.展开更多
Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electrom...Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators展开更多
In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed...In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.展开更多
The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment...The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment,and a lack of nonpoint pollution control.The problems of water pollution control at watershed level include a lack of thought and approach,developmental delay in the environmental standard system,an inadequate monitoring ability,and an inefficient implementation of laws and regulations.From 2006 to 2020,water pollution control and governance will be a national key specific project of science and technology in China.The strategies of this project include establishing a water pollution control system at watershed level,orienting a healthy aquatic ecosystem,conducting risk management,and using comprehensive methods.The goal is to establish and complete a technological system of pollution control and management in three five-year phases.The main tasks are to develop common technologies,management systems,and mechanisms for lake eutrophication control,river pollution control,urban water environmental pollution control,potable water safety,and water environmental management.The bottlenecks of water pollution control and management in China could be systematically removed,and the demonstration of the system engineering approach will be conducted at selected key watersheds.展开更多
Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their charac...Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their characteristics applicable for treatment and control of water eutrophication from the aspects of physics, chemistry, biochemistry and environmental factors regulation, and discusses the application and development trend for relevant technologies.展开更多
This paper elucidated the necessity and possibility of developing the technology of land treatment on the basis of the analysis of shortage and pollution status of water resources in China.The historical development o...This paper elucidated the necessity and possibility of developing the technology of land treatment on the basis of the analysis of shortage and pollution status of water resources in China.The historical development of this technology in the world was briefly reviewed and the distinction between land treatment and conventional wastewater irrigation was discussed in details. The fundamental characteristics and functions as well as the integrity and compatibility of this ecological engineering were also summarized. It was finally concluded that this technology for wastewater treatment has broad prospects of application in China.展开更多
On the background of analysis on region water environment safety in the Dongjiang Lake of south-central China, the source of pollution of water environment and its control are studied. The concept of region environmen...On the background of analysis on region water environment safety in the Dongjiang Lake of south-central China, the source of pollution of water environment and its control are studied. The concept of region environment disaster chain is put forward on the basis of combination study on the disaster chain theory and pollution problem in regional water environment. Through identification and analysis of pollution disaster resources in regional water environment of the Dongjiang Lake, the annual emission of the chemical oxygen demand (COD), ammonia nitrogen, total phosphorus (TP) and heavy metal (Cd, As, Pb) are counted. According to evaluation on structure proportion of contaminants in the Dongjiang Lake, agricultural non-point source is the uppermost pollution source, which accounted for 87.74% in total pollution load. Ammonia nitrogen, TP and COD are mainly contaminants accounted for 94.27% in total pollution load. By analyzing danger of contaminants in the lake, basic form of disaster chain of water environment pollution is built elementarily. It shows characteristics of branches and trunk basin disaster chain and embodies multisource disaster implication chain caused by human activities. Then, disaster resources chain-cutting methods for pollution prevention and control of regional water environment of the Dongjiang Lake are analyzed.展开更多
This study, with Hongdong Reservoir, is intended to evaluate the changes in water quality in the lake before and after rainfall in summer. Various non-point source pollutions are scattered around the reservoir, and to...This study, with Hongdong Reservoir, is intended to evaluate the changes in water quality in the lake before and after rainfall in summer. Various non-point source pollutions are scattered around the reservoir, and to determine the pollution level by pollution source, samples were taken at the same point before rainfall (1st), during rainfall (2nd) and after rainfall (3rd) and concentration was measured. Pollutant concentration curve at the measuring points (HDS1, HDS2, HDS3) appeared to be similar with the hydrological curve. When comparing the concentration immediately before rainfall with event mean concentration (EMC), SS and COD were 4 - 59 times and 1 - 4 times, respectively. However, when it comes to total nitrogen (T-N), concentration arrived at the reservoir stayed the range of 1.3 - 12.0 mg/L in all 3 cases without significant variation, which indicated that total nitrogen load is critical when arriving at the reservoir, irrespective of rainfall, and thus it’s necessary to consider non-point source pollution runoff also in addition to point source pollution when developing the water quality improvement measures in reservoir.展开更多
基金The fund supported by Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) under contract No. SML2021SP313the fundamental research funds for the Central Universities of Sun Yat-Sen University under contract No.23xkjc019the fund supported by China-Korea Joint Ocean Research Center of China under contract No. PI-2022-1-01
