盛泽镇污水管网改造工程设计实例

介绍了盛泽镇排水管网的现状和在排水管网设计中遇到的问题,对管网定线、水量预测、穿越河流等问题提出了解决措施,并就东南沿海城市管网设计提出了建议。     

Integrated modelling for the evaluation of infiltration effects.

The objective of the present study is the estimation of the potential benefits of sewer pipe rehabilitation for the performance of the drainage system and the wastewater treatment plant (WWTP) as well as for the receiving water quality. The relation of sewer system status and the infiltration rate is assessed based on statistical analysis of 470 km of CCTV (Closed Circuit Television) inspected sewers of the city of Dresden. The potential reduction of infiltration rates and the consequent performance improvements of the urban wastewater system are simulated as a function of rehabilitation activities in the network. The integrated model is applied to an artificial system with input from a real sewer network. In this paper, the general design of the integrated model and its data requirements are presented. For an exemplary study, the consequences of the simulations are discussed with respect to the prioritisation of rehabilitation activities in the network.     

低地坪高潮位地区的雨水管道淹没出流计算

根据水力学理论,阐述了重力流雨水管道淹没出流的水力计算方法,并结合工程实例,介绍了低地坪高潮位地区雨水管道淹没出流的简化计算方法。提出低地坪高潮位地区的重力流雨水管道应优先采用小坡降、低流速、大管径系统,以尽可能降低水位壅高对管道的不利影响。     

湖区真空下水道系统的设计

真空下水道系统凭借其自身优势在环境敏感地区(如湖区)具有较好的应用前景。与传统重力管网相比,真空下水道以阶梯敷设的方式输送污水,不受地形的限制。结合真空下水道的特点,提出了在湖区应用真空下水道系统的设计计算方法及经济分析。     

Evaluation of sewer infiltration/inflow using COD mass flux method: case study in Prague

The combined sewer system of the City of Prague, similar to other relevant locations, is strongly affected by infiltrating waters. The knowledge of their volume is one of the important parameters with respect to sewer system operation, maintenance and reconstruction. The methodology is based on the variation of diurnal chemical oxygen demand (COD) load and continuous water quality monitoring using in-line absorption spectrometry. This approach allows the identification of individual components of the diurnal wastewater hydrograph, in particular the contribution of parasitic water flow to wastewater discharge. The statistical relevance was tested using Monte Carlo simulations on a 7-year data series of flow rate. The results show that application of this methodology provides specific relevant information about individual sub-catchments within an entire sewer system, particularly in terms of absolute and relative values of I/I and structural state indicators. Processing of long-term data series gives clear information about the significance of the monitoring period length for the relevance of obtained results.     

Influence of characteristics on combined sewer performance

Elements of combined sewer systems are among others sub-catchments, junctions, conduits and weirs with or without storage units. The spatial distribution and attributes of all these elements influence both system characteristics and sewer performance. Until today, little work has been done to analyse the influence of such characteristics in a case unspecific approach. In this study, 250 virtual combined sewer systems are analysed by defining groups of systems, which are representative for their different characteristics. The set was created with a further development of the case study generator (CSG), a tool for automatic generation of branched sewer systems. Combined sewer overflow and flooding is evaluated using performance indicators based on hydrodynamic simulations. The analysis of system characteristics, like those presented in this paper, helps researchers to understand coherences and aids practitioners in designing combined sewers. For instance, it was found that characteristics that have a positive influence on emission reduction frequently have a negative influence on flooding avoidance and vice versa.     

Impact of dimension uncertainty and model calibration on sewer system assessment.

Assessments of sewer performance are usually based on a single computation of CSO (combined sewer overflow) volumes using a time series of rainfall as system loads. A shortcoming of this method is that uncertainties in knowledge of sewer system dimensions are not taken into account. Moreover, sewer models are rarely calibrated. This paper presents the impacts of database errors and model calibration on return periods of calculated CSO volumes. The impact of uncertainties is illustrated with two examples. Variability of calculated CSO volumes is estimated using Monte Carlo simulations. The results show that calculated CSO volumes vary considerably due to database errors, especially uncertain dimensions of the catchment area. Furthermore, event-based calibration of a sewer model does not result in more reliable predictions because the calibrated parameters have low portability. However, it enables removal of database errors harmonising model predictions and 'reality'.     

