scholarly journals Assessing the efficiency of different CSO positions based on network graph characteristics

2013 ◽  
Vol 67 (7) ◽  
pp. 1574-1580 ◽  
Author(s):  
R. Sitzenfrei ◽  
C. Urich ◽  
M. Möderl ◽  
W. Rauch
Keyword(s):  
Treatment Plant ◽  
Spatial Layout ◽  
Construction Costs ◽  
Sewer Systems ◽  
Significant Difference ◽  
Combined Sewer ◽  
The Impact ◽  
And Storage ◽  
Storage Units ◽  
Sewer Networks

The technical design of urban drainage systems comprises two major aspects: first, the spatial layout of the sewer system and second, the pipe-sizing process. Usually, engineers determine the spatial layout of the sewer network manually, taking into account physical features and future planning scenarios. Before the pipe-sizing process starts, it is important to determine locations of possible weirs and combined sewer overflows (CSOs) based on, e.g. distance to receiving water bodies or to a wastewater treatment plant and available space for storage units. However, positions of CSOs are also determined by topological characteristics of the sewer networks. In order to better understand the impact of placement choices for CSOs and storage units in new systems, this work aims to determine case unspecific, general rules. Therefore, based on numerous, stochastically generated virtual alpine sewer systems of different sizes it is investigated how choices for placement of CSOs and storage units have an impact on the pipe-sizing process (hence, also on investment costs) and on technical performance (CSO efficiency and flooding). To describe the impact of the topological positions of these elements in the sewer networks, graph characteristics are used. With an evaluation of 2,000 different alpine combined sewer systems, it was found that, as expected, with CSOs at more downstream positions in the network, greater construction costs and better performance regarding CSO efficiency result. At a specific point (i.e. topological network position), no significant difference (further increase) in construction costs can be identified. Contrarily, the flooding efficiency increases with more upstream positions of the CSOs. Therefore, CSO and flooding efficiency are in a trade-off conflict and a compromise is required.

Influence of characteristics on combined sewer performance

2012 ◽  
Vol 66 (5) ◽  
pp. 1052-1060 ◽  
Author(s):  
M. Möderl ◽  
M. Kleidorfer ◽  
W. Rauch
Keyword(s):  
Automatic Generation ◽  
Negative Influence ◽  
Positive Influence ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Different Characteristics ◽  
Further Development ◽  
Storage Units ◽  
System Characteristics

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.

The impact of rainwater reuse on CSO emissions

1999 ◽  
Vol 39 (5) ◽  
pp. 57-64 ◽  
Author(s):  
G. Vaes ◽  
J. Berlamont
Keyword(s):  
Rain Water ◽  
Water Runoff ◽  
Environmental Aspects ◽  
Reservoir Model ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Heavy Burden ◽  
Water Tanks ◽  
The Impact

The increasing consumption of drinking water puts a heavy burden on our future water resources. Therefore the reuse of rain water in households can be a good option to tackle this problem. On the other hand the rapidly drained rain water leads to problems in the combined sewer systems and watercourses. If the storage in the rain water tanks can be used to flatten the rain water runoff, rain water tanks can have an additional benefit. The effect of rain water tanks on the combined sewer overflow (CSO) emissions is therefore investigated with a reservoir model. Compared with storage in the combined sewer system or at the overflow, storage in rain water tanks will be more efficient in reducing the overflow emissions. However much more storage in rain water tanks must be provided to obtain the same overflow frequency as when downstream storage is used, because the storage in rain water tanks is less frequently available. When all the economical, social and environmental aspects are considered, rain water tanks can certainly be promoted as a good solution.

Evaluation of total emissions from treatment plants and combined sewer overflows

1998 ◽  
Vol 37 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Joachim Guderian ◽  
Andreas Durchschlag ◽  
Jürgen Bever
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
Simulation Tool ◽  
Combined Sewer Overflows ◽  
Flow Management ◽  
Sewer Systems ◽  
Optimal Value ◽  
Combined Sewer

Based upon the connection of a simulation program for combined sewer systems with the IAWQ-Activated Sludge Model No.1 the new simulation tool GEMINI was developed, which allows the calculation of sewer and sewage treatment plant as a unit. Some obtained results are presented in an example. They suggest, that for every treatment plant a rate of inflow is determinable, which leads to a minimum of total emissions out of sewer and treatment plant. The optimal value of sewage treatment plant inflow in the example is distinctly greater than the design flow rate fixed in German design rules. So it is recognizable that a rigid flow management for sewer and treatment plant does not always fulfil the aim of minimization of total emissions.