文摘The Bohai Sea(BS)is the unique semi-closed inland sea of China,characterized by degraded water quality due to significant terrestrial pollution input.In order to improve its water quality,a dedicated action named“Uphill Battles for Integrated Bohai Sea Management”(UBIBSM,2018–2020)was implemented by the Chinese government.To evaluate the action effectiveness toward water quality improvement,variability of the satelliteobserved water transparency(Secchi disk depth,Z_(SD))was explored,with special emphasis on the nearshore waters(within 20 km from the coastline)prone to terrestrial influence.(1)Compared to the status before the action began(2011–2017),majority(87.3%)of the nearshore waters turned clear during the action implementation period(2018–2020),characterized by the elevated Z_(SD)by 11.6%±12.1%.(2)Nevertheless,the improvement was not spatially uniform,with higher Z_(SD)improvement in provinces of Hebei,Liaoning,and Shandong(13.2%±16.5%,13.2%±11.6%,10.8%±10.2%,respectively)followed by Tianjin(6.2%±4.7%).(3)Bayesian trend analysis found the abrupt Z_(SD)improvement in April 2018,which coincided with the initiation of UBIBSM,implying the water quality response to pollution control.More importantly,the independent statistics of land-based pollutant discharge also indicated that the significant reduction of terrestrial pollutant input during the UBIBSM action was the main driver of observed Z_(SD)improvement.(4)Compared with previous pollution control actions in the BS,UBIBSM was found to be the most successful one during the past 20 years,in terms of transparency improvement over nearshore waters.The presented results proved the UBIBSM-achieved remarkable water quality improvement,taking the advantage of long-term consistent and objective data record from satellite ocean color observation.
基金supported by Jiangsu Qinglan Project of 2016Research Project of Jiangsu Provincial Party Committee titled "China democratic league: Regulation of malodorous black river and improvement of waterfront environment in city"Key Funding Project of Jiangsu Polytechnic College of Agriculture and Forestry (Grant No. 2016kj005)
文摘On the basis of on-the-spot investigation, the causes of urban black-odor water bodies and the problems existing in the treatment are analyzed, and the control techniques and management countermeasures for black-odor water bodies were put forward. The countermeasures include: treating from both the roots and the symptoms and combining multiple technologies; comprehensively managing and improve the monitoring systems; coordinating functions and implementing long-term management; opening information and innovating supervision platform; coordinating advance and promoting the construction of sponge city; diversified financing to form the market-oriented model of water pollution control.
文摘In recent years, water pollution has become increasingly serious in China. Meanwhile, decrease of water bodies in quality, frequent pollution incidents, safety of drinking water and water shortage have become prominent day by day. However, water pollution can not be controlled effectively. To clear underlying reasons for increasingly worsening water environment, the external effects of pollution behavior and fictitious property right of pollution control bodies were analyzed using property right theory, and then internal reasons for serious water pollution were discussed. Fi- nally, control measures of water pollution were put forward.
文摘Water pollution control planning for the Taizi River watershed,a typical Chinese case study,is presented in this paper. Based on comprehensive analysis.water quality in the watershed was assessed and predicated;water quality models for the river and reservoir were built;and function of water bodies and environmental assimilative capacity were determined ;and then the planning for industrial pollution sources and concentrated sewage treatment were made respectively.
文摘The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water environment. The reuse of wastewater could not only reduce the discharge of pollutants,but it could also increase the consumption of eco-environmental water. Therefore the reuse of wastewater is an important approach to improve the water environmental quality. Combined with the formulation process of Regulations of Beijing on Prevention and Control of Water Pollution,the current situations of prevention and control of water pollution in Beijing,the discharge of pollutant,water environmental quality,the population and economic development and water resources and so on were analyzed. And the bottlenecks that restricted the improvement of water environmental quality were found. And the necessity of solving the control of water pollution by reusing the wastewater and ensuring the consumption of eco-environmental water was analyzed from the perspective of the control of water pollution. And some legislative countermeasures were put forward,which provided new ideas for solving the problem of the prevention and control of water pollution and improving the water environmental quality. It was of important reference values for local governments( especially water-deficient regions) to make relative polices or plans of water pollution control and water environmental protection.
文摘Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and coastal waters in China, then makes a comprehensive analysis on future trends of water pollution in China. The authors hold that the economic power, technology level and management level have determinative influences on the current status and future trends of water pollution. At last, this paper discusses briefly the policies and measures for preventing and controlling water pollution in the light of the national conditions.
