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广州城市河流形态对河流自净能力的影响 总被引:2,自引:0,他引:2
构建了包括河道分维数、河道断面形态、河岸基质、河岸带宽度、河岸带植被盖度、河床底质状况、河床栖境复杂性共7项指标的城市河流形态评价体系,并以乌涌广州市开发区段为研究对象,通过定期水质监测研究河流形态对河流自净能力的影响。结果表明,该评价体系能够反映研究河段的形态差异;不同形态河段水体BOD5降解系数及多项水质指标沿程降解率均有显著性差异;河流形态评价得分较高的河段水体自净能力也较强;河流形态与NH3-N、SS、DO和浊度的降解存在相关性,是影响河流自净能力的重要因素。 相似文献
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Wetlands are important sinks for nutrients and constructed wetlands are current practice for stormwater treatment. For nitrogen, the main removal process is denitrification (microbial reduction of nitrate to nitrogen gas). The bacteria responsible for this process are mostly found in the sediments and in epiphytic biofilms growing on wetland macrophytes. This paper reports on a project which aimed at measuring denitrification potential in sediments and epiphyton in urban wetlands. This study showed that wetland sediments could support high rates of denitrification. Interestingly, the most polluted of the wetlands studied had the highest denitrification potential. The management implication from this result is that indicators of pollution, such as hydrocarbon levels, will not necessarily reflect the ability of a wetland to denitrify. Two of the wetlands were studied in more detail. Here the denitrification potential of the epiphyton on dominant macrophytes and sediments were measured. The results indicated that the potential denitrification activity of the epiphyton was comparable to those measured in the sediments. Hence, biofilms could play a significant part in removing nitrogen loads. This work contributes to a better knowledge of the functioning of wetlands. This will lead to improved design and management of wetlands used for treating stormwater. 相似文献
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3种天然材料改造直立式护岸对河道水质净化能力的影响 总被引:3,自引:0,他引:3
在具有直立式护岸的人工模拟河道中,把蚝壳、竹片和椰壳纤维垫3种天然材料分别直接覆盖在护岸表面,以研究其对提高河道自净能力的影响。结果表明:试验启动21 d后,3种材料覆盖后河道COD去除率分别达到93%,74%,94%,高于对照组的60%;NH3-N的去除率均达到95%,高于对照组的59%;NO-3-N质量浓度在3种材料护岸和对照护岸分别升高至5.9 mg/L,5.0 mg/L,5.8 mg/L和3.9 mg/L,而TP去除率分别达到71%,37%,78%,对照组为64%,3种材料对提高河道水质净化能力均有明显效果。竹片表面附着的微生物磷脂含量和脱氢酶活性最大,分别为12 nmol/cm和45.0μg/( mL· h),分别是蚝壳的3.4和1.6倍,是椰壳纤维垫的4.8和4.5倍,3种天然材料均能为微生物附着生长和繁殖提供空间,促进河道中污染物的降解。 相似文献
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通过建立黄河自净需水量模型,分别对黄河花园口以上河段以及利津断面的自净需水量进行计算。计算结果表明,在现状入黄城镇点源超标排放、入黄支流污染严重的情况下,实现黄河水质目标所需的稀释水量较大,黄河现状水资源无法满足要求。在入黄城镇点源达标排放、入黄支流实现入黄水功能区水质目标的前提下,黄河自净需水量随季节在年内变化不大,枯水低温期所需自净需水量稍高,其中90%保证率最枯月平均流量能够基本满足黄河自净需水量,但青铜峡、石嘴山、潼关等污染严重河段所需自净需水量仍然较大,对应最枯月平均流量保证率介于8.5%~87%之间。 相似文献
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深入贯彻落实科学发展观全面提升水文支撑保障能力 总被引:2,自引:2,他引:0
这次会议的主要任务是:深入贯彻党的十七大和十一七届三中全会精神,以科学发展观为指导,总结水义工作成效,分析水文发展形势,强化水文基础地位,明确水文工作思路,部署当前和今后一个时期的水文工作,努力开创水文工作新局面,为推进水利和经济社会又好又快发展,提供更加有力的水文支撑和保障。下面,我谈几点意见。 相似文献
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一、玉门市水资源概况及特征
玉门市位于甘肃省河西走廊西部.地处戈壁沙漠包围之中.总面积1.34万km2,其中绿洲面积1444.5km2.占总面积的10.7%。玉门市境内有疏勒河、石油河、白杨河、小昌马河四条常年性的河流。多年平均年径流量11.41亿m3, 相似文献
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Anaerobic ammonia oxidation (Anammox) has been identified as a new general process-strategy for nitrogen removal in wastewater treatment. In order to evaluate the role and effects of the Anammox process in wetlands, laboratory-scale model experiments were performed with planted fixed bed reactors. A reactor (planted with Juncus effusus) was fed with synthetic wastewater containing 150-200 mg L(-1) NH4+ and 75-480 mg L(-1) NO2(-). Under these operating conditions, the plants were affected by the high ammonia and nitrite concentrations and the nitrogen removal rate fell within the same range of 45-49 mg N d(-1) (equivalent to 0.64-0.70 g Nm(-2)d(-1)) as already