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通过对苏州市古城区内商业区、现代住宅区、老旧住宅区、交通区、园林旅游区这5种具有代表性的功能区路面降雨径流中SS、COD、TN、NH_3~+-N、TP水质指标的分析,探讨了不同功能区降雨径流中污染物浓度差别,不同污染物之间的相关性关系和初期冲刷效应。结果表明,路面降雨径流中污染物浓度存在空间分布差异,商业区和交通区路面径流污染最为严重,其中交通区SS的E_(EMC)值超出污水综合排放二级标准16.79倍,COD的E_(EMC)值超出地表水环境质量V类标准6. 88倍;降雨径流中SS与TP、TN、COD之间存在良好的相关性,交通区路面降雨径流中各污染物之间呈现极显著性相关;不同功能区路面降雨径流中污染物大多存在初期冲刷现象,交通区与园林旅游区出现初期冲刷频率高,商业区和老旧住宅区初期冲刷强度大,相比其他污染物,SS最易出现初期冲刷现象,降雨特征参数对初期冲刷效应有一定影响。 相似文献
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我国当前以实现分流制为规划指导原则,分流制下工业园区雨水径流污染对水环境存在较大潜在影响。在此背景下采用SWMM软件模拟降雨和实地调研相结合的方法,分析湖塘园区降雨径流的污染负荷。结果表明:0.25年一遇的降雨径流质量浓度峰值ρ(TN)=6.01 mg/L,ρ(TP)=0.02 mg/L,ρ(COD)=125.21 mg/L,该降雨重现期下的TN和COD浓度均远劣于GB 3838—2002《地表水环境质量标准》的Ⅴ类水标准;随着降雨重现期增大,径流污染物浓度峰值会进一步提高。排入受纳水体采菱港的污染物总量比例:径流中TN占园区总TN(径流+点源)排放量的25.9%,径流中TP占4.4%,COD占28.0%,COD、TN径流污染量占整个园区污染总量的比重较大。结合湖塘园区排水系统的实地调研,建议加强园区初期雨水截留、推广园区中水回用和推进园区与企业排口设置规范化,以有效降低园区雨水径流对周边水环境的影响。 相似文献
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北京市城区降雨径流污染特征监测与分析 总被引:1,自引:0,他引:1
选取北京市城区典型下垫面——屋面、路面、绿地和停车场的降雨径流进行水质监测,并分析与识别降雨径流污染特征。研究结果表明,该区域降雨径流主要污染物为SS、CODCr、TN,其中CODCr和TN平均值超过《地表水环境质量标准》(GB 3838—2002)Ⅴ类标准,SS超出《城镇污水处理厂污染物排放标准》(GB 18918—2002)二级标准,污染程度较为严重。屋面径流中TN与氨氮污染水平在各类典型下垫面中最高,说明大气干沉降对降雨径流中氮的污染贡献较大。研究中3个降雨场次中的径流污染过程存在不同程度的初期冲刷效应(First flush effect),初期冲刷效应的显著程度与降雨强度和雨前干期天数呈正相关。 相似文献
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以青岛市居民生活区与工业区的2座污水处理厂为研究对象,分析2015年全年进厂污水水质指标如BOD_5、COD、SS、NH_3-N、TN和TP等的变化规律。结果表明生活区污水处理厂全年进水各指标稳定,整体处于较高水平,反映了青岛地区常年缺水情况下居民的节水习惯。工业区污水处理厂全年进水指标中BOD_5、COD、SS、TP波动较大,有时会出现极端值,特别是在8月、9月和12月,这可能与某些季节性生产企业的废水排放有关,水质大幅波动可能会对污水处理工艺产生冲击;指标中NH_3-N与TN较为稳定,说明工厂企业含氮类污染物排放较少。BOD_5/COD,BOD_5/TN,BOD_5/TP比值分析表明,生活区污水处理厂进水中碳源较为充足,基本可以满足脱氮除磷的要求;而工业区污水处理厂的碳源明显不足。 相似文献
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《给水排水》2015,(11)
通过现场监测分析,研究了深圳光明新区国家低影响开发雨水综合利用示范区内透水沥青道路与滞留带对路面径流水质和水量的控制效果。研究结果表明:与传统沥青道路相比,透水沥青道路径流中的SS、COD、NH3-N、NO-3-N、TN和TP等污染物浓度分别降低了94.76%、83.84%、70.59%、33.33%、50.00%和65.96%,对径流总量和峰值流量的平均削减率分别达76.70%和74.92%。道路滞留带对COD、NH3-N、NO-3-N、TN和TP也具有一定的去除效果;在小雨事件下不外排雨水,在中雨、大雨和暴雨事件下,对径流总量和峰值流量平均削减率分别达65.71%和57.69%,同时具有明显的延迟峰值作用。 相似文献
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开展城市雨水径流监测,定量评估径流污染水平,分析污染规律及影响因素,可为科学制定水环境治理方案提供重要依据。以我国平原河网地区某城市一典型滨河片区为例,基于对不同下垫面雨水径流及周边河道常规污染物指标的监测,结合河道水环境质量时空变化特征,分析径流污染程度及对河道水环境的影响。结果表明,监测区域径流污染程度总体较高,其中COD、TN、TP指标的平均浓度均接近或超过地表水劣Ⅴ类水质;不同降雨事件、不同污染物、不同取样点雨水径流的初期冲刷程度均不相同,并且与降雨强度和前期污染物积累情况等因素密切相关;降雨过程中工商业发达、人员与交通密集区域排放的雨水径流增加了河道中COD、SS、TN、TP等污染物的浓度;对比结果显示监测区域部分污染物指标的城市径流污染物年排放量超过污水处理厂尾水污染物排放量。 相似文献
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强降雨下果园除草对径流中颗粒物及营养盐的影响 总被引:1,自引:0,他引:1
