DESIGN OF NABLUS-WEST WWTP

Prepared by: Supervised by: Allam Aghbar Islam Janem Mohammad Kukhun

Dr. Abdel Fattah R. Hasan

23/05/2012

An-Najah University Civil Engineering Department

Graduation Project #2

Content Background Objectives Population Analysis Wastewater Generation Stormwater and Infiltration SewerCAD Analyses Waste water treatment plant design Results and Recommendations

Background Location

Nablus district is located in the northern part of the West Bank.

Nablus

Background Topography

Nablus lies in a valley between two mountains, Ebal Mount and Gerzim Mount

ClimateClimate in Nablus is rainy in winter, hot and dry in summer

Ebal Mount

Gerzim Mount

Background Precipitation

The annual mean rainfall is 664 mm

HumidityThe mean annual relative humidity of Nablus district is 62%

R H

Objectives The ultimate goal of this project is to

enhance the sanitation sector in the Nablus city, that will lead to: Prevention of disease and nuisance condition Providing clean water supply for irrigation Avoidance contamination of water supply

Objectives

These goals should be established by achieving the following objectives of the project: Design of wastewater conveyance system Design of wastewater treatment plant

Study Area

Zawata

Beit wazan

Beit ebbaQosin

Der sharaf

NablusWest

East

Population Analysis1997 2007 2012

Palestinian Central Bureau of Statistics 248,102 317,298 356,129

Constant growth rate method 248,102 317,298 358,818Geometric growth rate

method 248,102 317,298 358,490

Arithmetic method 248,102 317,298 352,943

Population Analysis2007 2012 2042

West-Nablus 74,868 84,367 177,071Zawata 1,855 2,129 4,387

Beit wazan 1,046 1,178 2,474Beit ebba 3,116 3,497 7,370

Qosin 1,691 1,897 3,999Der sharaf 2,434 2,731 5,757

Total 85,010 95,799 201,058

Water Consumption

42.40 m3/year

≈ 120 L/day

Wastewater Generation Water consumption = 120 L/c.d Design period = 30 year Return flow = 80% Hourly peak factor = 3 Infiltration = 10% of mean daily

wastewater Stormwater generate only from the old

city

Stormwater Q storm = C × I × A = 3,042 L/s

C = 0.9 A = 27.6 ha I = 120 (L/s.ha) Return period = 4 years Rainfall duration = 12 (min)

0 20 40 60 80 100 120 1400

20406080

100120140160180200220

2 years4 years20 years

Rainfall duration (min)

Inte

nsity

(L/

s.h

a)

IDF curve

Wastewater GenerationPopulatio

n 2042Wastewater (L/s)

Infiltration (L/s)

Stormwater (L/s)

Total amount

(L/s)West-Nablus 74,868 590.2 19.7 3,024 3,634

Zawata 1,855 14.6 0.5 - 15.1Beit wazan 1,046 8.3 0.3 - 8.5Beit ebba 3,116 24.6 0.8 - 25.4

Qosin 1,691 13.3 0.4 - 13.8Der sharaf 2,434 19.2 0.6 - 19.8Study Area 201,058 670 22 3,024 3,717

The Main Trunk

SewerCAD Analyses Using manning equation in hydraulic

analysis Manning coefficient = 0.013 Velocity range: 0.5 - 4.5 m/s All pipes are circular and

made of concrete. Alldiameters are 1.4 m

SewerCAD Analyses

SewerCAD Analyses

SewerCAD AnalysesVelocity

(Average) (m/s)

Slope (m/m) Invert (Stop) (m) Stop Node Invert (Start)

(m) Start Node Label

4.03 0.01 421.46 MH-2 421.66 MH-1 CO-14.03 0.01 421.34 MH-3 421.44 MH-2 CO-24.03 0.01 420.11 MH-4 421.11 MH-3 CO-34.03 0.01 418.41 MH-5 419.01 MH-4 CO-44.03 0.01 416.66 MH-6 417.16 MH-5 CO-54.03 0.01 415.25 MH-7 415.95 MH-6 CO-64.03 0.01 414.19 MH-8 414.79 MH-7 CO-74.03 0.01 410.63 MH-9 411.38 MH-8 CO-84.03 0.01 407.98 MH-10 408.58 MH-9 CO-94.03 0.01 405.5 MH-11 406.1 MH-10 CO-104.03 0.01 403.93 MH-12 404.38 MH-11 CO-11

SewerCAD AnalysesProfile section

Design of wastewater treatment plant

Primary Screening Grit Removal Primary sedimentation

secondary Aeration Secondary sedimentation

Advanced Disinfection

Design of wastewater treatment plant

Screening This is the first step in preliminary

treatment process which aims to remove floating and suspended matter such as paper, cloth.

Quantity of screenings = 0.9 m3/dayDesign criteria

Bar spacing (mm)

Depth in the conduit (m)

slopeBar depth

(mm)Bar width

(mm)Velocity

(m/s)

50 0.53 60° 35 10 0.6

Grit Removal Chamber Grit chamber used to remove grit sand and

other material manly to protect moving mechanical equipment and pumps from unnecessary wear and abrasion

No. of tube Blower capacity Detention time (min) Length (m) Total Depth

(m) Width( m )

22 8.775 m3/min 4 19.5 3.5 4.5

Primary sedimentation tank It removes 90% to 95% of settealble

solid ,and remove 30% to 40% of BOD also reduce total suspended solid 50% to 70% .

No.Width

(m)Length

(m)

Total depth (m)

Slope %Weir

length (m)

Weir section

(m)

4 6 24 4 1.35 50 0.2 m

Aeration Is used to receive the flow from many

entrance to prevent the excess concentration of bacteria in one location.

Secondary sedimentation Tank (Biological Process)

The objective of biological treatment is to reduce BOD to be with the standard, using bacteria

Overflow rate (m3/m2.d) Detention time (hr) Weir loading

(m3/m.d) Flow rate (m3/d) average liquid depth (m)

20 3 110 40,000 2.1

No.Width

(m)Length (m) Total depth (m) Slope (%) Weir length (m) Weir section (m)

2 16 64 3 1.35 82.8 0.3

Disinfection The process designed to kill or inactivate most

microorganisms in wastewater, including essentially all pathogenic (disease-causing) organismsWidth (m)

Length (m)

Height (m)

1.6 64 4.8

Results and Recommendations

The main trunk can carry the wastewater without flooding .

In wastewater treatment plant design we followed a series of processes that helped to achieve the acceptable level of treated waste water.

The outputs of treatment processes are treated water and sludge. The treated water can be used as an irrigation water in wadi al-zomar ,for olive, almonds, that will lead to reduce the amount of pure water consumption for irragation and the extract sludge can also be used as a fertilizers.

Results and Recommendations

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