Table 3.6 Summary of BOD removal characteristics of various media treating settled wastewater
Description
Specific
surface
ft
2
/ft
3
Temperature
range
C
Influent
BOD range
mg/L
Depth
ft
Hydraulic
loading
range mgad n
a
K,
a at
20
C
1 1/2 in.
flexi rings
40.0
2–26
65–90
8
12.5–26.9
0.39
0.46
1 in.
clinker
61.5
7–17
220–320
8
0.96–1.2
2.56
0.865
2 1/2 in.
clinker
37.4
7–17
220–320
6
0.96–1.2
0.84
0.685
1 in. slag
60.0
7–17
220–320
6
0.96–1.2
0.30
0.865
2 1/2 in.
slag
33.0
7–17
220–320
6
0.96–1.2
0.75
0.640
1 in. rock
43.3
7–17
220–320
6
0.96–1.2
2.36
0.74
2 1/2 in.
rock
27.6
7–17
220–320
6
0.96–1.2
3.80
0.645
1 in.
rounded
gravel
44.5
7–17
200–320
6
0.96–1.2
3.00
0.625
2 1/2 in.
rounded
gravel
19.7
7–17
220–320
6
0.96–1.2
5.40
0.57
Surfpac
28.0
24
200
21.6
31–350
0.50
0.395
Surfpac
28.0
24
200
12
62–250
0.45
0.33
2 1/2 and
4 in. rock
filter
15.0
24
200
12
31–94
0.49
0.275
1 1/2 and
2 1/2 in.
slag
42.0
7-I 7
112–196
6
5–12.5
1.0.
0.87
1 to 3 in.
granite
29.0
16–18
186–226
6
2–16
0.4
0.312
3/4 in.
Raschig
rings
75.8
16–18
186–226
6
2–16
0.7
0.55
1 in.
Raschig
rings
52.2
16–18
186–226
6
2–16
0.63
0.42
1 1/2 in.
Raschig
rings
35.0
16–18
186–226
6
2–16
0.306 0.28
2 1/4 in.
Raschig
rings
22.7
16–18
186–226
6
2–16
0.276 0.25
Straight
block
28.2
16–18
186–226
6
2–16
0.345 0.2
a n and K are constants for Eq. (3.31); m is equal to 1
3 Biological Processes
135