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1.
Payet R  Obura D 《Ambio》2004,33(1-2):24-33
The complex interactions between human activities and the environment at the interface of land and water is analyzed with a focus on the Somali Current (East Africa), and Indian Ocean Island States, subregions of the Global International Waters Assessment (GIWA). These 2 subregions contain some of the world's richest ecosystems, including the high biodiversity forests of Madagascar and the diverse coastal habitats of the eastern African coast. These ecosystems support local communities and national and regional economies. Current and future degradation of these systems, from water basins to continental shelves, affects the livelihoods and sustainability of the countries in the region, and long-term efforts to reduce poverty. The assessments determined that pollution and climate change are the primary environmental and social concerns in the Islands of the Indian Ocean, while freshwater shortage and unsustainable exploitation of fisheries and other living resources are the primary environmental and social concerns in East Africa. The GIWA approach, through assessing root causes of environmental concerns, enables the development of policy approaches for mitigating environmental degradation. This paper explores policy frameworks for mitigating the impacts, and reducing the drivers, of 3 environmental concerns--freshwater shortage; solid waste pollution; and climate change--addressing social and institutional causes and effects, and linking the subregions to broad international frameworks. The common theme in all 3 case studies is the need to develop integrated ecosystem and international waters policies, and mechanisms to manage conflicting interests and to limit threats to natural processes.  相似文献   

2.
Food irradiation     
The use of irradation to improve the safety, protect the nutritional benefits, and preserve the quality of fresh and processed foods is a well established and proven technology. Over the past 30 years, the United States Government has invested in the science to confirm safety and in the technology to show application. The United States Department of Agriculture and the Food and Drug Administration have approved sources of ionizing radiation for the treatment of foods, and their application to most meats, fruits, vegetables, and spices. Despite the value of this technology to the food industry and to the health and welfare of the public, only minimal application of this technology occurs. This underscorces the importance of increasing the public’s understanding of radiation risks relative to other hazards. Accordingly, the Committee on Interagency Radiation Research and Policy Coordination of the Executive Office of the President has made recommendations for the creation of a centralized National Radiation Information Center that would work closely with Federal departments and agencies in responding to public queries about radiation issues and Federal programs.  相似文献   

