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1.
竹园放流工程与城市污水海洋处置   总被引:2,自引:0,他引:2  
沿海城市充分合理地利用海洋的自净能力,日益增加的大量城市污水收集后,经适当的陆上处理并最终通过深水管排放,是解决城市污水问题及可持续发展的对策之一。综述了城市污水海洋处置及国内外排海工程概况;上海市竹园放流工程运行前后长江口的水质、底质等环境状况监测资料的分析结果表明:竹园污水放流管自1993年12月完工启用后,由于初始稀释和输移扩散情况良好,并没有在长江口河口地区形成显著的污水混合区,初始稀释度符合或未超过国家标准(GWKB-2000),竹园放流管所排放的污水对长江口的影响轻微;阐述了陆上污水处理程度、污水再用、水污染防治、黄浦江水资源保育等问题和上海市污水排放与可持续发展之间的关系;并对长江三峡、南水北调工程实施后对长江河口地区可能造成的水质、生态影响进行了探讨。  相似文献   

2.
Physical and ecological responses of the coastal areas in the vicinity of Mumbai, India, due to relative sea level rise are examined by different inundation scenarios. Evaluation of potential habitat loss under sea level rise was made by incorporating the land use/land cover (LULC) adopted from the digital elevation model with the satellite imagery. LULC categories overlaid on 1.0, 2.0, 3.0 and 4.0 m coastal elevation showed that the coastal areas of Mumbai were mostly covered by vegetation followed by barren land, agricultural land, urban areas and water bodies. For the relative sea level rise scenarios of 1.0, 2.0, 3.0 and 4.0 m, the tidal inundation areas were estimated to be 257.85, 385.58, 487.56 and 570.63 km2, respectively, using GIS techniques. The losses of urban areas were also estimated at 25.32, 41.64, 54.61 and 78.86 km2 for the 1.0, 2.0, 3.0 and 4.0 m relative sea level rise, respectively, which is most alarming information for the most populated city on the eastern coast of India. The results conclude that relative sea level rise scenario will lead profound impacts on LULC categories as well as on coastal features and landforms in the adjoining part of Mumbai. The sea level rise would also reduce the drainage gradients that promote flooding condition to rainstorms and subsequently increase saltwater intrusion into coastal regions. Alterations in the coastal features and landforms correlated with inundation characteristics that make the coastal region more vulnerable in the coming decades due to huge development activities and population pressures in Mumbai.  相似文献   

3.
中国城市污水处理良性运营机制探讨   总被引:7,自引:0,他引:7  
污水处理不仅能减轻水污染排放,而又是开源节流、实现污水资源化的前提,是解决城市缺水问题的基本途径之一。然而中国城市污水处理面临着设施不足、处理率低和处理资金不足的问题。本文从分析产生上述问题的原因着手,提出城市污水处理业的发展必须走市场化的道路。  相似文献   

4.
Disposal of sewage wastes is a problem of increasing magnitude in the United States. New control measures enacted by Congress require consideration of land disposal of sludges and effluents. The volume of wastes involved and the possibility of contaminating ground water supplies and vegetation has great public health significance. The effectiveness of the sewage treatment process to remove chemical and biological contaminants and the operational efficiency of many sewage treatment plants are factors that must be given careful consideration before final selection of disposal methodology. The quality of our future water and food supplies will be affected either beneficially or adversely by current management decisions.  相似文献   

5.
长江河口近岸水体自然净化作用及其初步评价   总被引:9,自引:1,他引:8  
按照水体的净化机理,结合长江口和上海滨岸带近岸水体的物理、化学和生物等因素的实际特征,对近岸水体的自然净化作用进行了阐述和分析。并在历史资料和实测资料基础上,就近岸水体的自然净化作用进行了评价。评价结果表明,因长江河口近岸水体存在较强的自然净化作用机制,近岸水体体的自然净化能力较强,环境容量较大,但由于污染物输入量的不断增加,部分岸段近岸水体的环境质量有逐渐下降的趋势;近岸水体的自然净化作用具有明显的季节性变化,长江口南岸水域洪水季节水体的自然净化作用比估水季节强,而杭州湾北岸水域的自然净化作用表现为相反的变化趋势,因此建议在近岸污水排放过程中应考虑近岸水体的净化能力,遵循水体的自然净化作用规律。  相似文献   

