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1.
Caesium-137 and (239,240)PU were analysed in the water column along the Algerian coast. The (137)Cs activity concentration in surface water increased from the west to the east from 1.6 to 3.3 mBq L(-1), documenting a presence of Modified Atlantic Water (MAW) in the region. Higher concentrations observed in deep waters may be due to an intrusion of Levantine Intermediate Water (LIW), which has been carrying higher levels of (137)Cs from Chernobyl accident. The (239,240)Pu sub-surface concentration peaked at about 250 m water depth as a result of biogeochemical processes in the water column. The observed (239,240)Pu/(137)Cs activity ratio at the surface (0.003) was significantly lower than that in global fallout (0.04). This decrease exceeds that expected from radioactive decay of (137)Cs, and confirms that Pu due to its adsorption on sinking particles is more effectively removed from surface layers than is (137)Cs. An increase of the (239,240)Pu/(137)Cs activity ratio with depth suggests that (239,240)Pu, similarly as (137)Cs, should be also transported by advection to maintain the observed ratios in deep waters. An intrusion of LIW may enhance therefore both the (137)Cs and (239,240)Pu concentrations in deep waters. The average (238)Pu/(239+240)Pu activity ratio in seawater was 0.03+/-0.02, confirming a global fallout origin of Pu in the Algerian Basin. Caesium-137 and (239,240)Pu inventories in the water column were estimated to be from 2.7+/-0.5 kBq m(-2) to 3.8+/-0.7 kBq m(-2), and from 13.8+/-2.6 Bq m(-2) to 41+/-7B qm(-2), respectively. The (137)Cs massic activities in surface sediment were almost constant, the average activity was 9.0+/-0.8 Bq kg(-1). Sedimentation rates obtained using the (210)Pb method were from 0.1 to 0.7 cm y(-1), and resulting penetration depths of (137)Cs in the sediment cores were from 15 to over 40 cm. The (137)Cs peaks found in the sediment cores were associated with the Chernobyl accident (1986) and global fallout (1964). The (137)Cs inventories in the sediment were increasing from the west (180 Bq m(-2)) to the east (350 Bq m(-2)).  相似文献   

2.
水资源作为一种公共资源,由于其产权制度的不明晰,导致水资源的利用效率低下,污染和浪费现象严重,水环境形势严峻,水资源权属管理制度亟需改革。水资源权属管理应该重点关注水资源的使用权,包括取水权、农村集体经济组织水使用权、少量用水权和应急用水权。水资源确权登记是水资源权属管理改革中的基础和根本环节。文章通过演化博弈模型构建用水户之间的复制动态和进化稳定策略,论证建立水资源确权登记制度的理论支撑,结果表明一个区域内取水量越小,采取超额取水策略的用水户比例越大,当采取超额取水策略的用水户比例较高时,区域内各个用水户的期望收益和整体期望收益都较低,极易造成水资源使用过程中的用水矛盾冲突,而用水户采取限额取水策略能够增加总体的期望收益。本文明确了水资源产权确权与登记制度的主要含义,重点研究了水资源确权登记的范围包括取水权和农村集体经济组织水使用权,并在此基础上明确了取水权和用水权的确权主体和确权内容、水权确权登记的机关、确权和登记的具体程序,提出水资源确权在整个确权登记过程处于主导地位,而登记是取水权交易的前提条件,在此基础上提出对当前取水许可制度进行改革,按照产权制度的要求,强化水权的权属管理和水权的法律保护。据此,本文提出中央机构应与地方政府相互配合,明确分工,密切结合实际,做好水资源确权登记工作,改善水资源权属管理混乱的现状,加快水资源权属管理改革。  相似文献   

3.
Changes to natural organic compounds by acid deposition and subsequent effects on Al mobilization are not well understood. The HUMEX catchment-scale acidification experiment in western Norway offers a unique possibility for an integrated assessment of these interactions. In this report, the soil and soil water chemical data from the HUMEX site, from before and after the onset of experimental acidification, are used to characterize the catchment. Changes in soil water chemistry are discussed and controls on dissolved organic carbon are addressed in relation to Al mobilization. Decreases in the concentration of dissolved organic carbon (DOC) and organic Al fractions were found in soil water after the treatment started. These changes were related to an increase in soil water sulphate concentrations. The sulphate levels showed a significant increase (on a 95% level) in four of ten soil horizons while nitrate remained nearly unchanged. In organic soils, where the dissolved organic carbon content was high, the major control for monomeric aluminum concentration appeared to be the amount of exchangeable aluminum in the soil. In mineral soils, the gibbsite dissolution may govern inorganic Al concentrations in soil water, though substantial undersaturation was found when DOC was high.  相似文献   