3.
GOAL, SCOPE AND BACKGROUND: [corrected] Historically, landfills have been the simplest form of eliminating urban solid waste with the minimum cost. They have been the most usual method for discarding solid waste. However, landfills are considered authentic biochemical reactors that introduce large amounts of contaminants into the environment in the form of gas and leachates. The dynamics of generation and the movement of gas in landfills depend on the input and output parameters, as well as on the structure of the landfill and the kind of waste. The input parameters include water introduced through natural or artificial processes, the characteristics of the urban solid waste, and the input of atmospheric air. The main output parameters for these biochemical reactors include the gases and the leachates that are potentially pollutants for the environment. Control systems are designed and installed to minimize the impact on the environment. However, these systems are not perfect and a significant amount of landfill gas could be released to the atmosphere through the surface in a diffuse form, also known as Non-controlled emission. In this paper, the results of the Non-controlled biogenic gas emissions from the Lazareto landfill in Tenerife, Canary Islands, are presented. The purpose of this study was to evaluate the concentration of CH4 and CO2 in the soil gas of the landfill cover, the CH4 and CO2 efflux from the surface of the landfill and, finally, to compare these parameters with other similar landfills. In this way, a better understanding of the process that controls biogenic gas emissions in landfills is expected. METHODS: A Non-controlled biogenic gas emission survey of 281 sampling sites was carried out during February and March, 2002. The sampling sites were selected in order to obtain a well-distributed sampling grid. Surface landfill CO2 efflux measurements were carried out at each sampling site on the surface landfill together with soil gas collection and ground temperatures at a depth of 30-40 cm.The CH4 efflux was computed from CO2 efflux and from the ratio CH4/CO2 in the soil gas. Soil gas samples were collected at a depth of 30-40 cm using a metallic probe and 20 cc hypodermic syringes, and later stored in evacuated 10 cc vacutainers for laboratory analysis of bulk composition. The gas sample was introduced in a vacutainer filled with deionized water and displacing the water until the vacutainer was filled with the gas sample in order to avoid air contamination from entering. The surface landfill temperature of the landfill was measured at a depth of 40 cm using a digital thermometer type OMEGA 871A. Landfill gases, CO2 and CH4, were analyzed within 24 hours using a double channel VARIAN micro-GC QUAD CP-2002P, with a 10 meter PORAPLOT-Q column, a TCD detector, and He as a carrier gas. The analysis temperature was 40 degrees C and the injection time was 10 msec. Surface landfill CO2 efflux measurements were performed using a portable NDIR spectrophotometer Licor-800 according to the accumulation chamber method (Chiodini et al. 1996). The data treatment, aimed at drawing the flux map and computing the total gas output, was based on the application of stochastic simulation algorithms provided by the GSLIB program (Deutsch and Journel 1998). RESULTS: Diffuse CH4 and CO2 efflux values range from negligible values up to 7,148 and 30,573 g m(-2) d(-1), respectively. The spatial distribution of the concentration and efflux of CO2, CH4 and soil temperature, show three areas of maximum activity in the landfill, suggesting a non-uniform pattern of diffuse degassing. This correlation between high emissions and concentration of CO2, CH4 and soil temperatures suggests that the areas of higher microbial activity and exothermic reactions are releasing CO2 and CH4 to the atmosphere from the landfill. Taking into consideration the spatial distribution of the CO2 and CH4 efflux values as well as the extension of the landfill, the Non-controlled emission of CO2 and CH4 to the atmosphere by the Lazareto's landfill are of 167 +/- 13.3 and 16 +/- 2.5 t d(-1), respectively. DISCUSSION: The patterns of gas flow within the landfill seem to be affected by boundary materials at the sides. The basalt layers have a low permeability and the gas flow in these areas is extensive. In this area, where a basalt layer does not exist, the flow gas diffuses toward the sea and the flux emissions at the landfill surface are lower. This behavior reflects the possible dissolution of gases into water and the deflection of gases towards the surface at the basalt boundary. The proximity to the sea, the installation of a palm tree garden and, as a result, the contribution of water coming from the watering of this garden has reactivated the system. The introduction of sea water into the landfill and the type of boundary could be defining the superficial gas discharges. CONCLUSIONS: Results from this study indicate that the spatial distribution of Non-controlled emission of CO2 and CH4 at the Lazareto's landfill shows a non-uniform pattern of diffuse degassing. The northeast, central and northwest areas of the Lazareto's landfill are the three areas of high emissions and concentration of CO2 and CH4, and high temperatures. The correlation between high emissions and the concentration of CO2, CH4, and the high temperatures suggest that the areas of higher microbial activity and exothermic reactions are releasing more CO2 and CH4 to the atmosphere from the landfill. A high concentration of CO2 is probably due to the presence of methanotrophic bacteria in the soil atmosphere of the landfill. Patterns of gas flow within the landfill seem to be affected by boundary materials (basalt layers) of low permeability, and side boundaries of the flux emissions at the surface are higher. At the sides of seawater and sediment boundaries, flux emissions at the landfill surface are lower. This behavior reflects a possible dissolution of gases into the water and the deflection of gases towards the surface at the basalt boundary. With this study, we can compare the data obtained in this landfill with other landfills and observe the different levels of emission. The proximity to the sea and the installation of the palm tree garden palms and, as a result, the contribution of water coming from the watering of this garden has reactivated the system. Many landfills worldwide located in similar settings could experience similar gas production processes. RECOMMENDATIONS AND PERSPECTIVES: The need for investigating and monitoring sea water and sediment quality in these landfills is advisable. Concentrations and fluxes of contaminants and their impact in the area should be assessed. With this study we can compare the data obtained in these landfills with other landfills and observe the different levels of emission.  相似文献   

