A review of model development based on sewer sediments research in the UK

1996 ◽  
Vol 33 (9) ◽  
pp. 1-7 ◽  
Author(s):  
Rebecca Gent ◽  
Bob Crabtree ◽  
Richard Ashley
Keyword(s):  
Model Development ◽  
Urban Pollution ◽  
Simulation Models ◽  
Sewer System ◽  
Research Results ◽  
Sewer Systems ◽  
Sediment Deposits ◽  
Flow Quality ◽  
The Uk

A major programme of research into the nature, behaviour and occurrence of sediment deposits associated with sewer systems has been carried out in the UK since 1988. This research has been co-ordinated by the UK water industry's Urban Pollution Management Programme. The main driving force behind this research has been the need to collect fundamental data to support the development of sewer flow quality simulation models. Research results have significantly enhanced knowledge pertaining to sewer sediments and this has proved to be crucial to the development of reliable modelling tools to predict the quality of sewer system discharges. Particular advances have been made in the ability to understand and represent the effects of sewer sediment rheology and the attachment of pollutants to sediments. Many performance limitations of current models, such as MOSQITO and MOUSE TRAP, can be related to the modelling of sewer sediments. User requirements for the next generation of models will only be met if sewer sediments research results are fully utilised and further research can be tailored to meet end user driven modelling requirements. This paper reviews the results and applications of sewer sediments research in the UK and identifies additional research required to support further model development.

Laboratory study and computer model development related to gross solids' movement in combined sewers

1996 ◽  
Vol 33 (9) ◽  
pp. 39-47 ◽  
Author(s):  
John W. Davies ◽  
Yanli Xu ◽  
David Butler
Keyword(s):  
Computer Simulation ◽  
Pipe Flow ◽  
Model Development ◽  
Simulation Models ◽  
Laboratory Studies ◽  
Pilot Model ◽  
Sewer Systems ◽  
Flow Quality ◽  
Computer Simulation Models ◽  
Theoretical Considerations

Significant problems in sewer systems are caused by gross solids, and there is a strong case for their inclusion in computer simulation models of sewer flow quality. The paper describes a project which considered methods of modelling the movement of gross solids in combined sewers. Laboratory studies provided information on advection and deposition of typical gross solids in part-full pipe flow. Theoretical considerations identified aspects of models for gross solids that should differ from those for dissolved and fine suspended pollutants. The proposed methods for gross solids were incorporated in a pilot model, and their effects on simple simulations were considered.

SEWER SYSTEM ODOUR CONTROL IN THE LAKE BALATON AREA

1994 ◽  
Vol 30 (1) ◽  
pp. 195-204 ◽  
Author(s):  
A. Jobbágy ◽  
I. Szántó ◽  
Gy. I. Varga ◽  
J. Simon
Keyword(s):  
Cost Effective ◽  
Main Concern ◽  
Lake Balaton ◽  
Specific Procedure ◽  
Sewer System ◽  
Sewer Systems ◽  
Secondary Clarifier ◽  
Odour Control ◽  
Metabolic Advantage

In order to stop eutrophication and protect the water quality of Lake Balaton, the canalization and wastewater treatment system was redesigned in the late 70 s. Hence, regional sewer systems leading to sub-central treatment plants were established. Long retention times and long pressure sewer section, however, combined with the high sewage temperatures created a new environmental problem: the production of odorous and corrosive compounds such as hydrogen sulphide. In the present study, a preventive procedure to control anaerobic biodegradation processes in the sewage has been developed. It is based on the metabolic advantage of nitrate reduction over sulphate consumption. In a model experiment, problems deriving from the inappropriate application of nitrate addition were discovered, e.g. decreasing effectiveness by initiating undesired attached microbial growth, and denitrification and subsequent sludge loss in the secondary clarifier. The main concern of the system-specific procedure developed is to avoid local and general nitrate overdosing by an optimum arrangement of the dosing stations. This cost-effective procedure which prevents odour and corrosion problems has been successfully implemented in the Lake Balaton area.