4.
There is a mounting body of literature dealing generally with the dynamics of transitions of human systems towards sustainability and specifically with the different stages and processes of transitions. However, the question of why transition processes occur in the first place remains largely unexplained. This paper explores the concept of transition triggers, such as culture or material resource scarcity, and provides a theoretical framework to explain the emergence of a transition and its relation to recent developments in Spanish water policy. We adapt the general framework provided by current transition theory and gather empirical evidence and insights from processes occurring within the Spanish policy context and the Ebro river basin in particular. Our results show that the sole existence of biophysical limits to water use or development cannot explain the start of a possible sustainability transition in this domain in Spain. Changes in the existing water policies in the direction of sustainability were not ignited by people directly affected by water scarcities but by a coalition of sensitive agents, mostly from academia, NGOs and local constituencies, who managed to articulate new identities, integrate multiple sources of policy relevant knowledge, and develop new values under the umbrella of the new water culture movement.
Akgun IlhanEmail:
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5.
Routine bacteriological analysis of sewage work effluents and surface waters has not revealed evidence of Vibrio cholerae or Vibrio El Tor, whereas, non-agglutinating cholera vibrios of Heiberg's groups I and II [so-called non-agglutinating strains (NAG)] have been detected quite frequently. This frequency of NAG presence is approximately equivalent to the presence of Salmonella. Depending on local conditions, quantitative studies of equal amounts of sewage resulted in a ratio of about 1 NAG/102Salmonella/107E. coli.When it became known that NAG vibrios were capable of producing a clinical appearance in man that resembled cholera by its symptoms and severeness, NAG vibrios raised epidemiological interest. Unlike Salmonella, the nutrient requirements of NAG vibrios are moderate. The decisive factors for their persistence in the environmental are attributed to a certain chloride content in the water and an elevated pH value. Both factors are preferably present in sea water. Over a period of 3 yr, samples of water from the Baltic Sea (Lübecker Bucht) were regularly examined for the presence of NAG vibrios. During this period, there have been a number of positive findings in a sample of 100 ml water while identical samples were always Salmonella-negative.  相似文献   

6.
The goals of Integrated Water Resources Management (IWRM) can be achieved by embracing the principles of distributive governance, which places both customary and statutory water institutions on the same pedestal in the governance of water resources. As culture and traditions constitute intangible aspects of water resources management in rural Africa, the recognition of water governance systems grounded in local norms, which correspond better with the aspirations of local water users as against the expert-knowledge systems is desirable. Following the introduction of the statutory institutions in postcolonial Africa, customary institutions, which were once effective in regulating water resources became relegated to the background in those countries, including Botswana . Adopting a critical literature review approach, this article employs the concept of legal pluralism to analyze the institutional factors that create the disharmony between cultural and statutory water governance and management institutions. Findings indicate that water has been abstracted from its social nature and transformed into a tradable economic good. Ultimately, the local meanings and images encoded in water as a nature-given resource are overlooked, thus generating conflicts in water governance. The paper recommends the adoptions of legal pluralism under which water institutions need to embrace both customary and statutory institutions.  相似文献   

7.
Growing population, human settlements, industrialization and intensification in groundwater-based cultivation have resulted in severe onslaught on underground aquifers in West Bengal, an eastern province of India with high population density. The present paper focuses on this water resource management issue. The study shows that traditional, village-level surface water reservoirs which for centuries had supplemented irrigation in addition to providing water for all sorts of domestic needs are now in doldrums. Through statistical analysis, the study shows that for all practical purposes, there is very little effective management of these precious open-access water resources. The situation calls for paradigm shift in policy on water resource management that entails development of community-based management catalyzed by government intervention, external agencies and NGOs under supervision and control of local elected bodies.  相似文献   

8.
9.
Environment, Development and Sustainability - Application of advanced techniques to ensure the environment sustainability and freshwater ecosystem conservation is a paramount importance. Industrial...  相似文献   