4.
The sources and sinks of dissolved and particulate Pb, Cu and Zn were determined for the main basin of Puget Sound to understand the effect man has had on metal concentrations in both the water column and in the sediments. Municipal, industrial and atmospheric sources contributed about 66% of the total Pb added to the main basin of Puget Sound during the early 1980s. Advective inputs were the major sources of total Cu and Zn (approximately 40%) while riverine and erosional sources contributed about 30%. The discharge of the particle-bound trace metals from rivers minimized the influence of particulate anthropogenic sources, which constituted 50%, 23% and 18% of the total particulate Pb, Cu and Zn inputs, respectively. While advective transport was the major source of dissolved Cu and Zn (approximately 60% of all dissolved inputs), industrial, municipal and atmospheric inputs contributed about 85%, 30% and 38% of the dissolved Pb, Cu and Zn inputs, respectively. The sources of dissolved and particulate Cu and Zn were comparable with the sinks within the errors of the analyses indicating their quasi-conservative nature. Advection removed about 60% of the total Cu and Zn added to the main basin while 40% was deposited in the sediments of Puget Sound. Because of this quasi-conservative nature of Cu and Zn, anthropogenic inputs of Cu and Zn were dispersed from the system more than they were contained within main basin sediments. About 75% of the dissolved Pb discharged into the main basin of Puget Sound was lost from the dissolved phase and was balanced by a similar gain in the particulate phase. Because of this extensive scavenging and the effective retention of particles within the main basin, about 70% of the total Pb added to the main basin was retained within its sediments. These separate mass balances have utility in management decisions because they show the relative contributions from different sources and demonstrate whether the influences of dissolved and particulate inputs are reflected solely in the water column or the sediments, respectively.  相似文献   

5.
Day- and nighttime total suspended particulate matter was collected inside and outside Emperor Qin's Terra-Cotta Museum in winter and summer 2008. The purpose was to characterize the winter and summer differences of indoor airborne particles in two display halls with different architectural and ventilation conditions, namely the Exhibition Hall and Pit No. 1. The morphology and elemental composition of two season samples were investigated using scanning electron microscopy and energy dispersive X-ray spectrometry. It is found that the particle size, particle mass concentration, and particle type were associated with the visitor numbers in the Exhibition Hall and with the natural ventilation in Pit No. 1 in both winter and summer. Evident winter and summer changes in the composition and physicochemical properties of the indoor suspended particulate matters were related to the source emission and the meteorological conditions. Particle mass concentrations in both halls were higher in winter than in summer. In winter, the size of the most abundant particles at the three sites were all between 0.5 and 1.0 microm, whereas in summer the peaks were all located at less than 0.5 microm. The fraction of sulfur-containing particles was 2-7 times higher in winter than in summer. In addition to the potential soiling hazard, the formation and deposition of sulfur-containing particles in winter may lead to the chemical and physical weathering of the surfaces of the terra-cotta statues.  相似文献   

6.
为了探索污泥堆肥中重金属在土壤-植物系统中的积累与转移特性,通过温室盆栽实验,分析了污泥堆肥对草坪草高羊茅、黑麦草和白三叶生物量积累的情况,研究了污泥堆肥中Zn和Cu在植物和土壤中的分布特征。结果表明,污泥堆肥施用可以有效促进3种草坪草的积累生物量,在0~6 kg/m2的污泥堆肥施用量范围内,草坪草的生物量积累随着施用量的增加而提高。土壤中Zn和Cu的含量随污泥堆肥施加量的增加而增大,85%以上的Zn和Cu残留在土壤中。污泥堆肥中的Zn和Cu均可以被植物吸收,随着污泥堆肥施用量的增加,草坪草对Zn和Cu的吸收量增大,但当污泥堆肥施用量超过一定阈值时,草坪草吸收Zn和Cu不再增加,甚至减少;对于不同的草坪草,这一阈值有所不同。植物对Zn和Cu的吸收量只占土壤中Zn和Cu减少量的5%左右。根据生物富集系数(BCF)的计算结果推测,污泥堆肥的施用对土壤环境的影响大于对植物体内累积Zn和Cu的影响。  相似文献   

7.
利用白云石回收污泥厌氧消化液中的磷   总被引:4,自引:1,他引:3  
梅翔  杨旭  张涛  王欣  严伟  何珣  张怡  周宇翔 《环境工程学报》2012,6(11):3809-3816
为经济有效地从污泥厌氧消化液中回收磷,构建了以白云石提供钙镁源的磷回收方法,探讨了磷回收的工艺条件与效果。通过盐酸酸化厌氧消化液以降低其碳酸盐含量,同时利用白云石溶于冷稀盐酸的特性使其钙镁缓慢释放到酸化的厌氧消化液中形成第一步磷回收体系,考察体系酸化pH、白云石与厌氧消化液的固液比以及反应pH对白云石的钙镁释放和磷回收效果的影响;第一步磷回收后的上清液为第二步厌氧消化液磷回收提供钙镁源,研究投加钙磷摩尔比对磷回收效果的影响。实验结果表明,当固液比为5.0时,在酸化pH为4.0~4.5且酸化溶出时间为10 h以及反应pH为9.0的条件下,第一步磷回收产物以磷酸钙盐沉淀为主,厌氧消化液磷回收率及回收产物含磷率(以P2O5计)分别达到99.43%和38.49%;第一步磷回收后的上清液按一定的钙磷摩尔比投加到酸化后的厌氧消化液中进行第二步磷回收,当投加钙磷摩尔比为0.20时,在反应pH为9.0的条件下,回收产物同时含有磷酸钙盐和磷酸铵镁,厌氧消化液中氮、磷回收率分别达到13.19%和90.90%,回收产物氮、磷含量(以P2O5计)分别为0.26%和39.58%;经XRD、XRF、ICP及SEM等分析表征,2步磷回收的产物以磷酸钙盐和磷酸铵镁为主要成分,杂质少。研究表明,利用白云石为钙镁源,通过分别构建不同的磷回收体系可以分步从污泥厌氧消化液中经济有效地回收磷,且磷回收率和回收产物含磷率高。  相似文献   