reported by other authors. In order to stimulate the rate of nitrogen conversion, the planted reactor was inoculated with Anammox biomass. As a result, the rate of nitrogen removal was increased 4-5-fold and the toxic effects on the plants also disappeared. The results show that, in principle, subsurface flow wetlands can also function as an "Anammox bioreactor". However, the design of a complete process for the treatment of waters with a high ammonia load and, in particular, the realisation of simple technical solutions for partial nitrification have still to be developed. 相似文献
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《中华人民共和国抗旱条例》已经国务院第49次常务会议通过并于公布之日起施行、这是我国历史上有关抗旱工作的第一部法律.它的颁布非常及时,非常必要,标志着抗旱工作已经走上法制的轨道.必将更快更好地推动抗旱减灾工作的开展。 相似文献
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水体自净能力是影响水质指标变化的重要因素。以BOD5降解系数作为自净能力表征,选取南水北调中线总干渠河南段程沟、方城、沙河南、兰河北、新峰、苏张等6个监测断面2015年1月至2015年7月逐月BOD5监测数据和研究渠段各节制闸的流量、水深等数据,采用稳态一维BOD5降解模型对总干渠BOD5降解系数进行拟合。结果表明,研究渠段BOD5降解系数数值范围为0.024/d~0.054/d,与其他区域相比,总干渠的水体自净能力相对较小。研究渠段BOD5降解系数季节变化明显,1月-4月、7月的拟合k值分别为0.028/d(p0.05),0.033/d(p0.05),0.024/d(p0.05),0.039/d(p0.05),0.054/d(p0.05);但5月、6月的拟合k值均不具有统计显著性(p0.05),可能是由于桥面和路面降雨径流形成了外源有机物污染输入,造成渠道BOD5浓度波动较大。总干渠自净能力受温度影响显著,BOD5降解系数基本随温度的升高而增大,温度校正系数θ值为1.039。 相似文献
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提高小型水电站无功输出能力的新措施 总被引:2,自引:0,他引:2
小型水电站并入大网运行后,存在着发无功不足问题,以往,人们曾用增大发电机励磁电流的方法来增大无功输出,但收效甚微。笔者现从分析发电机无功功角特性入手,通过探发电机端电压变化对无功输出的影响,解决了这一问题。 相似文献
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随着人类社会的不断的发展,水资源不仅仅是支撑农业发展的命脉、同时也是维系工业发展的血脉。经济发展导致城市不断扩张,工业用水、农业用水、生活用水之间的矛盾日趋严重,并由此产生了各种水的问题,严重制约了城市的可持续发展,给城市带来了一系列的负面影响。本文通过对辽阳市的水资源进行深入的分析,提出了境外引调水、节水、非常规水源利用和加强水环境保护等措施,从而有效提高了辽阳市水资源的承载能力。 相似文献
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全球气候变暖作为一个不争的客观事实,不可避免地会对我国农业用水和粮食安全产生影响。分别将Palmer干旱指数(PDSI)、单位灌溉面积用水量(GIQ)、单位面积粮食产量(PHGO)作为气候变化、农业用水和粮食生产具体度量指标.分析了我国1949—2005年干旱指数、单位灌溉面积用水量、单位面积粮食产量年际变化特征,建立了单位灌溉面积用水量与干旱指数以及单位面积粮食产量与干旱指数的关系模型, 相似文献
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一、水资源的开发利用中要注重对河流水文测站的保护广西水力资源丰富,是国家"西电东送"工程重要的清洁能源基地,红水河龙滩水电站装机420万kW,是目前我国第三大水电站,经过5年的建设,到2007年10月已经有3台机组发电运行。近年,柳江、龙江及其支流中小型电站的发展速度也非常迅猛, 相似文献
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S Pankratz T Young H Cuevas-Arellano- R Kumar R F Ambrose I H Suffet 《Water science and technology》2007,55(3):63-69
The Sweetwater Authority's urban runoff diversion system (URDS) comprises constructed wetlands on a hillside between the town of Spring Valley and the Sweetwater Reservoir, California, USA. The URDS were designed to divert dry-weather and first-flush urban runoff flows from the Sweetwater reservoir. However, these constructed wetlands have developed into ecologically valuable habitat. This paper evaluates the following ecological questions related to the URDS: (1) the natural development of the species present and their growth pattern; (2) the biodiversity and pollutant stress on the plants and invertebrates; and (3) the question of habitat provided for endangered species. The URDS wetlands are comprised primarily of rush (Scirpus spp.) and cattails (Typha spp.). This vegetative cover ranged from 39-78% of the area of the individual wetland ponds. Current analyses of plant tissues and wetland sediment indicates the importance of sediment sorption for metals and plant uptake of nutrients. Analyses of URDS water following runoff events show the URDS wetlands do reduce the amount of nutrients and metals in the water column. Invertebrate surveys of the wetland ponds revealed lower habitat quality and environmental stress compared to unpolluted natural habitat. The value of the wetlands as wildlife habitat is constrained by low plant biodiversity and pollution stress from the runoff. Since the primary Sweetwater Authority goal is to maintain good water quality for drinking, any secondary utilization of URDS habitat by species (endangered or otherwise) is deemed an added benefit. 相似文献