10.
11.
Over the last decade, suppliers of drinking water have recognised the limitations of relying solely on end-product monitoring to ensure safe water quality and have sought to reinforce their approach by adopting preventative strategies where risks are proactively identified, assessed and managed. This is leading to the development of water safety plans; structured 'route maps' for managing risks to water supply, from catchment to consumer taps. This paper reviews the Hazard Analysis and Critical Control Point (HACCP) procedure on which many water safety plans are based and considers its appropriateness in the context of drinking water risk management. We examine water safety plans in a broad context, looking at a variety of monitoring, optimisation and risk management initiatives that can be taken to improve drinking water safety. These are cross-compared using a simple framework that facilitates an integrated approach to water safety. Finally, we look at how risk management practices are being integrated across water companies and how this is likely to affect the future development of water safety plans.  相似文献   

12.
The debate about the water resources shortages and finding appropriate solutions to close the water gap in many regions is still not finished. The Mediterranean region is among the most arid regions in the world and hosts more than the half of the world’s water-poor population. The situation is more severe in the southern shore of the Mediterranean, in particular, the Maghreb countries. In this region, water resources are very limited and polluted and most countries rely on groundwater yet overexploited. On the other hand, several factors, including rapid economic growth, expanding populations and changing climate, are driving up demand for water. This pushes forward the Maghreb countries to more and more rely on non-conventional and costly water resources such as wastewater treatment and desalination. Obviously, this bears a heavy burden on the economic growth within these countries. In this paper, rationalizing the virtual water trade and enhancing desalination using renewable energy are presented as two promising options to bridging the Maghreb’s water gap.  相似文献   

13.
Regional Environmental Change - The Brazilian Northeastern semi-arid region’s history has been characterized by drought, water scarcity, and poor living conditions. For the last...  相似文献   

14.
The term sustainability invites interest in the main factors that affect the deterioration of natural resources. Different hypotheses have been put forward concerning the relationship between water and its effect on different economic sectors. Several questions can be asked here, for example: Does a higher water withdrawal for one sector mean that this sector is adding more to the GDP or is it a sunk cost (it is the cost that should be ignored compared to the benefit of water withdrawal for an individual economic sector) compared with the benefits to the economy? Do social factors affect water withdrawal more than economic factors or are they both impacting equally? We aim to answer these questions and to shed light on different socio-economic factors that affect water withdrawal in different economic sectors. This study investigates, in depth, the interaction between humans and the environment and can be useful in monitoring the direct effect on water withdrawal from agricultural and non-agricultural sectors and on different national economic variables that act as an indicator for economic development and growth. We used simultaneous equation models in our analysis, both the three-stage least squares and the two-stage least squares to explore the relationships. For more credibility, we run the fixed and random effects of 2SLS. Our results showed the influence of trade openness and economic growth on water withdrawal for different economic sectors, and the effect of an increasing demand for water for non-agricultural purposes, which adds pressure on the agricultural sector and eventually may lead to rising food prices.  相似文献   

15.
Artificial wetlands and water quality improvement   总被引:19,自引:0,他引:19  
This paper illustrates the role of plants to assist the treatment of water pollution in man-made wetlands in tropical and temperate climates. It also considers the potential for environmental education of these wetland systems. The management and natural treatment of pollution is described in the Mai Po Marshes, Hong Kong and a wetland in London which is also an important site for birds. The design of the Putrajaya Lake and Wetland system in Malaysia is compared with a constructed wetland and lake for the treatment of urban surface runoff in a new residential development in the United Kingdom. The benefits of these natural systems are discussed in the context of the global trend for introducing sustainable methods of environmental management and low cost pollution treatment systems.  相似文献   

16.
Water quality criteria, as a means of distinguishing "good" water from "bad" water, have been employed for over 150 years. During the 1940s and 1950s, the formulation of water quality criteria and their role in water quality management were hotly debated in the United States as each state formulated its own approach to water pollution control. In 1965, when the federal government assumed control of water quality management in the US, a single, national approach to the formulation and use of criteria had to be selected and implemented nationwide. The purpose of this paper is to briefly review the history of criteria as a basis for water quality management in the US; note the different water quality management philosophies used by states prior to 1965; and summarize the relationship of criteria to monitoring over the past 30 years. Standards, as legal instruments, are developed for a specific water body by designating a use of the water (society value) and the criteria necessary to protect the use (a scientific finding). Standard violation, as a concept, tends to remain as a single-sample exercise (i.e., the sample measurement is either above or below the standard). Increasingly, however, there is a demand to classify large bodies of water (e.g., lake, river segment, or aquifer), over a set time period, such as a day, year, or decade, as either in compliance or in violation of water quality standards. No peer-reviewed, standardized method for computing standard "violations" has been widely accepted for this purpose. The paper ends with a call to develop such methods, if water quality managers must produce standard violation information (infer sample results) over time and space. Electronic Publication  相似文献   

