Biology Reference
In-Depth Information
1.E+00
Fraction of input m as s
that e xited the colum n
UCFL-71 4.5.E-06
UCFL-94 2.E-01
UCFL-131 <1.E-06
UCFL-167 <1.E-06
UCFL-263 <1.E-06
UCFL-348 n.d.
1.E-01
1.E-02
1.E-03
UCFL-71
UCFL-94
1.E-04
UCFL-131
UCFL-167
UCFL-263
UCFL-348
1.E-05
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01 1.E+00 1.E+01
Α
i
(-)
Fig. 4.2b:
retained bacteria, as fraction of input mass (
F
) and corresponding sticking
efficiency for the AGW experiments. Solid lines indicate fitted power law
distributions.
Furthermore, in DI, the fractions were relatively close to each other (roughly between 0.001 and
0.3), while in AGW, there appeared to be a fraction close to 1 with a high sticking efficiency,
and a very small fraction (roughly between 10
-2
and 10
-6
) with lower sticking efficiencies (0.1-
the column, without being retained. For the DI experiments, this fraction was 0.001 to 0.36;
indicating that 0.1-36% of the bacteria mass in the influent suspension must have had an
Α
value less than the lowest
Α
values determined for the most distant column segments.
For the AGW experiments, the
E. coli
fraction leaving the column without being retained varied
between less than 10
-6
and 0.2 (UCFL-94), indicating that, generally, removal of the
E. coli
mass, with concentrations around 1-7×10
5
cells/mL was complete, while for one strain (UCFL-
94) still 20% of the bacteria cells of the influent suspension must have had a sticking efficiency
less than 0.001.
4.3.3 Sticking efficiency distributions
Exponential, power-law and logarithmic distributions were used to fit the relation between
F
and Α
(
Table 4.2
,
Figures 4.2a
and
b
)
. In DI water,
R
2
-values for all exponential distribution fits
were below 0.8, ranging from 0.28 (UCFL-94) to 0.67 (UCFL-131). In addition, the
R
2
-values
were statistically insignificant (
p
-values > 0.05) with the exception of UCFL-131 (
p
= 0.02) and
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