8.
Ecotoxicity data with high reliability and relevance are needed to guarantee the scientific quality of environmental risk assessments of pharmaceuticals. The main advantages of a more structured approach to data evaluation include increased transparency and predictability of the risk assessment process, and the possibility to use non-standard data.In this collaboration, between the research project MistraPharma and the German Federal Environment Agency, a new set of reporting and evaluation criteria is presented and discussed. The new criteria are based on the approaches in the literature and the OECD reporting requirements, and have been further developed to include both reliability and relevance of test data.Intended users are risk assessors and researchers performing ecotoxicological experiments, but the criteria can also be used for education purposes and in the peer-review process for scientific papers. This approach intends to bridge the gap between the regulator and the scientist’s needs and way of work.  相似文献   

9.
It is the purpose of this study to demonstrate the procedure involved in simulating those average and maximum pollutant concentrations at or around an airport which fall under the control of the Clean Air Act. The information is useful, when planning new or expanding existing airports, when estimating the impact of airports on the surrounding air quality, and when assessing the effectiveness of control procedures. Simulation of airport air quality requires the accurate assessment of the temporal and spatial emission patterns. This involves the tabulation of air traffic density by type and engine, make and model of aircraft, and engine mode number; the use of fuel by different aircraft; the pollutant emission rates by engine model and operational mode; the allocation of emission rates to the respective runways, turn-off points, taxi-ways, and parking areas, and the time each aircraft spent in the different operational modes. The resulting emission pattern for the Honolulu International Airport reflects scheduled and unscheduled commercial and military jet and piston aircraft and nonaircraft operations. Using this and the appropriate meteorological information average and maximum surface concentrations were calculated and compared with local ambient air quality standards. The calculation of concentrations is based on a newly developed diffusion model incorporating harmonic mean wind speeds for every degree of wind direction as determined by a Parzen maximum likelihood interpolation technique, and the assumption of log-normal concentration distributions. It is shown that for some pollutants the air quality standards are substantially exceeded, and it is concluded that airports may have a considerable adverse impact on their surrounding air quality.  相似文献   

10.
The use of irradiation to improve the safety, protect the nutritional benefits, and preserve the quality of fresh and processed foods is a well established and proven technology. Over the past 35 years, the United States Government has invested in the science to confirm safety and in the technology to show application. The United States Department of Agriculture (USDA) and the Food and Drug Administration have approved sources of ionizing radiation for the treatment of foods, and their application to most meats, fruits, vegetables, and spices. Despite the value of this technology to the food industry and to the health and welfare of the public, only minimal application of this technology occurs. This underscores the importance of increasing the public's understanding of radiation risks relative to other hazards. Accordingly, in 1995, the Committee on Interagency Radiation Research and Policy Coordination of the Executive Office of the President made recommendations for the creation of a centralized National Radiation Information Center that would work closely with Federal departments and agencies in responding to public queries about radiation issues and Federal programs. This article updates a commentary published in 1996 (Young 1996). In the past six years, some progress has been made, including the establishment of a government operated Food Irradiation Information Center, and the completion of final rule making by USDA, thus permitting the safe treatment of meats and poultry. Despite these actions, little progress has been made on the public acceptance of this technology. The need for an informed public and for a better understanding of risks, i.e., risk communication, is noted.  相似文献   

