scholarly journals Method for assessing the impact of rainfall depth on the stormwater volume in a sanitary sewage network

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Edward Kozłowski ◽  
Dariusz Kowalski ◽  
Beata Kowalska ◽  
Dariusz Mazurkiewicz
Keyword(s):  
Mathematical Model ◽  
Wastewater Treatment Plants ◽  
Sewer System ◽  
Urban Floods ◽  
Sanitary Sewer ◽  
Combined Sewer ◽  
Rainfall Depth ◽  
Residuals Analysis ◽  
Local Water ◽  
The Impact

AbstractSanitary sewage network is relatively rarely considered as the cause of urban floods. Its hydraulic overload can result not only in flooding, but also sanitary contamination of subcatchments. Stormwater is the main reason for this overload. In contrast to the stormwater or combined sewer system, these waters infiltrate into the network in an uncontrolled way, through ventilation holes of covers or structural faults and lack of tightness of manholes. Part of stormwater infiltrates into the soil, where it leaks into pipelines. This greatly hinders assessing the quantity of stormwater influent into the sanitary sewer system. Standard methods of finding correlation between rainfall and the intensity of stormwater flow are ineffective. This is confirmed, i.a. by the studies performed in an existing network, presented in this paper. Only when residuals analysis was performed using the ARIMA and ARIMAX methods, the authors were able to develop a mathematical model enabling to assess the influence of rainfall depth on the stormwater effluent from the sewage network. Owing to the possibility of using the rainfall depth forecasts, the developed mathematical model enables to prepare the local water and sewerage companies for the occurrence of urban floods as well as hydraulic overload of wastewater treatment plants.

scholarly journals Application of material from used car tyres in geotechnics—an environmental impact analysis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9546 ◽  
Author(s):  
Aleksander Duda ◽  
Małgorzata Kida ◽  
Sabina Ziembowicz ◽  
Piotr Koszelnik
Keyword(s):  
Hazardous Waste ◽  
Impact Analysis ◽  
Normative Values ◽  
Sewer System ◽  
Galvanised Steel ◽  
Combined Sewer ◽  
Used Car ◽  
Initial Preparation ◽  
New Research ◽  
The Impact

This work begins with a literature-based discussion of the hazardous-waste problem represented by car tyres as hazardous waste, along with possible ways in which they might be utilised or managed. The impact of the material on the environment is characterised in the process, not least in the context of pollutants leached to the aquatic environment. Input in terms of new research results concerns the impact on water and soil of material from used car tyres being used in geotechnics. Specifically, tyre bales comprising 100–140 car vehicle tyres compressed into a lightweight block and secured by galvanised steel tie wires running around the length and depth of the bale, were researched, having been immersed in basins with alkaline and acidic water following initial preparation and pre-washing. The aim was to in some sense simulate—respectively—conditions in which rain and surface/ground water are involved, or else acid rain. To do that, the tyre bales were placed in the water for 120 days, with emerging leachate analysed after set intervals of time, with a view to changes in key physicochemical parameters of water being noted, as well as signs of the leaching of both undesirable components and priority substances, from tyres into the aqueous medium. Washing of the tyre bales was shown to induce slight pollution of water, with limited exceedance of normative values in respect of OWO content. However, this increase was not due to leaching of the Persistent Organic Pollutants tested for, but may rather have reflected contamination of tyres used, e.g., of soil at the place of previous storage. In general, waste water arising does not therefore contain substances that would stand in the way (legally) of its being discharged into a combined sewer system. Similar conclusions were arrived at through analysis of the leaching of pollutants from tyre bales exposed in the aforementioned pools of water of neutral and acidic reaction. Wastewater arising was not enriched significantly in impurities (be these metals, PAHs, phthalates, selected anions or cations), and there were therefore no exceedances of standards imposed for wastewater discharged to either waters or soil.

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.

