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
Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection ...Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.展开更多
Authors have conducted an experiment of irradiation using sound waves (frequency) including ultrasonic waves into water such as drinking water, sea water and forest water and wastewater so far. As a result, almost the...Authors have conducted an experiment of irradiation using sound waves (frequency) including ultrasonic waves into water such as drinking water, sea water and forest water and wastewater so far. As a result, almost the same effect of improvement of water quality was confirmed for each sound wave. Then, an environmental anthropological study of watershed management based on the sound was carried out assuming that a water quality management using the sound could be possible. The Goulburn River basin in the southern part of Australia in which indigenous peoples (Yorta Yorta) have been concerned with the management for a long time so far was selected as an objective drainage basin this time. As a result, a couple of environmental anthropological perspectives on watershed management were proposed.展开更多
The efficiency of phytosynthetic bacteria (PSB) to improve the water quality in saline alkali ponds was studied, the result showed that (1) PSB application could increase the content of DO, NO\+-\-3\|N and effective ...The efficiency of phytosynthetic bacteria (PSB) to improve the water quality in saline alkali ponds was studied, the result showed that (1) PSB application could increase the content of DO, NO\+-\-3\|N and effective phosphorus (EP) in ponds; (2) the changes of COD were not evident, just effective in later period after PSB application; (3) PSB application could decrease the contents of NH\+-\-4\|N (NH\-3\|N), NO\+-\-2\|N ; (4) PSB application could improve the structure of the effective nitrogen (EN) and EP, stimulate the growth of phytoplankton, and increase primary productivity, and finally increase the commercial profits of ponds because of the increase of EP and the decrease of EN contents; (5) the effect exerting speed of PSB was slower, but the effect sustaining time was longer; (6) the appropriate concentration of PSB application in saline alkali wetland ponds was 10×10 -6 mg/L, one time effective period was more than 15 days. So PSB was an efficient water quality improver in saline alkali ponds.展开更多
The sampling of environmental water should ensure the representativeness and integrity of the sampled water body,which has an important impact on the monitoring results.The sampling of different water bodies sampling ...The sampling of environmental water should ensure the representativeness and integrity of the sampled water body,which has an important impact on the monitoring results.The sampling of different water bodies sampling will result in different monitoring results.Based on the study on the problems and influencing factors in the sampling process of environmental water quality,improvement measures during the sampling process were elaborated in the paper,with the aim to strengthen on-site control of water sampling,and reduce adverse effects on monitoring results.展开更多
To overcome the shortcomings of the traditional methods of water quality evaluation, in this paper, a novel model combines particle swarm optimization (PSO), chaos theory, self-adaptive strategy and back propagation a...To overcome the shortcomings of the traditional methods of water quality evaluation, in this paper, a novel model combines particle swarm optimization (PSO), chaos theory, self-adaptive strategy and back propagation artificial neural network (BP ANN) that was proposed to evaluate the water quality of Weihe River in China. An improved PSO algorithm with a self-adaptive inertia weight and a chaotic learning factor tuned by logistic function was developed and used to optimize the network parameters of BP ANN. The values of average absolute deviation (AAD), root mean square error of prediction (RMSEP) and squared correlation coefficient are 0.0061, 0.0163 and 0.9903, respectively. Compared with other methods, such as BP ANN, and PSO BP ANN, the proposed model displays optimal prediction performance with high precision and good correlation. The results show that the proposed method has the good prediction ability for evaluating water quality. It is convenient, reliable and high precision, which provides good analysis and evaluation method for water quality.展开更多
This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income,...This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income, living near a polluted water source, using tap water instead of natural water, who are handicraft producers, and who have more members, are willing to pay more. However, households who rarely hear about environmental pollution issues and who are offered a higher bid are more likely to refuse to pay. Solutions to improve water quality are suggested such as to raise people’s awareness through communication channels and social organizations;to increase income associated with environmental protection policies;to construct wastewater treatment plants;to encourage the relocation of production establishments to industrial parks and industrial complexes;to put regulations on collection, payment and sanctions in case of not declaring and paying fees into village conventions;to promulgate circulars, and bylaws to concretize and simplify regulations and policies of the Government and the Ministry of Natural Resources and Environment.展开更多
Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution cont...Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution control plan based on water quality target management in the North Canal River catchment of Beijing section, in order to obtain effective water quality improvement programs. The ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) were taken as the main controlling pollutants. Water quality targets and basic water quality improvement scenarios were set up considering different intensities of population regulation scenarios and gradually strengthening emission control measures. The MIKE11 model was adopted to simulate the effects of a range of water quality improvement scenarios. Results indicated that the basic scenarios could dramatically improve the surface water environment. However, additional intensive and combined measure programs should be implemented to ensure that the water quality would basically meet the targets of corresponding water function zones. The results highlight the need to implement water conservation in water shortage urban river basin and show the importance of enhancing drainage communication and conducting ecological water replenishment in such kind basins. It is expected to provide a reference for the water environment management practice of other metropolis in the world facing both crisis of water resource shortage and water environment pollution.展开更多
The aim of this study is to estimate the effects of the accumulation of harmful heavy metals in the irrigation water resulting from the proximity of the various activities of various water: sewage, artesian wells and ...The aim of this study is to estimate the effects of the accumulation of harmful heavy metals in the irrigation water resulting from the proximity of the various activities of various water: sewage, artesian wells and industrial activities, particularly Borg El Arab Industrial area and take Nile water l Control (Bahig canal). The concentrations of these heavy metals in samples drawn from different distances from the source of irrigation in summer 2011 that contain the highest concentrations, followed by the winter of 2012. These results have shown that the amount of heavy metals in the samples at a distance of 50 meters is more than quantity of 5000 m by a 30 to 35 twice in water for irrigation, also the amount of heavy metals in the samples at a distance of 50 meters has values less than the permissible limits and disappeares completely at a distance of 5000 meters and that for different sources.展开更多
In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight wate...In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.展开更多
Increasing the quantity and improving the quality of cropland can alleviate the human-land contradiction and promote the sustainable development of agriculture especially in mountainous areas.With the support of the c...Increasing the quantity and improving the quality of cropland can alleviate the human-land contradiction and promote the sustainable development of agriculture especially in mountainous areas.With the support of the central government’s policies,Yan’an,Northern Shaanxi,China implemented a major land consolidation engineering project in the loess hilly-gully region from 2013 to 2018,achieving 33,333.3 ha of new cropland.However,the poor quality of some newly-constructed cropland at the initial stage hindered its efficient utilization.In order to overcome this problem,red clay and Malan loess were compounded in different volume ratios to explore the method to improve the cropland quality.The Root Zone Water Quality Model was used to simulate the effects of different soil treatments on soil water,nitrogen and maize growth.Experimental data were collected from 2018 to 2019 to calibrate and validate the model.The root mean square error(RMSE)of soil water content,nitrate nitrogen concentration,above-ground biomass,leaf area index were in the range of 11.72-14.06 mm,4.06-11.73 mg kg^(-1),835.21-1151.28 kg ha^(-1)and 0.24-0.47,respectively,while the agreement index(d)between measured and simulated values ranged from 0.70 to 0.96.It was showed that,compared with land constructed with Malan loess only(T1),the soil structure and hydraulic characteristics of land with a volume ratio of red clay and Malan loess of 2:1(T3)was better.Simulation indicated that,compared with T1,the soil water content and available water content of T3 increased by 14.4%and 19.0%,respectively,while N leaching decreased by 16.9%.The aboveground biomass and maize yield of T3 were 7.9%and 6.7%higher than that of T1,respectively.Furthermore,the water productivity and nitrogen use efficiency of T3 increased by 21.0%and 16.6%compared with that of T1.These results indicated that compounding red clay and Malan loess in an appropriate ratio was an effective method to improve soil quality.This study provides a technical idea and specific technical parameters for the construction or improvement of cropland in loess hilly-gully region,which may also provide reference for similar projects in other places.展开更多
