Design of Activated Sludge for Current Plant
I. Basic Data
1 Flow and loads for each line
number of lines
DWF average
DWF peak
maximum flow (3 lines)
total flow (flow in three lines)
2 Concentracions
COD
BOD
TKN
TP
TSS
3 Load
COD
BOD
TN
TP
SS
Unit
m3/h
m3/h
m3/h
m3/d
Wastewater Septic sludge
1
1
17.5
10
21
12
21
12
504
295
mg/l
mg/l
mg/l
mg/l
mg/l
827
414
77
12
336
2,347
704
140
25
1,261
kg/d
kg/d
kg/d
kg/d
kg/d
417
209
39
6
169
693
208
41
7
372
II. Mixed WW Fraction
Fraction
1 Inert solids
Unit
Value
FXI kgCOD/d
KgVSS/d
MXI KgVSS
305.01
206.09
618.27
Fsbi kgCOD/d
MXB KgVSS
556.06
332.78
2 Biomas
3 Endogenous residue
MXEH KgVSS
83.58
MXv KgVSS
1034.63
TSS KgVSS
ISS KgTSS
1513.69
479.06
4 Total VSS
5 Total TSS
III. Activated Sludge
MLSS (Xt)
Volume
mgTSS/L
Kg TSS/m3
m3
3500
3.5
137
graph
calculated
IV. Secondary Clarifier
BOD
Surface loading rate
Flow
Area
Diameter
No. of tanks
mg/l
m/h
m3/d
m2
m
unit
V. Sludge Production
TSS = 0.6TSS
BOD*0.6/(1+bh*SRT)
Sludge production
Wastage
Sludge concentration
VI. Sludge Drying Bed
Bed productivity
Batch Load
Safety factor
Sludge layer depth
Total bed area
Bed volume
drying cycle
521
0.87
799
38
7
1
calculated
graph
calculated
calculated
calculated
calculated
Kg TSS
Kg TSS
Kg TSS
kg/day
Kg TSS/m3
908
139
1,047
348.6
10.0
calculated
calculated
calculated
calculated
selected
kg/m2/d
kg/m2
1.5
30
1.2
0.3
279
84
20
selected
selected
selected
selected
calculated
calculated
calculated
m
m2
m3
days
1.20
1.10
surface loading rate (m/h)
1.00
100
0.90
125
150
0.80
175
200
0.70
0.60
0.50
0.40
3.0
3.5
4.0
4.5
MLSS (g/l)
5.0
5.5
Design Parameters
Temperature C
fcv
kgCOD/KgVS
Yhs
bh
fH
Rs
d
fi VSS/TSS
Sludge With the book data
COD
Particulate
Unbiodeg.
0.4
Biodeg
0.3
Total
0.7
VSS/TSS
0.57
23
1.48
0.45
0.419
0.200
3
Soluble
Total
0.3
0.0
0.3
Wastewater with the book data
COD
Unbiodeg.
Biodeg
w average
Particulate
Soluble
0.15
0.07
0.78
VSS/TSS
0.68
VSS/TSS
0.75
0.7
0.3