为探究夏季果园除草对果园面源污染的影响,采用人工模拟降雨的方法,研究了3种雨强(60 mm/h、120 mm/h、180 mm/h)及2种下垫面(有草样地和无草样地)条件下,果园地表径流中颗粒物(SS)及营养盐(TN、TP)的流失情况。试验结果表明,径流中TN、TP质量浓度与SS质量浓度均呈线性相关关系,TP与SS质量浓度之间的线性相关性更强(R~2=0.921 5);人工割草造成了径流中SS、TN、TP质量浓度升高,使其单位面积流失量分别增加了30%~46%、11%~29%、11%~22%,尤其是增大了降雨后期的流失量。因此,在夏季多雨、尤其是暴雨发生时段,应减少对果园中杂草的收割频次。 相似文献
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根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。 相似文献
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The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects. 相似文献
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In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment. 相似文献
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简述天湖水电站投运以来各种故障的表现形式,分析其原因,提出了相应的处理方法及措施,并对合理利用国内外设备提出建议。 相似文献
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Various designs of low‐head dams are used to rehabilitate streams or forestall upstream channel incision after channelization. We report on the efficacy of using notched sills and grade control structures (GCS) to restore the fish assemblage in Luxapallila Creek, Mississippi. We tested the null hypotheses that habitat variables and species richness, evenness, and assemblage structure would not differ among: (1) a channelized segment with no modifications; (2) a channelized segment mitigated by the installation of sills and GCS; (3) a segment upstream of the installations and undergoing channel incision; and (4) an unaltered segment. Although habitat variables changed, neither species richness, evenness, nor fish assemblage structure differed between mitigated and channelized segments with both exhibiting less richness and different assemblage structures than the unaltered segment. Lack of differences in species richness between the incised and unaltered segments suggest that the GCS may have halted the negative effects of upstream channel incision before species were extirpated. Conspicuous habitat differences between the altered (channelized and mitigated) and unaltered segments were lack of backwaters and canopy coverage and finer substrates in the altered segments. Our results suggest a more comprehensive rehabilitation strategy is required in Luxapallila Creek. Published in 2003 by John Wiley & Sons, Ltd. 相似文献
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NUMERICAL STUDY OF WAVE EFFECTS ON SURFACE WIND STRESS AND SURFACE MIXING LENGTH BY THREE-DIMENSIONAL CIRCULATION MODELING 总被引:1,自引:0,他引:1
LIANG Bing-chen LI Hua-jun LEE Dong-yong 《水动力学研究与进展(B辑)》2006,18(4):397-404
1. INTRODUCTION Coastal and continental shelf regions are characterized by intensive interaction between wave and current. These regions are of great economic significance to mankind. Therefore, the modeling of wave and current as well as their mutual int… 相似文献