6.
Malaysia is now a developing country and on her way towards being an industrialised one by the year 2020. Most of her industries and urban areas are located on the west coast of Peninsular Malaysia. In addition, the offshore area of the west coast is now one of the busiest shipping lanes in the world. These two phenomena make the intertidal and offshore areas of the west coast of Peninsular Malaysia interesting for scientific studies. Therefore, this study focused on both the offshore and intertidal sediments of the west coast of Peninsular Malaysia. Sampling for sediment samples were done from the northern to the southern ends of the peninsula and these sediment samples were analysed for Cu and Pb. It was found that total Cu concentrations ranged from 0.25 to 13.8 and 0.40 to 315 microg/g dry weight (dw) for offshore and intertidal sediments, respectively. For Pb, it ranged from 3.59 to 25.4 and 0.96 to 69.8 microg/g dw for the offshore and intertidal sediments, respectively. The ranges of Cu and Pb found from the west coast of Peninsular Malaysia were low in comparison to regional data. However, some intertidal areas were identified as receiving anthropogenic Cu and Pb. Geochemical studies revealed that the 'nonresistant' fraction for Pb contributed about 70.0% to 75.0% and 54.0% of the total Pb concentration in the offshore and intertidal sediments, respectively. As for Cu, the 'nonresistant' fraction contributed about 46.2% to 60.4% and 46.3% of the total Cu concentration in the offshore and intertidal sediments, respectively. The 'nonresistant' fraction contained mostly of anthropogenic metals besides natural origins. These 'nonresistant' percentages indicated that both the offshore and intertidal areas could have received anthropogenic-derived metals, which could be influenced by physico-chemical properties of the sediments. Although the present data indicated that contamination due to Cu and Pb in the west coast of Peninsular Malaysia especially in the offshore areas were not serious, regular biomonitoring studies along the west coast of Peninsular Malaysia are recommended.  相似文献   

7.
Iodine-131 reaches the marine environment through its excretion to the sewer by nuclear medicine patients followed by discharge through coastal and deepwater outfalls. 131I has been detected in macroalgae, which bio-accumulate iodine, growing near the coastal outfall of Cronulla sewage treatment plant (STP) since 1995. During this study, 131I levels in liquid effluent and sludge from three Sydney STPs as well as in macroalgae (Ulva sp. and Ecklonia radiata) growing near their shoreline outfalls were measured. Concentration factors of 176 for Ulva sp. and 526 for E. radiata were derived. Radiation dose rates to marine biota from 131I discharged to coastal waters calculated using the ERICA dose assessment tool were below the ERICA screening level of 10 μGy/hr. Radiation dose rates to humans from immersion in seawater or consumption of Ulva sp. containing 131I were three and two orders of magnitude below the IAEA screening level of 10 μSv/year, respectively.  相似文献   

8.
以望虞河引清调水实践为背景,利用引水调水现状及实测数据,建立适合太湖的二维水量水质数学模型,并模拟计算调水前后湖体各项水质因子浓度的空间变化规律。结果显示:水利调度影响下太湖湖体中高锰酸盐指数、氨氮、和总氮的浓度大体上有所减小,改善率分别为60%、160%和92%,总磷稍有反弹,其指标恶化了44%,太湖湖体水质总体改善面积37%,主要集中在贡湖、梅梁湖及东部湖区这些引排水水流流经的区域,表明“引江济太”调水工程对改善太湖局部湖区水质、保障太湖供水安全具有重要意义,可为其他类似水域的水污染治理提供科学参考和依据  相似文献   

9.
近年来由于淡水资源短缺和海水淡化处理成本的显著下降,海水淡化产业在全球范围内蓬勃发展。出于环境保护考虑,保证海水淡化后产生的高盐度尾液能够迅速与受纳海水掺混的排放口设计显得尤为重要。目前实践中广泛采用的型式是圆形倾斜淹没式排放,而之前的研究建议倾角设计与水平方向成60°为最佳。但伴随60°倾角的射流上升高度相对较高,可能不适用于排放入浅海海域。应用先进的粒子图像测速(PIV)和平面激光诱导荧光(PLIF)技术在实验室模拟较小角度(30°和45°)的排放,从而研究其掺混及稀释特性。通过实验数据整理得到相应的射流最大上升高度、碰撞点水平距离、碰撞点稀释度等属性,从而为浅海区的海水淡化高盐度尾液排放的工程设计以及相关规定的制定提供参考。  相似文献   

