Name of Work: 7.5 MLD Dhandhuka, Ahmedabad District ; Client: … · 2018-11-15 · n, Manning Coefficient 0.013 Value for concrete Available velocity 0.670 m/s Wetted perimeter 1.59

Prepared by:

SWA Environmental Consultants Engineers

Project Name: STP at Dhandhuka Date- 29-08-18

1 Inlet chamber 2.890 1.70 1.70 5.00 0.50 1

2 Bypass 1.20 1.20 2.50 0.50

3Screen Channel/

Chamber 5.5 6.65 0.83 0.70 0.50

1 operational mechanical and 1 manual

as standby; SWD for peak 1+1

4 Grit chamber 10.75 0.85 0.50 3.70 2

5 Parshall Flume 4.20 7.00 0.60 0.90 0.50 1

6Distribution

chamber/ channel 2.40 2.00 1.20 5.00 0.50

Channel directly connected to aeration

tank 2

7 Primary Clarifier 0.00

8 Anaerobic tank 147 131.3 26.3 4.6 5.7 5.0 0.60 Dimension of each basin 2

9 Anoxic tank 276 246.1 49.2 10.7 4.6 5.0 0.60 Dimension of each basin 2

10 Aeration Basin 1951 1742.0 348.4 16.4 21.2 5.0 0.60 Dimension of each basin 2

11 Secondary Clarifier 2298 1969.6 656.55 3.0 0.50 28.92 Dimension of each settling basin 1

12Chlorine contact

tank 207.6 167.71 76.88 12.40 6.20 2.20 0.50 1

13 Chlorine room 18.50 5.00 3.70 4.50

14 Sludge drying bed 105.6 64.18 82.81 8.28 10.00 0.78 0.50Not to be constructed (1 divided into 4

beds) 1

15 RAS Sump 204.1 164.1 80.08 2.0 0.50 10.10 1

16 Gravity thickner 215.1 194 43.01 4.50 0.50 7.40 1

17Thickened Sludge

sump 43.5 35 17.40 5.00 3.50 2.00 0.50 1

18 Recirculation Sump 3.5 1.60 1.50 1.50 0.50 1

19 Alum dosing tank 7.5 2

STP unit sizing summary

Name of Work: 7.5 MLD Dhandhuka, Ahmedabad District ; Client: GWSSB

Process Design and Hydraulic design for STP 7.5 MLD Dhandhuka (8.4 MLD Build Out)

No of

Unit/s

Sr.

No

Description of

Item

Area

(sq-m)

Length

(m)

Width

(m)

SWD/

Height

(m)

F.B

(m)

Dia

(m)Other Details

Vol each

(cum) w/o

FB

Vol

each

(cum)

Calculation by: Urv Patel 1 of 67

Prepared by:



20 Admin Block 16.00 4 4 3.50 As per tender specifications

21 Blower Room 20.00 5 4 5.00 Adjoining Admin block First floor 1.00

22 MCC room 54.00 9 6 3.50 As per tender specifications

23 Workshop 20.00 5 4 3.50 Adjoining Admin block Groundfloor 1.00

24Secondary Clarifier-

2 Future expansion 3 0.5 10.02 0.9 MLD

25 Centrifuge house 18.80 4.70 4.00 3.5

26 Guard room 5.8 2.4 2.4 3 As per tender specifications 1

Calculation by: Urv Patel 2 of 67

Prepared by: SWA Environmental

Consultants Engineers

Project Name: STP at Dhandhuka 29-08-18

Sr No. Parameter Value Unit Remarks

1 Flowrate 7.5 MLD Intermediate

312.50 cum/hr

2 Recirculated flow 5.00 % Asssumed 5 %

3 Recirculated flowrate 15.63 cum/hr

4 Average flowrate 0.09 cum/s

5 Peak factor 2.25 As per CPHEEO

6 Peak flowrate 0.200 cum/s

7 Flowrate 8.4 MLD Ultimate

350.00 cum/hr

8 Recirculated flow 5.00 % Asssumed 5 %

9 Recirculated flowrate 17.50 cum/hr

10 Average flowrate 0.10 cum/s



4 HFL at discahrge point 20.65 m As per site condition and tender document;

HFL of discharge point

5 G.L 20.65 m As per site condition and tender document

6 Density of Water 1000 kg/cum

7 Dynamic viscosity at 20 C 1.002E-03 Pa-s/sqm

1R.L for discharge point 20.65 m

Length of pipe 2600 m

Diameter of pipe 0.60 m

C/S area 0.28 sqm

Velocity 0.79 m/s As per Ultimate Peak

MOC RCC NP2

Hazen William Coefficient 140As per CPHEEO Nov-2013, Table-3.14, Page-

3.33

Hydraulic Slope 0.000379 m

Head loss 0.9864 mMinor head loss due to

contraction 0.02 m Outlet chamber to Pipe

Total head loss 1.002 m

Hydraulic Flow Diagram Calculations

Design Parameters

Hydraulic Gradient Line Calculations

Effluent Chamber to Discharge point

STP capacity 7.5 MLD (8.4 MLD Built out)

Ultimate conditions

Intermediate conditions

Calculation by: Urv Patel Page 3 of 67




Extra SWD for factor of

safety 0.230 m

W.L in Effluent chamber 21.89 m

2Downstream channel

Flow 805 cum/hr As per Ultimate Peak

Channel width after flume 0.60 m

Liquid depth provided 0.497 m

Free board provided 0.5 m

Length of channel 2.50 m

Mannings formulae

n, Manning Coefficient 0.013 Value for concrete

Available velocity 0.670 m/s

Wetted perimeter 1.59 m

C/S area 0.30 sqm

hydraulic radius 0.19

Slope 0.00

Head loss 0.001770892 m

Say 0.02 m

Water level at end of D/S

just before entering outfall 21.91 m

Head loss across the flume 0.41 m

Water level at start of D/S

channel 22.32 m

B.L of channel bottom at

start of D/S channel 21.42 m

Upstream ChannelFlow 805 cum/hr As per Ultimate Peak

Channel width 0.6 m




Mannings formulae

n, Manning Coefficient 0.013



C/S area 0.2981 sqm


Slope 0.0009

Head loss 0.0022 m

Say 0.02 m

Head loss in parshall flume channel - effluent chamber





Water level at start of the

U/S channel 22.34 m


start of U/S Channel21.85

3Loss from CCT to Outlet

chamber

WL in CCT Outlet chamber 22.34

Exit loss

v 0.21 m/sec As per Intermediate peak

k 1.00

Head loss 0.0021 m

Say 0.02

Free fall provided 0.075 m

Head loss in CCT

Flow 0.200 cum/s As per Intermediate peak

Channel Width 1.0 m

Liquid depth provided 2.2 m SWD of CCT



Mannings formulae




C/S area 2.27 sqm


Slope 0.0000042

Head loss 0.000176471 m

Say 0.01 m

WL in CCT 22.45 m

Loss from Inlet chamber to

CCT

Entry

V 0.21 m/sec As per Intermediate peak

k 0.50

Head loss 0.0011 m

Say 0.02

WL in CCT inlet chamber 22.47 m

Head loss in CCT tank & Chambers





3

3-aa Length of pipe 40 m Assumed length

b Diameter of pipe 0.50 m

c C/S area 0.20 sqm

d Velocity 1.02 m/s As per Intermediate peak

e MOC DI K9

f Hazen William Coefficient 140As per CPHEEO Nov-2013, Table-3.14, Page-

3.33

g Hydraulic Slope 0.000747 m

h Head loss in pipe 0.0299 m

iMinor head loss due to


jMinor head loss due to

expansion 0.026 m Pipe to CCT inlet chamber

hW.L in the Outlet chamber

of Secondary Clarifier 22.56 m

g Free fall from launder outlet 0.200 m As per tender document 11.1.2

2-b

Design flow 0.20 cum/s As per Intermediate peak

Length of launder 87.67 m Circumference of the clarifier

Width of launder 1.00 m

Water depth in launder 0.42 m

C/S area of flow in launder 0.42 sqm

Manning formula

n, Manning coefficient 0.013AS per CPHEEO Nov-2013, Table-3.11, Page-

3.29

Velocity 0.48 m/s

Wetted perimeter 1.84

C/S area 0.42 sqm

Hydraulic radius 0.23

Slope 0.0003

Head loss 0.0240 m

Total head loss 0.03 m

HGL/WL at D/S of the

launder 22.76 m

HGL/WL at U/S of the

launder 22.79 m

2-c

Design flow 718.75 cum/hr As per Intermediate peak

Discharge over all V notch

weir 0.200 cum/s

Pipeline

Launder

Head loss across weir

Secondary Sedimentation tank to Chlorine contact tank





Circumference of clarifier 90.809 m

Spacing of each weir 0.30 m

Number of weirs 300.00 nos

Discharge over each weir 0.00067 cum/s

Angle of weir 90

Discharge coefficient 0.6 Based on the angle of V notch selected

Head over each weir 0.047 mFormulae changes if V notch angle is

changed

Round-off 0.05 m

Free fall 0.075 m

HGL/WL in clarifier 22.92 m

4

Pipe line a Length of pipe 25 m

b Diameter of pipe 0.70 m

c C/S area 0.38 sqm

d Velocity 1.04 m/sAs per intermediate peak + RAS +

Reciculated

e MOC DI K9

f Hazen William Coefficient 140As per CPHEEO Nov-2013, Table-3.14, Page-

3.33

g Hydraulic Slope 0.00052 m

h Head loss in pipe 0.0131 m

iMinor head loss due to


jMinor head loss due to

expansion 0.027 m Pipe to Secondary Clarifier

kMinor head loss due to

bend (90 deg)0.110 m Due to bend on pipe in central shaft

90 degree bends

No 2.00

V 1.04 m/sAs per intermediate peak + RAS +

Reciculated

k 0.75

Head loss 0.08 m

Exit loss

v 1.04 m/secAs per intermediate peak + RAS +

Reciculated

k 1.00

Head loss 0.05 m

Aeration tank to Secondary Clarifier





Entry

V 1.04 m/sec As per ultimate peak + RAS + Reciculated

k 0.50

Head loss 0.03 m

Total head loss from

Aeration tank Outlet

chamber to Secondary

clarifier

0.34 m

W.L In aeration tank outlet

chamber 23.26 m

Free Fall in Outlet chamber

from aeration tank 0.08 m

W.L in the aeration tank

oulet weir 23.33

Head loss across outlet

weir Aeration tank outlet weir

Design flow 2875 cum/hr

Peak Factor X ( Q + RQ ) X 2 ; R=1 ;