The access to safe drinking-water is a global priority for sustainable development, as it has been recognized within the MDGs (Millennium Development Goals). Although the MDG’s target of halving the proportion of p...The access to safe drinking-water is a global priority for sustainable development, as it has been recognized within the MDGs (Millennium Development Goals). Although the MDG’s target of halving the proportion of people without sustainable access to safe drinking-water was met in 2010, the measurement method of the monitoring and evaluation indicator used ignored certain elements including the quality of water that should be underlined. Starting with a review of drinking-water and improved water source concepts, this study examines the limitations of measuring access to safe drinking-water in the context of the MDGs, and learns from the lessons to ensure a better performance in achieving the SDGs (Sustainable Development Goals).展开更多
Outbreaks of Ulva prolifera have continued in the South Yellow Sea of China(SYS)since 2007,becoming a serious marine ecological disaster.Large amounts of U.prolifera drift to the coast of the Shandong Peninsula to dis...Outbreaks of Ulva prolifera have continued in the South Yellow Sea of China(SYS)since 2007,becoming a serious marine ecological disaster.Large amounts of U.prolifera drift to the coast of the Shandong Peninsula to dissipate under the action of southeast monsoons and ocean surface currents.This causes serious harm to the ecological environment and economic activities of coastal cities.To investigate the impact of U.prolifera dissipation,this study extracted the spatiotemporal distribution of U.prolifera in the SYS from 2012 to 2020 based on the Google Earth Engine.The outbreak cycle of U.prolifera was determined by fitting analysis of outbreak time and coverage area through MATLAB.This study also looked at the effect of U.prolifera dissipation on water quality through field monitoring data.The results showed that the growth curve of the U.prolifera has a significant Gaussian distribution.The U.prolifera dissipates in Haiyang,China,in July and August every year and affects the offshore environment.Water quality parameters of seawater at different depths had significant differences after the U.prolifera dissipation.Changes in pH,chemical oxygen demand,nitrite nitrogen,nitrate nitrogen,ammonia nitrogen,chlorophyll a,total phosphorus,and suspended solids were more significant in surface seawater than in deeper water.Changes in the concentrations of dissolved oxygen and total nitrogen were more significant in the deep seawater(1.63 and 1.1 times higher than those in the surface seawater,respectively).The dissipation of U.prolifera releases a large amount of carbon and nitrogen into the seawater,which provides rich nutrients for phytoplankton and may cause secondary disasters such as red tide.These findings are useful for further understanding the rules of U.prolifera dissipation,as well as preventing and controlling green tide disasters.展开更多
In recent years, the beer industry is a biological food industry that consumes a lot of water, and it has developed rapidly in China. The sewage discharged from the mass production of beer poses a huge threat to the e...In recent years, the beer industry is a biological food industry that consumes a lot of water, and it has developed rapidly in China. The sewage discharged from the mass production of beer poses a huge threat to the environment. In order to evaluate and better solve the possible environmental impacts of beer treatment engineering projects, a brewery project in Foshan City is taken as an example to investigate the water pollution generation links of the engineering process including surface water and groundwater. According to the relevant technical methods and standards, water pollution factors are screened, and concentration and discharge are monitored. Through comprehensive analysis, predictive evaluation is obtained. It is confirmed that the project meets the requirements of national laws and regulations and environmental protection standards.展开更多
水质指标具有多元相关性、时序性和非线性的特点,为有效预测河流水质变化,针对水质数据存在缺失和异常的问题,提出基于灰色关联分析-门控循环单元(Grey Relational Analysis-Gated Recurrent Unit, GRA-GRU)的水质预测模型。以淮河流域...水质指标具有多元相关性、时序性和非线性的特点,为有效预测河流水质变化,针对水质数据存在缺失和异常的问题,提出基于灰色关联分析-门控循环单元(Grey Relational Analysis-Gated Recurrent Unit, GRA-GRU)的水质预测模型。以淮河流域水质数据为样本,使用线性插值修补缺失数据和剔除的异常数据。使用灰色关联分析计算不同水质指标间的相关性,选择高相关性的水质指标以确定输入变量,并使用门控循环单元(Gated Recurrent Unit, GRU)预测不同的水质指标。将GRA-GRU的预测结果与反向传播神经网络(Back Propagation Neural Network, BPNN)、循环神经网络(Recurrent Neural Network, RNN)、长短期记忆神经网络(Long Short Term Memory, LSTM)、GRU及灰色关联分析-长短期记忆神经网络(Grey Relational Analysis-Long Short Term Memory, GRA-LSTM)进行对比分析,结果显示GRA-GRU在不同水质指标预测上具有较好的适应性,可以有效降低预测误差。其中,与其他模型相比,GRA-GRU预测的化学需氧量在均方根误差上分别降低了3.617%、0.681%、0.478%、1.505%和0.471%。展开更多
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.
