14.2.3 Pilot Field Ex Situ Application
Ex situ pilot validation of the obtained laboratory results was carried out in the area
of Czech chemical factory, where the groundwater was strongly contaminated with a
wide range of organic contaminants. The most important contaminants were as
follows: aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes) and chlorinated aromatic hydrocarbons (chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene). During the initial monitoring process physicochemical
analysis of raw groundwater was carried out and the key parameters were determined
(Table 14.1). The list of detected contaminants and their concentration levels before
the tests are given in Table 14.2.
The pilot application to the target locality as a container test (i.e., ex situ
treatment) was carried out in July 2014 using a 1000 liters intermediate bulk
container (IBC) made of high-density polyethylene. The container was filled with
900 L contaminated groundwater pumped out from a borehole located in the area of
chemical factory surrounding. The whole pilot test consisted of three application
steps:
1. 350 g of commercial ferrates (% 0.4 g/L % 34 mg Fe
VI /L) was applied into the
container and the content was then mixed for 15 min.
2. After reduction of all dosed ferrates (visible detection by changing color of water
from violet to orange), the first dose of hydrogen peroxide with a volume of 4.5 L
(% 5 mL/L) was applied. The content of the container was subsequently mixed at
30-min intervals.
3. Four hours after the first application of hydrogen peroxide, the second dose of the
same amount 4.5 L H 2 O 2 (%5 mL/L) was applied.
Table 14.1 Qualitative parameters of the raw groundwater
Parameter
Value
Unit
pH
6.29
Conductivity
4270
μS/cm (20
C)
Acid-neutralizing capacity (ACN 4.5 )
10.09
mmol/L
Chemical oxygen demand (COD Cr )
1090
mg/L
Biochemical oxygen demand (BOD 5 )
551
mg/L
Total hardness
8.05
mmol/L
NH
4+
37.8
mg/L
Total inorganic nitrogen
10.66
mg/L
Sulfates
855
mg/L
Chlorides
504
mg/L
Nitrates
<3.0
mg/L
Nitrites
<0.10
mg/L
Phosphates
2.92
mg/L
Mineralization
3537
mg/L
Halogenated organic compounds (AOX)
6.42
mg/L
14 Field Study V: Combined Oxidation Technology Using Ferrates (Fe
IV–VI
). . .
319
Ex situ pilot validation of the obtained laboratory results was carried out in the area
of Czech chemical factory, where the groundwater was strongly contaminated with a
wide range of organic contaminants. The most important contaminants were as
follows: aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes) and chlorinated aromatic hydrocarbons (chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene). During the initial monitoring process physicochemical
analysis of raw groundwater was carried out and the key parameters were determined
(Table 14.1). The list of detected contaminants and their concentration levels before
the tests are given in Table 14.2.
The pilot application to the target locality as a container test (i.e., ex situ
treatment) was carried out in July 2014 using a 1000 liters intermediate bulk
container (IBC) made of high-density polyethylene. The container was filled with
900 L contaminated groundwater pumped out from a borehole located in the area of
chemical factory surrounding. The whole pilot test consisted of three application
steps:
1. 350 g of commercial ferrates (% 0.4 g/L % 34 mg Fe
VI /L) was applied into the
container and the content was then mixed for 15 min.
2. After reduction of all dosed ferrates (visible detection by changing color of water
from violet to orange), the first dose of hydrogen peroxide with a volume of 4.5 L
(% 5 mL/L) was applied. The content of the container was subsequently mixed at
30-min intervals.
3. Four hours after the first application of hydrogen peroxide, the second dose of the
same amount 4.5 L H 2 O 2 (%5 mL/L) was applied.
Table 14.1 Qualitative parameters of the raw groundwater
Parameter
Value
Unit
pH
6.29
Conductivity
4270
μS/cm (20
C)
Acid-neutralizing capacity (ACN 4.5 )
10.09
mmol/L
Chemical oxygen demand (COD Cr )
1090
mg/L
Biochemical oxygen demand (BOD 5 )
551
mg/L
Total hardness
8.05
mmol/L
NH
4+
37.8
mg/L
Total inorganic nitrogen
10.66
mg/L
Sulfates
855
mg/L
Chlorides
504
mg/L
Nitrates
<3.0
mg/L
Nitrites
<0.10
mg/L
Phosphates
2.92
mg/L
Mineralization
3537
mg/L
Halogenated organic compounds (AOX)
6.42
mg/L
14 Field Study V: Combined Oxidation Technology Using Ferrates (Fe
IV–VI
). . .
319