On the basis of experimental works of planning environmental impact assessment, works of planning environmental impact assessment such as each of the city＇s special planning and development zone planning were compreh...On the basis of experimental works of planning environmental impact assessment, works of planning environmental impact assessment such as each of the city＇s special planning and development zone planning were comprehensively promoted in Wuhan City, which effectively promoted the adjustment of Wuhan industrial structure, the rational layout of functions and the efficient utilization of resources, and laid a solid foundation for Wuhan City to be the supporting point for the rise of central China. Here, the work carried out in Wuhan was reviewed, combined with the new requirements of the current ecological civilization construction in Wuhan City, and the framework, the key technical points and the important focuses of the carrying out of the tracking evaluation of planning environmental impact assessment were proposed.展开更多
The unified dynamic theory reveals the substrate-based nonlinear growth phenomena. It means that the environment of high organism concentration and low substrate state is useful for the growth of weak floras. With eco...The unified dynamic theory reveals the substrate-based nonlinear growth phenomena. It means that the environment of high organism concentration and low substrate state is useful for the growth of weak floras. With ecological superior nitrification denltrification （ ECOSUNIDE ） technology, high sludge concentration by distributing influent to anaerobic and anoxic zones is carried out, and the ecological superiorities of nitrifiers, denitrifiers, and phosphate accumulating organisms （PAOs） get to be promoted. One of the anaerobic/anoxic/oxic（A/A/O） treatment lines of a sewage treatment plant with ECOSUNIDE technology for further investigation on the nutrient removal efficiency is reformed. The advantages of ECOSUNIDE, such as high efficiency and saving energy, are well demonstrated, even under the condition of low temperature （about 15℃） and carbon-resource （C/N ratio lower than 2. 5 ）. In ECOSUNIDE system, the effluent indexes as biochemical oxygen demand （BOD）, chemical oxygen demand （COD）, and NH3--N reach the Class I-A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB18918-2002 ）, and suspended substance （ SS ）, total nitrogen （TN）, and total phosphorus（TP） meet the Class I -B criteria. While the effluent qualities of A/A/O system only reach the secondary discharge standard. Through the comparison on the sludge character of ECOSUNH）E system with A/A/O, more abundant biofacies, darker and more intense zoogloea, more obvious filamentous bacterium, and clearer floes edges in ECOSUNIDE system are found.展开更多
Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied....Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied. Furthermore, the estimation of the region-time-length (RTL) parameter has been proposed to detect seismic quiescence before the occurrence of a large earthquake. In addition, the time-to-failure method has been used to estimate the time occurrence of large earthquakes. Hence, in this study, to gain deeper insight into seismic activity in the southern Zagros region, we utilized the RTL algorithm to identify the quiescence and activation phases leading to the Fin doublet earthquakes. Temporal variations in the RTL parameter showed two significant anomalies. One corresponded to the occurrence time of the first earthquake (2017-12-12);the other anomaly was associated with the occurrence time of the second event (2021-11-14). Based on a negative value of the RTL parameter observed in the vicinity of the Fin epicenters (2021), seismic quiescence (a decrease in seismicity compared to the preceding background rate) was identified. The spatial distribution of the RTL prognostic parameters confirms the appearance of seismic quiescence surrounding the epicenter of the Fin doublet earthquakes (2021). The time-to-failure method was designed using precursory events that describe the acceleration of the seismic energy release before the mainshock. Using the time-to-failure method for the earthquake catalog, it was possible to estimate both the magnitude and time of failure of the Fin doublet. Hence, the time-tofailure technique can be a useful supplementary method to the RTL algorithm for determining the characteristics of impending earthquakes.展开更多
The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto...The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto ambient aerosols(γHO_(2))has largely hindered the application of the measuredγHO_(2)to the global spatial prediction.Here we induced an offine method using LFP-LIF technique to measure the kinetics of HO_(2)uptake onto ambient aerosols collected in summertime and wintertime in Yokohama city,a regional urban site near Tokyo,Japan.By controlling the dominating parameters which infuenceγHO_(2),we were able to investigate the detailed HO_(2)uptake mechanism.We characterized the chemical composition of the collected ambient aerosols,including organics,inorganics,transition metals ions,etc.and modeledγHO_(2)using different mechanisms.Results show thatγHO_(2)increased with the increase in RH,and the aerosol states(“dry”or wet/aqueous)have large effects onγHO_(2).With fixed RH and aerosol chemical composition,γHO_(2)was highly dependent on pH and inversely correlated with[HO_(2)]_0.By combing the measuredγHO_(2)values with the modeled ones,we found that both the HO_(2)self-reaction and transition metal-catalyzed reactions should be accounted for to yield a single parameterization to predictγHO_(2),and different chemical compositions may have collective effects onγHO_(2).Results may serve for extending theγHO_(2)values measured at one observation site to different environmental conditions,which will help us to achieve more accurate modeling results concerning secondary pollutant formation(i.e.,ozone).展开更多
Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in C...Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.展开更多
