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101.
为考察生态塘湿地对农村面源污染水体氮截留效果及其影响因素,以洱海子流域生态塘湿地为例,对其基本设计参数和水质进行调查分析,评估生态塘湿地对氮的截留效果,识别不同形态氮在湿地中的迁移转化特征,剖析生态塘湿地中氮截留的主控因子.结果表明:①污水经生态塘湿地净化处理后,出水水质显著改善.出水氮达GB 3838—2002《地表水环境质量标准》Ⅲ类标准的比例为37.5%. ②Spearman相关分析表明,湿地净化效率与湿地氮输入密切相关,生态塘湿地可以有效实现氮的截留,η(TN)(η为去除率)分别与ρ(NH4+-N)(R=0.226,n=84)、ρ(TN)(R=0.215,n=84)呈显著正相关,与ρ(NO3--N)(R=-0.201,n=84)相关性不强,硝酸盐氮截留是其效率提高的主要制约因素. ③丰水期、枯水期高低水位交替运行有助于氮截留效率的稳定,枯水期生态塘几乎可以截蓄汇水分区内全部农村面源污水,实现污水的收集消纳及净化.丰水期和枯水期平均η(NH4+-N)分别为57.72%和55.30%;平均η(NO3--N)分别为49.45%和46.73%;平均η(TN)分别为54.41%和54.20%. ④单因素分析法有助于识别影响湿地氮净化效率的主控因子.研究显示,当生态塘湿地面积(< 8 000 m2)、库容(< 15 000 m3)、水深(< 2.0 m)在一定范围内时,氮净化效率与面积、库容、水深响应关系不显著,但合适的水深(< 0.4 m和>1.5 m)有利于氮的截留. 相似文献
102.
选取北京市某区的排水管道沉积物进行取样,采用高通量测序手段分析,结果表明变形菌门、广古菌门、拟杆菌门、厚壁菌门是排水管道沉积物微生物中的优势门类;在纲水平上,δ-变形菌纲、甲烷微菌纲、梭菌纲、拟杆菌纲占相对优势;在属水平上,功能性微生物硫酸盐还原菌(SRB)和产甲烷古菌(MA)普遍存在于各处管道.在所选的6段管段中,管段S3、S4处MA的相对丰度分别为20.6%、40.8%,高于其他管段,厌氧产甲烷的潜能较大,有发生可燃气积累的风险;管段S5、S6处的SRB相对丰度分别为9.14%、8.19%,高于其他管段,硫酸盐还原为硫化物的潜能较大,存在管道腐蚀的风险.RDA分析表明污水的DO、水温、硫酸根、TN与管道沉积物中微生物群落存在相关性. 相似文献
103.
Udai P. Singh James E. Scholl Ronald L. Wycoff 《Journal of the American Water Resources Association》1982,18(5):769-778
ABSTRACT: Two computer models, the Continuous Stormwater Pollution Simulation System (CSPSS) and the Computer Optimized Storm-water Treatment Program (COST), were developed to aid in performing water quality planning. This paper describes COST and its site specific applications to the Philadelphia urban area, using the results from an updated CSPSS receiving water simulation. COST provides a planning and conceptual design tool to identify the economically optimum combination of wet weather and dry weather pollution abatement alternatives. Economic analysis procedures incorporated are based on production theory and marginal cost analysis. This study demonstrates that by transforming BOD removal to reduction in low DO events, using CSPSS results, the benefits associated with pollutant removal can be accounted for explicitly by COST simulations. This is important because a pound of BOD removed from combined sewer overflow may be of more benefit to the receiving water than a pound of BOD removed from urban stormwater runoff. The selection of a pollution control strategy is often a difficult decision which should consider social, political, financial, and regulatory factors. It is suggested that such a selection can be based on evaluating the tradeoffs between total annual costs and receiving water improvements, as determined using the COST and CSPSS programs. 相似文献
104.
江西九连山区常绿阔叶林林冠截留量的估算 总被引:5,自引:1,他引:5
为了研究常绿阔叶林小流域的水分平衡,我们在江西九连山区进行了3a林外雨量、林内雨量和树干流量的观测,并据此进行了年林冠截留量的估算。观测结果表明,林冠截留率由一次降雨量为0.4~1mm的78.1%逐步降低到一次降雨量为60mm的3.4%~3.6%。一次降雨量大于60mm时,林冠截留率基本稳定在这一百分数。1988、1989和1990年3a的年降水量在1718.5~2116.5mm之间。估算结果表明,年林冠截留量在300~340mm之间,约为年降水量的16%~17.5%。 相似文献
105.
苏州河截流区外非点源污染调查 总被引:9,自引:2,他引:9
为了摸清苏州河截流区外的污染物量以及对苏州河下游段水质的影响,为苏州河截流污水工程的运行和进一步治理提供科学依据,采用美国环保局的非点源负荷函数和城区污染物流失量负荷模型等方法,对苏州河截流区外(黄渡—北新泾区段)地表径流等非点源污染负荷进行全面调查。结果表明:(1)非点污染源是目前苏州河截流区外最主要的污染源;其中,畜牧业污染为本区最大的非点污染源。(2)北新泾断面是本区污染物向下游(截流区)排放的主要控制点。(3)截流工程实施后,非点污染源将成为苏州河污染最主要的来源之一。 相似文献
106.