Assessing the impact of infiltration and exfiltration in sewer systems using performance indicators: case studies of the APUSS project

2006 ◽  
Vol 1 (1) ◽  
Author(s):  
A. Cardoso ◽  
V. Prigiobbe ◽  
M. Giulianelli ◽  
E. Baer ◽  
J. De Bénédittis ◽  
...  
Keyword(s):  
Case Studies ◽  
Performance Indicators ◽  
Treatment Plant ◽  
Structural Quality ◽  
State Variable ◽  
Sewer Systems ◽  
Functional Efficiency ◽  
The Impact ◽  
Made In

The structural quality and functional efficiency of sewer systems are key parameters to guarantee the transfer of domestic, commercial and industrial wastewater to treatment plants without infiltration nor exfiltration. Infiltration of groundwater is particularly detrimental to treatment plant efficiency, while exfiltration of wastewater can lead to groundwater contamination. The APUSS project associating universities, SMEs and municipalities in 7 European countries, developed new methods and techniques to assess and quantify infiltration and exfiltration (I/E) in sewer systems. This paper describes the establishment of a set of performance indicators (PI) developed to assess the impact of I/E on sewer systems and their application to three project case studies, in Italy and France, focusing on sewer systems characteristics, I/E measurements campaigns and PI application results. The methodology for PI definition consists in the selection and development of a sewer network property or state variable, which is expressive of aspects being scrutinized (I/E); the PI values are then calculated; finally, a classification of the PI values is made in relation to good or bad performance. The use of PI allows a standardized and objective comparison of the performance of sewer systems and constitutes a means to technically support the establishment of priorities for rehabilitation and/or construction investments taking into account I/E impacts.

scholarly journals Irrigation of a golf course with UV-treated wastewater: effects on soil and turfgrass bacteriological quality

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Brahim Bihadassen ◽  
Mohammed Hassi ◽  
Fatima Hamadi ◽  
Aicha Aitalla ◽  
Mohamed Bourouache ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Treatment Plant ◽  
Faecal Coliform ◽  
Treated Wastewater ◽  
Golf Course ◽  
Golf Courses ◽  
Bacteriological Quality ◽  
Significant Difference ◽  
Alternative Water ◽  
The Impact

Abstract This research was carried out to assess the impact of treated wastewater irrigation on soil bacteriological and physicochemical properties and turfgrass bacteriological quality. Two golf courses were studied: a golf course A irrigated with freshwater (FW) and a golf course B irrigated with UV-treated wastewater (UV-TW). The physicochemical parameters (electrical conductivity and pH) of the soil were determined. FW, UV-TW, lake-stored water (LSW), turfgrass, and soil were collected, and their bacteriological parameters were determined. These parameters include: Escherichia coli, faecal enterococci, and faecal coliform. The results showed that the soil irrigated with treated wastewater (S-TW) showed a significant increase in the pH when compared with the soil irrigated with freshwater (S-FW). However, no significant difference was recorded in soil electrical conductivity. Faecal indicators concentration of the irrigation water samples varied considerably, and the concentrations in LSW frequently exceed those of the water at the output of the treatment plant (UV-TW). The comparison of the faecal contamination between the two golf courses indicates no significant difference in E. coli and faecal coliform concentrations. However, a significant difference was detected in faecal enterococci contamination. This study confirms that, under appropriate conditions, treated wastewater produced by M’zar wastewater treatment plant can be used as an alternative water resource for golf courses irrigation in Agadir city, Morocco.

Balancing water quality and flows in combined sewer systems using real-time control

2020 ◽  
Vol 6 (5) ◽  
pp. 1357-1369
Author(s):  
Sara C. Troutman ◽  
Nancy G. Love ◽  
Branko Kerkez
Keyword(s):  
Water Quality ◽  
Control Algorithm ◽  
Treatment Plant ◽  
Source Control ◽  
Collection System ◽  
Real Time Control ◽  
Time Control ◽  
Sewer Systems ◽  
System P ◽  
Combined Sewer

An open-source control algorithm for combined sewers demonstrates how treatment plant benefits can be balanced with operation of the collection system.