文摘Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.
文摘Authors have conducted an experiment of irradiation using sound waves (frequency) including ultrasonic waves into water such as drinking water, sea water and forest water and wastewater so far. As a result, almost the same effect of improvement of water quality was confirmed for each sound wave. Then, an environmental anthropological study of watershed management based on the sound was carried out assuming that a water quality management using the sound could be possible. The Goulburn River basin in the southern part of Australia in which indigenous peoples (Yorta Yorta) have been concerned with the management for a long time so far was selected as an objective drainage basin this time. As a result, a couple of environmental anthropological perspectives on watershed management were proposed.
文摘The efficiency of phytosynthetic bacteria (PSB) to improve the water quality in saline alkali ponds was studied, the result showed that (1) PSB application could increase the content of DO, NO\+-\-3\|N and effective phosphorus (EP) in ponds; (2) the changes of COD were not evident, just effective in later period after PSB application; (3) PSB application could decrease the contents of NH\+-\-4\|N (NH\-3\|N), NO\+-\-2\|N ; (4) PSB application could improve the structure of the effective nitrogen (EN) and EP, stimulate the growth of phytoplankton, and increase primary productivity, and finally increase the commercial profits of ponds because of the increase of EP and the decrease of EN contents; (5) the effect exerting speed of PSB was slower, but the effect sustaining time was longer; (6) the appropriate concentration of PSB application in saline alkali wetland ponds was 10×10 -6 mg/L, one time effective period was more than 15 days. So PSB was an efficient water quality improver in saline alkali ponds.
文摘The sampling of environmental water should ensure the representativeness and integrity of the sampled water body,which has an important impact on the monitoring results.The sampling of different water bodies sampling will result in different monitoring results.Based on the study on the problems and influencing factors in the sampling process of environmental water quality,improvement measures during the sampling process were elaborated in the paper,with the aim to strengthen on-site control of water sampling,and reduce adverse effects on monitoring results.
文摘To overcome the shortcomings of the traditional methods of water quality evaluation, in this paper, a novel model combines particle swarm optimization (PSO), chaos theory, self-adaptive strategy and back propagation artificial neural network (BP ANN) that was proposed to evaluate the water quality of Weihe River in China. An improved PSO algorithm with a self-adaptive inertia weight and a chaotic learning factor tuned by logistic function was developed and used to optimize the network parameters of BP ANN. The values of average absolute deviation (AAD), root mean square error of prediction (RMSEP) and squared correlation coefficient are 0.0061, 0.0163 and 0.9903, respectively. Compared with other methods, such as BP ANN, and PSO BP ANN, the proposed model displays optimal prediction performance with high precision and good correlation. The results show that the proposed method has the good prediction ability for evaluating water quality. It is convenient, reliable and high precision, which provides good analysis and evaluation method for water quality.
文摘This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income, living near a polluted water source, using tap water instead of natural water, who are handicraft producers, and who have more members, are willing to pay more. However, households who rarely hear about environmental pollution issues and who are offered a higher bid are more likely to refuse to pay. Solutions to improve water quality are suggested such as to raise people’s awareness through communication channels and social organizations;to increase income associated with environmental protection policies;to construct wastewater treatment plants;to encourage the relocation of production establishments to industrial parks and industrial complexes;to put regulations on collection, payment and sanctions in case of not declaring and paying fees into village conventions;to promulgate circulars, and bylaws to concretize and simplify regulations and policies of the Government and the Ministry of Natural Resources and Environment.
