Transcript Sewer Systems - SWAP-bfz

Wastewater Workshop in Nairobi
29-th August till 03-rd September 2011
Sewer Systems
Dr.- Ing. Rainer-Werner Abendt
Nuremberg
Contact: [email protected]
Rainer Abendt
®
Sewer Systems
A Recap of the previous module indicated that:Sewage purification systems are necessary for
health. Because supply of clean water to the
population is indispensable for health provision.
(National Water Services)
But sewage systems are also important for
protection of groundwater or river water.
Why?
Because we need river or ground water to produce
drinking water !
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®
Sewer Systems
Sources of raw water in Bavaria
Millions.
m³/yr
%
value
groundwater from wells
700.7
74,8
groundwater from springs
163.8
17,5
bank filtrate, recharged groundwater
48.3
5,1
surface water
24.2
2,6
937.1
100
Total
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®
Sewer Systems
1 Effluent Standards (emission)
2
Water Quality Standards (imission)
3 Education Standards: labours and academic
4
4 Health and Safety Standards
3
1
2
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Sewer Systems
First step!
Without Stormwater Drainage
Evolution in sewer network:
- By-laws
Urban area
Treatment
plant
-auslässe
Evolution of water crowd:
Legal
Orders
- Sewer construction
Evolution of Water quality:
- Sewer operation
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Sewer Systems
Or First step!
With separate Stormwater Drainage
Evolution in sewer network:
- By-laws
-auslässe
Legal
Orders
Effluent in a river
Urban area
Treatment
plant
-auslässe
Evolution of water crowd:
Legal
Orders
- Sewer construction
Evolution of Water quality:
- Sewer operation
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®
Sewer Systems
Or First step!
Storm- and Wastwater mixed
Evolution in sewer network:
- By-laws
-auslässe
Urban area
Legal
Orders
Treatment
plant
Evolution of water crowd:
- Sewer construction
Stormwater
Effluents
Are the stormwater drains
connected to the trunk
sewer? If not, where does the
stormwater drain to?
-auslässe
Evolution of Water quality:
Legal
Orders
- Sewer operation
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®
Sewer Systems
Administration:
Finances;
By-laws:
Personnel
Connection approval;
Industrial monitoring;
Cost covering
Wastewater disposal
(Discharge and treatment)
Sewer operation:
Sewer construction:
General drainage;
Sewer network
expansion;
Maintenance, repair,
operation/control of
storage space and
outlets (provisions
under water law)
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Sewer Systems
• Pipe Varieties in
Nuremberg, Germany.
 These are examples of types of
pipes needed for various
transmission works
 In selecting a pipe material for
sewer service, the design
engineer must evaluate
standards for materials,
products and systems
 The standards must meet
international specifications and
must have passed Proficiency
Testing Programs for quality
assurance.
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®
Sewer Systems
Technical Standards of Materials
Product &Testing Standards guarantee quality.
Check the:pipe
diameter
Pipe Material
Pipe thickness
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®
First WASPA Annual International
DENConference
= Technical European Norms
8-9th September 2011, KICC Grounds, Nairobi, Kenya
Free trade
Rainer Abendt
®
Sewer Systems
Examples of Standards Quality of on Water
Materials:
CEN TC 155 „Plastics piping systems“ “
CEN TC 163 „Sanitary appliances “
CEN TC 164 „Water supply “
CEN TC 165 „Waste Water Engineering“
CEN TC 203 „Cast iron pipes “
CEN TC 208 „Elastomeric seals“
CEN TC 230 „Water analysis “
CEN TC 308 „Characterization of sludges“
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Sewer Systems
Example: ‘Visual inspection coding system,
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Sewer Systems
Wastewater types (QWW):
1. Domestic wastewater (QD)
such as: shower water
swimming pool water
flushing water
faecal water
2. Commercial and/or industrial wastewater (QInd)
such as: production water
treatment water
cooling water
3. Infiltration water (QIW)
4. Stormwater (rainfall) (QR)
5. Melt water
Daily amount of wastewater, normal in Europe:
average: 125 - 200 l / (per individuaI per day)
frequently: > 300 l / (per individual per day) due to increased amounts of
infiltration water (QIW)
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Sewer Systems
Parameters in Wastewater pollution (raw sewage):
Inhabitant-related loads in raw wastewater
BOD5 : 60 g/(per Individual per day)
COD: 120 g/(per Individual per day)
filterable solids: 70 g/(per individual per day)
Ptot: 1.8 g/(per individual per day)
Ntot: 11 g/(per individual per day)
Ntot in raw wastewater mainly as TKN
TKN (Total Kjeldahl Nitrogen): Norg + (NH4+ - N)
undissolved matter: 30 %
dissolved matter: 70 %
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Sewer Systems
Wastewater pollution (raw sewage):
Concentrations of minimum parameters in domestic
raw wastewater:
BOD5: 200 - 400 mg/l
COD: 400 - 800 mg/l
Ptot: 5 - 12 mg/l
Ntot: 30 - 75 mg/l
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The wastewater discharged into the sewer system should
not possess the following characteristics:
1. Free acids (pH values < 6.5) and strong lyes (pH > 8.5)
2. Salts in high concentrations
3. Strong poisons (toxic substances, e.g. Cu ions)
4. Oils and greases (mineral oils)
5. Hazardous and explosive gases (e.g. methane, petrol
fumes)
6. Odorous substances (e.g. sulphides from leather
processing)
7. Large quantities of suspended or heavy settleable solids
8. Radioactive substances (e.g. from hospitals)
9. High Temperatures (over 35 °C)
10. Heavy discoloration (e.g. from the textile processing
industry)
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®
Sewer Systems
The daily variation of waste water %
Q [l/s]
%
QKW
200
190
180
170
160
Reserve für
Regenwasser, QRW
150
Pipe capacity
for stormwater
140
130
120
110
100
Wastewater
90
Schmutzwasser
QSW
80
70
60
50
40
Infiltration Water
30
20
Fremdwasser
QFW
10
0
t [h]
5.00
Rainer Abendt
9.00
13.00
17.00
21.00
1.00
5.00
®
Sewer Systems
Cost Reduction:
 You can reduce your treatment costs, if you
ensure non-soiled wastewater does reach
the sewer network at all.
 In a mixed sewer net (rain and wastewater)
you can reduce your costs by building a
storm water tank at a quarter the distance
from the start of the trunk sewer with a drain
time of 10 to 15 minutes in the channel.
Rainer Abendt
®
Sewer Systems
Sewer network of Nuremberg
Treatment plants
Sewer network
Stormwater tank
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Schematic profile
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Diagram
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Water quality of the river
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Why Sewage Purification ?
Demands on water quality (Europe):
COD
BOD5
Ammonia
Ntot
Suspended Solid P
tot
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Sewer Systems
Administration
Financial
management
Legal orders
Personnel
Evolution in sewer network:
- By-laws
Automatic
monitoring
Documentation
?
Urban area
Government
control
Product 1
„Clean Water"
Treatment
plant
(Process
system)
Product 2
"Sludge"
Evolution of water crowd:
Legal orders
- Sewer construction
Demands on
the sludge
Evolution of Water quality:
- Sewer operation
Laboratory
Secure disposal
operating data
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®
Sewer Systems
How then does a
Treatment Plant look like ?
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®