Intermedaite ; One basin pulled out of

operation


weir 0.799 cum/s

Length of weir 16.4 m Per Basin




Angle of weir 90



changed

Round-off 0.2 m

Free fall 0.075 m

HGL/WL in Aeration tank 23.61 m

Head loss across inlet weir Between Anoxic tank and Anaerobic tank




operation


weir 0.799 cum/s









Angle of weir 90



changed

Round-off 0.15 m

Free fall 0.075 m

HGL/WL in Anoxic tank

outlet weir 23.61 m

HGL/WL in Anoxic tank 23.83 m

Head loss across inlet weir Between Anaerobic tank and Anoxic tank




operation


weir 0.799 cum/s





Angle of weir 90



changed

Round-off 0.2 m

Free fall 0.075 m

HGL/WL in Anaerobic tank

outlet weir 23.83 m

HGL/WL in Anaerobic tank 24.11

Free fall in anaerobic tank

influent weir from inlet

chamber

0.075 m

W.L in Inlet chamber 24.18

5

Flow rate

Channel from parshal flume to aeration tank distribution chamber





Length of channel 1.50 m Circumference of the clarifier

Width of channel 0.60 m

Water depth in channel 0.50 m

C/S area of flow in channel 0.3 sqm

Manning formula

n, Manning coefficient 0.013AS per CPHEEO Nov-2013, Table-3.11, Page-

3.29

Velocity 0.75 m/s At ultimate peak

Wetted perimeter 1.59

C/S area 0.30 sqm

Hydraulic radius 0.19

Slope 0.0009

Head loss 0.0013 m

Say 0.02 m

Free fall in Aeration tank

Distribution chamber 0.075 m

WL at the end of channel

just before Secondary

treatment inlet chamber

24.26 m

WL at the start of channel

just after Parshall flume 24.28 m End of D/S

B.L of Channel to Bilogical

treatment units23.78 m

6Downstream channel

Flow 805 cum/hr At ultimate peak

Channel width after flume 0.6 m




Mannings formulae




C/S area 0.30 sqm


Slope 0.00

Head loss 0.001062535 m

Head loss in parshall flume channel





Say 0.03 m

Water level at start of D/S 24.31 m

Head loss across the flume 0.41 m

Water level at end of U/S

channel 24.72 m


start of D/S channel 23.82 m

Upstream ChannelFlow 805 cum/hr At ultimate peak

Channel width 0.6 m




Mannings formulae

n, Manning Coefficient 0.013



C/S area 0.2981 sqm


Slope 0.0009

Head loss 0.0013 m

Say 0.02 m

Water level at start of the

U/S channel 24.74 m


start of U/S Channel24.25 0.49

7

Head loss in Grit Chamber 0.001288 At ultimate peak

Say 0.01

Free Fall 0.2 As per tender document Clause 11.1.2

W.L in Grit Chamber 24.95

B.L of Grit Chamber 24.10Drop in bottom of Grit

Chamber relative to BL of

parshall Flume

0.15 m

Head loss in gates &

Channel from Screen to

Grit chamber

0.05 m

WL between Grit &

Screen 25.00 m

Grit Chamber to Parshall Flume





8Depth of flow in D/S screen

channel 0.42 m

Head loss from D/S screen

channel to Grit chamber 0.05 m

W.L in D/S of screen

channel 25.05 m

B.L in D/S of Screen 24.63 m

Head loss across screen

(Max)0.28 m At ultimate peak

Drop in datum of U/S and

D/S0.15 m

B.L of U/S screen channel 24.78 m

W.L in U/S channel 25.18 m

Max head loss when screen

is 50% clogged 0.276 m

W.L in U/S channel (max) 25.34 mConsider this for calculation beyond as it is

the worst case scenario

W.L in the inlet chamber 25.39 m Incl Free fall of 0.05

4.74

7

Total Max head drop across

entire plant 3.50 m

This includes frictional head loss plus the

elevation choosen for last unit operation;

Not including 2600 m discharge line

Pumping required at or 5 m at inlet chamber

Total head loss

Screen Chamber






1 Flowrate 8.4 MLD Ultimate

350.00 cum/hr

Recirculated flow 5.00 % Asssumed 5 %

Recirculated flowrate 17.50 cum/hr

Average flowrate 0.10 cum/s Average + Reciculated



1a Detention time required 60 sec

bVolume required for peak

flow rate 13.42 cum As per ultimate peak

c Side water depth 5 m

d Surface area 2.683 sqm

e Length 1.70 m

f Breadth 1.70 m

g Free Board 0.5As per tender document Clause 11.1.2, Page

23, Vol-lll, Part-1

2a Detention time required 15 sec

bVolume required for peak

flow rate 3.35 cum

c Side water depth 2.5 m

d Surface area 1.342 sqm

e Length 1.20 m

f Breadth 1.20 m

g Free Board 0.5As per tender document Clause 11.1.2, Page

23, Vol-lll, Part-1

Bypass chamber

Screen chamber / Screen

Inlet Chamber

Design Parameters

Design Calculations







1 Flowrate 8.4 MLD

350.00 cum/hr



Average flowrate 0.10 cum/s



4 Width of rectangular bar 3 mm

5 Clear Spacing between bars 6 mm

6

Minimum velocity required

in the channel at average

flow

0.3 m/s As per CPHEEO page 5-30 Section 5.6.1.8

7Minimum velocity required

at peak flow 0.6 m/s As per CPHEEO page 5-30 Section 5.6.1.8

1

aAssume depth of flow in

screen chamber 0.4 m

b

Assume velocity of flow

through fine screen (Peak

flow)

1 m/s As per CPHEEO page 5-30 Section 5.6.1.8

cClear Area of opening

through fine screen 0.22 m

d Clear width of opening

through fine screen 0.56 m

f Total clear spacing 93 As per CPHEEO page 5-30 Section 5.6.1.8

g Total screen bar 92

h Total width 834 mm

0.83 m As per ultimate peak

iAngle of inclination to

horizontal 75 deg

2

a Velocity at peak flow 1.00 m/s

CHECK OKVelocity should be 0.6-1.2 m/s as per

CPHEEO page 5-30 Section 5.6.1.8

Velocity through screen openings


Fine Screen Chamber

Design Parameters

Design Calculations

Screen chamber / Screen





b Velocity at average flow 0.46 m/s

CHECK OKVelocity should be 0.3-1.2 m/s as per


3

a h (head loss) 0.13 m

CHECK OKAllowable head loss is 0.15 - 0.3 m as per


4

a Width of channel 0.83 m

b Depth of flow 0.4 m

cVelocity of flow in screen

channel @Peak flow 0.67 m/s

As per Tender Document Page 30 of 731,

Vol-lll, Part-1

Velocity of flow in screen 0.31 m/s As per Tender Document Page 30 of 731,

fLength of channel U/S of

Screen 4.2 m

Should be 5 X Channel Width As per CPHEEO

page 5-30 Section 5.6.1.8 & Tender

Document Page 30 of 731, Vol-lll, Part-1

6

1 2

a Datum height (z) 0 -0.15 Change Z_2 if the solver does not converge

b Depth of flow (d) 0.40 0.42 m

c Velocity of flow (V) 0.67 0.64 m/s

dHead loss due to screen

(h_L)0.13 m

R.H.S L.H.S Dummy

0.42 0.42 0.0000

Head loss through fine screen

Actual Velcotiy & Depth of flow D/S of screen chamber

Section

Screen channel

𝒁𝟏+ 𝒅𝟏 +𝑽𝟏𝟐

𝟐𝒈= 𝒁𝟐 + 𝒅𝟐 +

𝑽𝟐𝟐

𝟐𝒈+ 𝒉𝑳





7

1 2

a Datum height (z) 0 -0.15

b Depth of flow (d) 0.55 0.42 m

c Velocity of flow (V) 0.49 0.64 m/s

dHead loss due to screen

(h_L)0.28 m

R.H.S L.H.S Dummy

0.57 0.57 0.0000

ah_50 (Head loss at 50%

clogging) 0.276 m

Should be <0.6 m ; As per Metcalf and Eddy

5th Edition, Table 5-4 & 0.3 as per CPHEEO

CHECK OK m

b

Depth of flow at 50%

clogging U/S of screen

chamber

0.55 m

8

Angle of screen 75 deg

Length of screen 1.41 m0.5 Free board + 0.5 room for motor +

Length screen

Say 1.41 m

Projection length of screen

on D/S side 0.3649 m

Length of screen channel 1.36 m Projection length of screen + 1 m for bypass

Length of screen channel

D/S of screen as per

minimum criteria

2.49 m

Should be 3 X Channel Width As per CPHEEO

page 5-30 Section 5.6.1.8 & Tender

Document Page 30 of 731, Vol-lll, Part-1

Free Board 0.5 m As per tender document

Depth of screen channel 1.20 m0.5 Free Board + Datum height

compensation

ADepth of screen channel

provided 1.2 m

BLength of screen channel

U/S4.2 m

SUMMARY

Head loss through fine scree at 50% clogging

Screen Channel D/S Screen chamber

Section





CLength of screen channel

D/S2.49 m

Length of screen channel

D/S2.50 Say

D Width of screen channel 0.83 m

E Angle of screen 75 deg


channel (Avg)0.13 m


channel (Max) 0.28 m

Free Board 0.5 mAs per tender document Clause 11.1.2, Page

23, Vol-lll, Part-1



Consultants Engineers STP at Dhandhuka 29-08-18

Sr Parameter Value Unit Remarks

1 Flowrate 8.4 MLD

350.00 cum/hr






4 Size of grit particle to be 0.15 mm As per tender document

5 Temperature_Minimum 18 C Change as per field conditions

6 Kinematic Viscosity of water 0.00000114 sq-m/s Change as per minimum temperature

7 Specific gravity of the grit 2.65 unitless As per tender document

8 Gravitational accelaration 9.81 m/s^2

1

aSettling Velocity as per

stokes law 0.0177 m/s

b Reynolds number 2.34 unitless

Check Use transitions

law

If reynolds number is between 0.5-1000

then transitoins law should be used to

calculate the terminal settling velocity

Stokes law equation

Grit Chamber

Design Parameters

Design Calculations Settling velocity of the grit particle


Calculation by: Urv Patel 18of 67



cSettling Velocity as per

trasnitions law 0.0023 m/s

dSurface over flow rate for

100% removal 1533.46 m3/m2-d

In reality short circuting results inlower

efficiency

eEfficiency of removal of

desired particles0.78 %

f Measure of settling basin 0.13 fraction choose (1/8 for very good performance)