文摘Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution control plan based on water quality target management in the North Canal River catchment of Beijing section, in order to obtain effective water quality improvement programs. The ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) were taken as the main controlling pollutants. Water quality targets and basic water quality improvement scenarios were set up considering different intensities of population regulation scenarios and gradually strengthening emission control measures. The MIKE11 model was adopted to simulate the effects of a range of water quality improvement scenarios. Results indicated that the basic scenarios could dramatically improve the surface water environment. However, additional intensive and combined measure programs should be implemented to ensure that the water quality would basically meet the targets of corresponding water function zones. The results highlight the need to implement water conservation in water shortage urban river basin and show the importance of enhancing drainage communication and conducting ecological water replenishment in such kind basins. It is expected to provide a reference for the water environment management practice of other metropolis in the world facing both crisis of water resource shortage and water environment pollution.
文摘The aim of this study is to estimate the effects of the accumulation of harmful heavy metals in the irrigation water resulting from the proximity of the various activities of various water: sewage, artesian wells and industrial activities, particularly Borg El Arab Industrial area and take Nile water l Control (Bahig canal). The concentrations of these heavy metals in samples drawn from different distances from the source of irrigation in summer 2011 that contain the highest concentrations, followed by the winter of 2012. These results have shown that the amount of heavy metals in the samples at a distance of 50 meters is more than quantity of 5000 m by a 30 to 35 twice in water for irrigation, also the amount of heavy metals in the samples at a distance of 50 meters has values less than the permissible limits and disappeares completely at a distance of 5000 meters and that for different sources.
基金Supported by the National Natural Science Foundation of China(41901012)Project of Shaanxi Provincial Education Department(21JP040)+1 种基金Talent Fund Project of Weinan Normal University(2021RC04)National Innovation and Entrepreneurship Training Program for College Students(22XK019)。
文摘In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.
基金supported by the National Natural Science Foundation of China(Grant No.41931293)the National Key Research and Development Program of China(Grant No.2017YFC0504701)。
文摘Increasing the quantity and improving the quality of cropland can alleviate the human-land contradiction and promote the sustainable development of agriculture especially in mountainous areas.With the support of the central government’s policies,Yan’an,Northern Shaanxi,China implemented a major land consolidation engineering project in the loess hilly-gully region from 2013 to 2018,achieving 33,333.3 ha of new cropland.However,the poor quality of some newly-constructed cropland at the initial stage hindered its efficient utilization.In order to overcome this problem,red clay and Malan loess were compounded in different volume ratios to explore the method to improve the cropland quality.The Root Zone Water Quality Model was used to simulate the effects of different soil treatments on soil water,nitrogen and maize growth.Experimental data were collected from 2018 to 2019 to calibrate and validate the model.The root mean square error(RMSE)of soil water content,nitrate nitrogen concentration,above-ground biomass,leaf area index were in the range of 11.72-14.06 mm,4.06-11.73 mg kg^(-1),835.21-1151.28 kg ha^(-1)and 0.24-0.47,respectively,while the agreement index(d)between measured and simulated values ranged from 0.70 to 0.96.It was showed that,compared with land constructed with Malan loess only(T1),the soil structure and hydraulic characteristics of land with a volume ratio of red clay and Malan loess of 2:1(T3)was better.Simulation indicated that,compared with T1,the soil water content and available water content of T3 increased by 14.4%and 19.0%,respectively,while N leaching decreased by 16.9%.The aboveground biomass and maize yield of T3 were 7.9%and 6.7%higher than that of T1,respectively.Furthermore,the water productivity and nitrogen use efficiency of T3 increased by 21.0%and 16.6%compared with that of T1.These results indicated that compounding red clay and Malan loess in an appropriate ratio was an effective method to improve soil quality.This study provides a technical idea and specific technical parameters for the construction or improvement of cropland in loess hilly-gully region,which may also provide reference for similar projects in other places.
文摘The access to safe drinking-water is a global priority for sustainable development, as it has been recognized within the MDGs (Millennium Development Goals). Although the MDG’s target of halving the proportion of people without sustainable access to safe drinking-water was met in 2010, the measurement method of the monitoring and evaluation indicator used ignored certain elements including the quality of water that should be underlined. Starting with a review of drinking-water and improved water source concepts, this study examines the limitations of measuring access to safe drinking-water in the context of the MDGs, and learns from the lessons to ensure a better performance in achieving the SDGs (Sustainable Development Goals).