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G Langergraber C Prandtstetten A Pressl R Rohrhofer R Haberl 《Water science and technology》2007,55(7):71-78
Constructed wetlands (CWs) use the same processes that occur in natural wetlands to improve water quality and are used worldwide to treat different qualities of water. This paper shows the results of an Austrian research project having the main goals to optimize vertical flow beds in terms of surface area requirement and nutrient removal, respectively. It could be shown that a subsurface vertical flow constructed wetland (SSVFCW) operated with an organic load of 20 g COD x m(-2) x d(-1) (corresponding to a specific surface area demand of 4 m2 per person) can fulfil the requirements of the Austrian standard regarding effluent concentrations and removal efficiencies. During the warmer months (May - October), when the temperature of the effluent is higher than 12 degrees C, the specific surface area might be further reduced. Even 2 m2 per person have been proven to be adequate. Enhanced nitrogen removal of 58% could be achieved with a two-stage system (first stage: grain size for main layer 1-4 mm, saturated drainage layer; and second stage: grain size for main layer 0.06-4 mm, free drainage) that was operated with an organic load of 80 g COD x m(-2) x d(-1) for the first stage (1 m2 per person), i.e. 40 g COD x m(-2) x d(-1) for the two-stage system (2 m2 per person). Although the two-stage system was operated with higher organic loads a higher effluent quality compared to a single-stage SSVFCW (grain size for main layer 0.06-4 mm, free drainage, organic load 20 g COD x m(-2) x d(-1)) could be reached. 相似文献
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Chia-Ling Chang Tsung-Hung Hsu Yunn-Jiin Wang Jen-Yang Lin Shaw L. Yu 《Water Resources Management》2010,24(10):2339-2352
The Feitsui reservoir is a major water supply source for more than five million people in Northern Taiwan. The reservoir water quality has been good, but is threatened by eutrophication due to excessive nutrient input and siltation due to sediment loads. Recently, the water authorities in Taiwan have made considerable efforts to devise strategies using watershed conservation practices for the protection of Feitsui reservoir water quality. The control of non-point source pollution (NPS) represents one of the major strategies and the use of best management practices (BMPs) is under careful consideration. The objective of this study was to assess the effectiveness and cost of a full Feitsui watershed implementation of riparian buffer strips and other appropriate conservation practices. Based on the use of watershed simulation models and a statistical relationship between pollution reduction rate and the width and slope of a buffer strip, a methodology for the planning and design of riparian buffer strips was addressed. Data from field experiments were used to calibrate the coefficients of the regression equations. Several planning scenarios were evaluated by means of cost-benefit analysis coupled with net present value method. Data on local construction and maintenance costs for the selected design and location of buffer strips were used in the analysis. Based on several cost-benefit analyses, the scenario for installing buffer strips with 30 m width and 5% slope along both sides of tributary streams in the sub-watersheds with high nutrient (phosphorus) loadings was found to be most cost effective. 相似文献