初期雨水调蓄池控制溢流污染研究

利用苏州河沿岸典型排水系统雨天溢流水量、水质变化以及调蓄池处理技术的研究成果,与数学模型研究有机结合,建立了苏州河沿岸排水系统降雨径流水量水质与河网水量水质动态耦合的集成模型,计算分析了在3个典型年实际降雨条件下,苏州河沿岸调蓄池工程对溢流水量、溢流污染物的削减效果,以及控制溢流污染对苏州河水质的改善效果。     

城市中小河道截污主要方式和工程实例

目前上海中小河道基本未设雨、污水分流系统,不仅河道自身污染严重,而且当水量较大或汛期时,给苏州河带来极大污染。为此必须加快实施中小河道的截污纳管工程。介绍了沿河边敷设截污管道和河道内敷设截污管道的两种主要方式,以及溢流设施和玻璃钢接头的形式和具体施工。最后介绍了长宁区中小河道截污纳管工程的实例。     

上海市排水系统雨天出流的初期效应分析

以上海市苏州河沿岸5个代表性排水系统为研究对象，采用无因次累积负荷体积分数曲线[M（y）曲线]和b参数方法，对上海市排水系统雨天出流的初期效应现象进行了探讨。研究表明，若以30／80标准衡量，5个排水区域都没有初期效应。若以50／50标准判定，合流制系统具有微弱初期效应，分流制系统雨天出流水质变化过程随降雨事件不同而有很大波动，总体上没有初期效应。COD和BOD5比SS更具初期效应。各水质指标的初期效应强度随不透水比例增加而增加，随汇水面积增加而减小。研究成果为雨水存储池等城市面源污染控制设施的规划设计提供了依据．     

监测技术在排水管网运行管理中的应用及分析

针对排水管网溢流造成的城市污染问题,对监测技术在城市排水管网运行管理过程中的应用模式进行了探讨和案例分析,对监测数据的分析方法和监测数据支持下的模型动态模拟技术进行了研究。案例分析表明,通过对监测数据的分析和模拟可全面掌握整个排水管网系统内各个管道的水力负荷和水质状况,利用监测数据与模型的紧密集成使用的方法,可提高模型预测的可靠性和城市排水管网管理的科学性与高效性。     

合流制排水系统溢流实时控制方案的预评估

介绍了对排水系统实时控制方案进行预评估的意义,比较了不同实时控制方案应用潜力的预评估方法,并采用PASST法评估了实时控制减少合肥老城区溢流污染的潜力。根据合肥老城区以及上海市的排水系统状况对PASST法进行分析,初步探讨了PASST法在国内应用时需要改进的内容,为国内排水系统实时控制方案预评估工作的开展提供了参考和借鉴。     

合流制溢流调蓄处理工艺效果评估及优化对策

针对初期雨水及合流制溢流水质和水量波动大而引起的调蓄工程处理能力不足、运行能耗高及难以有效收集高负荷合流制溢流污水等问题,通过对不同时期进入调蓄工程的合流制溢流水质和水量特征的分析,结合调蓄工程处理工艺的沿程水质分析,考察了"微砂高效沉淀池+接触氧化池+D型滤池"工艺对合流制溢流的实际处理效果。结果表明,初期雨水及合流制溢流均呈水质和水量波动大、高氨氮、低COD的特征,氨氮是调蓄处理工艺出水水质达标的关键指标;同时,生化处理单元进水COD浓度低的特征不利于接触氧化池的生物挂膜,降低了工艺的实际处理能力。因此建议:(1)在接触氧化池后设置混凝加药装置,以保证出水SS和TP达标排放;(2)接触氧化池采用多点进水方式,并预留碳源投加装置;(3)增加精确曝气控制系统,实现节能降耗。     

基于管道沉积物控制的CSOs污染负荷削减分析

管道沉积物是合流制排水系统溢流(CSOs)污染的重要来源,因此控制沉积物对于削减CSOs污染具有重要意义。在合流制排水系统截流泵站的上游管道中安装穿孔管,给穿孔管提供高压水产生7.5 m/s以上的射流以冲洗管道,同时在截流泵站内设置旋流分离系统来去除冲洗水中的沉积物。对于水层较浅、管径为DN400、管长为40 m、沉积层厚度为3 cm的管道,可使管道流中的SS从冲洗前的75～170 mg/L增加到2 500～3 000 mg/L,且在2～3 min内冲洗干净。旋流分离器对冲洗水中SS的去除率达到55.6%。两周一次的管道例行清洗维护,可使CSOs中污染物降低25%左右,减轻了受纳水体的污染负荷。     