Development, Calibration and Further Data Requirements of the Sewer Flow Quality Model Mosqito

1990 ◽  
Vol 22 (10-11) ◽  
pp. 103-109 ◽  
Author(s):  
J. A. Payne ◽  
G. D. Moys ◽  
C. J. Hutchings ◽  
R. J. Henderson
Keyword(s):  
Oxygen Demand ◽  
Flow Simulation ◽  
River Basin Management ◽  
Research Centre ◽  
Quality Model ◽  
Sewer Systems ◽  
Wide Range ◽  
Flow Quality ◽  
Using Data ◽  
The Uk

MOSQITO is the initial version of a sever flow quality model being developed by Hydraulics Research Ltd and the Water Research Centre as part of the UK River Basin Management programme. MOSQITO I simulates the time-varying behaviour of suspended solids, biochemical oxygen demand, chemical oxygen demand, ammoniacal nitrogen and hydrogen sulphide on catchment surfaces and in sewer systems. The model produces discharge pollutographs for these determinands which can be used as input to a river water quality model. MOSQITO consists of four sub-models which represent washoff from catchment surfaces, foul water inflow, pollutant behaviour in pipes and channels, and pollutant behaviour in ancillary structures within drainage systems. These sub-models are linked to the flow simulation model incorporated in the WALLRUS package which is the latest computer implementation of the Wallingford Procedure. The rationale behind the model, its structure and its operational basis have been discussed elsewhere (Moys and Henderson, 1988) and are therefore described briefly so that emphasis can be placed on the aspects which follow. Calibration and verification of the model are being carried out using data from a variety of experimental catchments in the UK. These catchments have been selected to exhibit a wide range of characteristics and include separate and combined sewer systems. Results of the calibration work are presented together with illustrations of the performance of the various sub-models and the overall model.

Prediction of locations with sediment deposits in sewers

1996 ◽  
Vol 33 (9) ◽  
pp. 147-154 ◽  
Author(s):  
Ole Mark ◽  
Uros Cerar ◽  
Gustavo Perrusquía
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Transport Model ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Sewer Systems ◽  
Sediment Transport Model ◽  
Sediment Deposits ◽  
Combined Sewer ◽  
Movable Bed

The present paper presents an application of MOUSE ST, a general deterministic sediment transport model for sewer systems. MOUSE ST is used to predict the locations subjected to sedimentation in the sewer system of Ljubljana, Slovenia. The prediction is made by means of a sediment transport model with a movable bed. This model is run in parallel with the hydrodynamic MOUSE model. The results, in terms of locations with sediment deposits, are compared with field data from the sewer system in Ljubljana. Further, the model is used to predict the effect of the removal of the sediment deposits on the combined sewer overflows.

Pollutant Release from Sediments in Sewer Systems and Their Potential for Release into Receiving Waters

1993 ◽  
Vol 28 (8-9) ◽  
pp. 161-169 ◽  
Author(s):  
I. McGregor ◽  
R. M. Ashley ◽  
K. O K. Oduyemi
Keyword(s):  
Research Centre ◽  
Shear Stresses ◽  
Quality Models ◽  
Water Research ◽  
Sediment Samples ◽  
Lower Shear ◽  
Sewer Systems ◽  
Receiving Waters ◽  
Flow Quality ◽  
The Uk

A programme of work funded by the UK Water Research Centre (WRc) has been carried out to investigate the nature, occurrence and re-entrainment into the sewage flow of sewer sediments and their associated pollutants to provide data for the development of UK sewer flow quality models, MOSQITO and MOUSETRAP. Methodologies for the preparation of sewer sediment samples prior to chemical analysis are described. These methods have been developed to determine the level of pollutants released from sewer sediments which will be representative of the conditions found in the sewer environment. Application of progressively lower shear stresses to samples of sediment, from an extreme, via blending, to less severe preparative methods by means of a stirring technique, fractionate sediment samples so that the polluting potential may be assessed separately for both dissolved and resuspendable phases. Stirring preparative methods release less pollutants from a sediment sample than from the blending procedures, with the level of pollutant release being dependent upon the shear stress being applied to the sample, with higher shear values releasing as would be expected, more pollutants.