Donald A. Downing 《Journal of the American Water Resources Association》1975,11(2):345-355
ABSTRACT. The article proposes the use of certain water and sewer extension pricing and investment policies. Such policies would complement an urban growth policy designed to guide the location and timing of growth in urbanizing areas. Proposed pricing policies are based upon marginal cost principles. The types of pricing policies discussed include benefit assessments, connection fees, and user charges. Proposed investment policies deal with the division of financing responsiblities between the public and private sectors. Discussion of each proposal explains the economic influence of the proposed policies upon key decision makers in the land development process. The application of proposed pricing and investment policies in the case study communities is mixed. In Knoxville, Tennessee, where pricing and investment policies reflect the proposed policies, no urban growth policy exists. In Lexington, Kentucky, mixed pricing and investment policies do not complement what is a relatively good urban growth policy. In Greensboro, North Carolina, reasonably effective pricing and investment policies complement other policies which provide some guidance to the urban growth pattern. It is hoped that the article will increase the recognition of utility pricing and investment policies as one means of implementing urban growth policy. 相似文献
107.
ABSTRACT: Recent results from the Institute of Hydrology's hydrometeorological and hydrological studies on water use by forest and grassland confirm earlier predictions of a reduction in water yields following afforestation. This reduction is due primarily to the increased interception losses from forests. This paper shows how the water yield from uplands is related to the relative proportions of land under forest and hill farming, and estimates how water yields will change if a greater proportion of hill land is afforested. 相似文献
108.
Donald R. Glenn John G. Federico 《Journal of the American Water Resources Association》1971,7(5):1081-1092
ABSTRACT. Over the last few years, several studies sponsored by both government and interested national engineering associations have evaluated the relative merits of pressure sewer systems. Surprisingly little data has been forthcoming, however, with regard to the effects of pressure sewers on both the economics of land development and the country's water resources. The intention of our paper is to detail the salutary effects of pressure sewers on water supply resources, the indirect effect on other resources by decreasing the contribution of sanitary sewage to their pollution, and to illustrate where, in some locations of the country, pressure sewers would benefit the economics of land development. As engineers from a large industrial firm that has built hardware that will allow the concepts stated above to become realities, we will present data to enforce our convictions. Some effects on municipal treatment plants, and emplacement costs of the system are described. Since the main thrust of our paper is to treat the effect of pressure sanitary sewers on the water resources of the country, specific peripheral data is not presented at length. The pressure sewer effects on lowering water usage in homes and the decrease in groundwater contamination by replacing septic tanks with pressure sewers in selected locations is presented. Advanced technology concepts such as energy assisted sewer systems should be considered as a favorable economic manner in which to preserve selected water resources. During the 1965 drought that affected the Northeastern section of the U.S., a federal government document reported that there was really no shortage of water, but that present water resources lacked management. Pressure sewers may be a water resources management tool and an effective one if not promulgated as a cure-all for the water pollution problems facing this nation. 相似文献
109.
TiO2对聚偏氟乙烯膜的改性研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备TiO2胶体,用涂覆的方法拯TiO2胶体附在聚偏氟乙烯(PVDF)膜表面,测试磺化时间,浸泡时间对膜通量的影响,通过改变膜表面的性质,以及对截留率和接触角的测定,找出改性膜的最佳工艺条件。结果表明:从接触角来讲,磺化时间为2小时,浸凝的时间为10分钟时,改性膜的通量最好;改性膜的截留率普遍都高于未改性膜的截留率;改性后膜生物反应器的出水水质更好。为增加膜通量,延长膜寿命,降低膜反应器的成本,降低处理污水的造价提供了一种新的参考方向。 相似文献
110.
The Korea government has put in a lot of e ort to construct sanitation facilities for controlling non-point source pollution. The
first flush phenomenon is a prime example of such pollution. However, to date, several serious problems have arisen in the operation
and treatment e ectiveness of these facilities due to unsuitable design flow volumes and pollution loads. It is di cult to assess the
optimal flow volume and pollution mass when considering both monetary and temporal limitations. The objective of this article was to
characterize the discharge of storm runo pollution from urban catchments in Korea and to estimate the probability of mass first flush
(MFFn) using the storm water management model and probability density functions. As a result of the review of gauged storms for the
representative using probability density function with rainfall volumes during the last two years, all the gauged storms were found to be
valid representative precipitation. Both the observed MFFn and probability MFFn in BE-1 denoted similarly large magnitudes of first
flush with roughly 40% of the total pollution mass contained in the first 20% of the runo . In the case of BE-2, however, there were
significant di erence between the observed MFFn and probability MFFn. 相似文献