11.
预涂动态膜强化渗透与截留性能研究   总被引:1,自引:1,他引:0  
以二氧化钛粉体材料为涂膜剂,陶瓷管为基膜制备预涂动态膜,引入通量增强系数Zi和截留增强系数Fi研究了预涂动态膜制备条件对其强化渗透与截留性能的影响,并用SEM电镜对预涂动态膜和基膜表面形貌进行表征。结果表明:制备的预涂动态膜表面均匀密实,其孔径低于基膜平均孔径。预涂动态膜的渗透与截留性能随涂膜液pH值的增加而增加,在跨膜压差低于0.2 MPa、错流速度低于1.5 m/s,涂膜时间少于30 m in和涂膜液浓度低于0.4 g/L范围内,提高这些参数值有利于提高预涂动态膜的渗透与截留性能,超出此范围时,提高这些参数值对增强其渗透与截留性能的效果已不明显,其中错流速度的影响相对小些。跨膜压差为0.2 MPa,错流速度为1.5 m/s,涂膜时间30 m in,涂膜液浓度和pH值分别为0.4 g/L和10.2时为最佳制备条件。  相似文献   

12.
This paper discusses the approach used by the City of Chicago to encourage the implementation of an air resource management program in the metropolitan area. It explores the many facets that were helpful in designing and implementing the City of Chicago’s Five-Year Air Resource Management Program and the progress to date. Also highlighted is the social geography of the metropolitan area and the relationship of population growth and rapid industrial expansion to the area’s air pollution problem. Existing control programs in the Chicago Metropolitan Area are reviewed and are used to document the various elements essential for the success of an air resource management program. These include the Chicago Program, the Cook County Program, the State of Illinois Program and the Interstate Program between Illinois and Indiana. The authors devote considerable discussion to the methodology used to develop an air resource management program, including selection of goals, design of organization, technical development, definition of sources and effects, systems approach, and long- and short-range objectives. The importance of a public information and education program and its relationship to various segments of community leadership are also covered in this paper  相似文献   

13.
To categorize the marine environmental health status, the Oslo and Paris commissions have recently formulated Ecological Quality Objectives (EcoQOs) for many ecological features including the contamination of coastal bird eggs with mercury and organochlorines. In this study, we describe spatial and temporal patterns of egg contamination around the North Sea and compared them to the EcoQOs. Concentrations of mercury, polychlorinated biphenyl (??PCB) congeners, dichlorodiphenyltrichloroethane (??DDT) and derivatives, hexachlorobenzene (HCB) and hexachlorocyclohexane (??HCH) isomers were analysed in two tern species (Sterna hirundo and Sterna paradisaea) and Oystercatcher (Haematopus ostralegus) eggs collected between 2008 and 2010 in a total of 21 sites in seven countries surrounding the North Sea. Hg, ??PCB and HCB were highest in the southern sites, while ??DDT and ??HCH concentrations were greatest in eggs from the western North Sea and the Elbe estuary. There were rarely any consistent decreases over time for any compounds. In the terns, Hg, HCB and ??HCH increased at most sites, ??PCB and ??DDT in Sweden and Norway. In the Oystercatcher, HCB and ??HCH increased at more than the half of the sites, ??PCB, ??DDT and Hg at several German sites. In the terns, Hg, ??PCB and ??DDT exceeded the EcoQO in all, HCB in most years and sites. At most sites, ??HCH fulfilled the EcoQO in some study years. In the Oystercatcher, Hg, ??PCB and ??DDT exceeded the EcoQO in all or most years and sites. HCB and ??HCH fulfilled the EcoQO in some or all years at most sites. The EcoQO was exceeded most frequently in estuaries. We conclude that EcoQOs are suitable for drawing contamination patterns of the coastal North Sea in an easily understandable manner, offering the opportunity to harmonize the EcoQOs with coordinated environmental monitoring programmes.  相似文献   

14.
Hu X  Ding Z  Chen Y  Wang X  Dai L 《Chemosphere》2002,48(6):621-629
Through short-term exposure (7-d exposure), long-term exposure (16-d exposure) and exposure-recovery (7-d exposure + 9-d recovery), the bioaccumulation and distribution of La and Ce and their effects on growth of wheat seedlings were studied. Addition of La (0.5-25 mg/l) and Ce (0.5-25 mg/l) to the culture medium individually and in combination inhibited primary root elongation, reduced the dry weight of roots and shoots and the content of mineral elements (Ca, Mg, K, Cu, Zn). The damage increased with an increase in the concentrations of La and Ce in culture medium. Relative damage ratio increased with an increase in concentrations of La and Ce in the culture medium and with exposure time. Comparing exposure-recovery groups with long-term exposure groups, primary root lengths, dry weight of roots and shoots and the content of five mineral elements were higher. The accumulation of La and Ce in the seedlings was positively correlated with the concentrations of La and Ce in the culture medium and with exposure time. Bioaccumulation factors of La and Ce in roots were much higher than those of shoots. The uptake rates of La and Ce by the plants were much higher than the translocation rates from roots to shoots. The accumulation and distribution of La and Ce in the seedlings in exposure-recovery groups showed that there was very little excretion through metabolism during the recovery period, but redistribution occurred throughout the whole plant. No apparent selective uptake was found between La and Ce by the plants when they were applied in combination.  相似文献   