MOUSETRAP — A DETERMINISTIC SEWER FLOW QUALITY MODEL

1994 ◽  
Vol 30 (1) ◽  
pp. 107-115 ◽  
Author(s):  
R. Crabtree ◽  
H. Garsdal ◽  
R. Gent ◽  
O. Mark ◽  
J. Dórge
Keyword(s):  
Storm Event ◽  
Storm Events ◽  
Urban Wastewater ◽  
Quality Model ◽  
Short Term ◽  
Sewer System ◽  
Erosion And Deposition ◽  
Run Off ◽  
Flow Quality

Recent research into the behaviour of sediments and associated pollutants in sewers has formed the foundation for a dynamic pollutograph-based sewer flow quality simulation model called MOUSETRAP. This is a new component to the MOUSE sewer system hydraulic modelling package. MOUSETRAP has been developed by an international consortium of sewer model developers and users to predict short term variations in sewer flow quality and sediment transport in response to storm events. MOUSETRAP is composed of a series of modules to represent: the quality of surface run off; sediment and pollutant transport, erosion and deposition within pipes; and the biological and chemical processes within the sewer system. By representing the current understanding of real sewer sediments, this new tool gives the user the capability to simulate storm event pollutographs incorporating first foul flush phenomena. The paper describes the basis of the new MOUSETRAP modules. Results of initial theoretical testing and pilot study applications are presented to illustrate the model's capabilities and potential for use in the management of urban wastewater discharges.

The influence of near bed solids transport on first foul flush in combined sewers

1998 ◽  
Vol 37 (1) ◽  
pp. 131-138 ◽  
Author(s):  
S. Arthur ◽  
R. M. Ashley
Keyword(s):  
Significant Proportion ◽  
Research Programme ◽  
Solids Transport ◽  
System A ◽  
Sewer Systems ◽  
Storm Wave ◽  
Data Collection Program ◽  
Flow Quality ◽  
The Uk ◽  
Organic Particles

The problems associated with deposited sediments in sewers, and their transport through sewer systems have been the subject of detailed fieldwork programmes in the UK, and elsewhere in Europe. Existing laboratory, and some field based research exercises have focused on the relatively small, discrete particles. It is clear, however, that combined sewer systems have inputs which comprise of a significant proportion of large organic solids (faecal and food wastes), as well as the finer range of particle sizes. The increased concern regarding CSO spills into the environment has fuelled the recent development of sewer flow quality models, such as HYDROWORKS QM and MOUSETRAP, some of which make no attempt to represent the transport of these larger organic particles. Herein, the results of a collaborative research programme undertaken between three UK universities and a water authority are discussed. Transport at the bed in sewers, as “near bed solids”, is defined. Based on a comprehensive data collection program undertaken in the Dundee combined sewerage system, a method is presented which may be used to estimate the rate of sediment transport near the bed in sewers. The influence that solids in transport near the bed have on first foul flush in combined sewers is discussed. A methodology is proposed which may be used to estimate the extent to which sediment in transport near the bed in sewers contributes to first foul flush phenomena, by describing the movement of a storm wave along a conceptual sewer length.

Sewer system design moving into the 21st century – a UK perspective

2007 ◽  
Vol 55 (4) ◽  
pp. 273-281 ◽  
Author(s):  
R.M. Ashley ◽  
S.J. Tait ◽  
E. Styan ◽  
A. Cashman ◽  
B. Luck ◽  
...  
Keyword(s):  
21St Century ◽  
External Factors ◽  
Sewer System ◽  
Integrated Water Management ◽  
Industry Research ◽  
Current State ◽  
Sewer Systems ◽  
New Ideas ◽  
The Uk ◽  
Levels Of Service

