592
Discussion
Also for the production of gas,volatile acids and the gas/volatile acids - ratios are the following
functions developed:
° ·
0 5 4
(lg/l.d)
(3)
g
VA
g/VA
0.054 e 0.921 . L + e -0.309 . L
=
Q.Q4
0.04 + e -
0 ·
8 3 3 ·
L
= 1 4 . 0 e -
7 0 1 2 '
V A
(g VA/l.d)
dg/g · VA)
(4)
(5)
The combination of equations 4 and 5 gives:
0 5 6 e . 7 . 0 1 2 . VA
g
=
0.04+ e "
0 ·
8 3 3
L
(lg/l.d)
(6)
Equation 6 gives the gas production as a function of the BOD-load and production of volatile acids,
which is also distinguished by the BOD-load.
Oba = O b z ( l
0.5
0.0053 . e ° ·
7 8 3 ·
L + e - ° ·
6 3 3 ·
L
(g/D
(7)
As the BOD-carbon - ratios increase rapidly with growing loadings great quantities of carbon causing
the BOD must be incorporated in the volatile acids.
High Rate Digestion.
The data summarized in table 4 are converted in the same way as before.
BOD-load L g/O bz /l.d
gas production g lg/l.d
volatile acids VA gVA/l.d
g/VA - ratio lg/gVA
BOD-removal gOb/l.d
carbon in gas gC/l.d
BOD/carbon ratio gO b /gC
2.0
1.639
0.106
5.462
1.919
0.877
2.188
2.5
2.184
0.143
15.273
2.410
1.169
2.062
3.2
2.804
0.180
15.578
3.070
1.501
2.045
3.5
0.824
0.308
2.675
2.758
0.441
6.254
The corresponding equations are given below:
0.054
e - ° -
5 5 7 L + 0 . 6 1 1 . 1 0 -
1 4 . e
9 -
2 1 L
(lg/l.d)
(8)
VA
0.0241
0.04 + e - ° ·
8 3 3 ·
L
(g VA/l.d)
(9)
g/VA
14
e -1.727 . VA + 4 4 3 1 0 -3 e 23.026 . VA
(lg/gVA)
(10)
Introduction of equation 9 and 10 will give:
0.337
(0.04 + e -
0 ·
8 3 3 - L) ( e -1.727 . VA + 4 4 3 1 0 -3 e 23.026 . VA }
(lg/gVA)
(11)