10.
Coastal Regulations in India are traced back to the UN Conference on Human Environment, held in Stockholm in 1972. The Environment Protection Act (EPA) 1986 was enacted to implement India’s commitments as a signatory. The Coastal Regulation Zone (CRZ) Notification of 1991 was made under the provisions of the EPA in order to protect coastal environments and social and livelihood security of fishing community. This paper assesses the effects of CRZ rules and violations in the Mumbai Metropolitan Region, which has experienced tremendous growth due to the rapid industrialization and urbanization. This process has led to the destruction of mangroves and other important species of fish which play a crucial role in sustaining the coastal ecology and urban biodiversity; high population density and uneven growth have exacerbated adverse environmental and socioeconomic consequences. The Koli (fishing community) in this region faces huge problems of survival and sustenance in small-scale fishing, due to the rampant commercial fishing by big trawlers and large-scale dumping of waste materials by the industries surrounding the vicinity into the sea. In small but significant ways, the fishing communities through their traditional commons-based resource management and livelihood systems protect the coastal ecology and help the cities in reducing their carbon footprints. On the basis of primary field research in Thane–Mulund Creek Bhandup, Chimbai, and Sewri, this paper attempts to assess CRZ violations taking place on coastal areas and is causing damage to the coastal ecology. The research specifically has focused on the particular fishing-related activities and spaces—such as: jetties, parking of boats, access to sea, weaving and drying of nets, landing grounds, drying and cleaning of fish that are more affected by encroachment of seashore area and by CRZ rules violations. It evaluates the actions taken by Maharashtra Coastal Zone Management Authority and Bombay Municipal Corporation while implementing rules and making Integrated Coastal Zone Management plan for management of marine environment. It raises broader issues relating to the contradictions and complementarities involved in ICZM plans vis-a-vis management of biodiversity, within a larger context of rapid urbanization and demands for real estate growth. The paper argues that urban biodiversity management requires clear valuation of the long-term ecological and socioeconomic benefits of sustenance of coastal ecology and related livelihoods.  相似文献   

11.
The economy of Northeast Thailand is mainly based on agriculture. The transformation of forestlands to agricultural areas and the encroachment of riverbanks within the Phong watershed have caused severe soil erosion. Strong storms in rainy season exacerbate the problem of soil erosion. Difficulty in getting water drives people in the upstream region to live on riverbanks. Soil erosion affects water utility by increasing the turbidity in the Phong River and also by decreasing the water storage capacity of small reservoirs for the upstream residents, as well as that of the Ubolratana Dam. The rate of siltation in the Ubolratana Dam was estimated to be 1.5 million tons/year during 1965-1990. The main source of water supply is surface water in the Phong watershed, and fluctuating turbidity makes water treatment difficult. The maximum turbidity in the upstream Phong River exceeds 5000 NTU, whereas it is reduced to be about 300 NTU at the intake point of Khon Kaen Municipal Water Treatment Plant because the Ubolratana Dam works as a huge clarifier. Khon Kaen Municipal Waterworks has a daily water supply of 72,960 m3/day. The average amounts of alum used in the wet (May-October) and dry (November-April) periods are 42.33 g/m3 and 28.46 g/m3, respectively. The average costs of the amounts of alum used are 0.213 and 0.143 Bahts/m3 during the wet and dry periods, respectively. Fluctuation of turbidity in raw water makes it difficult to adjust alum dose, resulting in treated water quality unstable, and handling of sludge disposal difficult.  相似文献   