g Overflowrate for design 919.947 m3/m2-d < 959 m3/m2-d as per Tender document

2Dimension of Grit

chambers

Number of grit chamber 2 select

Surface area for each grit 10.50 sqm

Radius 1.83 m

Diameter 3.70 m

Water depth 0.85 mAs per Tender document Clause 14.4.3, Page

31, Vol-lll, Part-1

Hydraulic residence time for

peak flowrate 81.7 sec

> 60 sec as per Tender document Clause

14.4.3, Page 31, Vol-lll, Part-1

3Critical displacement

velcocity for resuspension

Trasnitions law eqaution




aCritical displacement

velocity 0.197 m/s

As per CPHEEO page 5.42 section 5.6.2.7.1.4

crtical velocity range from 0.17 to 0.256 m/s

bHorizontal component of

the velocity in the chamber 0.036 m/s

As per CPHEEO page 5.42 section 5.6.2.7.1.4

0.15-0.3 m/s range is used

c CHECK OK

4 Head loss through girt

Head loss through girt

chamber 0.00129 m

Coefficient of drag 5 select

Horizontal component of 0.07 m/s

As per ultimate peak

Number of grit chamber 2

Diamenter of Grit Chamber 3.70 m

Depth of Grit chamber 0.85 m

Free board 0.5 m

Classifier Slope 0.375

Height of Screw Conveyor 1.5 m From the bottom of the Grit chamber

Horizontal projection length 4.00 m

Length of screw conveyor 4.272 m

Summary





1 Flowrate 8.4 MLD

350.00 cum/hr






1

W 150

A 610

B (min) 600

C 315

D 391

F 300

G 600

K 75

Z 113

Parshal Flume

Design Parameters

Design Calculations


Dimensions of Plume

mm

Obtained from the Design parameter for

Parshall Flume (As per CPHEEO Nov-2013

Edition Page 5-46 Table 5.7 Section)




2a No of units 1

b Design flow each 805 cum/hr Normal flowrate

c Throat Width (w) 150 mm As per parshall flume equations/charts

d Head over the flume; 0.83 m As per parshall flume equations/charts

eHead at downstream of the

flume; H_b = Ha X 0.50.41 m

f Head loss at flume 0.41 m

g Velocity 0.75 m/s

h Area 0.30 sq m

i Width of channel 0.60 m

j Depth of flow 0.50 m

k Free board 0.50 m As per tender document

l Total depth of channel 1.40 m

m Length of channel U/S 3.00 mAs per parshal flume design considerations

CPHEEO; 20 X Throadt width

n Length of the channel D/S 1.50 m 10 X Throadt width

o Length of the flume 1.50 m As per the dimesions selected below

p

Providing additional Length

at D/S chaanel for

allowance of bypass gate

1.00 m

q Total length 7.00 m

D/S Length Parhsall Flume 1.50 m

U/S Length of Parshall

Flume 3.00 m

Length of Parshal Flume 1.50 m

Total Length of Flume 7.00 m

Width of Flume 0.60 m

Depth of Flume 1.40 m

Head Loss in Flume 0.41 m

Dimensions of Plume

Summary





1 Flowrate 7.5 MLD

312.50 cum/hr






1

aWidth of Parshall Flume

Channel 0.60 m

bNumber of distribution

chamber 1 m

cDetention time in each

chamber 60 sec

d Volume of each chamber 11.979 cum

h Width of channel 1.20 m

Water depth 5.00 m

Length 2.00 m

SWD 5.00 m

Length 2.00 m

Breadth 1.20 m

F.B 0.5 m

Summary

Distribution chamber

Design Parameters

Design Calculations

Distribution chamber dimension



Description Parameters Units COD

oxidation

NH4

oxidation

NO2

oxidation

Maxiumum Specific Growth rate µ_maxg bsCOD/g

VSS.d6.00 0.9 1

Half Velocity Constant K_s /K_nh4

/K_no2mg/L 8 0.5 0.2

Synthesis yield Ymg VSS/mg

sustrate0.45 0.15 0.05

Specific Endogenous Decay Rate b g VSS/g VSS.d 0.12 0.17 0.17

Fraction of Biomass that remain

as cell debrisf_d unitless 0.15 0.15 0.15

Half Velocity Constant for Oxygen K_o2 mg/L 0.2 0.5 0.9

Theta value Units COD

oxidation

NH4

oxidation

NO2

oxidation

µ_max unitless 1.07 1.072 1.063

b unitless 1.04 1.029 1.029

K_s /K_nh4

/K_no2unitless 1 1 1

TABLE-1 AERATION TANK DESIGN DATA (BIOKINETIC COEFFICIENT)

Reference: Metcalf & Eddy Edition-4, Section 8-3, Table-8.11, Page-705

Biokinetic parameter at 20 C

Temperature correction coeffcients for biokinetci parameters

µ_max = k * Y

Temperature 18 deg C

Description Parameters Units COD

oxidation

NH4

oxidation

NO2

oxidation

Maxiumum Specific Growth rate µ_maxg bsCOD/g

VSS.d5.24 0.783 0.88

Half Velocity Constant K_s /K_nh4

/K_no2mg/L 8 0.5 0.2

Synthesis yield Ymg VSS/mg

sustrate0.45 0.15 0.05

Specific Endogenous Decay Rate b g VSS/g VSS.d 0.111 0.161 0.161

Fraction of Biomass that remain

as cell debrisf_d unitless 0.15 0.15 0.15

Half Velocity Constant for Oxygen K_o2 mg/L 0.2 0.5 0.9

Description Parameters Units Range Typical

maximum specific sustrate

utilization rate k

g bsCOD/g

VSS.d4-12 6

half velocity constant Ks mg/L BOD 20-60 30

mg/L bsCOD 5-30 15

sysntesis yield coeficient Ymg VSS/mg

BOD0.4-0.8 0.6

mg VSS/mg

COD0.4-0.6 0.45

decay coeficient b g VSS/g VSS.d 0.06-0.15 0.1

Biokinetic parameter at T deg C

Biokinetic parameter at 20 C (Range of values)

Nitrification Flux (g NH4-N/sqm-

day)DO (mg/l)

Bulk liquid

NH4-N, mg/l

1.07 4 1

0.9 3 0.8

0.6 2 0.5

Pipe

Diameter

(inch)

Pipe Diameter

(mm)

Velocity

(m/min)

1-3 75-225 360-540

4-10 100-250 540-900

12-24 300-600 800-1200

30-60 750-1500 1100-2000

TABLE-2 AERATION TANK DESIGN DATA (NITRIFICATION FLUX IN BIOFILM)

However, Tender document

specifies 8 m/hr as max air

speed in aeration piping

TABLE-3 AERATION TANK DESIGN DATA (Design range of air veloicty in header pipe for Fine Bubble Membrane

diffusers )