15.
A wide range of delta morphologies occurs along the fringes of the Young Sound in Northeast Greenland due to spatial heterogeneity of delta regimes. In general, the delta regime is related to catchment and basin characteristics (geology, topography, drainage pattern, sediment availability, and bathymetry), fluvial discharges and associated sediment load, and processes by waves and currents. Main factors steering the Arctic fluvial discharges into the Young Sound are the snow and ice melt and precipitation in the catchment, and extreme events like glacier lake outburst floods (GLOFs). Waves are subordinate and only rework fringes of the delta plain forming sandy bars if the exposure and fetch are optimal. Spatial gradients and variability in driving forces (snow and precipitation) and catchment characteristics (amount of glacier coverage, sediment characteristics) as well as the strong and local influence of GLOFs in a specific catchment impede a simple upscaling of sediment fluxes from individual catchments toward a total sediment flux into the Young Sound.  相似文献   

16.
Background Scope and Aims. To realize the vision of sustainable development (SD) originating from the ‘only one earth’ philosophy, and to integrate the conceptions of ecology and sustainability into the planning and decision-making criteria of urban growth management, the establishment of a recycling-oriented society (ROS) is essential. However, before the above intention can be achieved, it is indispensable to develop a system of strategic indicators for supporting a radical reformation of the urban development plan. Therefore, this study, based on the conception of the new urban development pattern ROS, attempted to carefully choose a sample city in Taiwan for launching a preliminary case study, and furthermore designed and proposed a concise and strategy-oriented assessment indicator system termed ROSAIS. ROSAIS, on the one hand, can act as a compass for understanding resource using efficiency and recycling status during city development and, on the other hand, can serve as an implement supporting decision-making for ROS construction.Methods According to the definition and spirit of ROS, the structure of ROSAIS should clearly represent the relationship between resources and environment in human activities. The eco-efficiency indicator system (EEIS) and environmental symbiosis indicator system (ESIS) can be considered two key sub-indicator systems, and are the necessary components of ROSAIS. EEIS chooses the dominant production sectors in urban economic activities to calculate their eco-efficiency (EE). Separately, for obtaining a consensus regarding the framework of ESIS, the questionnaire approaches and expert consultation, together with the research experience and foundation of current relevant studies and indicator systems, are applied when crucial resource and environmental issues and respective indicators are selected.Results and Discussion The calculation results of EEIS in this case study indicated that among the three dominant production activities (agricultural, fishery, and animal husbandry sector) the fishery sector has the highest EE, which indicates that the fishery activities and resources significantly influence the sustainability of the economic-environmental system of the sample city. Furthermore, according to a consensus achieved in ESIS, local green spaces, resource recovery, energy consumption pattern change, freshwater conservation and greenhouse effect abatement were considered as the five crucial issues influencing how the case study city can develop into an ES-city. The rate of local green spaces, resource recycling, freshwater conservation and the rate of reduction of nonrenewable energy use as well as carbon dioxide (CO2) emissions were used to evaluate the above five issues.Conclusion This case study is unparalleled in Taiwan. Even in Japan, where ROS legislation has been implemented, this kind of study remains in the preliminary stages. Furthermore, when communicating the indicator results, it is essential to provide the context and countermeasures of the crucial issues that are faced. The two sub-indicator systems proposed in this case study could comply completely with the above-mentioned requirements. For example, the EEIS provides information for achieving a balance between environmental burden and economic benefits among dominant production sectors; the ESIS provides information for setting strategies for overcoming the crucial issues faced. Recommendation and Outlook This study recommends that urban planers should consider the construction of the corresponding strategic indicator system to be indispensable, and makes further use of the indicator results related to the environmental education of residents for identifying and promoting participation with ROS, and turning them into implements for supporting urban SD decision-making. Furthermore, a successful indicator system depends on data availability and quality. This study recommends that urban planers should pay considerable attention to constructing relevant data collection channels, databases and the data quality.  相似文献   