合流制溢流污染控制实践:以岳阳蛇皮套泵站为例

岳阳市蛇皮套泵站及调蓄池改造工程是典型的合流制溢流污染控制工程,设计通过科学的管网水力模型与系统的水文建模分析,基于海绵城市建设理念,在排口末端采用调蓄池与生态滤池组合工艺处理溢流水,达到精准治污的效果,并将处理设施结合景观设施进行设计,将黑臭水体改造为海绵公园。介绍了项目的基本情况以及泵站、调蓄池、生态滤池的设计规模和运行工况,并对设计方案进行长历时水文模型验证。模拟结果表明,在经济允许的情况下,采用该工艺措施可使受纳水体的溢流污染得到一定的控制,单位硬化面积的溢流COD污染负荷低于250 kg/(hm^2·a),生态滤池出水COD平均值为10.2 mg/L,生态滤池溢流频次为12.2次/年,调蓄池截流的COD污染负荷为2 343 t/a,生态滤池去除的COD污染负荷为105 t/a,分别占COD污染总量的48.2%和2.2%,而溢流污染量仅占2.3%,达到了一定的面源污染控制要求,生态环保效益明显。     

基于GIS的昆明主城区排水系统诊断研究

昆明主城区地处滇池流域北岸滨湖上游区域,污染负荷比重大,占流域污染负荷总量的约80%,目前昆明主城区二环路内区域为合流制排水系统,二环路外为分流制排水系统,在雨季雨、污合流污水溢流污染问题严重.在昆明市地下管线探测工作的基础上,对排水管网数据进行空间信息和属性信息处理,建立污染源与排水系统的拓扑关系,构建排水片区--子排水片区--排水单元结构网络.统计分析结果表明,昆明主城区的现状污水收集率约为81%;污水处理厂处理能力有限,在雨季大量合流污水不经处理而直接溢流排入河道,并汇入滇池.通过对典型排水区域船房河排水片区--第一污水处理厂纳污区域进行排水系统详查和污水产生--收集--处理全过程分析,确定依托沟渠主干的排水系统地下水渗入量约占系统收集总水量的35%,此截流式合流制与不完全分流制相结合的典型排水片区旱季污水收集率约为60%,在雨季典型降雨条件下,合流污水溢流率约为90%.此研究成果为昆明主城区排水系统的改造和污水处理厂的规划建设提供了一定依据,也为全面开展排水系统诊断工作奠定了基础.     

On hydraulic and pollution effects of converting combined sewer catchments to separate sewer catchments

The overall objective of this paper is to contribute to the standing debate concerning the advantages of separate sewer systems compared to traditional combined sewer systems. By a case study this investigation reveals that transformation of part of a town from being serviced with combined sewer systems to become serviced with separate sewer systems decreases the volumes of storm water and pollutants diverted to the waste water treatment plant and discharged as combined sewer overflow. This happens at the expense of an increase in volumes of storm water and pollutant loads diverted to local receiving waters when detention ponds are not built-in the new separate sewer systems. It is concluded that consequences can be fatal for receiving waters, if no retention of pollutants is integrated into the system.     

上海中心城区合流制排水系统雨天溢流水质研究

合流制排水系统雨天溢流已成为上海中心城区河道的主要污染源.为此,重点研究了上海中心城区某合流制排水区域JXB系统雨天污染物溢流的出流过程和污染物的事件平均浓度,并探讨了溢流污染物的初期效应.结果表明,降雨特性对污染物溢流过程的水质影响较大;该区域雨天溢流COD、BOD5、SS、NH3-N的事件平均浓度分别为268、101、110、9.5 mg/L,SS浓度明显低于相关研究的结果;分析溢流污染物的初期效应表明,JXB系统排江污染物的初期效应较为显著,其中COD和BOD5的初期效应比SS的显著.     

调蓄池及其在苏州河治理中的应用

初期雨水对河道的冲击污染已成为解决河道污染的主要难题之一。该文介绍了调蓄池的原理、分类、运行方式和除污效果;介绍了调蓄池在上海苏州河环境综合整治二期工程梦清园活水公园的应用探索;如苏州河沿线4座调蓄池建成后,预测每年排入苏州河的COD将减少2300t,即削减53.2%。这为调蓄池在我国的应用创造了良好的开端。     

Diffuse and point pollution impacts on the pathogen indicator organism level in the Geum River, Korea

The pathogens originating from diffuse pollution have raised much concern recently. In many countries, pathogen levels are monitored in surface water by measuring the pathogen indicator organism level, which indicates the concentration of pathogen associated microorganisms to determine contamination. Among indicator organisms, total coliform, fecal coliform, and Escherichia coli were selected for study, and their concentration as well as their flow rate were monitored at monitoring stations from October, 2001 to April, 2003. Monitoring stations include six sampling stations in the Geum River, two small watersheds used for forestry and agricultural land, one large wastewater treatment plant, one separate sewer overflow site, and one separate sewer overflow site in the Geum River basin. The coliform concentration of the combined sewer overflow was the highest, followed by the runoff from agricultural land use, the separate sewer overflow, and the runoff from forestry land use. The Pearson correlation coefficient for flow rate against total coliform concentration was 0.71 and was significant at 0.01 level, while the Pearson coefficient for other water quality constituents showed weak correlation (-0.36 to +0.37) against flow rate. Coliform concentration showed higher correlation against suspended solid concentration or flow rate during storm flow condition than during low flow condition. Two different relationship lines could explain the relationships between the flow rate and coliform loadings. Load duration curve technique was presented to assess the relative contributions of diffuse and point source pollution to the pathogen level at monitoring sites in the Geum River.     

