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131.
浑河沈阳段“十一五”期间水体构成及污染来源分析   总被引:1,自引:1,他引:0  
李家玲 《环境保护科学》2012,38(2):40-42,93
介绍了浑河沈阳段"十一五"期间水体的构成,分析了其支流水质状况以及浑河沈阳段主要污染来源。结果表明,支流河是浑河补水的主要来源,污水处理厂尾水已成为支流河和浑河干流的主要补水来源,其中上游径流38%,污水厂排水8%及细河、蒲河、满堂河和白塔保河等5条支流河补水54%;浑河沈阳段污染源数量最多的是农业源,占浑河流域沈阳段污染源的55.33%;其次是生活源,占浑河流域沈阳段污染源的26.19%;再次是工业源,占浑河流域沈阳段污染源的18.43%;最少的是集中式污染治理设施,占浑河流域沈阳段污染源的0.05%。  相似文献   
132.
沈阳市污水处理设施建设现状与前景分析   总被引:1,自引:1,他引:0  
通过对沈阳市各排水系统以及各区域污水处理厂建设情况进行调查,论述污水处理厂建设运行对纳污河流水质改善的作用,并对现阶段存在的问题进行了分析,最终提出污水处理厂合理建设及有效运行的相关保证措施。  相似文献   
133.
以沈阳市建设的第一座大型人工湖泊丁香湖为研究对象,针对丁香湖在基础设施建设、生态系统功能恢复等方面存在诸多现实问题为例,通过依势修整、科学引蓄、补水调换、人工生态浮岛和水生植物布设、局部复氧曝气和辅助的抑藻手段等综合治理措施,使丁香湖水质得到有效改善、生物多样性得到恢复。  相似文献   
134.
雨水径流污染是城市面源污染的主要形式,通过对镇江市城区2011年10场降雨径流水质监测,分析了镇江市城区降雨径流水质。结果表明,镇江市城区降雨径流存在一定污染,直接排入城市地表水体会对其造成污染。其主要污染指标为COD、BOD5、NH3-N、TP和总悬浮颗粒物,重金属含量较低,基本不存在重金属污染。各种不同类型雨水径流水质污染程度差异较大,天然降雨、屋面径流,大市口路面径流水质相对较好,基本能达到Ⅲ或Ⅳ类水体的水质标准;泵站、排口径流、河道径流污染较重,大多属于超Ⅴ类水体;南门大街路面径流污染最为严重,部分水质指标接近工业废水。  相似文献   
135.
为策应江苏省生态建设和农村环境质量的改善,及早实现环境保护参与农村农业社会经济发展综合决策和提升环保管理水平的目标,本文着重对江苏里下河腹部地区水环境状况进行了调查与分析,揭示出乡镇企业、农业面源、水产畜禽养殖、生活污水和废弃污染物排放,造成水环境污染以及对社会、经济、环境建设与发展的影响,有较强的真实性、针对性和代表性。首次研究了改善江苏里下河腹部地区农村水污染防治的对策和措施,不仅为里下河地区"十二五"期间水环境污染防治与管理提供依据还为江苏省乃至全国低洼水域的农村污染物控制和管理起到启示。  相似文献   
136.
利用1995年至2010年浑河干流7个常规监测断面的历年监测数据,通过统计分析确定浑河水质的主要污染指标为氨氮、总磷(TP)、化学需氧量(COD)和生化需氧量(BOD)。并指出1995~2000年间,浑河有机污染突出,2000年以后,浑河水质氮、磷污染更为突出,有机污染有所改善。并详细分析了这四项主要污染指标的时间及水期间分布规律,为浑河流域水污染治理及编制流域规划提供技术支撑。  相似文献   
137.
