基于GIS的污水回用管网节点用水量统计方法

在GIS环境中 ,对城市土地利用规划栅格图进行分类 ,并对导入的污水回用管网CAD图形构建几何网络 ,通过几何网络中的节点划分泰森多边形确定节点供水区域范围 ,分类统计各节点供水区域内的土地利用面积 ,根据分别对应的回用水定额 ,进行回用水量统计计算 ,为污水回用系统规划提供依据     

节点流量和水损系数的不确定性对供水管网水力特性的影响

供水管网的节点用水量和水损系数具有明显的不确定性,为研究节点用水量和水损系数的不确定性对供水管网水力特性的影响,提出了在假定他们的随机变化服从正态分布的条件下,采用蒙特卡罗随机抽样法,对所获的每组节点用水量和水损系数的抽样值,应用稳态的水力模型计算相应的节点测压管水头和管段流量,得出节点测压管水头和管段流量的统计值的计算方法。文中给出了该算法在两管网中的应用。     

EPANET模型在人工湿地配水管网设计中的应用

在天津市空港经济区污水处理厂尾水处理人工湿地输水管网设计中,建立规划管网的EPANET水力模型,采用湿地污染物去除一级动力学方程确定管网中节点的用水量,根据水力模型的管网平差计算结果—节点压力、管段流速以及水头损失进行分析,调整初始设计不合理的管段管径,解决了不同地块的人工湿地如何合理地配水以及管网压力过高的问题,提高了人工湿地管网设计的合理性,降低了管网的投资和运行成本,对湿地的配水管网设计提出了探讨性建议.     

三峡库区山地城市排水体制和管网方案的选择

通过对三峡库区山地城市排水管网的现状分析,并结合山地城市特殊的地形特点,确定了山地城市的排水体制;重庆是典型的山地城市,以唐家沱污水处理厂管网布置为例,具体分析了山地城市排水体制和管网布置方案的选择,通过对方案的经济、技术、施工等方面详细对比,选择了最优方案。     

给水管网微观模型中节点流量在线预测计算方法研究

阐述了研究区域时总用水量数据整理、时总用水量预测、制作用水模式曲线、节点流量预测值计算 ,建立了给水管网微观模型中节点流量在线预测计算方法 ,并在实践中加以验证。     

城市排水管网系统改造技术

1.现有城市排水管网系统存在的问题1.1城市排水管网系统的新旧层次突出排水管网的质量和设计在很大程度上制约着城市排水系统的工作效率及其使用年限。现在仍有部分城市使用明清时期、解放前的排水设施,如故宫的排水系统为明清时期修建的排水明沟和暗沟以及新中国成立后修建的污水管线,历经将近600年,许多地下管网仍在发挥重要作用。我们不否认这套设施的可取之处,但面对城市化的发展,有些设施已经存在超负荷工作的情况,当然城市的相关主管部门也对管道进行了更换,这便造成了城市排水管网系统新旧层次突出的问题。     

基于拓扑关系构建的城市污水管网优化设计

在城市污水管网优化设计过程中,提出利用数组记录关联管段及其编号的方法来构建污水管网的拓扑关系;根据各关联管段及其节点的参数比较确定下游管段的初始控制参数,并以各管段的平均坡度作为控制依据进行污水管网的优化设计.采用VB语言编制了污水管网优化设计程序,并用广东某城镇的污水管网对程序进行了验证.     

利用“最小夜流量”检测小区供水管网泄漏

针对小区地下供水管网暗漏难以发现的问题,本文介绍了用估算最小夜间流量测漏的方法。即将独立的供水区域的理论估算最小夜流量与实际检测夜间用水量相比较,如实测值大于估算值,则管网有水量泄漏,再在区域内通过闸阀的开闭,缩小漏点范围,最后用相关检漏仪和听漏仪进行定位。     

建立节点连续性方程求解污水管网设计流量

针对污水管网设计中设计流量计算工作量大的问题,在分析城市污水管网结构的基础上,提出了管段及节点的编号方法,建立了污水管网节点连续性方程,以求解污水管网设计流量.结合实例,采用Matlab语言编写求解程序,并验证了程序的可行性.     