An integrated approach for improving the wastewater discharge and treatment systems

1998 ◽  
Vol 37 (1) ◽  
pp. 341-346 ◽  
Author(s):  
A. Pfister ◽  
A. Stein ◽  
S. Schlegel ◽  
B. Teichgräber
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Integrated Approach ◽  
Highly Qualified ◽  
Combined Sewer Overflows ◽  
Dynamic Interactions ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Model Components ◽  
Research Studies

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.

Deep tunnel sewerage system phase 2 – hydraulics

2019 ◽  
Vol 14 (2) ◽  
pp. 409-422
Author(s):  
D. Brocard ◽  
S. J. Gan ◽  
L. Y. Koh ◽  
T. W. Tan ◽  
W. I. Cox ◽  
...  
Keyword(s):  
Treatment Plant ◽  
Ground Level ◽  
Second Phase ◽  
Deep Tunnel ◽  
Sewerage System ◽  
Sewer Systems ◽  
Tunnel Section ◽  
Combined Sewer ◽  
Odour Control ◽  
System Phase

Abstract The Deep Tunnel Sewerage System (DTSS) is aimed at providing a robust and efficient means of catering to Singapore's used-water needs. DTSS2 is the second phase of this project, comprising an approximately 30-km long South Tunnel, a 10-km long Industrial Tunnel, 60-km of Link Sewers and a new Water Reclamation Plant integrated with a NEWater facility. In contrast with tunnels designed to store overflows in combined sewer systems, the DTSS tunnels convey used-water all the time from Singapore's separated system. This paper describes hydraulic analyses that were conducted during the feasibility study and preliminary design. The topics covered include hydraulic modelling of the entire system with the main goal of ensuring system resilience, air management to avoid odours at ground level, and isolation of tunnel section using gates for potential maintenance or repair. The resilience analyses concentrated on the system functionality in case of a failure, to ensure that used-water can be safely conveyed to a treatment plant. The air management system included several odour control facilities and air jumpers to avoid escape of odorous air from the system and the isolation gates requires detailed hydraulic analyses to cater to the high heads involved.

Comparison and optimization of the performance of natural-based non-conventional coagulants in a water treatment plant

2019 ◽  
Vol 69 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Atefeh Kaji ◽  
Masoud Taheriyoun ◽  
Amir Taebi ◽  
Mohammad Nazari-Sharabian
Keyword(s):  
Water Treatment ◽  
Tannic Acid ◽  
Ferric Chloride ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Calcium Lactate ◽  
Drinking Water Standard ◽  
Significant Difference ◽  
Natural Coagulants ◽  
The Impact

Abstract This study aims to assess the efficiency of two natural-based coagulants, namely calcium lactate and tannic acid, and compare them with conventional coagulants, including polyaluminium chloride (PACl) and ferric chloride. Jar test experiments were performed on the raw inlet water of the Isfahan water treatment plant (IWTP) in Iran. Response surface methodology was implemented to design and optimize the experiments. The factors considered in the design were coagulant dose, pH, initial turbidity, and temperature. Results showed the acceptable efficiency of natural coagulants in turbidity reduction, so that they meet the potable standard levels. The final water turbidity in the optimum condition for calcium lactate, tannic acid, PACl, and ferric chloride were 0.58, 0.63, 0.56, and 0.76 NTU, respectively. The comparison between the performances of the coagulants showed no significant difference in turbidity removal. However, the sludge volume produced as well as the impact on pH alteration after coagulation–flocculation were lower when using natural coagulants than with conventional coagulants. Also, the residual aluminum for PACl measured was higher than the desired limit according to Iran's drinking water standard. Finally, the simple additive weighting method was used to rank the four coagulants based on the selected criteria. The results showed that the natural coagulants could be preferable to the conventional coagulants if the concerns regarding disinfection by-product formation due to their residual organics were resolved. Since this issue was fixed in the IWTP due to the ozonation process, calcium lactate was proposed as an efficient alternative to PACl.

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