WEF MOP & Reference: Metcalf & Eddy Edition-5, Table-9.25, Page-1007

Reference: Metcalf & Eddy Edition-5, Table-9.25, Page-1007



Sr

No.Parameter Value Unit Remarks

1 Flowrate 7.5 MLD

312.50 cum/hr






4 Influent COD 425

5 Effluent COD desired 50

BOD 250

TCOD in

nbsCOD

nbpCOD

TSS 375 As per tender document

VSS 365 Assumed

VSS_COD 0.125

nbVSS 25

TKN 50 Ammonia + Organic Nitorgen

NH4-N 45TP 7.1

Select SRT 8.1 days

Changed based on the nutrient removal

req; For BOD removal use 3-5 days & For

BOD + Nitrification use 8-10 days

Select X,TSS 3000 mg/l Change based on process ASP, SBR,

Extended aeration

Temperature (Min) 18 deg C

Temperature (Max) 35 deg C

BOD 10

COD 50

TSS 10

Total Nitorgen 10 TKN + Nitrates

Total Phophorous 2

NH4-N 1Lower than prescribed upper limit of 5

mg/l

Aeration tank

Design Parameters

Enter Wastewater characteristics

Enter Design parameter

Treated Sewage Quality

mg/l

mg/l





1-A

a Outlet BOD 0.375 mg/l

µmax, 20 deg C, g/g-d 0.90

Kn, mg/L 0.50

µmax theta 1.07

Kn, theta 1.00

bn, g/g-d 0.17

bn theta 1.03

Temperature, deg C 18.00

µmax, g/g-d 0.78

Kn 0.50

bn 0.16

DO 1.50 Choosing worst case scenario

Ko 0.50

Assumed effluent N, mg/L 0.50 Choosing lower than required effluent limit

µ, g/g-d for CSTR 1 stage 0.13

1 stg CSTR required SRT, days 7.51 days

SRT provided 8.10 days

b Initial Guess for Nox 34.92 mg/l Start with initial guess of 80% of TKN

c P_X,Bio,VSS Biomass Production

Heterotrophic Biomass Solids 754.80 kg/day

Non Biodegradable VSS in influent 101.747 kg/day

Nitrifier Biomass solids 17.08 kg/day

d Nox (Based on P_x, Bio) 35.03 First iteration

e P_X,Bio,VSS

Heterotrophic Biomass Solids 754.80 kg/day

Non Biodegradable VSS in influent 101.75 kg/day

Nitrifier Biomass solids 17.13 kg/day

f Nox (Based on P_x, Bio) 35.03 mg/l

CONVERGED

g P_X,Bio,VSS 873.7 kg/day

h P_X,VSS 1061.2 kg/day

i P_X,TSS 1290.4 kg/day Sludge production

Aeration tank size - BOD removal + Nitrification Single Stage

Design Calculations

Check what SRT is enough for complete

nitrification




Mass of VSS in aeration tank

j Mass of TSS in aeration tank 10451.9 kg

k Volume of Aeration tank 3484.0 cum Total for both the basins

Detention time (HRT) 10.62 hours Intermediate Average + Recirculated

F/M 0.22g BOD/g VSS

* d

0.15-0.25 as per Tender document clause

14.5.7 and MLVSS=0.8 MLSS

Number of aeration basin 2 nos

Side water depth of aeration

basin 5 m

Surface aera for each basin 348.4 sqm

Breadth of each aeration

basin 16.41 m

Length of each aeration basin 21.24 m

L/B ratio 1.29

1-B

a Active biomass 1549.8 mg/l Ref: Metcalf & Eddy Edition-4, Chapter-7,

Section-7.6, Page 592, Equation-7.42

b IR ratio

Recycle ratio operating normal 0.5

Recycle capcity provided 1 Times Q

Effluent Nitrates (Assumed) 8 mg/l Total Nitrogen effluent minus Ammonia

Nitrogen Effluent (2 mg/l)

IR (Iternal Recycle ratio)

required 2.88 Based on stoikiometry

IR capacity provided 4 Times QAs per tender document Volume-3A, part-

2, Clause-14.5

c Nox Feed to Anoxic tank

Nitrate concentration entering

via IR & R flow 8 mg/l

Total flowrate into anoxic tank 25340.63 cum/d (IR + R)*Q

Nox Feed to Anoxic tank 202725 g/d

d Anoxic tank volume

First iteration 2.5 h

Volume of anoxic tank 820.3125 cum

e F/M_b ratio 1.47 g/g-d

Denitrification Design

CHECKS




f rbCOD/bCOD 30.00 %

gSpecific Denitrification Rate

(SDNR) @ 20 C 0.27 g/g-d

Using Curve generated from ASM1 model

simulations; Ref from Metcalf & Eddy

Edition-4, Section-8.5, Page-754-755,

Figure-8.23; Considering F/Mb ratio

calculated above & rbCOD as 30%

(assumed as per literature review)

SDNR temp corrections 0.3 g/g-d

SDNR IR corrections Based on Metcalf & Eddy Edition-4, Section-

8.5, Page-756, Equation-8.45 & 8.46

If IR = 2 0.24 g/g-d

If IR =3-4 0.23 g/g-d

SDNR selected 0.23 g/g-d

h Amount of NO3-N reduced 296493 g/d

Amount feed/Amount reduced 0.68

Excess capacity 31.6 % Lower detention time can be used

New HRT as per excess

capacity 0.79 hr

Reducing the size of Anoxix tank by the

excess capacity

New HRT provided for re-

evaluation 1.5 hr SDNR will be higher for smaller HRT

Volume of Anoxic tank (both

basins) 492.19 cum Intermediate Average + Recirculated

F/M_b 1.29 g/g-d

New SDNR values based on the

methodology mentioned

before

0.36 g/g-d

SDNR temp corrections 0.3 g/g-d

SDNR IR corrections Based on Metcalf & Eddy Edition-4, Section-

8.5, Page-756, Equation-8.45 & 8.46

If IR = 2 0.33 g/g-d

If IR =3-4 0.32 g/g-d

SDNR selected 0.32 g/g-d

Amount of NO3-N reduced 234347.3 Based on new HRT

Excess capacity ratio 1.16

Excess capacity 15.60 %

Number of Anoxic tank

provided 2.00

Volume of each Anoxic tank 246.09 cum Intermediate Average + Recirculated

Breadth of Anoxic tank 4.6 m 1200.65325

SWD of Anoxic tank 5 m 1240.619029

Length of Anoxic tank 10.7 m 2812.5




L/B ratio 2.33 m

Anoxic zone mixing energy

required 10

kW/10^3

cum of tank

Anoxic zone mixing energy

required 2.46 kW per basin

3.30 hp

4.00 hp 1 in each basin

Internal recycle pump

sizing

IR fow rate required per basin 1414.06 cum/hr per basin (4 X Q X Peak + Reciiculated) /

number of basin

Pumping head required 8 mHeight of aeration tank + 2m as a factor

safety for head loss

Pumping power required 32.4 BkW

Efficiency of the pump 0.7 %

Shaft power required 61.98 hp

Shaft power required 46.24 kW @duty point metioned above

Shaft power provided 75 hpCheck with manufacturer data for a pump

match

1-C

Detention time 0.8 hours Flowrate 0.091 cum/sec As per average + Recirculated

Volume required 262.50 cum

Number of basins 2.00

Volume of each basin 131.25

SWD 5

Length 4.6

Breadth 5.7

Ratio 1.24

2-Aa Oxygen demand 2022.53 kg/day

Oxygen credit from

Denitrification 579.79 kg/day

Oxygen demand 60.11 kg/hr Considering denitrification

b Calculating SOTR Standard Oxygen Trasnfer Rate

EBPR or Phosphorous removal design

Aeration requirement -

Provide 1 nos (Working) + 1 nos (Standby) 75 hp Pumps for Internal recycle per basin




c Temperature of wastewater 35 deg-C

Based on Maximum wastewater

temperate in the influent parameter

section

d AOTR 60.11 kg/hr Actual Oxygen Trasfer Rate required

e C, 20 deg cel 9.09 mg/l From Saturation table

fC, t deg cel

8.3 mg/l From Saturation table and temp of ww

g C, tank 2 mg/l For ASP

hAlpha

0.6 Typical value : 0.65 OR based on tender

iBeta

0.95 Typical value : 0.95 OR based on tender

j F 0.8 Typical value : 0.9 OR based on tender

k Mid depth correction factor 0.4 0.25-0.4

l Depth of diffusers 4.8

m Temp correction 0.70

n Elevation of site 30 m As per site elevation from sea level

o Std barometric pressure 0.997 atm

p Saturated DO due to pressure

from water column 10.78 mg/l

q Standard Oxygen Trasnfer Rate 298.03 kg/hr

r Trasfer efficiency 0.24 fraction 5% per meter submergence @ 4.8 m

sWeight of Oxygen per cum of

air 0.27623

kg O2/cum-

air0.27623

u Normal Temperature 20 .

v Temperature of Air 49

wAir Flowrate required in terms

of NTP (AOTR) 4495.6 Ncum/hr

Discharge side capacity; Will be lower if

trasfer eff is higher

x C/S are of both aeration tank 697 sqm

y Air volume for mixing 6.5 cum/hr-sqm > 1.8-2.7 cum/hr-sqm as per tender

2-D TOTAL HEAD LOSSa Total head loss in piping 10.0 mm Ref 2-C-1,2,3

bTotal head loss in in Elbow,

Valves, Tee & Meteres 80.8 mm Ref 2-C-1,2,3

cTotal head loss in blower

assembly 0.0 mm Ref 2-C-4

dHead loss in fine bubble

diffuser250.0 mm As per manufacturer data

e Submergence head 4800.0 mm 200 mm diffuser height

f Head loss due to clogging 257.0 mm 5 % of a+b+c+d

Detailed Head loss calculation for the air piping & piping diameter is provided under 2-B , 2-C-1,2,3,4 in a

sperate worksheet




gTotal head loss across the

pneumatic system 5397.9 mm Desired blower pressure head required

SELECT BLOWER WITH :-Air Flowrate required 4495.6 Ncum/hr Discharge side capacity @ NTP

HEAD 5.40 m Submergence + Head loss in air piping

Inlet temp 322.15 K

Maximum assumed 49 C (for peak

estimate) as per tender notice Volume-3A,

Part-2, 5.1

Air flow @ Max Inlet

temprature 4940.29 cum/hr @ Max air temperature i.e. 49 C

Air flow @ 35 Inlet

temprature 4730.97 cum/hr @ Max air temperature i.e. 35 C

Density of air at 49 C 1.0914 kg/cum @ 49 C temp & 30 % Humidity

Weight of air flowrate 1.4977 kg/s @ Max air temperature i.e. 49 C

Universal gas constant 8.314 J/mole.K

Inlet temperature 322.15 K 49 dec C

Aboslute inlet pressure 0.98 atm

Absolute outlet pressure 1.52 atm

n 0.28

Molecular weight of dry air 28.97

Efficiency 0.75

Power requirement 86.6 kW Not actual motor rating

Power requirement 116.1 hp Not actual motor rating

Motor required as per Mfg.