Agriculture-oriented cities in Northeastern China have experienced frequent atmospheric pollution events.Deeper understandings of the pollution characteristics,haze causes and effects of management on local air qualit...Agriculture-oriented cities in Northeastern China have experienced frequent atmospheric pollution events.Deeper understandings of the pollution characteristics,haze causes and effects of management on local air quality are crucial for conducting integrated management approaches for the sustainable development of agriculture-oriented cities.Taking a typical agriculture-dominant city(i.e.,Suihua)in Northeast China,we analyzed in detail the characteristics and causes of atmospheric pollution and evaluated the straw-burning prohibition using multisource data.The results showed a clear temporal pattern of air quality index(AQI)on an annual scale(i.e.,2015-April 2019),with two typical pollution periods occurring in late autumn and early spring.The large areas of concentrated straw burning at local and regional scales accounted for the first period(i.e.,October and November),while dust emissions and farming disturbances comprised the second period.The interannual variation in pollution periods among these years was large,showing similar trends from 2015 to 2017 and the postponed late-autumn pollution period in 2018.Our evaluation has shown that the prohibition effect of straw burning significantly improved air quality in 2018,with a reduction of 59%±88%in the PM2.5 concentrations in October and November compared to 2015–2017.However,From October to April of the following year,the improvement effect was not significant due to postponement of straw burning to February or March.Our analysis also highlighted the roles of meteorological conditions,Therefore,combined with the promotion of straw utilization,scientifically prescribed burning considering the burning amount and location,meteorological conditions and regional transportation should be implemented.展开更多
Remediation of organochlorine pesticide (OCP)-contaminated soils is urgently required especially in China. The present study investigated the removal of OCPs from two soils by triton X-100 (TX- 100)-enhanced washing c...Remediation of organochlorine pesticide (OCP)-contaminated soils is urgently required especially in China. The present study investigated the removal of OCPs from two soils by triton X-100 (TX- 100)-enhanced washing coupled with powdered activated carbon (PAC) adsorption treatment of the solution. Two contaminated soils, including a silt clay contaminated w计h chlordene, dichloro- 2,2-6is(p-chlorophenyl)ethanes (DDDs), and dichlorodiphenyltrichloroethane (DDT) and a sandy loam containing chlordanes and mirex, were selected. Effects of varied operating parameters, including TX-100 dosage, liquid/soil (L/S) ratio, and extraction time, on the contaminant removal were examined. For both soils, OCP removal was clearly enhanced with increasing TX-100 in extraction solution and L/S ratio. Meanwhile, the removal efficacy was also impacted by soil texture and characteristics and contents of the contaminants. Moreover, by using PAC as an absorbent, a significant decrease in the contaminants in the extraction solutions was detected, and TX-100 could be further reused. Our investigation suggests that surfactant-enhanced washing combined with activated carbon selective adsorption would be an alternative to remediate OCP-contaminated soils.展开更多
Efficient management of air quality requires a comprehensive emission inventory to support decision-making on air quality improvement.This article presents a comprehensive framework for detailed emission inventory dev...Efficient management of air quality requires a comprehensive emission inventory to support decision-making on air quality improvement.This article presents a comprehensive framework for detailed emission inventory development in cities with low-quality basic data,which examines the emission of primary criteria pollutants(CO,NO_(x),SO_(2),PM_(2.5),PM_(10),and VOC)from mobile sources,residential,commercial,and public services,fuel stations,transport terminals,energy conversion sections,and industries.This research was applied to Tabriz in Northwest Iran,one of the polluted medium-sized cities with a population of 1.77 million.Results show the city daily emission per capita is 569.8 g of CO,68.6 g of NO_(x),38.6 g of VOC,17.6 g of SO_(x),and 3.7 g of PM.Vehicular emissions accounted for 98%of CO,91%of VOCs,61%of NO_(x),and 56%of PM;meaning alternative policy strategies in vehicles would reduce emissions rapidly.Fifteen applicable and effective scenarios in transport and one concerning stationary sourceswere proposed and reduction potential of themwas evaluated.Effectiveness of the public transport improvement and replacement of old passenger cars were founded the key scenarios.These two alternatives decrease 14 and 2 tons of SO_(2) and 6797 and 2394 tons of NO_(x) annually with the cost of$99.5 MM and$366.5 MM,respectively.The findings of this study provides the choice of travel method by each citizen is a function of cost,speed,comfort and safety of travel;therefore,all the requirements of any scenarios must be fully considered in the implementation step.展开更多
The mass concentration and major chemical components of fine particulate matter were measured before,during and after Beijing＇s massive parade commemorating 70th anniversary of the Chinese Victory in World War II on ...The mass concentration and major chemical components of fine particulate matter were measured before,during and after Beijing＇s massive parade commemorating 70th anniversary of the Chinese Victory in World War II on September 3,2015.Regional emission inventory,positive matrix factorization（PMF）,observations from space and backward air mass trajectories were jointly applied to identify the major pollution sources and their temporal and spatial variations.The contributions of emissions variations and the meteorological conditions related to the＂parade blue＂phenomenon in Beijing and its surrounding areas were investigated in detail.The main cause of the decreased PM（2.5）mass concentration was attributed to the absolute reduction in emissions of primary air pollutants.The chemical composition of PM（2.5）varied significantly before,during and after the parade.Fugitive dust particles were well controlled,the secondary formation of PM（2.5）was reduced along with the controlled gaseous precursors＇emissions from vehicles and industrial sources during the temporary intensified control period.During the parade period,the SO2and NO2column concentrations in Beijing and the surrounding areas decreased sharply,indicating that the coordinated reduction in primary emissions from the surrounding areas of Beijing played an important role in lowering the ambient concentration of SO2and NO2and accordingly lowered PM（2.5）and improved the regional air quality.A comparison of the temperature,humidity,and wind speed and direction during the same periods in 2014 and 2015 showed that the meteorological conditions positively influenced the achievement of＂parade blue＂.展开更多