17.
Artificially prepared sediments were used to assess the effects of sediment composition on inorganic Hg partitioning, speciation and bioavailability. Organic coating in sediment greatly increased the Hg partitioning and the amount of bioavailable Hg bound with the clay and the Fe and Mn oxides, but had little effect on that bound with the quartz and calcium carbonate as a result of weaker binding of humic acids and fulvic acids. The clay content increased the concentration of Hg in the sediments but inhibited the gut juice extraction due to the strong binding of Hg-organic matter (OM) complexes. Most Hg in the sediments was complexed by OM (mainly distributed in the organo-complexed phase and the strongly complexed phase), and the Hg-OM complexes (especially Hg in the strongly complexed phase) in sediments contributed much to gut juice extraction. Redistribution of Hg-OM complexes between sediments and gut juices may occur during gut juice extraction and modify Hg bioavailability and speciation in sediments.  相似文献   

18.
小型CAF气浮设备处理滇池含藻水的试验研究   总被引:2,自引:0,他引:2  
采用自制的小型涡凹型气浮(CAF)设备处理滇池含藻水,结果表明,在气浮时间为1min,分离时间为6min的条件下,聚硅硫酸铁铝(PFASSI)用量为40mg/L时,对藻类和浊度的净化效率最大分别为801%和786%;在聚丙烯酰胺(PAM)的用量为2mg/L时,对藻类和浊度的净化效率分别为959%和932%。使用PFASSI(20mg/L)和PAM(1mg/L)的组合絮凝剂时,滇池含藻水的含藻量由557mg/L降到557mg/L,浊度由375度降到27度,二者的去除率分别为99%和928%。  相似文献   

19.
Field monitoring was practiced from 2001 to 2003 to evaluate the input (irrigation, atmospheric deposition, and fertilizer application) and the output (uptake and accumulation into the above-ground biomass of rice plants and leaching) of cadmium (Cd) in a contaminated paddy field in Tokyo. The cadmium concentrations of irrigated water, open-bulk precipitation, soil solution (leaching water), rice plants collected at the harvesting stage and the chemical fertilizer and the cow manure compost applied were determined. The Cd flux of each factor was calculated by multiplying the Cd concentration by the volume or mass of the media. The annual input-output balance of Cd in the paddy field in 2001 and 2002 was estimated to be -5.44 [corrected] g ha(-1) and -2.01 [corrected] g ha(-1), respectively, indicating the loss of Cd from the paddy field, although the losses accounted for only 0.24% [corrected] and 0.089% [corrected] of the total amount of Cd in the ploughed layer soil in 2001 and 2002, respectively. Among the factors involved, the input from fertilizers (including manure compost) and the output due to the uptake by rice plants played a major role in the balance. The former largely depended on the types and amounts of fertilizers applied, and the latter on the water management practices in the paddy field, such as flooding and drainage of the surface water.  相似文献   

20.
汞、铅、铬污染土壤的微生物修复   总被引:2,自引:0,他引:2  
利用裂褶菌(Schizophyllum commune)GGHN08-116菌株,以棉籽壳、玉米秸等为固体发酵底物修复受汞、铅、铬污染的土壤。通过菌丝穿透重度重金属土壤实验,研究了菌丝在穿透土壤过程对交换态重金属的影响以及该菌株子实体对重金属离子的富集能力,同时,通过盆栽实验研究了在重度重金属污染土壤上,施用不同比例的固体发酵料对污染土壤中汞、铅、铬及其胡萝卜根茎质量、产量的影响,研究结果表明,该菌株能穿透厚度为5 cm的土壤,并有子实体生成,土壤pH值略有下降,与对照差异不显著;与对照相比,土壤中交换态汞、铬含量均显著下降,而交换态铅差异不显著,子实体中除汞含量符合标准外,铅、铬均超出了GB 7096-2003,GB 2762-2005规定标准。在固体发酵料处理下土壤中交换态汞、铅、铬含量均显著下降,胡萝卜根茎中均未检测到汞、铅含量,铬含量也符合GB 2762-2005规定标准。GGHN08-116菌株及其固体发酵产物具有修复受重金属污染土壤的能力。  相似文献   

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