Quantifying the inherent uncertainty in the quantity and quality of domestic wastewater

1996 ◽  
Vol 33 (2) ◽  
pp. 65-78 ◽  
Author(s):  
Eran Friedler ◽  
David Butler

Results from two surveys in S.E. England are used to illustrate and quantify the inherent uncertainty in the quantity and quality of domestic wastewater at the fundamental level of discharges from domestic appliances. The uncertainties in three principal areas are elucidated. Volumetric discharges are shown to vary significantly for several appliances particularly when used in “running to waste” mode. Pollutant load also varies and information is presented for a number of different appliance-pollutant combinations. The frequency of use is known to vary throughout the day, but figures are presented to quantify the extent of the spread of the data during each hour of the day. A means of integrating the various elements of uncertainty is proposed. Quantification should enable better control of treatment plants and improve forecasting of the influence of combined sewer overflows on receiving waters, hence enhancing the management of the associated risk.

1997 ◽  
Vol 36 (8-9) ◽  
pp. 355-359
Author(s):  
L. Fuchs ◽  
D. Gerighausen ◽  
S. Schneider

For the city of Dresden a general master plan was set up based on investigations of the hydraulic capacity of the sewer system, the loads from combined sewer overflow and the treatment plant. The total emission from combined sewer overflows and treatment plant was the main criteria for the analysis of the efficiency of different renovation alternatives. The effect of the different alternatives on the quality of the receiving waters was investigated with a water quality model and evaluated with different approaches.


1990 ◽  
Vol 22 (10-11) ◽  
pp. 163-171 ◽  
Author(s):  
J. Seager ◽  
R. G. Abrahams

Intermittent discharges of storm sewage from combined sewer overflows continue to be one of the principal causes of poor water quality in many urban rivers in the UK. Despite the persistent nature of this problem, very little attention has been given to the study of how discharges of varying magnitude, duration and frequency affect the ecological quality of receiving waters. This information is of critical importance for deriving meaningful water quality criteria for the control of intermittent pollution. This paper describes the results of a study which has been carried out on Pendle Water, a river which flows through the urban catchment of Burnley, Lancashire, UK. Both the chemical and biological quality of Pendle Water are adversely affected by storm sewage discharges during heavy rainfall events. The ecological investigation has been primarily concerned with impact of these episodic discharges on benthic invertebrate communities and physiological responses in fish. Quantitative sampling of macroinvertebrates has indicated that storm sewage discharges may have a significant impact on the structure and diversity of benthic communities in receiving waters. Physico-chemical properties of habitats appear to be altered in a way which tends to favour the proliferation of certain pollution-tolerant species and decrease the abundance of taxa intolerant of organic pollution. Insitu bioassays, including the WRc Mark III Fish Monitor, have been deployed to investigate physiological responses to storm events of different magnitude, duration and frequency. Results are discussed in relation to their application in the field validation of proposed water quality criteria for the control of intermittent pollution from combined sewer overflows.


2013 ◽  
Vol 8 (3-4) ◽  
pp. 409-416
Author(s):  
J. Pollert

In 2005 one of major Czech manufacturers of glass reinforced plastic pipes asked the Department of Sanitary and Ecological Engineering to develop a new type of combined sewer overflows (CSO) chamber that could become a part of their manufacturing programme. The main requirements were economy of production, easy and fast installation on the field and increased protection of receiving waters. A simple object consisting of a pipe placed above another one was designed. The object begins with a stilling chamber formed by a conical expansion of the inlet pipe. It is separated from the overflow object itself by a downflow baffle designed to trap floating objects. The CSO chamber is equipped by a flow regulation device (e.g. vortex valve or throttle pipe) at the end. Excess water flows through a slit in the top of the bottom pipe into the upper pipe and from there to the receiving water. More than 15 prototypes were already installed in the Czech and Slovak Republics and more than 20 are planned to be built in Europe. We hope this type of CSO CHAMBER will help to decrease the cost of construction of new sewers and reconstruction of old ones. Its higher efficiency of separation of suspended particles might also contribute to the improvement of the quality of receiving water bodies according to Water Framework Directive 2000/60/EC.


2007 ◽  
Vol 56 (3) ◽  
pp. 31-38 ◽  
Author(s):  
R. Woźniak ◽  
U. Dittmer ◽  
A. Welker

The EU Water Framework Directive (WFD) calls for a good quality of all water bodies. Retention soil filters (RSF) have been developed to treat discharges from combined sewers systems. RSF have proved over the past 15 years to be the most effective measure to meet the EU WFD standards, especially for small or particularly sensitive receiving waters, which require an enhanced reduction of emissions from combined sewer overflows (CSOs). The paper presents results from laboratory-scale experiments, in which the oxygen measurement in the filter plays a main role. The results show remarkable differences in oxygen concentrations in different filter depths. The highest oxygen consumption takes place in the upper part of the filter. In the lower part the re-aeration of sewage from the soil air dominates. This indicates that the biological activity is limited to the upper part of the filter. The availability of oxygen in the filter is a sign for degradation of wastewater compounds (ammonium, COD) under certain conditions and already takes place during the filter operation. The removal of ammonium especially cannot be strictly divided into phases of sorption during the loading and oxidation during the dry period any more.


2003 ◽  
Vol 47 (4) ◽  
pp. 149-156 ◽  
Author(s):  
F. Schlütter ◽  
O. Mark

In a number of industrialised countries there is an effort made to reduce pollutant discharges from combined sewer overflows. After establishing proper treatment plants the CSO discharges are contributing with a higher percentage of the total pollutant load on the receiving waters. The acknowledgement of this issue has made the authorities in some countries issue requirements for maximum allowed pollutant loads and water quality from individual CSOs. However, in order to make standards for CSO emissions knowledge about the current state is needed and subsequently others needs to be able to document that they are in compliance with the standard. The question is how to calculate the annual pollutant load from a given CSO? The purpose of this article is to present results from calculation of annual loads in different ways.


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