Impact of dimension uncertainty and model calibration on sewer system assessment

2005 ◽  
Vol 52 (5) ◽  
pp. 35-42 ◽  
Author(s):  
H. Korving ◽  
F. Clemens
Keyword(s):  
Model Calibration ◽  
Catchment Area ◽  
Return Periods ◽  
Sewer System ◽  
Model Predictions ◽  
Combined Sewer ◽  
System Assessment ◽  
Database Errors ◽  
Event Based ◽  
The Impact

Assessments of sewer performance are usually based on a single computation of CSO (combined sewer overflow) volumes using a time series of rainfall as system loads. A shortcoming of this method is that uncertainties in knowledge of sewer system dimensions are not taken into account. Moreover, sewer models are rarely calibrated. This paper presents the impacts of database errors and model calibration on return periods of calculated CSO volumes. The impact of uncertainties is illustrated with two examples. Variability of calculated CSO volumes is estimated using Monte Carlo simulations. The results show that calculated CSO volumes vary considerably due to database errors, especially uncertain dimensions of the catchment area. Furthermore, event-based calibration of a sewer model does not result in more reliable predictions because the calibrated parameters have low portability. However, it enables removal of database errors harmonising model predictions and ‘reality’.

INTEGRATED PLANNING OF IMPROVEMENTS OF SEWER SYSTEM AND TREATMENT PLANT FOR SUBURBS OF COPENHAGEN

1994 ◽  
Vol 30 (1) ◽  
pp. 157-166 ◽  
Author(s):  
O. B. Hansen ◽  
J. Pedersen
Keyword(s):  
Waste Water Treatment ◽  
Treatment Plant ◽  
Cost Effective ◽  
Total System ◽  
Integrated Planning ◽  
Sewer System ◽  
Sanitary Sewer ◽  
Combined Sewer ◽  
Sewer Rehabilitation ◽  
Realtime Control

An integrated planning study for improvements of sewer system and treatment plant for a catchment in western Greater Copenhagen is presented. Alternative improvements of the total system are analysed using a mathematical model for the runoff in the sewer system taking into account the interdependencies between sewer system and treatment plant. The most cost-effective solution was identified through optimization of the hydraulic capacity of the treatment plant. The improvements of the selected solution consist of a realtime control (RTC) system for the combined sewer network, elimination of faulty connections to the separate sanitary sewer system, rehabilitation of untight sewers and extension of the treatment plant to meet stricter effluent criteria. The study was implemented as an interdisciplinary excercise between specialists in the fields of sewer modelling, sewer rehabilitation and waste water treatment.

Design of self-cleansing sanitary sewer systems with the use of flushing devices

2009 ◽  
Vol 60 (4) ◽  
pp. 901-908 ◽  
Author(s):  
T. Goormans ◽  
D. Engelen ◽  
R. Bouteligier ◽  
P. Willems ◽  
J. Berlamont
Keyword(s):  
Surface Waters ◽  
Sewer System ◽  
Sewer Pipes ◽  
Hydrodynamic Simulations ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Increased Risk ◽  
Combined Sewer ◽  
Maintenance Requirements

Many European countries tend to shift from constructing combined sewer systems to separate ones, in order to optimise wastewater treatment efficiency and reduce CSO impact on surface waters. An economic design minimises maintenance requirements by aiming at self-cleansing pipes. However, providing the necessary slopes for self-cleansing sanitary sewer pipes often is unfeasible in flat regions, resulting in an increased risk of loss of hydraulic capacity or blocking. To reduce these risks, flushing tanks can be installed in the sewer system. Where most other researchers contribute to a better understanding of the hydraulics of flushing, this paper rather tries to formulate a methodology to design and test flushing devices in sanitary sewer systems using standards and hydrodynamic simulations. Therefore, several aspects that require consideration when incorporating flushing devices into a sanitary sewer system are discussed. For instance, when flushing sanitary sewers the increase in discharge has to be explicitly considered. A Belgian case study is used to investigate the suitability of the developed methodology. Although the pipe slopes in the methodology are derived assuming uniform flow, the simulation results comply with it. Furthermore, pressurisation of the conduits due to multiple flushing waves remains within acceptable limits.

