The most significant increase of the degree was observed after the NANOFER
STAR application. There was a short increase of the degree of dechlorination in
boreholes AW5–57 (25%), AW5–58 (17%), during the first 7 days. After 1 week,
the degree of dechlorination decreased slowly. In the borehole AW5–58, the rising
trend lasted up to 28 days when the degree increased to 66% from previous 46%
before the injection. Overall, the values of the degree remained above the
pre-application values for 2 months, which reflects the duration of the process of
dechlorination.
In contrast, there were no signs of the ongoing process of dechlorination after the
NZVI-C3 application. It seems that it was caused by the inhibition when the
contaminant was adsorbed on carbon coat of the particles. Therefore, no products
of dechlorination emerged.
Not very strong increase in the degree of dechlorination lasting up to 20 days was
shown after the NANOCOMPOSITE with CMC. The addition of CMC into the
suspension of nZVI, which prevents iron from oxidation, probably decreased the
reactivity of the particles. Longer but less intensive course of the degree of dechlorination was observed. Therefore, the process of dechlorination was probably present
in the subsurface but was not as striking as it was after the previous injection of bare
NANOFER STAR nZVI.
5.5 Conclusions
Three separate nZVI applications determined remedial potential of particular materials. The NANOFER STAR nZVI application, which caused the temporary reduction of 39%, was considered the most efficient. It proved the applicability of
NANOFER STAR nZVI for remediation of ClE. NANOFER STAR application
showed a very high reductive potential on TCE (decrease of 84%) and VC (decrease
of 60%) throughout the whole pilot test.
The NZVI-C3 material showed its ability for ClE dechlorination, especially by
sorption on carbon. The process of sorption increases the applicability of this method
in sites contaminated by pollutants that need more complex method of remediation
such as heavy metals. The addition of CMC into the suspension of nZVI leads to the
improvement of mobility of nZVI particles but also deterioration of reductive
potential of nZVI due to occupation of its surface by CMC. Therefore, CMC cannot
be recommended as a convenient and economical stabilizer especially in case of
relatively expensive nZVI.
References
Adetutu EM, Gundry TD, Patil SS, Golneshin A, Adigun J, Bhaskarla V, Aleer S, Shahsavari E,
Ross E, Ball AS (2015) Exploiting the intrinsic microbial degradative potential for field-based in
102
V. Stejskal and N. Vacková
STAR application. There was a short increase of the degree of dechlorination in
boreholes AW5–57 (25%), AW5–58 (17%), during the first 7 days. After 1 week,
the degree of dechlorination decreased slowly. In the borehole AW5–58, the rising
trend lasted up to 28 days when the degree increased to 66% from previous 46%
before the injection. Overall, the values of the degree remained above the
pre-application values for 2 months, which reflects the duration of the process of
dechlorination.
In contrast, there were no signs of the ongoing process of dechlorination after the
NZVI-C3 application. It seems that it was caused by the inhibition when the
contaminant was adsorbed on carbon coat of the particles. Therefore, no products
of dechlorination emerged.
Not very strong increase in the degree of dechlorination lasting up to 20 days was
shown after the NANOCOMPOSITE with CMC. The addition of CMC into the
suspension of nZVI, which prevents iron from oxidation, probably decreased the
reactivity of the particles. Longer but less intensive course of the degree of dechlorination was observed. Therefore, the process of dechlorination was probably present
in the subsurface but was not as striking as it was after the previous injection of bare
NANOFER STAR nZVI.
5.5 Conclusions
Three separate nZVI applications determined remedial potential of particular materials. The NANOFER STAR nZVI application, which caused the temporary reduction of 39%, was considered the most efficient. It proved the applicability of
NANOFER STAR nZVI for remediation of ClE. NANOFER STAR application
showed a very high reductive potential on TCE (decrease of 84%) and VC (decrease
of 60%) throughout the whole pilot test.
The NZVI-C3 material showed its ability for ClE dechlorination, especially by
sorption on carbon. The process of sorption increases the applicability of this method
in sites contaminated by pollutants that need more complex method of remediation
such as heavy metals. The addition of CMC into the suspension of nZVI leads to the
improvement of mobility of nZVI particles but also deterioration of reductive
potential of nZVI due to occupation of its surface by CMC. Therefore, CMC cannot
be recommended as a convenient and economical stabilizer especially in case of
relatively expensive nZVI.
References
Adetutu EM, Gundry TD, Patil SS, Golneshin A, Adigun J, Bhaskarla V, Aleer S, Shahsavari E,
Ross E, Ball AS (2015) Exploiting the intrinsic microbial degradative potential for field-based in
102
V. Stejskal and N. Vacková