The region along the Taihang Mountains in the North China Plain(NCP) is characterized by serious fine particle pollution. To clarify the formation mechanism and controlling factors, an observational study was conducte...The region along the Taihang Mountains in the North China Plain(NCP) is characterized by serious fine particle pollution. To clarify the formation mechanism and controlling factors, an observational study was conducted to investigate the physical and chemical properties of the fine particulate matter in Jiaozuo city, China. Mass concentrations of the water-soluble ions(WSIs) in PM_(2.5) and gaseous pollutant precursors were measured on an hourly basis from December 1, 2017, to February 27, 2018. The positive matrix factorization(PMF) method and the FLEXible PARTicle(FLEXPART) model were employed to identify the sources of PM_(2.5). The results showed that the average mass concentration of PM_(2.5) was 111 μg/m^(3) during the observation period. Among the major WSIs, sulfate, nitrate, and ammonium(SNA) constituted 62% of the total PM_(2.5) mass, and NO_(3)^(-) ranked the highest with an average contribution of 24.6%. NH_(4)^(+) was abundant in most cases in Jiaozuo. According to chemical balance analysis, SO_(2)-4, NO_(3)^(-), and Cl^(-) might be present in the form of(NH_4)_(2)SO_4, NH_4NO_3, NH_4Cl, and KCl. The liquid-phase oxidation of SO_(2) and NO_(2) was severe during the haze period. The relative humidity and pH were the key factors influencing SO_(4)^(2-) formation. We found that NO_(3)^(-) mainly stemmed from homogeneous gas-phase reactions in the daytime and originated from the hydrolysis of N_(2)O_5 in the nighttime, which was inconsistent with previous studies. The PMF model identified five sources of PM_(2.5) : secondary origin(37.8%), vehicular emissions(34.7%), biomass burning(11.5%), coal combustion(9.4%), and crustal dust(6.6%).展开更多
Hexachlorobenzene （HCB） is a chlorinated aromatic hydrocarbon that was widely used for seed dressing in prevention of fungal growth on crops, and also as a component of fireworks, ammunition, and synthetic rubbers. ...Hexachlorobenzene （HCB） is a chlorinated aromatic hydrocarbon that was widely used for seed dressing in prevention of fungal growth on crops, and also as a component of fireworks, ammunition, and synthetic rubbers. Because of its resistance to degradation and mobility, HCB is widely distributed throughout the environment and is accumulated through food chains in different ecosystems. In this study, a preliminary investigation was carried out on the bioaccumulation and the toxic effects of HCB in the microbial （protozoan in particular） communities in the Fuhe River, Wuhan, a water body receiving industrial wastewaters containing HCB and other pollutants, using the standardized polyurethane foam units （PFU） method. Field samples were taken from eight stations established along the Fuhe River in January and August 2006. The concentration ratios of HCB in microbial communities and in water were 9.66-18.64, and the microbial communities accumulated 13.29-56.88 μg/L of HCB in January and 0.82-10.25 μg/L HCB in August. Correlation analysis showed a negative correlation between the HCB contents in the microbial assemblage, and the number of species and the diversity index of the protozoan communities. This study demonstrated the applicability of the PFU method in monitoring the effects of HCB on the level of microbial communities.展开更多
Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic species.In this study,the spatial distribution of five endemic and threatened spec...Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic species.In this study,the spatial distribution of five endemic and threatened species belonging to the genus Onosma(including O.asperrima,O.bisotunensis,O.kotschyi,O.platyphylla,and O.straussii)was investigated under present and future climate change scenarios:RCP2.6(RCP,representative concentration pathway;optimistic scenario)and RCP8.5(pessimistic scenario)for the years 2050 and 2080 in Iran.Analysis was conducted using the maximum entropy(MaxEnt)model to provide a basis for the protection and conservation of these species.Seven environmental variables including aspect,depth of soil,silt content,slope,annual precipitation,minimum temperature of the coldest month,and annual temperature range were used as main predictors in this study.The model output for the potential habitat suitability of the studied species showed acceptable performance for all species(i.e.,the area under the curve(AUC)>0.800).According to the models generated by MaxEnt,the potential current patterns of the species were consistent with the observed areas of distributions.The projected climate maps under optimistic and pessimistic scenarios(RCP2.6 and RCP8.5,respectively)of 2050 and 2080 resulted in reductions and expansions as well as positive range changes for all species in comparison to their current predicted distributions.Among all species,O.bisotunensis showed the most significant and highest increase under the pessimistic scenario of 2050 and 2080.Finally,the results of this study revealed that the studied plant species have shown an acute adaptability to environmental changes.The results can provide useful information to managers to apply appropriate strategies for the management and conservation of these valuable Iranian medicinal and threatened plant species in the future.展开更多
To investigate the composition and possible sources of particles, especially during heavy haze pollution, a single particle aerosol mass spectrometer（SPAMS） was deployed to measure the changes of single particle spe...To investigate the composition and possible sources of particles, especially during heavy haze pollution, a single particle aerosol mass spectrometer（SPAMS） was deployed to measure the changes of single particle species and sizes during October of 2014, in Beijing. A total of 2,871,431 particles with both positive and negative spectra were collected and characterized in combination with the adaptive resonance theory neural network algorithm（ART-2a）. Eight types of particles were classified： dust particles（dust, 8.1%）, elemental carbon（EC, 29.0%）, organic carbon（OC, 18.0%）, EC and OC combined particles（ECOC, 9.5%）,Na-K containing particles（Na K, 7.9%）, K-containing particles（K, 21.8%）, organic nitrogen and potassium containing particles（KCN, 2.3%）, and metal-containing particles（metal,3.6%）. Three haze pollution events（P1, P2, P3） and one clean period（clean） were analyzed,based on the mass and number concentration of PM_（2.5）and the back trajectory results from the hybrid single particle Lagrangian integrated trajectory model（Hysplit-4 model）. Results showed that EC, OC and K were the major components of single particles during the three haze pollution periods, which showed clearly increased ratios compared with those in the clean period. Results from the mixing state of secondary species of different types of particles showed that sulfate and nitrate were more readily mixed with carbon-containing particles during haze pollution episodes than in clean periods.展开更多