datasheet 90.0 kW

Excess 112 kW 25% excess flow capacity

3-Ab Detention time 60 sec

c Volume required per CCT 11.979 cum As per intermedaite peak

d Side water depth 5 m

e C/S area 2.396 sqm

f Length 2.00 m

g Breadth 1.20 m

h Free board 0.5

3-B

a Detention time 60 sec

b Volume required 11.979 cum As per intermedaite peak

c Side water depth 4 m

d C/S of chamber 2.995 sqm

e Length 2.00 m

Outlet chamber

Inlet chamber




f Breadth 1.50 m

g Free board 0.5

4Flowrate (Intermediate

Average)0.182 cum/s

At intermediate average + recirculated

Flowrate (Intermediate Peak) 0.399 cum/sAt Intermediate peak +RAS + reciculated

Velocity required at peak flow1.1

m/s

0.6-1.2 m/s as per Tender document and

CPHEEO

C/S area of pipe 0.3630 sqm

Diameter 0.6800 m

Diameter (provided) 700.00 mm Standard size

Velocity at ultimate peak flow 1.04 m/sShould be between 0.6-1.2 m/s as per

CPHEEO

Velocity at intermediate

average flow 0.47 m/s

Should be between 0.3-1.2 m/s as per

CPHEEO

5HRT for Anoxic Zone 1.5

Check total HRT for Biological Treatment Units

Pipe from aeration tank to secondary clarifier





1 Flowrate 1.88 MLD 25 % of 7.5 MLD as per tender document

78.13 cum/hr 3






4Specific gravity of volatile

solids 1.00

5Specific gravity of fixed

solids 2.65

6Solids concentration in

sludge wasted 1 % w/w

7Specific gravity of 1% w/w

solids sludge 1.002

Based on Volatile Solids to Fixed solids ratio

of 70:30

1

aSludge wasting reqired per

day from SST 32.20 cum

Assuming 1 % w/w solid concentration and

1.002 sp gr

bSludge wasting as

percentage of total flow 0.43 %

Varied from 1-3 % depending on the SRT

and Secondary clarifier stability

c Fraction of volatile solids 0.7

d Fraction of fixed solids 0.3

eOverall specific gravity of

solids 1.23

fSpecific gravity of the

dewaterd sludge 1.04 20 % w/w

gVolume of Sludge after

dewatering to 20% w/w6.21 cum/day

hWeight of Sludge after

dewatering to 20% w/w6451.8 kg/day

iVolume of sludge drying

bed required for dewatering 24.84 cum

4 day drying cycle & 25% cacpcity as per

tender document

j SDB area required 82.81 sqm Considering 30 cm sludge layer depth for

optimum dewatering

k Length 10.00 m

l Breadth 8.28 m

Solids production & Sizing for sludge drying bed

Metcalf and Eddy Edition-5 Table 13-7 Page

1457

Metcalf and Eddy Edition-5 Table 13-7 Page

1457 OR TENDER DOCUMENT

Sludge Drying Bed

Design Parameters

Design Calculations





Number of sludge drying

bed 4

Length of each sludge

drying bed 8.3 m

mBreadth of each sludge

drying bed 2.5 m

nThickness of coarse sand

(Layer-1)0.3 m

oThickness of Broken stone

metal (Layer-2)0.075 m with size 25 mm

pThickness of Broken Stone

metal (Layer-4) 0.075 m with size 32 mm

qThickness of Broken Stone

metal (Layer-3) 0.075 m with size 75 mm

r Thickness of stone (Layer-4) 0.15 m with size 100-150 mm

sTotal height of Sludge

drying bed 1.275 m With 0.3 m Free board & 0.3 m Sludge layer





1 Flowrate 8.4 MLD

350.00 cum/hr






4 Aeration basin SOP 1.00 mg/l As per tedner document Clause 14.5.18

5 Plant effluent target SOP 0.25 mg/l As per tedner document Clause 14.5.18

6 Commercial Alum form

7 Purity of Alum 99 % As per tedner document Clause 14.5.18

8 Alum Soution strength 10 % As per tedner document Clause 14.5.18

9Alum Solution Design

Storage period 2 days As per tedner document Clause 14.5.18

10 Dry Alum Storage period 30 days As per tedner document Clause 14.5.18

1Metal to Initial Soluble

phosphorous ratio

(Me_dose : P initial)

2.60Based on Figure 6-13 (Sazabo et al), Metcalf

& Eddy Edition-5 Section 6-4

Aluminium dose required 1.70 mg/l

Al dose required per day 14.27 kg/day

Fraction Al in Alum 0.04 Alum Molar mass=666.5 g/mole

Alum required per day 352.5 kg/day

Alum solution required 3525.11 Litre/day Assuming 10% w/w solution

Alum solution storage

required 7050.22 Litre/day

No of Alum dosing tank

provided 2.00

Total volume required 14100.45 Litre Considering 2 day storage period

Vol of tank provided 7050.2228 Litre

Vol of each tank provided 7500 Litre

Design Calculations

Calculation of Alum dosing

Alum Dosing tank STP capacity 7.5 MLD (8.4 MLD Built out)

Design Parameters




2Alum storage required 10575.3 kg 30 day storage

Vol of alum 6.0 cum Assuming 1760 kg/cum of density

Height of storage area

required 2 m

Length of storage area

required 2 m

Breadth of storage area

required 1.50 m

Calculation of Alum storage area





1 Flowrate 7.5 MLD Intermediate average

312.50 cum/hr






4 Assumed RAS flowrate 1

fraction of

plant flow

rate

Maximum assumed for peak loading ; In

reality it would not exceed 0.5

1-A

a Solids loading rate 80 kg/sqm-dayAs per tender 25-120 kg/sqm-day for

average flow

bSurface area required as per

SLR590.63 sqm

Based on 100 % RAS flow rate and above

SLR

c Solids loading rate (Peak) 170 kg/sqm-day As per tender 170 kg/sqm-day for peak flow;

d Surface area required as per

SLR (Peak)625.37 sqm Based on 100% RAS + Peak & Recirculated

e Surface overflow rate 12cum/sqm-

day

As per tender document 8-12 cum/sqm-day

for average flow; As per CPHEEO Nov-2013

Section 5.7.4.2.5, Table 5.8, Page 5.53 8-15

cum/sqm-day for average & 25-35 cum/sqm-

day for peak;

fSurface area required as per

SOR656.25 sqm Average + Reciculated

g Surface overflow rate (Peak) 35cum/sqm-

day

As per tender document 25-35 cum/sqm-

day for peak; As per CPHEEO Nov-2013

Section 5.7.4.2.5, Table 5.8, Page 5.53 8-15

cum/sqm-day for average & 25-35 cum/sqm-

day for peak;

hSurface area required as per

SOR (Peak)506.25 sqm Peak + Recirculated

h Surface area selected 656.25 sqm Maxiumum of al of the above

i Number of clarifier 1

Tank sizing -As per conventional ASP

Secondary Clarifier

Design Parameters

Design Calculations





jSurface area of each

clarifier 656.25 sqm

k Diameter 28.92 m

n Side water depth (Sewage) 2.70 m

Sludge storage depth 0.30 m

Total SWD 3.00

OKBottom Slope 0.1 1:8 to 1:12 as per CPHEEO

Volume of each clarifier 1969.64 cum

HRT (Q+ RQ) 3.00 hrs For R=1, Considering RAS flow + Avg Q +

Recirculated

o Free board 0.5 m

p Total height 3.50 m

Total volume 2298.81 cum Including F.B

Check Weir loading rate 173.44 cum/m-day Should be <185 cum/day-m

OK

1-B1-B-1 Overflow in launder is from 1 side

a Flowrate 0.20 cum/s As per intermediate peak

b

Velocity of flow in the

launder to avoid deposition

of solids

1.00 m/s 0.6-1.2 m/s as per CPHEEO manual

c C/S area of flow 0.20 sqm

d Depth of flow 0.42 m

e Width of launder 0.48 m

f Width of launder provided 1.00 m

g Free fall provided 0.08 m

h Free Board 0.50 m

i Total depth of launder 1.00 m

jWidth of launder outlet to

Collection chamber 1.00 m

1-B-2

a Detention time 45 sec

b Volume required 8.98 cum As per intermediate peak

cSide water depth of outlet

chamber 2.70

m


>3-3.5 As per CPHEEO Nov-2013 Section

5.7.4.2.5, Table 5.8, Page 5.53

Secondary clarifier detailing Launder

Outlet chamber




e Length 1.83 m

f Breadth 1.83 m

g Free board 0.5 m

1-B-3

Bottom Slope 0.10 As per CPHEEO manual 1:8 to 1:12

A 3.50 m Including 0.5 m F.B.