12.
Water quality scenarios around an offshore outfall off Kochi were simulated using MIKE21 water quality model, assuming a high Biochemical Oxygen Demand (BOD=50 mg l(-1)) effluent discharge. The discharge is introduced into the model through an outfall located at a distance of 6.8 km from the shore at a depth of 10 m. Three scenarios were simulated with different discharge rates such as 2, 5 and 10 m3 s(-1), with BOD load of 8640, 21,600 and 43,200 kg day(-1) respectively. Model simulations were carried out to estimate the assimilation capacity of the waters off Kochi for the three discharge rates. The results show that for 10 m3 s(-1) effluent discharge, the initial BOD of 50 mg l(-1) reduced to 3.33 mg l(-1) at the outfall after 48 h. High BOD values were confined to an elliptical area of approximately 8 km2 around the outfall. Based on this, the assimilative capacity of the waters off Kochi in terms of BOD can be estimated as 38,000 kg day(-1). It is suggested that offshore waters could be used as a feasible alternative to the Kochi backwaters for the disposal of treated effluent.  相似文献   

13.
Long-term irrigation with sewage water adds large amounts of carbon, major and micro- nutrients to the soil. We compared the spatial distribution of N, P, K and other micronutrients and toxic elements in the top 0.6 m of an alluvial soil along with their associated effects on the composition of crops and ground waters after about three decades of irrigation with domestic sewage effluent as a function of distance from the disposal point. Use of sewage for irrigation in various proportions improved the organic matter to 1.24-1.78% and fertility status of soils especially down to a distance of 1 km along the disposal channel. Build up in total N was up to 2908 kg ha(-1), available P (58 kg ha(-1)), total P (2115 kg ha(-1)), available K (305 kg ha(-1)) and total K (4712 kg ha(-1)) in surface 0.15 m soil. Vertical distribution of these parameters also varied, with most accumulations occurring in surface 0.3 m. Traces of NO3-N (up to 2.8 mg l(-1)), Pb (up to 0.35 mg l(-1)) and Mn (up to 0.23 mg l(-1)) could also be observed in well waters near the disposal point thus indicating initiation of ground water contamination. However, the contents of heavy metals in crops sampled from the area were below the permissible critical levels. Though the study confirms that the domestic sewage can effectively increase water resource for irrigation but there is a need for continuous monitoring of the concentrations of potentially toxic elements in soil, plants and ground water.  相似文献   

14.
基于太湖流域典型丘陵水源地平桥河流域12个采样点的水质监测数据,综合运用聚类分析和主成分分析法对平桥河流域水质时空变化及影响因素进行分析。聚类分析显示,按照水质相似性将平桥河流域水质分为枯水期、平水期、丰水期3个季节时段和中上游丘陵河谷区、下游紧邻平桥镇的平原区、下游暗沟出口区3个典型空间区域。主成分分析显示:(1)枯水期水质以氮污染为主导因素,磷和有机污染次之,受流量减小、流速缓慢导致的营养盐富集的影响加大;平水期水质以氮污染为主导因素,磷污染次之,受茶园等大量施肥导致的农业面源污染的影响;丰水期水质以氮和磷污染为主导因素,受到水稻种植等农业活动和大量降雨径流的影响。(2)中上游丘陵河谷区水质以氮和磷污染为主导因素,有机污染次之,受到茶园种植等农业活动导致的面源污染的影响;下游紧邻平桥镇的平原区水质以氮和磷的污染为主导因素,有机污染次之,受到居民生活污水和农业生产的影响;下游暗沟出口区水质以氮污染为主导因素,有机污染和磷污染次之,受到生活污水、农业生产和畜禽养殖的影响。研究结果可为太湖流域丘陵区水源地保护和管理提供参考。  相似文献   

15.
海南省洋浦经济开发与海岸环境资源保护研究   总被引:1,自引:0,他引:1  
本文在分析研究洋浦经济开发区海岸带具有独特的优良环境与资源条件的基础上,指出开发区的规划项目将造成的海岸环境资源问题,并提出了海岸环境资源利用与保护的对策和措施。  相似文献   

16.
Vietnam is a tropical to subtropical country located on the eastern Asian coast where the Red (Song Hong) and Mekong rivers discharge into the sea. The catchments of these two transboundary rivers cover parts of six countries, and their water and sediment discharges greatly influence the coastal seas of Vietnam. The impact of human activities include changes in the supply and distribution of water, sediments, and nutrients; changes in the relationships and balance among dynamically interacting factors and processes; and changes in the quality of the coastal and marine environments due to the increased use and accumulation of pollutants and the loss of habitats. These impacts have resulted in increasing unpredictability and severity of coastal problems such as floods, erosion, sedimentation, and saltwater intrusion; environmental pollution; and the degradation of ecosystems, with accompanying decrease in biodiversity and fishery productivity.  相似文献   