The removal of As（III） and As（V） from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experimen...The removal of As（III） and As（V） from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experiment： grind precipitate dust （GPD） and cast iron shot （CIS）. The X-ray diffraction analysis indicated the presence of Fe~ on GPD and CIS. Batch experiments were performed under different concentrations of As（III） and As（V） and at various initial pH levels. Results showed that waste cast iron was effective in the removal of arsenic. The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result. In the adsorption of both As（III） and As（V）, the adsorption capacity of GPD was greater than CIS, mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS. Results also indicated the removal of As（III） and As（V） by GPD and CIS was influenced by the initial solution pH, generally decreasing with increasing pH from 3.0 to 10.5. In addition, both GPD and CIS were more effective at the removal of As（III） than As（V） under given experimental conditions. This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.展开更多
This paper reviewed the meaning of facility agriculture and the development status and trends of facility agriculture at home and abroad,analyzed the development status and existing problems of facility agriculture in...This paper reviewed the meaning of facility agriculture and the development status and trends of facility agriculture at home and abroad,analyzed the development status and existing problems of facility agriculture in Guangxi,and proposed corresponding solutions to the problems in the development of facility agriculture in Guangxi,aiming to provide reference for promoting the sustainable development of facility agriculture in Guangxi.展开更多
Decadal changes in the subseasonal evolution and the phase-locked climatological intraseasonal fluctuation of summertime rainfall over the Korean Peninsula before and after the mid-1990s are investigated.The activity ...Decadal changes in the subseasonal evolution and the phase-locked climatological intraseasonal fluctuation of summertime rainfall over the Korean Peninsula before and after the mid-1990s are investigated.The activity and the migration speed of the monsoon rain band over the East Asian region are altered in the recent decade,resulting in the drier conditions in late spring and the earlier onset of Changma.In early August when a climatological monsoon break was clear in the earlier decade,the precipitation has increased dramatically with a meridional coherency.The response to the enhanced convection over the South China Sea and southeastern China provides a favorable condition for more precipitation in early August through the changes in moisture transport and tropical cyclone passage.展开更多
[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas ...[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas of Northern Guangdong, combined with field investigation, the natural environment of Karst mountain areas in northern Guangdong was analyzed. [ Result] The Karst topography of the area is widely distributed. Most places were in subtropical climate zone, with high temperature and rainfall in the same period, and abundant precipitation. There was a large area of contiguous distribution of limestone with dissolution area. Vegetations included typical limestone evergreen and deciduous broadleaved mixed forest, limestone shrub and grassy slopes in mountain and hill. Limestone vegetation had typical limestone mixed evergreen broadleaf forest, limestone shrub, limestone hilly mountain grass slope. [ Conclusion] The study provided theoretical basis for the protection of natural environment of Karst mountain areas in northern Guangdong.展开更多
Precipitation and temperature are the most abiotic factors that greatly impact the yield of crop,particularly in dryland.Barley,as the main cereal is predominantly cultivated in dryland and the livelihood of smallhold...Precipitation and temperature are the most abiotic factors that greatly impact the yield of crop,particularly in dryland.Barley,as the main cereal is predominantly cultivated in dryland and the livelihood of smallholders depends on the production of this crop,particularly in arid and semi-arid regions.This study aimed to investigate the response of the grain yield of dryland barley to temperature and precipitation variations at annual,seasonal and monthly scales in seven counties of East and West Azerbaijan provinces in northwestern Iran during 1991-2010.Humidity index(HI)was calculated and its relationship with dryland barley yield was evaluated at annual and monthly scales.The results showed that the minimum,maximum and mean temperatures increased by 0.19℃/a,0.11℃/a and 0.10℃/a,respectively,while annual precipitation decreased by 0.80 mm/a during 1991-2010.Climate in study area has become drier by 0.22/a in annual HI during the study period.Negative effects of increasing temperature on the grain yield of dryland barley were more severe than the positive effects of increasing precipitation.Besides,weather variations in April and May were related more to the grain yield of dryland barley than those in other months.The grain yield of dryland barley was more drastically affected by the variation of annual minimum temperature comparing with other weather variables.Furthermore,our findings illustrated that the grain yield of dryland barley increased by 0.01 t/hm^(2) for each unit increase in annual HI during 1991-2010.Finally,any increase in the monthly HI led to crop yield improvement in the study area,particularly in the drier counties,i.e.,Myaneh,Tabriz and Khoy in Iran.展开更多
文摘On the basis of experimental works of planning environmental impact assessment, works of planning environmental impact assessment such as each of the city＇s special planning and development zone planning were comprehensively promoted in Wuhan City, which effectively promoted the adjustment of Wuhan industrial structure, the rational layout of functions and the efficient utilization of resources, and laid a solid foundation for Wuhan City to be the supporting point for the rise of central China. Here, the work carried out in Wuhan was reviewed, combined with the new requirements of the current ecological civilization construction in Wuhan City, and the framework, the key technical points and the important focuses of the carrying out of the tracking evaluation of planning environmental impact assessment were proposed.
