Lecture Series: Water, Soil & Atmosphere Part: Introduction into Urban Water

Transcription

1 Lecture Series: Water, Soil & Atmosphere Part: Introduction into Urban Water Thomas Ertl Universität für Bodenkultur Wien Department für Wasser-Atmosphäre- Umwelt

2 Content: Introduction into Urban Water (30 min. ;-) Mass flows & Processes in Urban Water Management Mass flow concepts Water flow, sediment & pollutant transport, management Physical Processes: Example: Hydraulics: stormwater runoff, open channel flow Chemical and Biological (Bio-chemical) Processes Processes in water bodies Self cleaning, impacts (spatial and time scales) Treatment in technical plants Water Quality and index class / Classification

3 Subsystems & components in the urban water system SWT (Schmitt & Huber, 2005, adopted from Gujer, 1999)

4 Mass flow concept of Austrian CSO Guideline ( )

5 Sewer system of Vienna mainly combined system Straßenkanäle km Hauskanal km Anschlussgrad 99 %

6 Combined Sewer Overflow Friedensbrücke Entlastungsereignis am in den Donaukanal (?? mm NS/24h) Google maps Foto: Ertl, June 2010

7 Mass flow between urban water components Micropollutants Schmitt & Huber (2005) Micropollutants

8 Stormwater Hydraulics Rational Method Rainfall intensity r Area A Stormwater peak run-off / discharge Q r A R = I * A * C = run-off coefficient C * I * A

9 ( )

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11 Surface runoff and channel routing Rainfall, Runoff Runoff generation Runoff concentration time Want more details? VU Channel routing

12 Emission & Quality Standards Combined Approach Erbe (2004)

13 "combined approach ( : WFD, 2000) (i) emission limit values and (ii) quality standards (i) On the source side, all existing technology-driven source-based controls must be implemented as a first step (ii) On the effects side, overall objective of good status for all waters, 13

14 Sources and processes regarding nutrients in water bodies (VENOHR et al. 2009, cited in STOBIMO - BMLFUW, 2011)

15 Co-ordination of objectives good status for all waters by a set deadline (WFD, 2000) Key objectives: general protection of the aquatic ecology specific protection of unique and valuable habitats protection of drinking water resources protection of bathing water All these objectives must be integrated for each river basin. 15

16 Waterbody quality (WFD, 2000) The Waterbody quality is an evaluating parameter, influenced mainly by all kinds of (wastewater) discharges and infiltration of non-point pollutants as well as the condition of the riverbed including the riverbanks and the community of organism living in this water (biocoenosis). Parameters for the description of the Waterbody quality are: Morphological aspects (shape of the water) Physical aspects (light intensity, temperature etc.) Chemical aspects (Oxygen saturation, nutrients, toxic substances) Biological properties (species of animals and plants, saprobic index = Indication of the level of organic pollution)

17 Excursus: Advection / Dispersion (Wikipedia) Advection, in chemistry, engineering and earth sciences, is a transport mechanism of a substance, or a conserved property, by a fluid, due to the fluid's bulk motion in a particular direction. An example of advection is the transport of pollutants or silt in a river. A dispersion is a system in which particles are dispersed in a continuous phase of a A dispersion is a system in which particles are dispersed in a continuous phase of a different composition (or state). See also emulsion. A dispersion is classified in a number of different ways, including how large the particles are in relation to the particles of the continuous phase, whether or not precipitation occurs, and the presence of Brownian motion. There are three main types of dispersions: Coarse dispersion (Suspension), Colloid, Solution

18 Receiving Water Impacts ( ) Time and spatial scales for processes in receiving water (Butler & Davies, 2000)

19 Pollutants/sediments and processes for quality modelling in sewers ( )

20 Self cleaning processes of flowing waters Self cleaning processes are natural procedures changing: Substances in load and concentration and Characteristics like temperature towards the natural conditions. Self cleaning processes starts with the intake of different substances: Natural substances like leaves, wood or soil particles Anthropogenic loads like wastewater (effluent of WWTP or untreated wastewater)