基金supported by the National Natural Science Foundation of China(Grants No.51179108and50909066)the Key Research Foundation of Nanjing Hydraulic Research Institute(Grant No.Y711007)
文摘For the evaluation of construction quality and the verification of the design of water conservancy and hydropower engineering projects, and especially for the control of dam safety operation behavior, safety monitoring sensors are employed in a majority of engineering projects. These sensors are used to monitor the project during the dam construction and operation periods, and play an important role in reservoir safety operation and producing benefits. With the changing of operating environments and run-time of projects, there are some factors affecting the operation and management of projects, such as a certain amount of damaged sensors and instability of the measured data. Therefore, it is urgent to evaluate existing safety monitoring sensors in water conservancy and hydropower engineering projects. However, there are neither standards nor evaluation guidelines at present. Based on engineering practice, this study examined some key techniques for the evaluation of safety monitoring sensors, including the evaluation process of the safety monitoring system, on-site detection methods of two typical pieces of equipment, the differential resistor sensor and vibrating wire sensor, the on-site detection methods of communication cable faults, and a validity test of the sensor measured data. These key techniques were applied in the Xiaolangdi Water Control Project and Xiaoxi Hydropower Project. The results show that the measured data of a majority of sensors are reliable and reasonable, and can reasonably reflect the structural change behavior in the project operating process, indicating that the availabilities of the safety monitoring sensors of the two projects are high
基金Supported by the Innovation and Entrepreneurship Training Program for College Students of Shaanxi Province in 2022(S202211396028)Innovation and Entrepreneurship Training Program for College Students of Shaanxi Province in 2021(S202111396068).
文摘To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were analyzed on the basis of analyzing the development and protection process of foreign water sources.The results show that for the comprehensive control of water sources,it is needed to pay attention to the accurate grasp of the current environmental quality of water sources and carefully analyze the problems in the ecological environment of water sources.Besides,it is necessary to ensure the water quality and quantity of sources,focus on the implementation of environmental remediation and ecological restoration,implement regional protection of water sources,and combine engineering and non-engineering measures to take comprehensive control of environmental problems.
基金Chongqing University Postgraduates’ Science and Innovation Fund (No.200701Y1B0270213)
文摘We established a hydrodynamic model to simulate the pollutant transport and decay process in the case of a pollution incident in the sections of the Yangtze and the Jialing passing through the city area of Chongqing. The Boussinesq assumptions and the Navier-Stokes equations of incompressible fluid were applied to setting up the pollutant diffusion equations and the equations for the decay process. E. coli was taken as the example pollutant, and chloride dosage, light, temperature and ultraviolet intensity were considered in the equations for bacterial decay process. The calculated values of the fluid velocities in the two rivers agree well with corresponding measured results, indicating an ideal accuracy of the model. In simulation, the concentration of E. coli in water was assumed to be zero before the accident. The upriver boundary velocity was ?1.35 m/s for the Jialing flow and 1.75 m/s for the Yangtze flow, and the downriver boundary was water depth set at 0. Simulation results show that the bacteria are transported downstream along the riverbank. A long and narrow pollutant belt develops at 12 h after the start of the accident ascribed to the quick longitudinal transfer. After the pollution sources are cut off, the pollutant concentration decreases slowly, mostly by advection and diffusion, suggesting inadequate self-purification ability of the rivers and the necessity of effective decontaminating measures in the case of a pollution incident. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body of the Three Gorges Reservoir.
基金This research was supported by the Third Xinjiang Scientific Expedition Program(2021xjkk010102)the National Natural Science Foundation of China(41261047,41761043)+1 种基金the Science and Technology Plan of Gansu Province,China(20YF3FA042)the Youth Teacher Scientific Capability Promoting Project of Northwest Normal University,Gansu Province,China(NWNU-LKQN-17-7).
文摘Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with complex terrain and variable climate,as the research subject.Based on Google Earth Engine,we used Landsat data and the Open-surface Water Detection Method with Enhanced Impurity Control method to monitor the spatiotemporal dynamics of surface water area in Gansu Province from 1985 to 2022,and quantitatively analyzed the main causes of regional differences in surface water area.The findings revealed that surface water area in Gansu Province expanded by 406.88 km2 from 1985 to 2022.Seasonal surface water area exhibited significant fluctuations,while permanent surface water area showed a steady increase.Notably,terrestrial water storage exhibited a trend of first decreasing and then increasing,correlated with the dynamics of surface water area.Climate change and human activities jointly affected surface hydrological processes,with the impact of climate change being slightly higher than that of human activities.Spatially,climate change affected the'source'of surface water to a greater extent,while human activities tended to affect the'destination'of surface water.Challenges of surface water resources faced by inland arid and semi-arid areas like Gansu Province are multifaceted.Therefore,we summarized the surface hydrology patterns typical in inland arid and semi-arid areas and tailored surface water'supply-demand'balance strategies.The study not only sheds light on the dynamics of surface water area in Gansu Province,but also offers valuable insights for ecological protection and surface water resource management in inland arid and semi-arid areas facing water scarcity.