基金Key Extension Program on Scientific and Technological Achievements of China (No. 2004EC000132) Technology Fund of China University of Mining and Technology,China (No. 0P080307)
文摘The unified dynamic theory reveals the substrate-based nonlinear growth phenomena. It means that the environment of high organism concentration and low substrate state is useful for the growth of weak floras. With ecological superior nitrification denltrification （ ECOSUNIDE ） technology, high sludge concentration by distributing influent to anaerobic and anoxic zones is carried out, and the ecological superiorities of nitrifiers, denitrifiers, and phosphate accumulating organisms （PAOs） get to be promoted. One of the anaerobic/anoxic/oxic（A/A/O） treatment lines of a sewage treatment plant with ECOSUNIDE technology for further investigation on the nutrient removal efficiency is reformed. The advantages of ECOSUNIDE, such as high efficiency and saving energy, are well demonstrated, even under the condition of low temperature （about 15℃） and carbon-resource （C/N ratio lower than 2. 5 ）. In ECOSUNIDE system, the effluent indexes as biochemical oxygen demand （BOD）, chemical oxygen demand （COD）, and NH3--N reach the Class I-A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB18918-2002 ）, and suspended substance （ SS ）, total nitrogen （TN）, and total phosphorus（TP） meet the Class I -B criteria. While the effluent qualities of A/A/O system only reach the secondary discharge standard. Through the comparison on the sludge character of ECOSUNH）E system with A/A/O, more abundant biofacies, darker and more intense zoogloea, more obvious filamentous bacterium, and clearer floes edges in ECOSUNIDE system are found.
文摘Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied. Furthermore, the estimation of the region-time-length (RTL) parameter has been proposed to detect seismic quiescence before the occurrence of a large earthquake. In addition, the time-to-failure method has been used to estimate the time occurrence of large earthquakes. Hence, in this study, to gain deeper insight into seismic activity in the southern Zagros region, we utilized the RTL algorithm to identify the quiescence and activation phases leading to the Fin doublet earthquakes. Temporal variations in the RTL parameter showed two significant anomalies. One corresponded to the occurrence time of the first earthquake (2017-12-12);the other anomaly was associated with the occurrence time of the second event (2021-11-14). Based on a negative value of the RTL parameter observed in the vicinity of the Fin epicenters (2021), seismic quiescence (a decrease in seismicity compared to the preceding background rate) was identified. The spatial distribution of the RTL prognostic parameters confirms the appearance of seismic quiescence surrounding the epicenter of the Fin doublet earthquakes (2021). The time-to-failure method was designed using precursory events that describe the acceleration of the seismic energy release before the mainshock. Using the time-to-failure method for the earthquake catalog, it was possible to estimate both the magnitude and time of failure of the Fin doublet. Hence, the time-tofailure technique can be a useful supplementary method to the RTL algorithm for determining the characteristics of impending earthquakes.
基金supported by the Key-Area Research and Development Program of Guangdong Province (No.2020B1111360003)the Japan Society for the Promotion of Science (JSPS,No.16H06305)the Natural Science Foundation of Guangdong Province (No.2020A1515110526)。
文摘The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto ambient aerosols(γHO_(2))has largely hindered the application of the measuredγHO_(2)to the global spatial prediction.Here we induced an offine method using LFP-LIF technique to measure the kinetics of HO_(2)uptake onto ambient aerosols collected in summertime and wintertime in Yokohama city,a regional urban site near Tokyo,Japan.By controlling the dominating parameters which infuenceγHO_(2),we were able to investigate the detailed HO_(2)uptake mechanism.We characterized the chemical composition of the collected ambient aerosols,including organics,inorganics,transition metals ions,etc.and modeledγHO_(2)using different mechanisms.Results show thatγHO_(2)increased with the increase in RH,and the aerosol states(“dry”or wet/aqueous)have large effects onγHO_(2).With fixed RH and aerosol chemical composition,γHO_(2)was highly dependent on pH and inversely correlated with[HO_(2)]_0.By combing the measuredγHO_(2)values with the modeled ones,we found that both the HO_(2)self-reaction and transition metal-catalyzed reactions should be accounted for to yield a single parameterization to predictγHO_(2),and different chemical compositions may have collective effects onγHO_(2).Results may serve for extending theγHO_(2)values measured at one observation site to different environmental conditions,which will help us to achieve more accurate modeling results concerning secondary pollutant formation(i.e.,ozone).
文摘Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.
