Deriving discharge strategies to reduce CSO in urban drainage systems

1997 ◽  
Vol 36 (8-9) ◽  
pp. 259-263
Author(s):  
K.-J. Breur ◽  
P. E. R. M. van Leeuwen ◽  
N. P. Dellaert
Keyword(s):  
System Performance ◽  
Major Part ◽  
Design Procedure ◽  
Urban Drainage ◽  
Specific Situation ◽  
Storm Events ◽  
Maximum Reduction ◽  
Actual Design ◽  
Heavy Storm

This paper discusses the design of discharge strategies for urban drainage operation. The design procedure applies a tuneable strategy which can be adjusted to a specific situation by adjusting a few parameters which reflect the discharge priority of the various districts of the system. The actual design procedure, a procedure of simulation and analysis of the system performance, is explained in a case study. Apart form the method, the case study shows that a near optimal performance (maximum reduction of overflow volume) can be realised by applying an “event” average strategy (one strategy for all type of inflow events). Furthermore, the case study shows that the major part of the total overflow volume is caused by very heavy storm events.

Identification of nitrosamine precursors from urban drainage during storm events: A case study in southern China

Chemosphere ◽  
2016 ◽  
Vol 160 ◽  
pp. 323-331 ◽  
Author(s):  
Er Bei ◽  
Xiaobin Liao ◽  
Xiangting Meng ◽  
Shixiang Li ◽  
Jun Wang ◽  
...  
Keyword(s):  
Southern China ◽  
Urban Drainage ◽  
Storm Events

Effectiveness of green roofs in reduction of rainfall-fed runoff: A case study in Dublin, Ireland

2021 ◽  
Author(s):  
Bidroha Basu ◽  
Arunima Sarkar Basu ◽  
Srikanta Sannigrahi ◽  
Francesco Pilla
Keyword(s):  
Flood Control ◽  
Water Retention ◽  
Green Roof ◽  
Green Roofs ◽  
City Centre ◽  
Urban Drainage ◽  
Storm Events ◽  
Land Area ◽  
Runoff Reduction

<p>Increase in extreme rainfall and storm events due to climate change and decrease in water retention in soil due to urbanization has increased the risk of flooding in cities globally. Since majority of the cites are mostly developed, expanding the conventional urban drainage system to account for the excess runoff produced by the rainfall event has limited scope. The challenge is to develop sustainable urban drainage systems (SUDS) to reduce runoff and create a flood control system in major cities. One of the SUDS that are becoming popular is the use of nature-based solutions (NBSs). A set of conventional NBSs to mitigate flood risk include bioswales, bio-retention, tree pits, infiltration trenches. However, even though their performance in flood control is found to be effective, they require considerable land area for deployment, which might be difficult to obtain in cities. For this purpose, green roofs have becoming popular as an alternative NBS in flood control, as it does not require any additional land area for deployment. This study investigates the effectiveness of a green roof in reduction of runoff via real-world case study. A green roof deployed in the CHQ building located at the city centre in Dublin, Ireland has been considered for the study. The green roof has a total size of 70 sq. m. Performance of the green roof in runoff reduction was measured based on rainfall and water retention data collected at four modular units, each having 1 sq. meter area, located at the centre of the roof with an IoT weight scale. The data has been collected for 1 week at 3-minute interval, and the reduction in runoff with and without the presence of the green roof has been estimated. The performance of the green roofs in runoff reduction was found to vary between 20-40% depending on the intensity of storm events.</p>

scholarly journals Info-Gap robustness pathway method for transitioning of urban drainage systems under deep uncertainties

2017 ◽  
Vol 76 (5) ◽  
pp. 1272-1281 ◽  
Author(s):  
Jonatan Zischg ◽  
Mariana L. R. Goncalves ◽  
Taneha Kuzniecow Bacchin ◽  
Günther Leonhardt ◽  
Maria Viklander ◽  
...  
Keyword(s):  
Climate Change ◽  
System Performance ◽  
Water Cycle ◽  
Urban Drainage ◽  
Urban Water ◽  
System State ◽  
Network Layout ◽  
Urban Water Cycle ◽  
Over Time