浅谈山地城市污水管网改造设计

简要分析了山地城市排水管网现状及实现雨污水分流改造的重要性,提出山地城市排水管网改造设计过程中需注意的几个关键问题,结合具体的工程实例介绍了污水管网改造实施过程中解决排水管道系统短距离、大落差,以及管道穿越特殊构筑物等方面的技术方案.     

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.     

污水处理系统的集成控制策略研究

以实现河流水质目标为前提,充分利用河流纳污能力,根据不同环境与气候条件调节污水处理厂运行状况和排水管网的污水排放量,可有效保护河流生态质量。基于城市污水处理系统集成仿真平台,提出了4种以河流水质为目标的城市污水处理系统集成控制方案,通过对排水管网和污水处理厂的协调控制,实现了河流水质的改善。仿真结果验证了集成控制策略的有效性。     

Impact of water source management practices in residential areas on sewer networks - a review

Prolonged drought which has occurred everywhere around the world has caused water shortages, leading many countries to consider more sustainable practices, which are called source management practices (SMPs) to ensure water availability for the future. SMPs include the practices of water use reduction, potable water substitution and wastewater volume reduction such as water demand management, rainwater harvesting, greywater recycling and sewer mining. Besides the well known advantages from SMPs, they also contribute to the alteration of wastewater characteristics which finally affect the process in downstream infrastructure such as sewerage networks. Several studies have shown that the implementation of SMPs decreases the wastewater flow, whilst increasing its strength. High-strength wastewater can cause sewer problems such as sewer blockage, odour and corrosion. Yet, not all SMPs and their impact on existing sewer networks have been investigated. Therefore, this study reviews some examples of four common SMPs, the wastewater characteristics and the physical and biochemical transformation processes in sewers and the problems that might caused by them, and finally the potential impacts of those SMPs on wastewater characteristics and sewer networks are discussed. This paper provides sewer system managers with an overview of potential impacts on the sewer network due to the implementation of some SMPs. Potential research opportunities for the impact of SMPs on existing sewers are also identified.     

Urban total phosphorus loads to the St. Clair-Detroit River System

The St. Clair-Detroit River System watershed is a large, binational watershed draining into the connecting channel between lakes Huron and Erie. In addition to extensive agricultural lands, it contains large urban areas that discharge phosphorus from point source facilities, runoff of impervious surfaces, and overflows of combined sewers. To help guide actions to reduce phosphorus input to Lake Erie, we analyzed the spatial and temporal dynamics of loads from the three largest urban areas in the watershed (southeast Michigan; Windsor, Ontario; and London, Ontario), and used a previously calibrated storm water management model (SWMM) to explore options for reducing loads around metro Detroit. Point sources in these three urban areas contribute, on average, 81% of the total urban load and 19% of the Detroit River’s total phosphorus (TP) load to Lake Erie, while combined sewer overflows and runoff both contribute about 10% each to the urban load and about 2.5% each to the Detroit River’s load to Lake Erie. Most of the urban load (56%) comes from a single point source, the wastewater treatment facility in Detroit; however, TP loads from that facility have decreased by about 51% since 2008 due to improvements in wastewater treatment. Model simulations suggest that increasing pervious land area or implementing green infrastructure could help reduce combined sewer overflows in certain upper portions of the metro Detroit sewer system, but reductions were much less expressed for wet-weather discharge from the system.     

Saline sewage treatment and source separation of urine for more sustainable urban water management