21 Self cleaning processes of flowing waters The intensity of cleaning processes is depending on: Kind of discharged substance Existence of appropriate organism (species and number) Existence and availability of nutrients (kind and amount) General conditions (mixing, temperature, ph-value, Oxygen concentration) The self cleaning rate is a result of a long-term adaptation process of the organism to the specific situation concerning pollutants and loading

22 Self cleaning mechanisms in water bodies ( ) Self cleaning mechanisms are various: Usually the interaction of the different processes leads to the monitored reductions or changes of substances. [WFD, 2000] Physical Chemical Bio-chemical Sedimentation, Flocculation, Dispersion, Separation processes due to different density Adsorption, Precipitation, acid-base balance, ORP Metabolism within the food chain, plants and animals die-off, inactivation of pathogens, stripping of volatile substances, equilibrium of gases or energies at the intersection of liquid and gaseous phases

23 Self cleaning processes as pattern for wastewater treatment technologies ( : Mudrack & Kunst, 1994) fixed biofilm reactor suspended biofilm reactor

24 Vertical flow constructed wetland (fixed biofilm reactor)

25 Vertical flow constructed wetlands (fixed biofilm reactor) Styrian examples (Foto: Ertl, 2011)

26 Hauptkläranlage Wien ab 1980 Activated sludge system (suspended biofilm reactor) Schotterfang Schneckenpumpwerk Sozialgebäude Rechen Sandfang Vorklärbecken Zwischenklärbecken Klärschlammeindicker Belebungsbecken 1. Stufe Auslaufpumpwerk C-Elimination ( : ZELINKA, 2010)

27 Hauptkläranlage Wien ab 2005 Activated sludge system (suspended biofilm reactor) Schotterfang Klärschlammeindicker Schneckenpumpwerk Sozialgebäude Rechen Sandfang Vorklärbecken Belebungsbecken 1. Stufe Zwischenklärbecken Auslaufpumpwerk Zwischenpumpwerk Nachklärbecken Verdichterstation Lager und Werkstätten Belebungsbecken 2.Stufe N-Elimination ( : ZELINKA, 2010)

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30 Result: e.g. Biological Status of Austrian Rivers 2005 ( ) 30

31 List of Abbreviations BMPs Best Management Practise BOD Biochemical Oxygen Demand C Coefficient (C*I*A) C-Elimination Carbon-Elimination COD Chemical Oxygen Demand CSO Combined Sewer Overflow DO Dissolved Oxygen eta R Efficiency of (comb.) sewer system discharging storm runoff to the WWTP FFST First Flush Stormwater Tank I Intensity (C*I*A) N Nitrogen Excess Rainfall N eff O 2 Oxygen ORP Oxidation-Reduction-Potential P Phosphorous PO4 Phosphate Q DWF Dry Weather Flow Q I/I Infiltration/Inflow (Parasite Flow) RB19 ÖWAV Guideline 19 (CSO Concept) SRQ Surface Runoff Quality SWT StormWater Tank V Neff Volume of runoff from Neff WQ Water Quality WWTP WasteWater Treatment Plant

32 References BMLFUW (Ed., 2011) Stoffbilanzmodellierung für Nährstoffe auf Einzugsgebietsebene (STOBIMO-Nährstoffe) als Grundlage für Bewirtschaftungspläne und Maßnahmenprogramme Endbericht. Butler, David and John Davies: Urban Drainage, Spon Press, 2010 Erbe V. (2004) Integrierte Modellierung. Presentation (in german) at the Hochschulgruppe Meeting in Luxemburg. Gujer, Willi : Siedlungswasserwirtschaft, Springer, 2007 Ministry of Life (2011) Facts and Figures. Schmitt, Theo and W. C. Huber (2005) The scope of integrated modeling - system boundaries, sub-systems, scales and disciplines. Proceedings of the 10th ICUD. Copenhagen WFD (2000) Water Framework Directive

33 Priv-Doz. Dr. Thomas Ertl Universität für Bodenkultur Wien Department für Wasser-Atmosphäre-Umwelt Institut für Siedlungswasserbau, Industriewasserwirtschaft und Gewässerschutz Muthgasse 18, A-1190 Wien Tel.: , Fax: thomas.ertl@boku.ac.at,