In the urban water cycle, there are different ways of handling stormwater runoff. Traditional systems mainly rely on underground piped, sometimes named ‘gray’ infrastructure. New and so-called ‘green/blue’ ambitions aim for treating and conveying the runoff at the surface. Such concepts are mainly based on ground infiltration and temporal storage. In this work a methodology to create and compare different planning alternatives for stormwater handling on their pathways to a desired system state is presented. Investigations are made to assess the system performance and robustness when facing the deeply uncertain spatial and temporal developments in the future urban fabric, including impacts caused by climate change, urbanization and other disruptive events, like shifts in the network layout and interactions of ‘gray’ and ‘green/blue’ structures. With the Info-Gap robustness pathway method, three planning alternatives are evaluated to identify critical performance levels at different stages over time. This novel methodology is applied to a real case study problem where a city relocation process takes place during the upcoming decades. In this case study it is shown that hybrid systems including green infrastructures are more robust with respect to future uncertainties, compared to traditional network design.

Wastewater treatment and nutrient removal in the combined reactor

1998 ◽  
Vol 38 (1) ◽  
pp. 87-95 ◽  
Author(s):  
M. Roš ◽  
J. Vrtovšek
Keyword(s):  
Organic Compounds ◽  
Industrial Wastewater ◽  
Design Procedure ◽  
Order Reaction ◽  
Treated Wastewater ◽  
Nitrification Rate ◽  
Zero Order Reaction ◽  
Aerobic Reactor ◽  
Complex Organic

A combined anaerobic anoxic aerobic reactor for the treatment of the industrial wastewater that contains nitrogen and complex organic compounds as well as its design procedure is presented. The purpose of our experiments was to find a simple methodology that would provide combined reactor design. The reactor is based on the combination of anaerobic, anoxic and aerobic process in one unit only. It was found that the HRT even under 1 hour in the anaerobic zone is long enough for the efficient transformation of complex organic compounds into readily biodegradable COD which is then used in dentrification process. In the N-NO3 concentration range 1.5-50 mg/l the denitrification rate could be expressed as half-order reaction when the CODrb was in excess. N-NO3 removal efficiency is controlled by the recycle flow from the aerobic to the anoxic zone. Nitrification rate can be expressed as first, half or zero-order reaction with respect to effluent N-NH4 concentration. Nitrification rate depends on the dissolved oxygen concentration and hydrodynamic conditions in the reactor. Case study for design of a pilot plant of the combined reactor for treatment of pre-treated pharmaceutical wastewater is shown. Characteristics of pre-treated wastewater were: COD=200 mg/l, BOD5=20 mg/l, N-Kjeldahl=80 mg/l, N-NH4=70 mg/l, N-NOx<1 mg/l, P-PO4=5 mg/l. Legal requirements for treated wastewater were: COD=<100 mg/l, BOD5<5 mg/l, N-NH4=<1 mg/l, N-NOx=<10 mg/l.

scholarly journals Impact Assessment Analysis of Sea Level Rise in Denmark: A Case Study of Falster Island, Guldborgsund

2021 ◽  
Vol 13 (13) ◽  
pp. 7503
Author(s):  
Alexander Boest-Petersen ◽  
Piotr Michalak ◽  
Jamal Jokar Arsanjani
Keyword(s):  
Climate Change ◽  
Impact Assessment ◽  
Sea Level Rise ◽  
Sea Level ◽  
Alternative Methods ◽  
Projection Data ◽  
Storm Events ◽  
Cascading Effects ◽  
Local Levels

Anthropogenically-induced climate change is expected to be the contributing cause of sea level rise and severe storm events in the immediate future. While Danish authorities have downscaled the future oscillation of sea level rise across Danish coast lines in order to empower the coastal municipalities, there is a need to project the local cascading effects on different sectors. Using geospatial analysis and climate change projection data, we developed a proposed workflow to analyze the impacts of sea level rise in the coastal municipalities of Guldborgsund, located in Southeastern Denmark as a case study. With current estimates of sea level rise and storm surge events, the island of Falster can expect to have up to 19% of its landmass inundated, with approximately 39% of the population experiencing sea level rise directly. Developing an analytical workflow can allow stakeholders to understand the extent of expected sea level rise and consider alternative methods of prevention at the national and local levels. The proposed approach along with the choice of data and open source tools can empower other communities at risk of sea level rise to plan their adaptation.

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