Real time control of the sewer system of Boulogne Billancourt — A contribution to improving the water quality of the Seine

Confronted with the problem of overflows from its combined sewer system into the River Seine during rainfall, the Department of the Hauts de Seine (which covers some thirty urban districts on the west side of Paris) has decided to implement the real time control of its sewer system. To initiate this plan, as the town of Boulogne Billancourt seemed to be a particularly favourable site for the use of such techniques, a project to control its sewer system in real time has been implemented within the scope of the SPRINT 226 programme financed by the European Community.The preliminary studies, based on a MOUSE computer model of the sewer system, showed that the real time control of the sewer network under study had a high potential benefit, since it would allow an 80% reduction of the volumes of waste water discharged into the Seine annually in the study zone. Following on from these encouraging results, the installation of a complete real time control system was set in hand. The system, at present undergoing testing and evaluation, consists principally of a MOUSE ON LINE real time model and a system for forecasting rainfall by means of radar images.     

Aerobic transformations in sewer systems: are they relevant?

In-sewer transformation processes affect wastewater quality. Especially during dwf the transformation processes can exert a significant influence on wastewater quality. The transformation rates under aerobic conditions were estimated from an oxygen mass balance over a sewer reach. Oxygen probes were installed at the upstream and downstream end of the sewer reach. Moreover, 14 wastewater samples, taken at the downstream end of the sewer reach, were used to measure the oxygen uptake rate and the water quality parameters COD(total), COD(dissolved) and ammonium. The results show that the rate of fluctuations in COD concentrations in sewer systems is an order of magnitude higher than the aerobic transformation rate. Consequently, it is concluded that the aerobic transformations in sewer systems are generally not relevant with respect to the influent fluctuations for Dutch wastewater systems. However, in situations with very long aerobic transport times, the aerobic conversions can be significant. An ASM1 based model concept for transformations in sewer systems was used to study the applicability of the model for Dutch sewer conditions. The difference between the measured and simulated values was rather low for the range of upstream dissolved oxygen and COD(total), COD(dissolved) and COD(suspended) levels. Therefore, it is concluded that the ASM1 based sewer model properly describes the changes in dissolved oxygen level in an aerobic sewer reach.     

地下排水管道流量检测技术进展

排水管道属于资金密集型市政基础工程.准确掌握管道内水流状况,是改善排水系统管理、科学制定管道系统改扩建方案的必要条件,也是今后利用先进技术建立管道系统模型、实现计算机实时控制的基础.系统总结了排水管道流量测试的常规技术,提出了适用性评估方法,介绍了目前国际上较为先进实用的排水管道流量检测设备及其在上海的应用,以期推动国内排水管道的流量检测与排水系统的管理水平.     

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

The present paper describes the Heisingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Heisingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.     

Einsatz des elektronischen Spiegels für den betrieblichen Überblick im Kanalsystem

Maintaining public sewer systems is one of sewer operators’ key responsibilities. Thus, information regarding the condition of the sewer system based on regular inspections is crucial in order to ensure operability and identify areas in need of rehabilitation. Condition assessments are usually carried out either directly by operational staff or indirectly, by means of CCTV inspection. However, alternative inspection methods are also available, including a manhole-zoom camera. Within the framework of the ongoing INNOKANIS project of the University of Natural Resources and Life Sciences, Vienna four different manhole-zoom camera models have been tested to date. One aspect of this testing focused on structural and operational condition assessments in sewer systems. Based on these results, the manhole-zoom camera can provide a simple, quick and cost-effective operational overview in terms of the need for rehabilitation, cleaning or further inspection. Despite certain limitations that have to be considered when using this inspection device, it represents an effective tool for optimising operations of the sewer system.     

Integrated modelling of sewer system and wastewater treatment plant for investigating the impacts of chemical dosing in sewers

Chemicals are often dosed to control the production and accumulation of hydrogen sulfide in sewers. The biological and/or chemical actions of these chemicals have profound impacts on the composition of wastewater entering a WWTP, thereby affecting its performance. In this paper, an integrated modelling methodology for simultaneously investigating the effects of dosing of chemicals in sewer network and N and P removal at the downstream WWTP is reported. The sewer system is modelled using a sewer model (SeweX), and the WWTP is modelled using ASM2d model with some modifications. The importance of integrated modelling in sewer management is also demonstrated.     

OPTIMAL OPERATIONAL CONTROL OF INTERCEPTOR SEWER SYSTEM

1. INTRODUCTIONAn interceptor sewer system is usually composed of pipes, detention tanks and pumping stations［1］ . Most combined sewer systems, such as that in Liverpool, discharge directly to the river. In order to alleviate pollution discharges into t…     

自动化监测系统在上海城市排水防汛管理中的应用

在进行排水系统达标改造等工程建设的同时,建立防汛排水自动化监测系统,以非工程措施提高排水运行效率,实现排水防汛工作新突破已成为业内共识.介绍了上海城市排水防汛自动化监测系统的结构组成和主要功能,结合系统在排水防汛上的应用情况,对系统的进一步发展提出设想.     

