Environmental Engineering Reference
In-Depth Information
16 EPA-PAH
N,S,O-
heterocycles
Other PAH
BTEX, indane,
indene, TMB
2.6%
0.9%
Gate 4 and 5
effluent concentration
<1% of influent
96.5%
Sum each: 2 μg/L
Gate 5
influent
Sum: 245 μg/L
4.5%
6%
0.5%
6%
95.1%
23%
65%
AB12
Gate 4
influent
Sum: 325 μg/L
Sum: 9979 μg/L
FIGURE 13.5
Aerial view and overview of the cleanup performance of the Karlsruhe F&G according to
the latest monitoring campaigns conducted by the RUBIN R&D program between 2007 and
2009. Upstream concentration values are given on the right (influent), and downstream results
are given in the box on the left (effluent). A very good retardation efficacy/cleanup perfor-
mance regarding all contaminants of concern is verified. (Courtesy by Leuphana University of
Lueneburg, Professor Dr. W. Ruck, Dr. W. Palm.)
confirmed in an on-site pilot-scale study performed with a sedimentation
tank (removal of ferric iron), and two bioreactors in which it was found that
more than 99.5% of the pollutants were degraded. This biodegradation activ-
ity corresponded well with a significant increase in the growth of the rel-
evant bacteria. The repeated addition of moderate concentrations of H
2
O
2
produced a more favorable result compared with the addition of high con-
centrations at a single dosing port and one point in time only. The modular
design of the pilot-scale Bio-PRB equipped with three separated bioreactors
is in accordance with the guideline concept for EC-PRBs that requires access
to the reactors in the event of malfunction. An effective distribution of the
water over the entire bioreactor length and depth was accomplished by an
open water area. Within this, the groundwater flow is guided to a connect-
ing pipe. The lamella separator is needed to achieve the sedimentation of
precipitated iron. The construction of the pilot Bio-PRB at Offenbach initially
caused a heavy disturbance to the local hydrogeochemical conditions. About
1 year after its erection, this disturbance had more or less disappeared. A zone
with reduced hydraulic conductivity in the outflow of the system caused a
significant reduction in the groundwater flow through the reactive zone: this
varied from 30% to 65% of the expected value. The problem was successfully
addressed by amending some design features. The devices for injecting H
2
O
2
and nutrients did not work well during the first phase of the testing period
(unstable dosage rates and several pump failures were encountered). The
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