基金The National Natural Science Foundation of China under contract No.42071385the Shandong Natural Science Foundation under contract No.ZR2019MD041+1 种基金the Open Project Program of Shandong Marine Aerospace Equipment Technological Innovation Center,Ludong University under contract No.MAETIC2021-12the Yantai Science and Technology Innovation Development Plan Project under contract No.2022MSGY062。
文摘Outbreaks of Ulva prolifera have continued in the South Yellow Sea of China(SYS)since 2007,becoming a serious marine ecological disaster.Large amounts of U.prolifera drift to the coast of the Shandong Peninsula to dissipate under the action of southeast monsoons and ocean surface currents.This causes serious harm to the ecological environment and economic activities of coastal cities.To investigate the impact of U.prolifera dissipation,this study extracted the spatiotemporal distribution of U.prolifera in the SYS from 2012 to 2020 based on the Google Earth Engine.The outbreak cycle of U.prolifera was determined by fitting analysis of outbreak time and coverage area through MATLAB.This study also looked at the effect of U.prolifera dissipation on water quality through field monitoring data.The results showed that the growth curve of the U.prolifera has a significant Gaussian distribution.The U.prolifera dissipates in Haiyang,China,in July and August every year and affects the offshore environment.Water quality parameters of seawater at different depths had significant differences after the U.prolifera dissipation.Changes in pH,chemical oxygen demand,nitrite nitrogen,nitrate nitrogen,ammonia nitrogen,chlorophyll a,total phosphorus,and suspended solids were more significant in surface seawater than in deeper water.Changes in the concentrations of dissolved oxygen and total nitrogen were more significant in the deep seawater(1.63 and 1.1 times higher than those in the surface seawater,respectively).The dissipation of U.prolifera releases a large amount of carbon and nitrogen into the seawater,which provides rich nutrients for phytoplankton and may cause secondary disasters such as red tide.These findings are useful for further understanding the rules of U.prolifera dissipation,as well as preventing and controlling green tide disasters.
基金Supported by Key Fields of Universities in Guangdong Province (Science and Technology Service for Rural Revitalization)(2021ZDZX4023)2021 Undergraduate Teaching Quality and Teaching Construction Project of Guangdong Province (Guangdong Education Gao Han [2021] 29)+1 种基金Zhaoqing University Quality Engineering and Teaching Reform Project (zlgc 201931)Zhaoqing University Students’Innovation and Entrepreneurship Training Program in 2022 (X 202210580130)。
文摘In recent years, the beer industry is a biological food industry that consumes a lot of water, and it has developed rapidly in China. The sewage discharged from the mass production of beer poses a huge threat to the environment. In order to evaluate and better solve the possible environmental impacts of beer treatment engineering projects, a brewery project in Foshan City is taken as an example to investigate the water pollution generation links of the engineering process including surface water and groundwater. According to the relevant technical methods and standards, water pollution factors are screened, and concentration and discharge are monitored. Through comprehensive analysis, predictive evaluation is obtained. It is confirmed that the project meets the requirements of national laws and regulations and environmental protection standards.
文摘水质指标具有多元相关性、时序性和非线性的特点,为有效预测河流水质变化,针对水质数据存在缺失和异常的问题,提出基于灰色关联分析-门控循环单元(Grey Relational Analysis-Gated Recurrent Unit, GRA-GRU)的水质预测模型。以淮河流域水质数据为样本,使用线性插值修补缺失数据和剔除的异常数据。使用灰色关联分析计算不同水质指标间的相关性,选择高相关性的水质指标以确定输入变量,并使用门控循环单元(Gated Recurrent Unit, GRU)预测不同的水质指标。将GRA-GRU的预测结果与反向传播神经网络(Back Propagation Neural Network, BPNN)、循环神经网络(Recurrent Neural Network, RNN)、长短期记忆神经网络(Long Short Term Memory, LSTM)、GRU及灰色关联分析-长短期记忆神经网络(Grey Relational Analysis-Long Short Term Memory, GRA-LSTM)进行对比分析,结果显示GRA-GRU在不同水质指标预测上具有较好的适应性,可以有效降低预测误差。其中,与其他模型相比,GRA-GRU预测的化学需氧量在均方根误差上分别降低了3.617%、0.681%、0.478%、1.505%和0.471%。