B 1.80 m 0.5 clearance around central shaft

C 1.00 m

D 2.36 m

E 1.36 m

F 13.56 m

1-B-4

Flowrate 0.399 cum/s As per intermediate peak + 100% RAS

Velocity required 0.9 m/s AS per CPHEEO and tender document

C/S area 0.444

Diameter required 0.752 m

Diameter provided 0.8 m

1-B-5

Diameter of feed well 4.34 m10-20 % of tank diameter as per CPHEEO

Page 5-58 Section 5.7.4.2.7 Nov,2013

Height of feed well 2 m1-2 m as per CPHEEO Page 5-58 Section

5.7.4.2.7 Nov,2013

Downward velocity 0.01 m/s

CHECK velocity OKNO specifications in CPHEEO; <0.75 m/s as

per Metcalf and Eddy Edition-5, Page-387,

Section-5.6

Secondary clarifier dimensions

Clarifier

Feed Well

Central shaft of Clariflocculator




1-B-6

Velocity provided @

intermedate peak flow +

100% RAS

0.25 m/s

0.1-0.25 m/s as per CPHEEO Page 5-58

Section 5.7.4.2.7 Nov,2013 ; 0.75 m/s at

peak flow and 0.3-0.45 m/s at average flow

as per Metcalf and Eddy Edition-5, Page-

387, Section-5.6

Area of outlet ports or slots 1.5972 sqm

Number of ports 3

Area for each port 0.5324 m

Length of each port 0.800 m

Breadth of each port 0.670 m

Total of breadth for all ports 2.010 m

Spacing bewteeen each port 0.126 m o/o distance; Should not be negative

Height of ports from water

level 0.3 m 0.3-0.6 from water level as per

Distance between the lower

feed port level and depth of

feedwell

0.900 mNo specification in CPHEEO; Ideally around 1

m to prevent short circuting

2-A

a Slude RAS flow per clarifier 0.20 cum/sec As per intermediate peak + 100% RAS

b Velocity of flow in pipe 1.20 m/s

cC/S area of sludge removal

pipe 0.17 sqm

d Diameter 0.460 m As per CPHEEO sludge pipe should be

minimum 150 mm in dia

11.69 inch

e Diameter provided 0.5 m

f C/S area 0.2 sqm

gVelocity during peak

flowrate 1.02 m/s 100 % RAS of 2.25 Peak Flowrate

hVelocity during 50% RAS of

Average flowrate 0.23 m/s

Assuming 50% RAS flowrate; Should be 0.3-

0.6 m/s as per CPHEEO manual

i Velocity during 30 % RAS 0.14 m/s Assuming 30% RAS flowrate; Should be 0.3-

0.6 m/s as per CPHEEO manual

hAt 50 % RAS flow of Average

flow

Intermittent

RAS flow

Regulation

required

Sludge piping (Secondary Clarifier to RAS sump)

Discharge ports on central column




iAt 30 % RAS flow of Average

flow

Intermittent

RAS flow

Regulation

required

hRAS flow duration per hours

@ 30% RAS flowrate16.72 min/hr

Assuming a 0.5 m/s flow velocity ; This can

be also modified in terms of min/30 min,

min/20 min and so on based on the RAS

MLSS & Flowrate conditions

hRAS flow duration per hours

@ 30% RAS flowrate27.87 min/hr

Assuming a 0.5 m/s flow velocity ; This can

be also modified in terms of min/30 min,

min/20 min and so on based on the RAS

MLSS & Flowrate conditions

2-B

aVolume of sludge to be

widrawn per day128.78 cum/day

b Velocity of flow in pipe 1 m/s Valve controlled


pipe 0.001490 sqm


Minimum 150 mm in dia

1.11 inch Not as per standards


As per CPHEEO sludge pipe should be

Minimum 150 mm in dia & Tender Clause

13.1.15 Page 27 Vol lll Part-2

f C/S area 0.03 sqm

g Flowrate 2713.0 cum/day

1.9 cum/min

hWAS pumping duration per

4 hours 11.39 min

This can be modified as per the operator

requirement

WAS flow in each release 21.46 cum

WAS flowrate in each

release 113.04 cum/hr

WAS flow velocity in the

RAS pipe 1.00 m/s 0.6-1.2 as per CPHEEO manual

3-A

RAS flow required actually 359.4 cum/hr 50% RAS at intermedaite average flow for

both bains



Sludge piping for WAS to Sludge thickner (Via T junction from Pumped RAS line to Aeration

tank)

Electro-mechanical equipment sizing for RAS pump




Pumping power required 7.98 BkW Actual for both basins

Efficiency of the pump 0.9 %Lower efficiency assumed; in reality it is

around 70-85 %


Shaft power provided 12.5 hpThis wil be the average power consumption

for RAS for both basins

Max RAS flowrate required

per basin 359.4 cum/hr

As per 100% RAS of intermedaite peak per

basin

Pumping head required 8 m


Efficiency of the pump 0.75 % Efficiency assumed 70-85 %


Shaft power provided 15 hp Higher as a factor of safety

3-B-1

Flowrate required 41.0 cum/day

3.414 cum/hr 12 hours of operation




Efficiency of the pump 0.4 %Lower efficiency assumed due for Scre

Pump


Shaft power provided 1 hpCheck with manufacturer data for a pump

match

3-B-2Piping-1 from Sludge

Thickner to Thickned sludge

sump

200 mmMinimum size selected based on CPHEEO

Sludge gravity line

Piping-2 from Thickned

sludge sump to centrifuge 200 mm

As per teder document pumped line should

be >=200 mm as per Clause 13.1.15 Page 27

C/S are of pipe -2 0.031 sqm

Velocity 0.03 m/s Minimum velocity for sludge line should be

0.6 m/s

Decrease line

size

Electro-mechanical equipment sizing for WAS screw pump (From Sludge thickner to

Centrifuge)

Piping after Thickner

Provide 1 W + 1 S, 15 hp Pump per basin for RAS pumping

However, RAS flow capacity to be provided is as per 100% of Influent (Peak) flow rate

Installed Max capacity




5Detention time (of 100 %

RAS ratio)0.5 hr

As per tender document Clause 14.5.14

Page 39 Vol lll Part-2

Volume 164.1 cum As per average + Reciculated flow

Diameter 10.1 m As per tender document Clause 14.5.14


Surface area 80.1 sqm

Height 2.0 mAs per tender document Clause 14.5.14


If rectangle

Length 10.0 m

Breadth 8.01 m

4

Solid loading rate 30 kg/sqm-d

Daily Sludge production 1290 kg/day in TSS

Surface area as per SLR 43.0 sqm As per Daily Sludge production

Diameter 7.4 m

Check Hydraulic loading 0.7 m3/m2-day Should be <4-8 cum/sqm-day as per Metcalf

& Eddy; Edition-4, Page 1492

Depth of Thickner

Assumed depth of thickning

zone 1.5 m

Volume of Sludge blanket 64.5 cum

Amount of Solids in

thickening zone as per 3%

Solids w/w

1993.6 kg

Quantity of solids held in

thickening zone 1290.4 kg/day

SRT in Thickening zone 1.5 days

SVR in Thickening zone 0.60.5-2 as per as per Syed Qasim Edition-2,

Page 654

Clear liquid zone 1 m0.5-1 m as per Syed Qasim Edition-2, Page

665

Settline zone 2 m1.5-2 m as per Syed Qasim Edition-2, Page

665

Thickening zone 1.5 m0.5-1 m as per Syed Qasim Edition-2, Page

665

Total liquid depth 4.5 m

Gravity thickner

RAS sump




Bottom Slope 0.17 m2:12 or 3:12 as per Syed Qasim Edition-2,

Page 655

Bottom Slope 0.17

A 4.50 m

B 1.00 m 0.5 clearance around central shaft

C 0.75 m

D 0.95 m

E 0.20 m

F 1.21 m

6

HRT required 10 hrs

Volume of thickened

sludge produced per day

after gravity thickening

41.76 cum 3% thickening assumed and 1.03 sp gr

Hours of operation for

Thickened Sludge

Pumping station

12 hr/day

Averaged flow rate

considering above hours

of operation

3.48 cum/hr

Volume of Thickened

sludge sump 34.8 cum

SWD of sump 2 m Limited to 2 m as per tedner document

C/S Area of sump 17.4 sqm

Diameter 4.7 m

if rectangle

Length 5

Breadth 3.48 m

say 3.5

Thickned Sludge sump

Gravity thickner dimension




6Flowrate (Average) 0.09 cum/sec Intermedaite average + Recirculated

Flowrate (Peak) 0.200 cum/sec Intermedaite peak + Recirculated

Velocity required at peak

flow1.2 m/s


CPHEEO

C/S area of pipe 0.17 sqm

Diameter 0.460 m

Diameter (provided) 500.00 mm Standard size

Velocity at peak flow 1.02 m/sShould be between 0.6-1.2 m/s as per

CPHEEO

Velocity at average flow 0.46 m/sShould be between 0.3-1.2 m/s as per

CPHEEO

Pipe from each secondary clarifier to chlorine contact tank





1 Flowrate 7.5 MLD

312.50 cum/hr






4Coliform count after

aeration tank 1000000 per 100 ml

Adapted from Metcalf and Eddy Table 12-13

Edition-4 & US EPA Design Manual

5Required coliform count

after chlorination 80 per 100 ml As per tender document

Reduction required 99.99 %

6Residual chlorine

requirement 1 mg/l As per tender document

1-Aa Detention time at peak 14 min At intermediate peak

b

Volume required for peak

flow rate for both CCT

compartments

167.71 cum

c Retention time as per

avergae + Recirculated 30.67 min > 30 min at average flow

dSide water depth of chlorine

contact tank 2.2 m

e Surface area 76.2 sqm

f Number of compartments 2.0

gSurface area for each

compartment 38.1

h Length 6.20 m 12.4

i Breadth 6.20 m

n Ratio of length/breadth 1.00

oNumber of baffles along the

length 5

Baffle will divide along the length mentiond

in 1-A-h

p Spacing between the baffles 1.0 m

q Pass width 1.0 m

Chlorine contact tank

Design Parameters

Design Calculations

Chlorine contact tank size





s Effective L/W ratio 41.0

> 8 Approaches plug flow as per Table 5.13,

Page 5-79, Chapter-5, CPHEEO Manual Nov,

2014 Edition; Around 40 as per tender

document

t Total travel length 42.4 m

1-Ba Detention time 45 sec

b Volume required per CCT 8.98 cum

c Side water depth 2.2 m

d C/S area 4.084 sqm For each CCT

e Length 2.03 m For each CCT

f Breadth 2.03 m For each CCT

g Free board 0.5

1-Ba Detention time 45 sec

b Volume required 8.98 cum

cSide water depth of outlet

chamber 2.2

m


e Length 2.03 m

f Breadth 2.03 m

g Free board 0.5

2

Fraction removal desired 0.00008Ratio of Coliform remaining to initial

coliform

n (slope of inactivation

curve)2.8

Based on coefficient based on Metcalf and

Eddy Section 12-3 Edition 4

b (intercept of inactivation

curve) 4

Based on coefficient based on Metcalf and

Eddy Section 12-3 Edition 4 ; For coliform 4

and for feacal coliform 3

Ct (dosage X contact time)

value 116.2 mg-min/l Based on Colins selleck model

Chlorine dosage required 3.87 mg/lBased on 30 min contact time; Actual

contact time is higher for safer side

Collection chamber / Outlet chamber

Inlet chamber

Chlorine dosing required




3a Summer temperature 28 deg C 22000

b Winter temperature 10 deg C

Activation energy at pH Value Unit

7 34,340

8.5 26,800

9.8 50,250

10.7 62810

c pH of wastewater assumed 8

dContact time required in

Summer 9.63 min

Based on Vant Hoff's Arrhenius Equation &

Peak flow detention time

eContact time required in

Winter 23.03 min

Based on Vant Hoff's Arrhenius Equation &

Peak flow detention time

fChlorine dosage required in

summer 1.22 mg/l Excluding the residual chlorine requirment

gChlorine dosage required in

winter 2.91 mg/l Excluding the residual chlorine requirment

hChlorine demand due to

decay 2

i

Total Chlorine dosage

required in summer (Peak

demad)