基金funded under the auspices of the National Key R&D Program of China(No.2017YFC0212303)the Open Project of State Key Laboratory of Urban Water Resource and Environment,the Harbin Institute of Technology(No.2016TS08)+3 种基金the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.QYZDB-SSW-DQC045)the National Natural Science Foundation of China(No.41775116)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2017275)Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.IGA-135-05)。
文摘Agriculture-oriented cities in Northeastern China have experienced frequent atmospheric pollution events.Deeper understandings of the pollution characteristics,haze causes and effects of management on local air quality are crucial for conducting integrated management approaches for the sustainable development of agriculture-oriented cities.Taking a typical agriculture-dominant city(i.e.,Suihua)in Northeast China,we analyzed in detail the characteristics and causes of atmospheric pollution and evaluated the straw-burning prohibition using multisource data.The results showed a clear temporal pattern of air quality index(AQI)on an annual scale(i.e.,2015-April 2019),with two typical pollution periods occurring in late autumn and early spring.The large areas of concentrated straw burning at local and regional scales accounted for the first period(i.e.,October and November),while dust emissions and farming disturbances comprised the second period.The interannual variation in pollution periods among these years was large,showing similar trends from 2015 to 2017 and the postponed late-autumn pollution period in 2018.Our evaluation has shown that the prohibition effect of straw burning significantly improved air quality in 2018,with a reduction of 59%±88%in the PM2.5 concentrations in October and November compared to 2015–2017.However,From October to April of the following year,the improvement effect was not significant due to postponement of straw burning to February or March.Our analysis also highlighted the roles of meteorological conditions,Therefore,combined with the promotion of straw utilization,scientifically prescribed burning considering the burning amount and location,meteorological conditions and regional transportation should be implemented.
基金supported by the National Natural Science Foundation of China (Nos. 41571316, 41201311, and 41301278)the Environmental Protection Scientific Research Subject of Jiangsu Province, China (No. 2013026)the National High Technology Research and Development Program (863 Program) of China (No. 2009AA063103)
文摘Remediation of organochlorine pesticide (OCP)-contaminated soils is urgently required especially in China. The present study investigated the removal of OCPs from two soils by triton X-100 (TX- 100)-enhanced washing coupled with powdered activated carbon (PAC) adsorption treatment of the solution. Two contaminated soils, including a silt clay contaminated w计h chlordene, dichloro- 2,2-6is(p-chlorophenyl)ethanes (DDDs), and dichlorodiphenyltrichloroethane (DDT) and a sandy loam containing chlordanes and mirex, were selected. Effects of varied operating parameters, including TX-100 dosage, liquid/soil (L/S) ratio, and extraction time, on the contaminant removal were examined. For both soils, OCP removal was clearly enhanced with increasing TX-100 in extraction solution and L/S ratio. Meanwhile, the removal efficacy was also impacted by soil texture and characteristics and contents of the contaminants. Moreover, by using PAC as an absorbent, a significant decrease in the contaminants in the extraction solutions was detected, and TX-100 could be further reused. Our investigation suggests that surfactant-enhanced washing combined with activated carbon selective adsorption would be an alternative to remediate OCP-contaminated soils.
文摘Efficient management of air quality requires a comprehensive emission inventory to support decision-making on air quality improvement.This article presents a comprehensive framework for detailed emission inventory development in cities with low-quality basic data,which examines the emission of primary criteria pollutants(CO,NO_(x),SO_(2),PM_(2.5),PM_(10),and VOC)from mobile sources,residential,commercial,and public services,fuel stations,transport terminals,energy conversion sections,and industries.This research was applied to Tabriz in Northwest Iran,one of the polluted medium-sized cities with a population of 1.77 million.Results show the city daily emission per capita is 569.8 g of CO,68.6 g of NO_(x),38.6 g of VOC,17.6 g of SO_(x),and 3.7 g of PM.Vehicular emissions accounted for 98%of CO,91%of VOCs,61%of NO_(x),and 56%of PM;meaning alternative policy strategies in vehicles would reduce emissions rapidly.Fifteen applicable and effective scenarios in transport and one concerning stationary sourceswere proposed and reduction potential of themwas evaluated.Effectiveness of the public transport improvement and replacement of old passenger cars were founded the key scenarios.These two alternatives decrease 14 and 2 tons of SO_(2) and 6797 and 2394 tons of NO_(x) annually with the cost of$99.5 MM and$366.5 MM,respectively.The findings of this study provides the choice of travel method by each citizen is a function of cost,speed,comfort and safety of travel;therefore,all the requirements of any scenarios must be fully considered in the implementation step.
基金funded by the National Natural Science Foundation of China (Nos. 21377012, 21177012, 40975061)the National Science and Technology Support Programme of the Ministry of Science and Technology of China (Nos.2014BAC23B02, 2014BAC06B05)the Special Programme on Public Welfare of the Ministry of Environmental Protection (No. 201409022)
文摘The mass concentration and major chemical components of fine particulate matter were measured before,during and after Beijing＇s massive parade commemorating 70th anniversary of the Chinese Victory in World War II on September 3,2015.Regional emission inventory,positive matrix factorization（PMF）,observations from space and backward air mass trajectories were jointly applied to identify the major pollution sources and their temporal and spatial variations.The contributions of emissions variations and the meteorological conditions related to the＂parade blue＂phenomenon in Beijing and its surrounding areas were investigated in detail.The main cause of the decreased PM（2.5）mass concentration was attributed to the absolute reduction in emissions of primary air pollutants.The chemical composition of PM（2.5）varied significantly before,during and after the parade.Fugitive dust particles were well controlled,the secondary formation of PM（2.5）was reduced along with the controlled gaseous precursors＇emissions from vehicles and industrial sources during the temporary intensified control period.During the parade period,the SO2and NO2column concentrations in Beijing and the surrounding areas decreased sharply,indicating that the coordinated reduction in primary emissions from the surrounding areas of Beijing played an important role in lowering the ambient concentration of SO2and NO2and accordingly lowered PM（2.5）and improved the regional air quality.A comparison of the temperature,humidity,and wind speed and direction during the same periods in 2014 and 2015 showed that the meteorological conditions positively influenced the achievement of＂parade blue＂.