17.
Oil spill response, whether planned by government agencies, oil spill cooperatives or individual companies, can be planned and carried out with the goal of minimizing ecological impacts, not merely removing visible oil. Two oil spill cooperatives on the west coast are implementing such planning. First, a coastal survey was conducted in the cooperative's area of responsibility. Physical processes and habitat types were examined. Oil spill cleanup guidelines were written for each habitat type. Biologically sensitive areas, those sites most vulnerable to oil spill impacts, were identified. Strategies were developed to protect most sensitive areas, i.e., prevent spilled oil from reaching them. Protection is the preferred option because it prevents both the impact of the oil and subsequent cleanup activities. Protected areas can often serve as repopulation centers for surrounding sites that may have been impacted. If minimizing ecological impact is to be a prime focus of oil spill response, ecologists should be involved in both the planning before and the field efforts during such spill events.  相似文献   

18.
The horizontal distribution and quantitative characteristics of macrozoobenthos were studied in small lakes of the Darwin Nature Reserve (southern Vologda oblast). The aggregation index varied in the open areas of acid lakes, which indicated that communities of small acid water bodies were unstable. The aggregation was the lowest in the open area of a neutral lake. In acid lakes, the number and biomass of macroinvertebrates were the highest near the coasts. In the neutral lake, conversely, these values were maximum in open areas and low near the coast due to a strong pressure of predatory invertebrates and fish. An aggregating effect of invertebrate predators was observed near the coasts of lakes of different types.  相似文献   

19.
A reconnaissance study has been made on the distribution of 238U, 234U, 232Th and 230Th in soils, water, suspended particulate matter (SPM) and bottom sediments in the Kali river basin around Kaiga, its estuarine region and the adjacent Arabian Sea to obtain the baseline data of U-Th series nuclides in view of the commissioning of nuclear power reactors at Kaiga, near Karwar, on the southwest coast of India. Drainage basin soils developed over greywackes (the dominant litho-unit upstream) are lower in 238U/Al and 232Th/Al ratios by factors of 3-5 in comparison with those developed over tonalitic gneisses (the dominant litho-unit downstream). The dominance of the former type of soils is reflected in the composition of river-bottom sediments derived from the upstream drainage basin during the monsoon. The 232Th in bottom sediments tends to increase towards the estuarine and coastal areas, presumably due to deposition of heavy minerals and onshore transport of coastal sediments into the estuary. The dissolved U in the Kali river is low (0.001-0.02 microg/l) when compared to the major Indian rivers as the Kali river flows through U-poor greywackes. Thus, the input of dissolved U to the Kali estuary is dominated by sea water. Although there is some evidence for the removal of dissolved U at low salinity during estuarine mixing, its behaviour is conservative in the lower estuary (at higher salinities). The removal rate of dissolved U from the Kali river basin is similar to that reported from other tropical river basins. The U flux from all the west-flowing rivers of Peninsular India is estimated at 26.3 x 10(6) g/yr to the Arabian Sea which is about 2% of the flux from the Himalayan rivers to the Bay of Bengal.  相似文献   

20.
This study identifies shallow well water contamination sources near the Mae-Hia waste disposal site and the clarification of the extent of well water contamination caused by leachate generated from the disposal site. The water of 40 shallow wells around the Mae-Hia disposal site, where three potential sources of groundwater pollution exist, was sampled and analyzed for physical, chemical, and biological characteristics. Water samples were taken every month from June 1989 to May 1990 along with a measurement of well water levels in order to estimate the groundwater flow direction. Comparison with the drinking water standards/guidelines showed that well water in the study area was not suitable for drinking due to the high contamination of total and fecal coliforms and moderate contamination by nitrate and manganese. It was found that the level of conductivity, total solids, color, chloride, chemical oxygen demand, sodium, copper, and lead in the groundwater of wells located adjacent to the disposal site were higher than in other areas. In addition, higher concentrations of sodium, chloride, calcium, and magnesium in the wells located downstream of the groundwater flow were recorded. Estimation of a leachate plume using chloride as an indicator showed that the wells located in the eastern part of the disposal site, a dominant direction of groundwater flow, were contaminated by leachate generated from the waste disposal site.  相似文献   

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