4.22 mg/l Including residual + Demand due to decay

j

Total Chlorine dosage

required in winter (Peak

demand)

5.91 mg/l Including residual + Demand due to decay

kTotal chlorine required daily

(Summer)31.62 kg/day

lTotal chlorine required daily

(Winter)44.31 kg/day

m 15 day storage for (Summer) 474.3 kg

n 15 day storage for (Winter) 664.7 kg

oNumber of toner units

required 1 unit/ 15 day Assuming standard size of toner as 990 kg

p Standby toner unit 1 unit/ 15 day As per tender document

Change in chlorine dosage required due to change in hypothetical contact time

Impact of temperature on Chlorine dose

J/mole




4

Length of Chlorine toner 2.2 m As per standard dimensions of 990 kg toner

Diameter of Chlorine toner 0.8 m As per standard dimensions of 990 kg toner

Number of toner required 2

Spacing between tonner 1 m

Area required by the toner 7.92 sqm including 0.25 m spacing on all 4 sides

Area required by chlorine

dosing assembly 7.5 sqm

Extra area required for

shower, emergency

netralization tank etc.

2.64 sqm

Total area requried 18.06 sqm

Length of Chlorine room 5.00 m

Breadth of Chlroine room 3.70 m

Height of Chlorinator room 4.5 m

5

aFlowrate (Intermediate

Average)0.0911 cum/s

Considering Return flow ; Ref Secondary

Clarifier Calculations

bFlowrate (Ultimate Peak) 0.224 cum/s

Considering Return flow ; Ref Secondary

Clarifier Calculations

c

Velocity required at peak

flow1

m/s


CPHEEO

d C/S area of pipe 0.2236 sqm

e Diameter 0.5337 m

f Diameter (provided) 600.00 mm As per tender document

gVelocity at peak flow 0.79 m/s


CPHEEO

hVelocity at average flow 0.32 m/s


CPHEEO

Length of Chlorine tank 12.40 m

Breadth of chlorine contact

tank 6.20 m

Summary

Chlorine room

Pipe from CCT Outlet chamber to Outfall




Side water depth of Chlorine

contact tank 2.20 m

Free Board 0.5 m

Number of baffles 5

Spacing between the baffles 1.0 m

Total travel length 42.36666667 m

Ratio of L/B 2.00

Chlorine required per day 44.31 kg Maximum required (In winter)

Chlorine required per cum 5.91 g/cum Maximum required (In winter)

Chlorine required per MLD 5.9 kg/MLD Maximum required (In winter)





1 Flowrate 7.5 MLD

312.50 cum/hr






1 TSS generation 1290.35 kg/day

2 Percentage solids 1.00

3Actual WAS flow required

based on TSS generation 5.4 cum/hr Based on 1% w/w solids concentration

4 Percentage of Average flow 1.72 % Of Average flow

5 Percentage of Average flow 1.89 %10% factor of safety as per tender document

page 49Section 14.10.6

6Choosing worst case

scenario 5 %

More than 10% factor of safety over the

WAS flow

7 Recirculation sump flow 15.63 cum/hr

8 Dentention time 10 min As per tender

9 Volume of sump 2.60 cum

10 Volume of sump provided 3.5 cum

Depth 1.5 mAs per tender document page 49Section

14.10.6

C/S area 2.3

Length 1.60

Breadth 1.46

say 1.5

Design Calculations

Drain Sump STP capacity 7.5 MLD (8.4 MLD Built out)

Design Parameters


Prepared by:



Item No Equipment Name Working

Units

Efficiency of

Equipment

(%)

B kW for

operatio

n

Motor-

Efficiency

(%)

Motor Rating (kW)

(For effective power

consumption- Not

actual motor rating)

Actual Total

Motor rating

(hp)

Operating

Hours

(h/day)

Total Power

Consumption

(kWh/day)

1 Mechanical Fine screen 1 90 1 98 1.1 1.5 12 13.6

2 Belt Conveyor 1 90 0.5 98 0.6 0.5 1 0.6

3 Grit Collector (Scraper) 2 80 0.45 98 1.1 1.5 12 13.8

4 Grit Clasiffier 2 90 0.45 98 1.0 1.0 6 6.1

5 Organic Return Pump 2 90 0.5 98 1.1 0.5 0.5 0.6

6 Anaerobic tank mixer 2 90 0.65 98 1.47 2.0 12 17.7

7 Anoxic tank mixer 2 90 1 98 2.3 4.0 12 27.2

8 Process Air blower 1 70 36 98 52.5 150.0 24 1259.5

9 RAS pump 2 90 2.7 98 6.1 30 24 146.9

10 WAS Screw Pump 1 50 0.44 98 0.90 1.00 2 1.8

11 Internal Recycle 2 90 9 98 20.4 150.0 24 489.8

12 Secondary Scraper 1 90 0.9 90 1.1 1.5 24 26.7

13 Dewatering unit 1 70 10 80 17.9 2 35.7

14 Agitator PE preparation 1 90 0.5 90 0.6 0.5 0.5 0.3

15 PE pump dosing 1 90 0.5 90 0.6 2 1.2

16 Pump chlorine booster 1 90 0.65 90 0.8 1.0 24 19.3

17 Lighting 15.0

18 Auto valves/ Sluice gate 15 90 1 90 16.7 1.0 0.5 8.3

19 EOT cranes

20Other miscellaneous

load 10.0

TOTAL 346.0 2094.1

Power Calculations

Calculation by: Urv Patel

Prepared by:



279.2077

Calculation by: Urv Patel




1 Flowrate 7.5 MLD

312.50 cum/hr






Max dosing 10.00 mg/l

Max Chlorine requirement

per day 75.0 kg/day


per MLD 10.00 kg/ML


per cum10.00 g/cum

TSS generation 1290.35 kg/day

DWPE required per ton dry

solids 2.0 kg/ton

DWPE required per day 2.58 kg/day

DWPE required per MLD 0.34 kg/MLD

DWPE required per cum 0.34 g/cum

Alum required per day 352.51 kg/day For detailed calculation please see Alum

Dosing Calculation

Alum required per MLD 47.00 kg/MLD

Alum required per cum 0.047 kg/cum

DWPE requirement

Alum requirement

Chemical Calculations STP capacity 7.5 MLD (8.4 MLD Built out)

