Influence of Mechanical Blending on Aerobic Digestion
423
100,
CD
z
z
<
Έ
UJ
rr
ω
if)
>
4 0
2 0
u
Control, kc* 0 0 3 3 4 day*
1
Blended , k - 0 0 3 8 5 day
D
VSS m g / l
SS m g / l
Blended,
2335
4918
t - ·
Control ,
2 6 0 4
Sludge Blended - lmin.~
G = 3 3 9 3 sec
5265
Twice/Day
-I
Aeration Rate »0-66
scfm
* — #
^
12
DAYS
Fig. 2
Typical auto-oxidation and settleability of sludge.
between 0.1 and 0.66 scfm had changed correspondingly the DO concentration but
showed no significant effect on the rate of auto-oxidation. Therefore, for present work a
medium aeration rate of 0.30 scfm was used.
Observations
The kinetic expression for aerobic biodegradation in endogenous phase can be
represented by the following equations (Loehr 1965):
d S
= - b S
(2)
dt
or
S
= e .-bt = io-kt
(3)