基金sponsored by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.Grant XDA19040201)the National Natural Science Foundation of China(No.41877314)。
文摘The region along the Taihang Mountains in the North China Plain(NCP) is characterized by serious fine particle pollution. To clarify the formation mechanism and controlling factors, an observational study was conducted to investigate the physical and chemical properties of the fine particulate matter in Jiaozuo city, China. Mass concentrations of the water-soluble ions(WSIs) in PM_(2.5) and gaseous pollutant precursors were measured on an hourly basis from December 1, 2017, to February 27, 2018. The positive matrix factorization(PMF) method and the FLEXible PARTicle(FLEXPART) model were employed to identify the sources of PM_(2.5). The results showed that the average mass concentration of PM_(2.5) was 111 μg/m^(3) during the observation period. Among the major WSIs, sulfate, nitrate, and ammonium(SNA) constituted 62% of the total PM_(2.5) mass, and NO_(3)^(-) ranked the highest with an average contribution of 24.6%. NH_(4)^(+) was abundant in most cases in Jiaozuo. According to chemical balance analysis, SO_(2)-4, NO_(3)^(-), and Cl^(-) might be present in the form of(NH_4)_(2)SO_4, NH_4NO_3, NH_4Cl, and KCl. The liquid-phase oxidation of SO_(2) and NO_(2) was severe during the haze period. The relative humidity and pH were the key factors influencing SO_(4)^(2-) formation. We found that NO_(3)^(-) mainly stemmed from homogeneous gas-phase reactions in the daytime and originated from the hydrolysis of N_(2)O_5 in the nighttime, which was inconsistent with previous studies. The PMF model identified five sources of PM_(2.5) : secondary origin(37.8%), vehicular emissions(34.7%), biomass burning(11.5%), coal combustion(9.4%), and crustal dust(6.6%).
基金Project supported by the Key Project of Chinese Ministry of Education(No.104250).
文摘Hexachlorobenzene （HCB） is a chlorinated aromatic hydrocarbon that was widely used for seed dressing in prevention of fungal growth on crops, and also as a component of fireworks, ammunition, and synthetic rubbers. Because of its resistance to degradation and mobility, HCB is widely distributed throughout the environment and is accumulated through food chains in different ecosystems. In this study, a preliminary investigation was carried out on the bioaccumulation and the toxic effects of HCB in the microbial （protozoan in particular） communities in the Fuhe River, Wuhan, a water body receiving industrial wastewaters containing HCB and other pollutants, using the standardized polyurethane foam units （PFU） method. Field samples were taken from eight stations established along the Fuhe River in January and August 2006. The concentration ratios of HCB in microbial communities and in water were 9.66-18.64, and the microbial communities accumulated 13.29-56.88 μg/L of HCB in January and 0.82-10.25 μg/L HCB in August. Correlation analysis showed a negative correlation between the HCB contents in the microbial assemblage, and the number of species and the diversity index of the protozoan communities. This study demonstrated the applicability of the PFU method in monitoring the effects of HCB on the level of microbial communities.
文摘Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic species.In this study,the spatial distribution of five endemic and threatened species belonging to the genus Onosma(including O.asperrima,O.bisotunensis,O.kotschyi,O.platyphylla,and O.straussii)was investigated under present and future climate change scenarios:RCP2.6(RCP,representative concentration pathway;optimistic scenario)and RCP8.5(pessimistic scenario)for the years 2050 and 2080 in Iran.Analysis was conducted using the maximum entropy(MaxEnt)model to provide a basis for the protection and conservation of these species.Seven environmental variables including aspect,depth of soil,silt content,slope,annual precipitation,minimum temperature of the coldest month,and annual temperature range were used as main predictors in this study.The model output for the potential habitat suitability of the studied species showed acceptable performance for all species(i.e.,the area under the curve(AUC)>0.800).According to the models generated by MaxEnt,the potential current patterns of the species were consistent with the observed areas of distributions.The projected climate maps under optimistic and pessimistic scenarios(RCP2.6 and RCP8.5,respectively)of 2050 and 2080 resulted in reductions and expansions as well as positive range changes for all species in comparison to their current predicted distributions.Among all species,O.bisotunensis showed the most significant and highest increase under the pessimistic scenario of 2050 and 2080.Finally,the results of this study revealed that the studied plant species have shown an acute adaptability to environmental changes.The results can provide useful information to managers to apply appropriate strategies for the management and conservation of these valuable Iranian medicinal and threatened plant species in the future.