国内外对合流制管道溢流污染的控制与管理

随着城市化进程的加快,城市雨水问题以及合流制排水管道的溢流污染问题变得日益严重.合流制管道的溢流污染已成为部分城市改善水体水质的主要制约因素之一.若未经有效处理的溢流污水直接排入水体中,不仅会严重地破坏水环境功能,还将危及人类健康.介绍了国内外部分城市控制合流制管道溢流污染的概况,分析了我国目前控制合流制管道溢流污染存在的问题和不足,讨论国外经验对我国的启示并提出一些建议,为我国对合流制管道的溢流污染控制提供借鉴.     

The potential to retrofit sustainable drainage systems to address combined sewer overflow discharges in the Thames Tideway catchment

Experience of retrofitting sustainable drainage systems (SuDS) in the United Kingdom is limited, and there are no well‐established procedures for evaluating the feasibility, value or cost‐effectiveness of doing this, particularly at the catchment scale. This paper demonstrates a two‐phase process for evaluating the potential to retrofit SuDS to address combined sewer discharges in three subcatchments within the Thames Tideway catchment of London. The first phase evaluates what might be achieved with various levels of disconnection (‘global’ disconnection scenarios) using hydraulic models, while the second phase considers how disconnection might practically be achieved. High levels of disconnection are technically possible but practicably difficult. In selected cases, and with aggressive implementation of SuDS, combined sewer overflow CSO discharges could potentially be eliminated or reduced to acceptable levels without the need for any modifications to underground assets. However, retrofit SuDS could not eliminate the requirement for some form of sewer modification in any subcatchments.     

Full-Scale Testing of Mechanically Raked Bar Screens

Combined sewer overflows are a known source of aesthetic pollution in urban watercourses, and screens have traditionally been used as a means of preventing such pollution. The authors have established the effectiveness of combined-sewer overflow bar screens in preventing the visual pollution of rivers and have determined the factors which influence screen efficiency so that guidance can be given on improving the performance of future installations. A field study has been undertaken to monitor existing bar screens with different bar spacings. The hydraulic performance of the overflow chambers has been established, and the sources and type of visual pollutants have been identified. Analysis of the field data has established that screen performance (for the main polluting solids) depends on (a) screen bar spacing, (b) mean rate of flow through the screens, and (c) frequency of raking. Overall, mechanically raked bar screens are likely to achieve retention efficiencies of less than 50%.     

A combined methodology for the hydraulic rehabilitation of urban drainage networks

During medium and high intensity storm events, urban drainage networks can rapidly reach their maximum capacity, and subsequently floods can occur. Owing to the non-linearity of the processes involved, it is evident that the return period of a rainfall is different from the return period of the generated overflows. Therefore, the assessment of the maximum overflow volume related to a given return period is a key element in the management of urban drainage networks, since it may cause problems to infrastructure and economic losses. In this paper, a combined methodology for the hydraulic rehabilitation of such networks is proposed, by expressing their hydraulic critical conditions in terms of overflow volumes rather than rainfall volumes and considering both observed rainfall data and synthetic hyetographs derived from statistical analysis. The first application of the proposed methodology to the sewer network of the Mesola Municipality is presented and commented on.     

Stochastic modeling of total suspended solids (TSS) in urban areas during rain events

The load of total suspended solids (TSS) is one of the most important parameters for evaluating wet-weather pollution in urban sanitation systems. In fact, pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), phosphorous and organic compounds are adsorbed onto these particles so that a high TSS load indicates the potential impact on the receiving waters. In this paper, a stochastic model is proposed to estimate the TSS load and its dynamics during rain events. Information on the various simulated processes was extracted from different studies of TSS in urban areas. The model thus predicts the probability of TSS loads arising from combined sewer overflows (CSOs) in combined sewer systems as well as from stormwater in separate sewer systems in addition to the amount of TSS retained in treatment devices in both sewer systems. The results of this TSS model illustrate the potential of the stochastic modeling approach for assessing environmental problems.     

基于暴雨雨型的设计径流量研究及应用

为简化排水模型在城市排水防涝规划中的应用,利用武汉短历时暴雨雨型,采用三角概化法推导出雨型径流量计算公式。通过武汉雨型径流量设计程序在9个排水区的应用,在相同重现期标准下与武汉暴雨强度公式进行对比,同频率雨型设计径流量的平均绝对值相对误差为1.29%,最大误差<5%。采用相关因子拟合公式计算排水区节点雨水汇流时间,可建立雨型径流量节点管控简化模型,无需排水管网建模,可实现城市排水防涝规划水位管控,也可进行雨水溢流污染控制调节池容量的计算。     

新型排水体制在城市排水系统规划中的应用

在传统排水体制的基础上,分析了城市排水体制在实际运行中存在的问题,提出了截流式分流制和溢流污水处理-截流式合流制两种新型的排水体制.介绍了两种新型排水系统的工作原理、设计参数等,以期为新建城区的管网建设和老城区的管网改造提供借鉴.