The continuing conundrum of the LEA proteins   总被引:9,自引:0,他引:9  
Research into late embryogenesis abundant (LEA) proteins has been ongoing for more than 20 years but, although there is a strong association of LEA proteins with abiotic stress tolerance particularly dehydration and cold stress, for most of that time, their function has been entirely obscure. After their initial discovery in plant seeds, three major groups (numbered 1, 2 and 3) of LEA proteins have been described in a range of different plants and plant tissues. Homologues of groups 1 and 3 proteins have also been found in bacteria and in certain invertebrates. In this review, we present some new data, survey the biochemistry, biophysics and bioinformatics of the LEA proteins and highlight several possible functions. These include roles as antioxidants and as membrane and protein stabilisers during water stress, either by direct interaction or by acting as molecular shields. Along with other hydrophilic proteins and compatible solutes, LEA proteins might also serve as “space fillers” to prevent cellular collapse at low water activities. This multifunctional capacity of the LEA proteins is probably attributable in part to their structural plasticity, as they are largely lacking in secondary structure in the fully hydrated state, but can become more folded during water stress and/or through association with membrane surfaces. The challenge now facing researchers investigating these enigmatic proteins is to make sense of the various in vitro defined functions in the living cell: Are the LEA proteins truly multi-talented, or are they still just misunderstood?  相似文献   
138.
Achievement of at least “good ecological status” in all waterbodies under the EU Water Framework Directive by 2015 will in some cases be a challenge. The twin challenge is to manage expectations of policy makers for such waterbodies as to a realistic length of time required for improvement in water quality. Hence, understanding the source, transformation processes and residence time of nitrate in a hydrological system is an essential part of meeting such challenges. On a dairy farm with 24 shallow groundwater wells, the dual isotopic composition of nitrate (δ15N and δ18O) was used to clarify nitrate sources, to assess spatial and temporal variability in nitrate concentrations and to determine if and where denitrification was occurring. Vertical travel time was estimated to correlate nitrate concentrations with management practices. Organically derived nitrogen was the predominant source contributing to groundwater nitrate concentrations. Denitrification was identified as prevalent within specific regions of the study site. The distinct low temporal variability in the isotopic data suggests constancy among nitrate sources and processes over time across the study site. Vertical travel times of up to 3 years were estimated on site indicating the influence of recent management practices on nitrate concentrations. Very slow horizontal migration of groundwater (decades) indicates a legacy of older management practices. Stable isotope techniques, together with an understanding of time lag, provide an extra mechanism to test the efficacy of monitoring and mitigation programmes.  相似文献   
139.
Many regions of the world are predicted to experience water scarcity due to more frequent and more severe droughts and increased water demands. Water use efficiency by plants can be negatively affected by soil water repellency (SWR). It is timely to review existing techniques to remedy SWR. Ideally remediation addresses the origins of a problem. However, the fundamental mechanisms of how and why SWR develops are still poorly understood. In this review it was hypothesized that SWR occurs where the balance of input-decomposition of organic matter is impaired, due to either increased input or decreased decomposition rates of hydrophobic substances. Direct and indirect strategies to remedy SWR were distinguished. While direct remediation aims at abolishing the causes of SWR, indirect strategies seek to manage sites with SWR by treating its symptoms. The 12 reviewed strategies include applying surfactants, clay, slow-release fertilizers, lime, and fungicides, bioremediation of SWR through stimulating earthworms, choosing adapted vegetation, irrigation, cultivation, soil aeration and compaction. Some of the techniques have been applied successfully only in laboratory experiments. Our review highlights that it is not straightforward to cure SWR based on easily measurable and site-specific soil and vegetation properties, and that long-term, large-scale field experiments are required to improve the understanding of the evolution of SWR as cornerstone to develop cost-effective and efficient remediation strategies. We also identified current research gaps around the diagnosis and prevention of SWR.  相似文献   
140.
This paper introduces a new methodological approach of the ecological footprint explicitly addressing the sustainability of water supplies, which we call the water supply footprint (WSF). The WSF calculates the catchment area or water supply hinterland of a certain society and can serve as a strategic planning tool for local or regional water supplies linking the water demand with the water supply in a water supply footprint matrix. Based on regional water balances it estimates how much water can be appropriated for human use in an environmentally sustainable way.The proposed method is tested on the South East Queensland water supply in Australia, an area where water use restrictions are regularly imposed on the population. Applying the proposed method indicates that supply shortages may be avoided by considerably changing the organisation of water supply, thereby reducing and possibly even avoiding the necessity for large-scale supply side measures like additional sweet water reservoirs or desalination plants. In that way it is demonstrated that the WSF method is applicable at an early and strategic stage of water supply planning.  相似文献   
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