Environmental Engineering Reference
In-Depth Information
100
Abiotic column
Biotic column
80
Epibon Y12×40 GAC
(Donau carbon)
T = 285K/pH~7
Anaerobic conditions
O
N
60
S
N
H
S
40
O
20
0
FIGURE 11.10
A comparison of front velocities in the “biotic” and “abiotic” columns. Front velocities are
defined as the mass-loaded activated carbon per time (in mg/h). Front velocities obtained from
nine concentrations in maximum were found to be linear within the run period for both col-
umns (98 days). Error bars are uncertainties of the slope of the velocity functions. A fast break-
through for phenol and benzene was found and the front velocities of both compounds were
obtained only from two concentrations. See text for the definition of velocities used.
were comparable and it was not possible to detect differences for any com-
pound within the statistical uncertainties. Nevertheless, for the “abiotic col-
umn” any potential biological degradation was inhibited as discussed in
the experimental section. Hence, processes on this column, although using
real groundwater, are not influenced by degradation reactions of micro-
organisms, and pure adsorption was observed. The order of compounds,
sorted by front velocities and presented in Figure 11.10 was used to rank all
compounds (see Table 11.5) with respect to their adsorption behavior.
Qualitatively and as assumed from their adsorption parameters, phenol
and benzene were the worst-adsorbing compounds (see order in Table 11.5),
and pyrene and fluoranthene were the best. The worst-adsorbing heterocy-
cles were benzofuran (O-heterocycle), benzothiophene (S-heterocycle), and
isoquinoline (N-heterocycle). Unfortunately for many of the compounds,
Freundlich parameters
N
and
K
were not determined in this study and are
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