Sterols: a tracer of organic matter in combined sewers.

The important organic pollution of combined wet weather flows (WWF), its acute impact on receiving waters have been widely demonstrated. The main three possibly origins for this organic pollution are: runoff water (streets and roofs), wastewater and erosion of sewer sediments in combined sewer system. This work, for tracing the origin of organic particles bound in combined sewer system, has been focused on the innovative use of sterols. So, eight sterols have been selected and analysed for each kind of sample. Results are represented in contents of sterols (microg g(-1)) and in sterol profiles (%).The comparison of contents and profiles leads the separation between two groups: runoff water, characterized by the total absence of coprostanol, epicoprostanol and coprostanone, and the group of sewer deposits (gross bed sediment (GBS), organic layer (OL), biofilms) and wastewater. Moreover, sewer deposits and wastewater can be distinguished by their sterol contents and profiles. To evaluate their contribution to WWF a comparison between sterol signatures is done which shows that these effluents have a strong similarity in profiles and in contents of sterols to the organic layer.     

基于COMGIS的城市排水管网规划辅助系统设计

通过深入比较GIS平台与CAD平台的优缺点,研究开发了基于COMGIS组件MapObjects的城市排水管网规划GIS辅助系统,在GIS平台上同时实现了管网绘制、管网计算、管网调整三大功能,并且在方案绘制阶段建立了管网中“检查井-管道-排水区域”之间的空间拓扑关系,实现了管网设计与计算的“一体化”,从而大大简化了计算的繁琐程度,提高了方案设计和优选的效率。     

Simulation of the wastewater temperature in sewers with TEMPEST.

TEMPEST is a new interactive simulation program for the estimation of the wastewater temperature in sewers. Intuitive graphical user interfaces assist the user in managing data, performing calculations and plotting results. The program calculates the dynamics and longitudinal spatial profiles of the wastewater temperature in sewer lines. Interactions between wastewater, sewer air and surrounding soil are modeled in TEMPEST by mass balance equations, rate expressions found in the literature and a new empirical model of the airflow in the sewer. TEMPEST was developed as a tool which can be applied in practice, i.e., it requires as few input data as possible. These data include the upstream wastewater discharge and temperature, geometric and hydraulic parameters of the sewer, material properties of the sewer pipe and surrounding soil, ambient conditions, and estimates of the capacity of openings for air exchange between sewer and environment. Based on a case study it is shown how TEMPEST can be applied to estimate the decrease of the downstream wastewater temperature caused by heat recovery from the sewer. Because the efficiency of nitrification strongly depends on the wastewater temperature, this application is of practical relevance for situations in which the sewer ends at a nitrifying wastewater treatment plant.     

Estimation of Urban Impervious Fraction from Satellite Images and Its Impact on Peak Discharge Entering a Storm Sewer System

The runoff coefficient in an urban basin is highly influenced by the impervious and pervious surface fractions since they affect the entity of rainwater entering a storm sewer system. Today these fractions can be estimated by reading high resolution satellite images that are readily available at a relatively low cost. However, this approach involves a certain margin of error when it comes to identifying the various types of cover and hence the total extent of impervious and pervious surfaces. The first problem addressed in this paper thus lies in assessing to what degree the error in the estimation of the two fractions—as derived from a reading of satellite images of the area taken into consideration—may impact the estimation of peak discharge which will be used in turn as a basis for designing or verifying a storm sewer system. A further aspect affecting the entity of rainwater that flows into a storm sewer system is the manner in which the impervious and pervious fractions are connected to the system itself. This type of information may not be deduced from satellite images, but only from an extensive field survey. However, such surveys are feasible only for areas of limited size, whereas they become prohibitive in terms of time and cost in the case of large catchments. An investigation was thus made into whether disregarding the type of connection would significantly affect the peak discharge taken as reference for the design or verification of a storm sewer system. The two above-mentioned problems were addressed in reference to a real case, represented by the town of Codigoro (Ferrara, Italy), in which five small basins with different types of land cover were selected. The results of our analysis show that an estimation of impervious and pervious fractions from high resolution satellite images is sufficiently precise and acceptable for estimating the peak discharge entering the sewer system. By contrast, disregarding the information on how the different areas are connected to the sewer system may lead to a marked overestimation of discharges.