Change in external factors, such as environmental legislation and climate change, will mean the future of sewerage systems is likely to be different from the past. Combined sewerage systems comprise the vast majority of existing sewers in countries such as the UK. A study funded by UK Water Industry Research Ltd has reviewed the current state of sewerage within the UK, the likely drivers for change and the consequent future impacts over a 75 year timescale. Potential responses to address the anticipated changes have also been considered. It is concluded that due to the wide extent and value of existing sewer systems, these will continue to be used for the foreseeable future. However, in order to meet the major challenges as a result of changing external factors, these need to be operated more effectively, new ideas need to be explored and moves to develop better and more integrated water management systems need to be started if sewer systems in the UK are to provide the anticipated required levels of service well into the 21st Century.

A demonstration of the benefits of integrated wastewater planning for controlling transient pollution

1996 ◽  
Vol 33 (2) ◽  
pp. 209-218 ◽  
Author(s):  
B. Crabtree ◽  
W. Earp ◽  
P. Whalley
Keyword(s):  
Water Quality ◽  
Sewage Treatment ◽  
Urban Pollution ◽  
Research Programme ◽  
Simulation Models ◽  
Cost Effective ◽  
Combined Sewer Overflows ◽  
Detailed Simulation ◽  
The Uk ◽  
Traditional Approaches

The Urban Pollution Management (UPM) Research Programme has been the UK Water Industry's response to the need to limit the risk of transient pollution of receiving waters resulting from intermittent discharges, such as combined sewer overflows. Demonstrating that the UPM tools, such as MOSQITO, STOAT and MIKE 11, can be used to produce cost-effective and reliable solutions to practical problems is considered to be a major element in promoting the benefits of the UPM Procedure approach by eliminating the uncertainty of water quality impact associated with more traditional approaches. A demonstration of the full UPM Procedure for inland situations has been carried out in the city of Derby, in the UK, where high levels of investment are planned for both sewerage and sewage treatment. Detailed simulation models were calibrated and verified and then used with the simplified pollution modelling tool, SIMPOL, to evaluate the integrated environmental impact of a possible sewerage upgrading option. The results indicated that this option would meet wet-weather water quality requirements at a reduced cost compared to alternatives derived from traditional planning procedures which had a high degree of uncertainty in meeting water quality objectives.

Mousetrap: modelling of real sewer sediment characteristics and attached pollutants

1995 ◽  
Vol 31 (7) ◽  
pp. 43-50 ◽  
Author(s):  
R. W. Crabtree ◽  
R. Ashley ◽  
R. Gent
Keyword(s):  
Storm Event ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Sewer System ◽  
Sediment Types ◽  
Run Off ◽  
Phase Liquid ◽  
Flow Quality ◽  
Physical And Chemical

A dynamic, pollutograph based sewer flow quality simulation model is an essential tool to aid in the control of intermittent pollution from combined sewer overflows (CSOs). Such a model can be used in conjunction with river impact models to provide an objective methodology for the control of intermittent sewage discharges. A new component to the MOUSE package has been developed, called MOUSETRAP, which is composed of a series of deterministic modules to represent the quality of surface run-off, sediment and pollutant transport within the pipe network, and the biological and chemical reactions within the sewer system. MOUSETRAP can be used to predict sewer flow quality and, hence, CSO spill concentrations and loads over time. The results of recent research into the behaviour of sediments and associated pollutants in sewers have shown that these aspects are crucial to the development of a reliable, deterministic sewer flow quality model. MOUSETRAP, by representing the physical and chemical characteristics and behaviour of real sewer sediment types has the ability to simulate storm event pollutographs incorporating first foul flush phenomena. MOUSETRAP achieves this by representing pollutants associated with dissolved phase liquid transport and pollutants associated with sediments including bed deposits, bed load and settleable suspended solids. The results of data collection are used to characterise sewer sediments and a theoretical basis for the modelling of sediments and sediment attached pollutants in MOUSETRAP is considered. Finally, the model default values for characteristics of the surface, deposited foul flow and in-pipe sediment types in MOUSETRAP are presented.

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