Environmental Engineering Reference
In-Depth Information
0.9
0.8
0.7
0.6
MOS1 _Channel max
0.5
MOS2_Channel max
0.4
MOS3_Channel max
0.3
ScCell1_Channel max
0.2
ScCell2_Channel max
0.1
0
Figure 13.5d. Syringe 4: sludge with TYG (1:100),
Klebsiella mobilis
1/1000, gas mixture 2/3 N
2
and
1/3 air. See Fig. 13.5a for explanations.
Table 13.3. Bacterial densities after 9.5 hours of cultivation in the PMEU Scentrion®.
Klebsiella
sp.
Escherichia coli
Aerobic
Microaerobic
Aerobic
Microaerobic
10
8
10
7
10
8
10
8
a
1
×
5
×
1
×
1
×
2
×
10
8
<
1
×
10
7
1
×
10
8
1
×
10
7
b
10
8
10
8
10
7
10
7
c
1.5
×
1
×
<
1
×
<
1
×
10
9
10
8
10
7
10
7
d
1.5
×
4
×
<
1
×
<
1
×
used washing water was derived from a circulated system after the biological purification, and
still contained organic materials. This kind of application suggests that various wastewaters could
be combined with biomass raw materials in order to achieve correct water densities as well as
suitable carbon and energy sources for the exploited microflora. The growth of microbes was
not inhibited by this liquid matrix, as indicated by Table 13.3 summing up the levels of
Kleb-
siella
sp
.
and
Escherichia coli
amongst variable mixed microflora. The a-d refer to cell densities
corresponding to Figure 13.5 as measured by colony counts on CromAgar™ medium.
13.9 THERMOPHILIC PROCESSES
As generally understood on the basis of thermodynamics, any chemical reaction is speeded up as
the temperature is rising up. In biotechnology, this requires often the selection of new production
organisms. However, because of the nature of the biological systems it is not always that simple
to achieve the improvements. The entire process has to be considered in the planning of the
manufacturing of the fuels or bulk chemicals. This includes the resistance to heat or the product
by the facilities, as well as the ability of the organism to exploit the particular raw materials
available. In all cases the overall biotechnological principle of three fundamentals has to be taken
into account, and none of them should be developed independently, namely (i) the choice of micro-
organism, (ii) understanding its physiology, and (iii) the reactor design including the downstream
processing. In a comparative study by the Finnish Environment Institute regarding the methane
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