Design Parameters

Chlorine requirement



Consultants Engineers 29-08-18

Qmin Qmax W A B (min) C D F G K Z

0 5 75 460 450 175 255 150 300 25 56

5 30 150 610 600 315 391 300 600 75 113

30 170 225 865 850 375 566 300 750 75 113

45 250 300 1350 1322 600 831 600 900 75 225

170 250 450 1425 1397 750 1010 600 900 75 225

250 350 600 1500 1472 900 1188 600 900 75 225

350 500 900 1650 1619 1200 1547 600 900 75 225

500 700 1200 1800 1766 1500 1906 600 900 75 225

700 850 1500 2100 2060 2100 2625 600 900 75 225

850 1400 2400 2400 2353 2700 3344 600 900 75 225

As per CPHEEO Nov-2013 Edition Page 5-46 Table 5.7 Section 5.6.2.8.1

Flowrate capacity (MLD) Dimensions in mm

PARSHALL FLUME DESIGN DATA



Sr

No.Parameter Value Unit Remarks

2-B

Air flow per diffuser 9.0 Ncum/hr 5-12 Ncum/hr as per specification

Number of diffuser required

per each basin 250.0 nos for each basin

Diameter of diffuser 65.0 mm As per manufacturer

Length of diffuser 1000.0 mm As per manufacturer

Diffuser in each row & column

if the grid is square 15.8

Diffusers along the row 3.0 Along the breadth

Diffusers along the column 13.0 Along the length

Number of columns 3.0

Number of diffuser per column 13.0

Spacing between diffuser

along each column 1.3 m

Spacing between diffuser

along each row 4.1 m Should not be negative

OK

2-C2-C-

1Horizontal diffuser header 1st stage piping laterally along the grid

aNumber of diffuer in each

header16

b Air flow in each header 144.0 Ncum/hr

c Pipe diameter 3.0 inch

0.0762 m

d Velocity 526.5 m/min

Should be between 360-540 m/min for pipe

diameter between 1-3 inch as per Metcalf &

Eddy Edition-5, Table 5-29, Page 435

Head loss calculation

e f (friction factor) 0.023765

f D (Diameter) 0.0762 m

g Q (Air flowrate) 2.4Ncum/mi

n

h L (Length of pipe) 21.4 m Change according to difusser configuration

i P (Air supply pressure) 1.5 atm Atmospheric pressure + Depth of water

column

Aeration- Air piping head loss

Aeration- Air Piping

Air piping system - Extension from Aeration tank calculation sheet

Design Parameters





jHead loss as per Darcy-

Weishbach 1.52 mm

k Number of Elbow 2.00

l Number of Tee 16.00

m Head loss due to Elbow 3.12490 mm

n Head loss due to Tee 50.00 mm

2-C-

2

Header pipe connecting 2

stage-1 pipe Stage-2 line

aNumber of diffuer in each

header32



0.1016 m





e Head loss calculation

f f (friction factor) 0.0216

g D (Diameter) 0.1016 m

h Q (Air flowrate) 4.8Ncum/mi

n

i L (Length of pipe) 10.62 m Along the breadth

j P (Air supply pressure) 1.5 atm Atmospheric pressure + Depth of water

column

kHead loss as per Darcy-

Weishbach 0.65 mm

l Number of Elbow 1.00

m Number of Tee 1.00

n Head loss in Elbows 2.52 mm

o Head loss in Tees 2.52 mm

2-C-

3

Header pipe connecting

Stage 2 head with Tee and

combining with piping from

second rank

Stage-3 line

aTotal number of diffuser in the

main header32



0.1016 m












n

i L (Length of pipe) 20.0 mChange according to difusser configuration

& Blower Location


column


Weishbach 1.23 mm





2-C-

4

Header pipe connecting

Stage 3 pipes from both

aeration tank

Stage-4 line

aTotal number of diffuser in the

main header64



0.1016 m









n

i L (Length of pipe) 30.0 mChange according to difusser configuration

& Blower Location


column


Weishbach 6.64 mm





2-C-

4

Head loss in blower

assembly




a Air filter losses 40.0 mm

13-76 mm as per Wastewater Treatment

Plant by S.Qasim Second Edition, Table-13-

15, Page-514

b Silencer losses 13.0 mm

13-38 for centrifugal & 152-216 as per

Wastewater Treatment Plant by S.Qasim

Second Edition, Table-13-15, Page-514

c Check valve losses 100.0 mm

20-203 mm as per Wastewater Treatment

Plant by S.Qasim Second Edition, Table-13-

15, Page-514

2-D TOTAL HEAD LOSS

a Total head loss in piping 10.0 mm Ref 2-C-1,2,3

bTotal head loss in in Elbow,

Valves, Tee & Meteres 80.8 mm Ref 2-C-1,2,3

cTotal head loss in blower

assembly 153.0 mm Ref 2-C-4

dHead loss in fine bubble

diffuser250.0 mm As per manufacturer data

e Submergence head 5000 mm

f Head loss due to clogging 274.7 mm 5 % of a+b+c+d

gTotal head loss across the

pneumatic system 5768.5 mm Desired blower pressure head required





From To

1 Pumping Station Inlet Chamber 500 306 DI K9 As per tender

2Inlet Chamber By-

PassDischarge invert 600 50 RCC NP2

Combines with

common by pass

3Parshall Flume By-

PassDischarge invert 600 75 RCC NP2

4Distribution

chamber Aeration tank

None; Directly

connected via

channel

5 Aeration tank Secondary Clarifier 700 25.0 DI K9

6Aeration tank By-

PassDischarge invert 600 25.0 RCC NP2

7 Secondary Clarifier Chlorine Contact tank 500 20 DI K9

8Chlorine Contact

tank Discharge invert 600 2600 RCC NP2

1 RAS Sump Anoxic tank-1 300 55 DI K9

As per peak

intermediate per

basin

2 RAS Sump Anoxic tank-2 300 60 DI K9

As per peak

intermediate per

basin

3 Aeration tank-1 Anoxic tank-1 600 30 DI K9

As per peak

intermediate per

basin

4 Aeration tank-2 Anoxic tank-2 600 30 DI K9

As per peak

intermediate per

basin

5 Seondary clarifier RAS Sump 500 20 DI K9

7 RAS Sump Gravity Thickner 200 5 DI K9

8 Gravity Thickner Thickned Sludge Sump 200 5 DI K9

9Thickned Sludge

Sump Centrifuge 200 10 DI K9

Sludge & Return piping

Hydrualic & Sludge Piping for STP

Pipeline connecting Sr No.

Diameter

(mm)

Approx.

Length

(m)

STP 7.5 MLD (8.4 MLD Built out)

MOC Remarks

Hydraulic piping





From To

1 Pumping Station Inlet Chamber 0

2 Inlet chamber Bypass 450X450 1 Sluice gate

3 Inlet chamber Screen Channel 450X450 2 Sluice gate

4 Screen Channel Grit chambers 450X450 4 Sluice gate

5 Parshal Flume Bypass Channel 450X450 1 Sluice gate After Grit chamber

6Distribution

chamber

Biological treatment

unit450X450 2 Sluice gate

7 Primary Clarifier Sludge bleed tank 0 NA

8Primary Clarifier

sludge bleed tank Sludge sump 0 NA

9Primary Clarifier

drainage 0 NA

10

Aeration tank

Distribution

chamber

Outlet chamber 450X450 1 Sluice gate By-pass

11 Air line Aeration tank 200.00 2 Butterfly Isolating airflow to

each basin if required

12Aeration tank

Sludge Sludge sump 450.00 0 Sluice valve

Only applicable for

SBR type plant

13 Aeration tank Anoxic tank 600.00 2 Sluice valve For both the basin

14 Aeration tank Anaerobic tank Sluice valve For both the basin

15 Blower Aeration tank 300.00 4 Butterfly 2+2

16 Blower Aeration tank 300.00 4 NRV 2+2

17 Secondary clarifier RAS bleed 500.00 1Telescopic

arrange-ment

18 Seondary Clarifier RAS Sump 500.00 1 Sluice valve

19 RAS Sump Gravity Thickner 200.00 1 Sluice valve

20 RAS Sump Anaerobic tank 300.00 2 Sluice valve For both basin

21 RAS Sump Anoxic tank Sluice valve For both basin

22 RAS pumps 150.00 8 Sluice valve Isolation 4 for each

set per basin

23 Gravity thickner Thickned sludge sump 200.00 1Knife gate/

Sluice valve Due to thicker

24Thickened Sludge

sump Centrifuge 50.00 4 Sluice valve

isolation for

Centrifuge feed

pump

Gates & Valves STP 7.5 MLD (8.4 MLD Built out)

Sr No. Flow

Size Number Type Remarks





25CCT distribution

chamber 450X450 2 Sluice gate NA if only 1 CCT

26DWPE dosing

system

Centrifuge & Thickened

Sludge Sump 12.70 12 Ball valve 3 inch manual

27Alum dosing

system

Post Aeration Outlet

chamber 12.70 12 Ball valve 3 inch manual

Valve/Gate Number

Sluice gate 13

Sluice valve 2

Sluice valve 4

Sluice valve 10

Sluice valve 10

Sluice valve 4NRV 4

Butterfly 4Butterfly 2

Ball valve 24 12.70

300.00

300.00

50.00

300.00

300.00

200.00

Size (mm)

450X450

600.00

200.00





2 Parameter Value Unit Remarks

1 Flowrate 7.5 MLD

312.50 cum/hr



Average flowrate +

Recirculated 0.09 cum/s



1 Flowrate 8.5 MLD

354.17 cum/hr



Average flowrate +

Recirculated 0.10 cum/s



1 By-pass line From all applicable units

Design Flow 0.23 cum/s Ultimate peak

C/S velocity 1.0 m/s

C/S area required 0.23 sqm

Diameter 0.537 m

Diameter provided 600 m

MOC RCC NP2

2Distribution chamber to

aeration tank

3 Aeration tank to SST

Design Flow 0.40 cum/s Ultimate peak



Diameter 0.651 m

NO pipe, directly connected to aeration tank via channel

Design Calculations

Ultimate

Intermediate

Piping calculation STP capacity 7.5 MLD (8.4 MLD Built out)

Design Parameters





MOC DI K-9

4 SST to CCT Secondary clarifier to Chlorine Cont Tank

Design Flow 0.20 cum/s Intermediate peak



Diameter 0.460 m


MOC DI K-9

5 Aeration tank to Anoxic

Design Flow 0.40 cum/s Intermediate peak per basin X 4



Diameter 0.582 m


MOC DI K-9

6 SST to RAS sump With telescopic arrangement

Design Flow 0.200 cum/s AS per 100% of intermedaite peak



Diameter 0.48 m


MOC DI K-9 m

7RAS pump to Anaerobic

tank 1 line for each basin

Design Flow 0.100 cum/s Intermediate peak per basin



Diameter 0.29 m


MOC DI K-9 m

8

aVolume of sludge to be

widrawn per day128.78 cum/day

b Velocity of flow in pipe 1 m/s Valve controlled

Sludge piping for WAS to Sludge thickner (Via T junction from Pumped RAS line to Aeration

tank)





pipe 0.001490 sqm


Minimum 150 mm in dia

1.11 inch Not as per standards


As per CPHEEO sludge pipe should be

Minimum 150 mm in dia & Tender Clause

13.1.15 Page 27 Vol lll Part-2

f C/S area 0.03 sqm

g Flowrate 2713.0 cum/day

1.9 cum/min

hWAS pumping duration per 4

hours 11.39 min

This can be modified as per the operator

requirement

WAS flow in each release 21.46 cum

WAS flowrate in each

release 113.04 cum/hr

WAS flow velocity in the RAS

pipe 1.00 m/s 0.6-1.2 as per CPHEEO manual

9

Piping-1 from Sludge

Thickner to Thickned sludge

sump

200 mmMinimum size selected based on CPHEEO

Sludge gravity line




be >=200 mm as per Clause 13.1.15 Page 27



0.6 m/s Decrease line

size




be >=200 mm as per Clause 13.1.15 Page 27,

However 200 mm size contradicts with

minimum velocity criteria



0.6 m/s OK

Gravity thickner to Thickned Sludge Sump

Name of Work: 7.5 MLD Dhandhuka, Ahmedabad District ; Client: … · 2018-11-15 · n, Manning Coefficient 0.013 Value for concrete Available velocity 0.670 m/s Wetted perimeter 1.59

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