17.
The volume of industrial and domestic wastewater is increasing significantly year by year with the change in the lifestyle based on mass consumption and mass disposal brought about by the dramatic development of economies and industries. Therefore, effective advanced wastewater treatment is required because wastewater contains a variety of constituents such as particles, organic materials, and emulsion depending on the resource. However, residual chemicals that remain during the treatment of wastewaters form a variety of known and unknown by-products through reactions between the chemicals and some pollutants. Chronic exposure to these by-products or residual chemicals through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. For example, residual aluminium salts in treated water may cause Alzheimer's disease (AD). As for carbon nanotubes (CNTs), despite their potential impacts on human health and the environment having been receiving more and more attention in the recent past, existing information on the toxicity of CNTs in drinking water is limited with many open questions. Furthermore, though general topics on the human health impacts of traditional water treatment chemicals have been studied, no comparative analysis has been done. Therefore, a qualitative comparison of the human health effects of both residual CNTs and traditional water treatment chemicals is given in this paper. In addition, it is also important to cover and compare the human health effects of CNTs to those of traditional water treatment chemicals together in one review because they are both used for water treatment and purification.  相似文献   

18.
The occurrences of trihalomethanes (THMs) and haloacetics (HAAs) in the water supply in Beijing and Canada were investigated. The concentrations of THMs and HAAs in Beijing and Canada were below the maximum contaminant levels specified by the USEPA and WHO standards. The multi-pathway risk assessment (assessed through oral ingestion, dermal absorption and inhalation exposure to drinking water) was used to assess the cancer risk and the hazard index of THMs and HAAs from fifteen waterworks in Beijing, China and three treatment plants using different disinfection processes in Canada. Residents in Beijing and residents who were served by three treatment plants using different disinfection processes in Canada had a higher risk of cancer through oral ingestion than through the other two pathways. The cancer risk resulted from disinfection by-products (DBPs) was 8.50E-05(for males), 9.25E-05(for females) in Beijing, China, while it was 1.18E-04, 1.44E-04 in Canada. The risk was higher when water treatment plants used surface water source than when they used ground water source and mixture water source in Beijing. The risk showed different changes in three treatment plants using different disinfection processes in Canada. The lifetime cancer risk for THMs followed the order: Plant 2>Plant 1>Plant 3. And, the lifetime cancer risk for HAAs was: Plant 1>Plant 2>Plant 3.  相似文献   

19.
An in vitro approach was performed to assess the quality of drinking water collected at two treatment/distribution networks located near the source (Plant #1) and the mouth of River Po (Plant #2). The water was sampled at different points of each distribution network, before (raw water) and after the chlorine dioxide disinfection, and in two points of the pipeline system to evaluate the influence of the distribution system on the amount and quality of the disinfection by-product. Cytotoxicity and genotoxicity of water extracts were evaluated in human peripheral lymphocytes and Hep-G2 cells by the use of the micronucleus (MN) test and Comet assay. Raw water samples of both plants induced cytotoxic effects, but not the increases of MN frequency in Hep-G2 cells and in human lymphocytes. Increases of DNA damage in human leukocytes was detected by Comet assay for raw water of Plant #2 at concentration ≥ 0.25 Leq/mL. The disinfection process generally has reduced the toxicity of water samples, even if potential direct DNA-damaging compounds have been detectable in drinking water samples. The proposal approach, if currently used together with chemical analysis, can contribute to improve the monitoring drinking water.  相似文献   

20.
Based on production data published by the Brazilian Mineral Water Producers Association, bottled mineral waters were bought at the market, covering, at least, 50% of the annual production of each Brazilian geographical region. 228Ra, 226Ra and 210Pb were analyzed and the weighted mean values obtained for Brazilian mineral waters were 0.097, 0.027 and 0.066 Bq l-1 respectively. Individual effective dose rate estimates due to ingestion of mineral water in Brazil were of the order of 10-100 microSv yr-1, depending on the geographical region. Based on the available data, it was also possible to evaluate the per caput effective dose rate and the highest value obtained was 4.3 microSv yr-1 for the northern region.  相似文献   

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