While energy consumption and its associated carbon emission should be minimized in wastewater treatment, it has a much lower priority than human and environmental health, which are both closely related to efficient water quality management. So conservation of surface water quality and quantity are more important for sustainable development than green house gas (GHG) emissions per se. In this paper, two urban water management strategies to conserve fresh water quality and quantity are considered: (1) source separation of urine for improved water quality and (2) saline (e.g. sea) water toilet flushing for reduced fresh water consumption in coastal and mining cities. The former holds promise for simpler and shorter sludge age activated sludge wastewater treatment plants (no nitrification and denitrification), nutrient (Mg, K, P) recovery and improved effluent quality (reduced endocrine disruptor and environmental oestrogen concentrations) and the latter for significantly reduced fresh water consumption, sludge production and oxygen demand (through using anaerobic bioprocesses) and hence energy consumption. Combining source separation of urine and saline water toilet flushing can reduce sewer crown corrosion and reduce effluent P concentrations. To realize the advantages of these two approaches will require significant urban water management changes in that both need dual (fresh and saline) water distribution and (yellow and grey/brown) wastewater collection systems. While considerable work is still required to evaluate these new approaches and quantify their advantages and disadvantages, it would appear that the investment for dual water distribution and wastewater collection systems may be worth making to unlock their benefits for more sustainable urban development.     

An integrated approach for improving the wastewater discharge and treatment systems

Since treatment plants have been built all over Germany during the last decades, the water quality of receiving streams has been improved remarkably. But there are still a lot of quality problems left, which are caused e.g. by combined sewer overflows (CSO), treatment plant effluents or rainwater discharges from separate sewer systems. At present different efforts are undertaken to control sewer systems in order to improve the operation of urban drainage systems or more generally, design processes. The Emschergenossenschaft and Lippeverband (EG/LV) are carrying out research studies, which are focusing on a minimization of total emissions from sewer systems both from wastewater treatment plant (WWTP) effluents and from CSO. They consider dynamic interactions between rainfall, resultant wastewater, combined sewers, WWTP and receiving streams. Therefore, in an advanced wastewater treatment, a model-based improvement of WWTP operation becomes more and more essential, and consequently a highly qualified operational staff is needed. Some aspects of the current research studies are presented in this report. The need and the use of an integrated approach to combine existing model components in order to optimize dynamic management of combined sewer systems (CSS) with a benefit for nature are outlined.     

Quantification of pollution loads from CSOs into surface water bodies by means of online techniques.

Based on novel technologies, a modular online monitoring station suitable for continuous application in sewer networks, wastewater treatment plants and receiving water bodies has been designed. The monitoring station serves as the backbone of a water quality pilot network. As one part of this network a sewer monitoring station has been installed at a combined sewer overflow in Graz to quantify pollution concentrations and loads in the combined sewer and into the receiving water and is operated since October 2002. The design and equipment of the measurement station and first operating experiences and results are given in this paper.     

ArcEGMO-URBAN--hydrological model for point sources in river basins.

The new model ArcEGMO-URBAN aims at deterministic and spatiotemporal modelling of water, nitrogen and phosphorus fluxes from all urbanised areas of a river basin considering all potential sources. Pollution loads are calculated for discrete urban patches and balanced on the level of hydrological subbasins. Modelling results can be defined by the user of any level of spatial and/or temporal aggregation, e.g. matter balances for river basins or river sections and years or months, respectively. To process spatial data, a Geographic Information System is linked to the model. Information on urban land use and general characteristics of river basins is based on digital coverages, partly generated from remote-sensing data. Moreover, statistical data, e.g. on population, sewer systems, wastewater treatment plants etc. are included. Stormwater runoff from impervious surfaces is calculated as one input to the sewer network. Wastewater is considered with its main sewer system, pumping stations and treatment plants. Finally, the discharge is balanced for discrete river sections. Modelling results attest ArcEGMO-URBAN its ability to realistically quantify matter fluxes and major pollution sources as well as their seasonal variation. This makes the model an applicable tool for the analysis of scenarios with e.g. varying population distribution or climatic and technological conditions.     

广州市中心城区典型合流制排水口污染负荷排放规律分析

随着广州市中心城区河道水环境治理力度的加大,合流制溢流污染问题越来越突出,对城市河道水体构成了日益严重的威胁。本文选取广州市中心城区典型合流制排水口进行了18场降雨的径流污染监测,总结了在典型小雨、典型中雨及典型大雨场次下排水口各水质指标随降雨历时的变化规律,同时分析了18场降雨的排水口最高浓度、平均浓度与总降雨量的关系,研究成果可为合流制污染控制工程的设计提供参考。