Upgrading of wastewater treatment plants to achieve advanced standards concerning nutrient removal

1994 ◽  
Vol 29 (12) ◽  
pp. 49-58
Author(s):  
S. Buß ◽  
J. Einfeldt ◽  
H. Günter ◽  
T. Werner
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Tourism Industry ◽  
Sewer System ◽  
Design Concepts ◽  
Multi Stage ◽  
Split Flow ◽  
Combined Sewer ◽  
Flow Treatment

According to the general wastewater administration rule, it is allowed for the single state authorities of Germany to make the minimal requirements on quality of wastewater discharge more restrictive then those given by the federal government. Schleswig-Holstein particularly has made extensive use of this rule in the past years. On addition of fluctuations due to tourism, industry or combined sewer system, the general criteria for the layout of wastewater treatment plants (WWTP) are presently unsatisfactory in order to meet these requirements. More detailed and comprehensive studies need to be carried out to fulfill these stricter demands. By illustrating four case studies of WWTP designs of size between 43,000 and 640,000 total number of inhabitants and population equivalents (PT), possible solutions will be presented. With the aid of land-registers, intensive measurement series and semi-technical and full scale experiments, design concepts including multi-stage and split flow treatment could be established.

scholarly journals Economic analyses for optimizing the construction of separate sewer in a hybrid sewer system

2010 ◽  
Vol 62 (11) ◽  
pp. 2536-2542
Author(s):  
Home-Ming Chen ◽  
Shang-Lien Lo
Keyword(s):  
Marginal Cost ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Quality Standard ◽  
Sewer System ◽  
Sanitary Sewer ◽  
Combined Sewer ◽  
River Quality ◽  
Economic Analyses ◽  
Effective Analysis

Metropolitan Taipei located in north Taiwan uses a hybrid sewer system consisting of mostly separate sewer for the populated regions, and partly combined sewer for less populated regions. This study used the concept that Marginal Cost of Control (MCC) equals to Marginal Benefits of Control (MBC) to establish the method for studying the optimal household connection percentage, and the most cost-effective construction of the separate sewer in the hybrid sewer system. Results indicate the improvement of the receiving water quality in a cost-effective analysis manner. The most cost-effective sanitary sewer construction can be reached when the stream Biochemical Oxygen Demand (BOD5) meets the river quality standard, which can be applied in other cities and existing systems.

scholarly journals Impact of atmospheric precipitation on the volume of wastewater inflowing to the treatment plant in Nowy Targ

2020 ◽  
Vol 171 ◽  
pp. 01009
Author(s):  
Elwira Nowobilska-Majewska ◽  
Tomasz Kotowski ◽  
Piotr Bugajski
Keyword(s):  
Treatment Plant ◽  
Atmospheric Precipitation ◽  
Test Results ◽  
Dry Period ◽  
Sewer System ◽  
Drain Pipe ◽  
Combined Sewer ◽  
The Impact ◽  
The City ◽  
Research Period

The study determines the impact of precipitation on the amount of wastewater flowing into the treatment plant in Nowy Targ. The research period covered the years 2016 and 2017, in which the amount of precipitation and average daily wastewater inflows (during the so-called dry period, i.e. days without precipitation and in the so-called wet period, i.e. days with precipitation) were analyzed. The research period was divided into 5 characteristic ranges in terms of the amount of precipitation. It was found that on days with different intensity of precipitation, the amount of rainwater (in the total amount of wastewater flowing into the treatment plant) ranges from 14.2% to 32.5%. Taking into account the absolute values, it was found that the average daily amount of wastewater inflow on days with precipitation was from 14361 to 18248 m3∙d-1 compared to wastewater inflow on days without precipitation (12323 m3∙d-1). The obtained test results should be a signal for sewage network operators for the performance of intensive and effective actions aimed at eliminating illegal connections of drain pipe for rainwater and yard drains to sanitary collectors and the replacement combined sewer system to distribution sewer system in the city of Nowy Targ.

The Impact of Light Polarisation on Light Field of Scenes with Multiple Reflections

2020 ◽  
pp. 108-115 ◽  
Author(s):  
Vladimir P. Budak ◽  
Anton V. Grimaylo
Keyword(s):  
Mathematical Model ◽  
Light Field ◽  
Global Illumination ◽  
Multiple Reflections ◽  
Software Environment ◽  
The Monte Carlo Method ◽  
Mueller Matrices ◽  
Volume Integration ◽  
The Impact

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

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