KING INSTITUTE, GUINDY, FOR 1927-28
47
TABLE I1.—Analyses of Septic Tank effluents, Engineering College— cont.
Period III—December 1926 to March 1927.
Time of stay of sewage in the tanks— 12 hours.
N u m b e r .
Source.
Date.
Ammonia-
cal
nitrogen.
Albumi -
noid
nitrogen.
Oxygen
absorbed
in 4 hours.
1927.
1 5
Open tank .,,-,
•••
4414
...
12th January
...
SOS
1.08
0.29
1.65
Closed tank ...
...
...
Do.
..•
...
1.19
0.24
1.57
16
Open tank ...
•••
l ••
...
19th January
...
1,111
1.08
0.20
1.29
Closed tank ...
0,1
1,11
...
Do.
...
•••
1.00
0.16
1.27
1 7 Open tank ...
•••
•••
•••
20th January
...
.•.
1.44
0.36
1.08
Closed tank -
•••
•••
•••
Do,
•••
1.20
0.33
1.68
I
18
Open tank ...
...
... 21st January
...
,„
0.96
0.29
1.32
Closed tank ......
-..•
..
Do.
•••
•••
0.88
0.18
1.38
19
Open tank ...
...
...
25th January
...
123
1 . 1 2 . 0.22
1.52
Closed tank ...
•••
•••
...
Do.
...
...
1 . 2 8 0.16
1.62
20
Open tank ...
•••
...
... 26th January
...
.1.9
1.10
0.16
1.50
Closed tank ...
.••
6•4
Do.
•••
•••
1 . 1 2 0.18
1.52
21
Open tank ...
•••
•••
...
3rd February ...
..•
1.28
0.26
1.81
Closed tank ...
I 40
Do.
...
•••
1.41
0.26
1.77
f
22 Open tank ...
•••
••.
... 4th February -
•••
1 . 0 1 0.22
1.58
Closed tank -
•••
...
...
Do.
...
...
1.15
0.24
1.62
23
Open tank •..
•••
•••
... 8th February ...
•••
1.76
0 26
1.77
Closed tank ...
6941
.,.•
Do.
•••
...
1 . 7 7 0 24
1.96
24
Open tank ...
•..
...
• el
9th February ...
•..,
1.12
0 24
1.69
Closed tank ...
•••
••.
Do.
...
•••
1 . 4 1 0.23
1.84
25
Open tank ...
•••
...
- 10th February ...
.-
1 . 2 0 0.22
1.67
Closed tank ...
...
4•4
•••
Do.
-
•••
1 . 1 2 0.22
1.84
r
26 Open tank ...
.••
.„ 11th February ...
•••
1.36
0.28
1.67
Closed tank -
•.•
..•
...
Do.
...
1 . 2 8 0.22
2.07
27
Open tank ...
...
... 15th February ...
a • e
0.94
0.28
1.66
Closed tank ..,
•••
••.
...
Do.
„.
•..
0.90
0.30
2.38
28 Open tank ...
944
4"
22nd February _
•••
1.30
0.20
1.71
••••
Closed tank ...
.••
...
Do.
...
1 . 3 2 0.27
1.82
29 Open tank ,...
•••
25th February ,.. •
...
1.63
0.26
1.96
Closed tank ,..
•••
•••
,..
Do.
...
...
1 76
0 26
1.98
30
Open tank ...
,.,.
..•
.,.
4th March
••.
...
1 . 0 8 0.28
1.66
Closed tank ...
•••
...
...
Do.
•••
0.90
0.22
1.55
31
Open tank ...
...
•••
9.13
9th March
••,1
•••
1 . 0 1 0.22
1.70
Closed tank ,..
•••
Do.
...
0.96
0.20
1.70
32
Open tank ...
...
... 16th March
...
...
0.88
0 14
1.48
Closed tank -
•••
...
•••
Do.
...
•••
0.80
0.26
1.57
33
r Open tank ...
•••
004
17th March
...
0.83
0.18
1.45
...
Closed tank ...
-
...
Do.
...
•••
...
0.88
0.20
1.45
34 I Open tank ...
4,4
•••
.04
18th March
-
0.88
0.20
1.77
Closed tank -
-
...
.•.
Do.
...
0 88
0.20
1.73
35 I Open tank ...
...
•••
... 22nd March
-
...
0.88
0.22
1.71
Closed tank ...
.••
•••
-
Do.
...
••.
0.86
0.16
1.70
36 I Open tank ...
•••
...
- 24th March
•••
..„
0.90
0.22
1.80
1 Closed tank ...
•••
-
...
Do.
...
••.
0 88
0.18
1.89
„
3`r
Open tank ,..
494
25th March
...
•••
0.96
0.16
1.70
Closed tank ...
t••
•••
•••
Do.
.••
0.88
0.18
1.66
38
I Open tank ...
.••
••• 29th March
•••
•••
0.90
0.24
1.80
I. Closed tank ...
...
...
•••
Do.
•••
P••
1.04
0.22
1 96
39
Open tank -
...
•••
... 31st March
•••
"4
1.08
0.16
1.69
Closed tank ...
n ••
•••
9.1
Do.
000
9•4
0.92
0.14
1.73
Source.
Ammoniacal
nitrogen.
Albuminoid
nitrogen.
Oxygen
absorbed
in 4 hours.
Percentage of
purification
in the tanks,
based on
albuminoid
nitrogen.
Average.
Open tank
...
11.14
• • •
0.99
0.22
1.49
0 • •
Closed tank ...
•••
• • I
0.96
0.20
1.59
.•.
Average for the whole year.
Time of stay varied from 24 to 12 hours.
Total number of paired observations for the tanks—104.
Open tank
...
...
...
0.84
0.18
1.23
41.9
Closed tank ...
...
...
0.79
0.16
1.25
48.4