文摘Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators
文摘In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.
基金the project of the National Key Specific Project of Science and Technology of China for“Water Pollution Control and Governance,”“Functional zoning of river basin water ecology and water quality target oriented management technology”(Grant No.2008ZX07526).
文摘The present water pollution situation at watershed level in China has been systematically analyzed.The causes of water pollution are attributed to the extensive economic developmental pattern,poor wastewater treatment,and a lack of nonpoint pollution control.The problems of water pollution control at watershed level include a lack of thought and approach,developmental delay in the environmental standard system,an inadequate monitoring ability,and an inefficient implementation of laws and regulations.From 2006 to 2020,water pollution control and governance will be a national key specific project of science and technology in China.The strategies of this project include establishing a water pollution control system at watershed level,orienting a healthy aquatic ecosystem,conducting risk management,and using comprehensive methods.The goal is to establish and complete a technological system of pollution control and management in three five-year phases.The main tasks are to develop common technologies,management systems,and mechanisms for lake eutrophication control,river pollution control,urban water environmental pollution control,potable water safety,and water environmental management.The bottlenecks of water pollution control and management in China could be systematically removed,and the demonstration of the system engineering approach will be conducted at selected key watersheds.
基金Supported by the Project for Commission of Science and Technology of Chaoyang District in Beijing Municipality(KC1105)
文摘Eutrophication is one of the important reasons for water pollution and is also the problem for water pollution treatment at home and abroad. This article takes an overview on various technical methods and their characteristics applicable for treatment and control of water eutrophication from the aspects of physics, chemistry, biochemistry and environmental factors regulation, and discusses the application and development trend for relevant technologies.
文摘This paper elucidated the necessity and possibility of developing the technology of land treatment on the basis of the analysis of shortage and pollution status of water resources in China.The historical development of this technology in the world was briefly reviewed and the distinction between land treatment and conventional wastewater irrigation was discussed in details. The fundamental characteristics and functions as well as the integrity and compatibility of this ecological engineering were also summarized. It was finally concluded that this technology for wastewater treatment has broad prospects of application in China.
文摘On the background of analysis on region water environment safety in the Dongjiang Lake of south-central China, the source of pollution of water environment and its control are studied. The concept of region environment disaster chain is put forward on the basis of combination study on the disaster chain theory and pollution problem in regional water environment. Through identification and analysis of pollution disaster resources in regional water environment of the Dongjiang Lake, the annual emission of the chemical oxygen demand (COD), ammonia nitrogen, total phosphorus (TP) and heavy metal (Cd, As, Pb) are counted. According to evaluation on structure proportion of contaminants in the Dongjiang Lake, agricultural non-point source is the uppermost pollution source, which accounted for 87.74% in total pollution load. Ammonia nitrogen, TP and COD are mainly contaminants accounted for 94.27% in total pollution load. By analyzing danger of contaminants in the lake, basic form of disaster chain of water environment pollution is built elementarily. It shows characteristics of branches and trunk basin disaster chain and embodies multisource disaster implication chain caused by human activities. Then, disaster resources chain-cutting methods for pollution prevention and control of regional water environment of the Dongjiang Lake are analyzed.
文摘This study, with Hongdong Reservoir, is intended to evaluate the changes in water quality in the lake before and after rainfall in summer. Various non-point source pollutions are scattered around the reservoir, and to determine the pollution level by pollution source, samples were taken at the same point before rainfall (1st), during rainfall (2nd) and after rainfall (3rd) and concentration was measured. Pollutant concentration curve at the measuring points (HDS1, HDS2, HDS3) appeared to be similar with the hydrological curve. When comparing the concentration immediately before rainfall with event mean concentration (EMC), SS and COD were 4 - 59 times and 1 - 4 times, respectively. However, when it comes to total nitrogen (T-N), concentration arrived at the reservoir stayed the range of 1.3 - 12.0 mg/L in all 3 cases without significant variation, which indicated that total nitrogen load is critical when arriving at the reservoir, irrespective of rainfall, and thus it’s necessary to consider non-point source pollution runoff also in addition to point source pollution when developing the water quality improvement measures in reservoir.