基金supported by the National Natural Science Foundation of China (No.41205115)
文摘To investigate the composition and possible sources of particles, especially during heavy haze pollution, a single particle aerosol mass spectrometer（SPAMS） was deployed to measure the changes of single particle species and sizes during October of 2014, in Beijing. A total of 2,871,431 particles with both positive and negative spectra were collected and characterized in combination with the adaptive resonance theory neural network algorithm（ART-2a）. Eight types of particles were classified： dust particles（dust, 8.1%）, elemental carbon（EC, 29.0%）, organic carbon（OC, 18.0%）, EC and OC combined particles（ECOC, 9.5%）,Na-K containing particles（Na K, 7.9%）, K-containing particles（K, 21.8%）, organic nitrogen and potassium containing particles（KCN, 2.3%）, and metal-containing particles（metal,3.6%）. Three haze pollution events（P1, P2, P3） and one clean period（clean） were analyzed,based on the mass and number concentration of PM_（2.5）and the back trajectory results from the hybrid single particle Lagrangian integrated trajectory model（Hysplit-4 model）. Results showed that EC, OC and K were the major components of single particles during the three haze pollution periods, which showed clearly increased ratios compared with those in the clean period. Results from the mixing state of secondary species of different types of particles showed that sulfate and nitrate were more readily mixed with carbon-containing particles during haze pollution episodes than in clean periods.
基金supported by the Brain Korea 21 of SafeSustainable Infrastructure Research Group,Seoul National University
文摘The removal of As（III） and As（V） from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experiment： grind precipitate dust （GPD） and cast iron shot （CIS）. The X-ray diffraction analysis indicated the presence of Fe~ on GPD and CIS. Batch experiments were performed under different concentrations of As（III） and As（V） and at various initial pH levels. Results showed that waste cast iron was effective in the removal of arsenic. The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result. In the adsorption of both As（III） and As（V）, the adsorption capacity of GPD was greater than CIS, mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS. Results also indicated the removal of As（III） and As（V） by GPD and CIS was influenced by the initial solution pH, generally decreasing with increasing pH from 3.0 to 10.5. In addition, both GPD and CIS were more effective at the removal of As（III） than As（V） under given experimental conditions. This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.
基金Supported by Guangxi Science and Technology Planning Project(GK AB18221096)Fund of Guangxi Academy of Agricultural Sciences(CNK 2015YT322019ZX121).
文摘This paper reviewed the meaning of facility agriculture and the development status and trends of facility agriculture at home and abroad,analyzed the development status and existing problems of facility agriculture in Guangxi,and proposed corresponding solutions to the problems in the development of facility agriculture in Guangxi,aiming to provide reference for promoting the sustainable development of facility agriculture in Guangxi.
基金the Korea Meteorological Administration(KMA) Research and Development Program under Grant CATER 2006- 4205 and by BK21 program.Partial support for M.Kimoto was given by the Innovative Program of Climate Change for the 21st Century of the Japanese Ministry of Education, Culture,Sports,Science and Technology.
文摘Decadal changes in the subseasonal evolution and the phase-locked climatological intraseasonal fluctuation of summertime rainfall over the Korean Peninsula before and after the mid-1990s are investigated.The activity and the migration speed of the monsoon rain band over the East Asian region are altered in the recent decade,resulting in the drier conditions in late spring and the earlier onset of Changma.In early August when a climatological monsoon break was clear in the earlier decade,the precipitation has increased dramatically with a meridional coherency.The response to the enhanced convection over the South China Sea and southeastern China provides a favorable condition for more precipitation in early August through the changes in moisture transport and tropical cyclone passage.
基金Supported by Guangdong Excellent Innovational Youth Training Program(LYM11126)National Natural Science Fund(30870469,31170486)
文摘[ Objective] The aim was to study the natural environment of Karst mountain areas in northern Guangdong. [ Method] Through the col- lection of topography, climate, soil and vegetation data in the Karst mountain areas of Northern Guangdong, combined with field investigation, the natural environment of Karst mountain areas in northern Guangdong was analyzed. [ Result] The Karst topography of the area is widely distributed. Most places were in subtropical climate zone, with high temperature and rainfall in the same period, and abundant precipitation. There was a large area of contiguous distribution of limestone with dissolution area. Vegetations included typical limestone evergreen and deciduous broadleaved mixed forest, limestone shrub and grassy slopes in mountain and hill. Limestone vegetation had typical limestone mixed evergreen broadleaf forest, limestone shrub, limestone hilly mountain grass slope. [ Conclusion] The study provided theoretical basis for the protection of natural environment of Karst mountain areas in northern Guangdong.
文摘Precipitation and temperature are the most abiotic factors that greatly impact the yield of crop,particularly in dryland.Barley,as the main cereal is predominantly cultivated in dryland and the livelihood of smallholders depends on the production of this crop,particularly in arid and semi-arid regions.This study aimed to investigate the response of the grain yield of dryland barley to temperature and precipitation variations at annual,seasonal and monthly scales in seven counties of East and West Azerbaijan provinces in northwestern Iran during 1991-2010.Humidity index(HI)was calculated and its relationship with dryland barley yield was evaluated at annual and monthly scales.The results showed that the minimum,maximum and mean temperatures increased by 0.19℃/a,0.11℃/a and 0.10℃/a,respectively,while annual precipitation decreased by 0.80 mm/a during 1991-2010.Climate in study area has become drier by 0.22/a in annual HI during the study period.Negative effects of increasing temperature on the grain yield of dryland barley were more severe than the positive effects of increasing precipitation.Besides,weather variations in April and May were related more to the grain yield of dryland barley than those in other months.The grain yield of dryland barley was more drastically affected by the variation of annual minimum temperature comparing with other weather variables.Furthermore,our findings illustrated that the grain yield of dryland barley increased by 0.01 t/hm^(2) for each unit increase in annual HI during 1991-2010.Finally,any increase in the monthly HI led to crop yield improvement in the study area,particularly in the drier counties,i.e.,Myaneh,Tabriz and Khoy in Iran.
