Ensuring reliable structural condition of sewers is an important criterion for sewer rehabilitation decisions. Deterioration models applied to sewer pipes support the rehabilitation planning by means of prioritising pipes according to their current and predicted structural status. There is a benefit in applying such models if sufficient inspection data for calibration, an appropriate ...
The chemically enhanced primary treatment works in Hong Kong will be upgraded for biological nitrogen removal. This study proposed a novel approach to waive the upgrading by urine source-separation, onsite nitrification and discharge of nitrified urine into sewers to achieve in-sewer denitrification. Human urine was collected and a lab-scale experiment for full urine nitrification was conducted. ...
As urban sewer infrastructures age, it becomes increasingly important to make effective decisions to maintain the structural condition of the sewers at an acceptable level. To support the decision-making process, the utility manager can apply sewer deterioration models. However, the quality of the decision support from such models is dependent on the accuracy and reliability of the ...
Applications such as real-time control, uncertainty analysis and optimization require an extensive number of model iterations. Full hydrodynamic sewer models are not sufficient for these applications due to the excessive computation time. Simplifications are consequently required. A lumped conceptual modelling approach results in a much faster calculation. The process of identifying and ...
Pluvial flooding in urban areas is characterized by a gradually varying inundation process caused by surcharge of the sewer manholes. Therefore urban flood models need to simulate the interaction between the sewer network and the overland flow in order to accurately predict the flood inundation extents. In this work we present a methodology for linking 2D overland flow models with the storm ...
As urbanisation and climate change progress, the frequency of flooding will increase. Each flood event causes damage to infrastructure and the environment. It is thus important to minimise the damage caused, which can be done through planning for events, real-time control of networks and risk management. To perform these actions, many different simulations of network behaviour are required ...
This paper presents an integrated modeling approach that combines the legacy urban runoff and the legacy storm sewer models with data exchange at runtime to simulate sewer flows with real-time rainfalls. A software system called IRES has been developed to demonstrate the proposed approach. IRES uses the RUNOFF and the EXTRAN block of Storm Water Management Model (SWMM) as the legacy urban ...
A comprehensive flow monitoring network can provide powerful insight about the performance of a sanitary sewer collection system. Accurate flow monitoring data reveals numerous system details, such as sewer usage patterns, the presence of sediments, groundwater infiltration, rainfall-dependent inflow and infiltration, stream intrusion, and sewer exfiltration or leakages. Knowledge of these ...
Abstract A comprehensive flow monitoring network can provide powerful insight about the performance of a sanitary sewer collection system. Accurate flow monitoring data reveals numerous system details, such as sewer usage patterns, the presence of sediments, groundwater infiltration, rainfall-dependent inflow and infiltration, stream intrusion, and sewer exfiltration or leakages. Knowledge of ...
The reported research project focuses on using a database which contains details of customer contacts and CCTV data for a key Scottish catchment to construct a GIS based sewer condition model. Given the nature of the asset registry, a key research challenge was estimating the age of individual lengths of pipe. Within this context, asset age was inferred using the estimated age of surface ...
The presence of high concentrations of hydrogen sulfide in the sewer system can result in corrosion of the concrete sewer pipes. The formation and fate of hydrogen sulfide in the sewer system is governed by a complex system of biological, chemical and physical processes. Therefore, mechanistic models have been developed to describe the underlying processes. In this work, global sensitivity ...
The phenomenon of urban flooding due to rainfall exceeding the design capacity of drainage systems is a global problem and can have significant economic and social consequences. The complex nature of quantitative precipitation forecasts (QPFs) from numerical weather prediction (NWP) models has facilitated a need to model and manage uncertainty. This paper presents a probabilistic approach for ...
ABSTRACTFor the assessment of combined sewer overflows detailed models are not necessary. Physically based conceptual models give an optimal balance between model uncertainty and uncertainty in the input data. Besides, it is important that continuous long term simulations are performed. To prove this, in this paper the calibration of a reservoir model is discussed. The emission results of the ...
In this study we compared three overland flow models, a full dynamic model (shallow water equation), a local inertial equations model (gravity wave model), and a diffusive wave model (parallel diffusive wave model). The three models are coupled with the same full dynamic sewer network model (SIPSON). We adopted the volume exchange between sewer and overland flow models, and the hydraulic head ...
The Orange County Sanitation District (OCSD or District) owns and operates the regional collection system in north and central Orange County, California. The system, which includes over 400 miles of trunk sewers, conveys approximately 250 million gallons of wastewater per day from local sewers within a 471-square-mile service area to two treatment plants. Recently, the District updated the ...
To implement any effective odour and corrosion control technology in the sewer network, it is imperative that the airflow through gravity sewer airspaces be quantified. This paper presents a full dynamic airflow model for gravity sewer systems. The model, which is developed using the finite element method, is a compressible air transport model. The model has been applied to the North Head ...
May proposed two dimensionless parameters of transport (η) and mobility (Fs) for self-cleansing design of sewers with deposited bed condition. The relationships between those two parameters were introduced in conditional form for specific ranges of Fs, which makes it difficult to use as a practical tool for sewer design. In this study, using the same experimental data used by May and ...
Our CSO Monitoring solutions combines MAP Rain and machine learning to compare the historic performance of assets with historic rainfall. We then use this analytis to deliver actionable insights that predict the operation of the CSO, or other similar geometries in MAP, to current and forecast rainfall. Key features Three different modes of operation Rainfall. Expected operation is driven ...
The collection system of a major city at the Persian Gulf was simulated for bulk water hydrogen sulfide and the release of sewer gas to the urban atmosphere. Geometry data on 870 km of sanitary sewer and data on dry weather flow entering all nodes in the catchment was exported from a Mike Urban database and imported to the sewer process model WATS. The process model then routed sewage and sewer ...
The problems related to hydrogen sulfide in terms of deterioration of sewer networks, toxicity and odor nuisance have become very clear to the network stakeholders and the public. The hydraulic and (bio)chemical phenomena and parameters controlling sulfide formation, emission and their incidences in sewer networks are very complex. Recent research studies have been developed in gravity and ...