8 Reappraisal of Permeable Reactive Barrier as a Sustainable …
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boiled for 10 min, after the mixture of immobilised biochars with SRM was used as
PRB filler.
The development in the field of reactive materials synthesis is continuously taking
path ahead. The reactive fillers are now composed of layers of different adsorbent
materials, composites of multiple compounds and so on. There have been many new
green materials and green technologies which are and will continue to remediate
the contaminants from groundwater (Kumari et al. 2017). Several of these materials
tested at batch scale are i) removal of Cr by Mn powder from battery waste solution
(Kumari et al. 2018b) ii) remediation of E. Coli. by Ag nanoparticles by corn cob silica, and to name few technologies i) vermicomposting for Cu and Zn removal (Gogoi
et al. 2015) ii) fouling control with the help of pre-oxidation combined with coagulation (Deka et al. 2020). The given Table (8.4) shows different PRB materials for
different contaminants found in the groundwater, both geogenic and anthropogenic.
8.9 Case Studies and Economic Viability
The case studies are very limited in developing countries than the developed ones.
McGovern et al. (2002) designed and built a funnel and gate PRB for remediating
the petroleum hydrocarbon (toluene, ethylbenzene, xylene, alkanes) in southeastern
Australia. After an operation period of ten months, ‘peat’ was proved to be effective
reactive material with a removal efficiency of 72% overall. Germany was among the
few countries which adopted PRBs without any further delay between years 1998–
2001 (Birke et al. 2003) which also includes world’s largest funnel and gate system
PRB installed at Edenkoben with six gates with the length being approximately
450 m. Wantanaphong et al. (2005) studied a wide range of reactive materials both
natural and waste materials including (i) clinoptilolite (ii) calcified seaweed granules
(iii) crushed cocoa shell iv) chitin shells (v) fly ash, and the surface area was found
to be maximum in flash powder. The order of the efficiency of these materials in
removing the metals Pb, Cd, Zn and Cu was fly ash > chitin > clinoptilolite > calcified
seaweed > clay soil > cocoa shell. Several new materials are also making their way
to reactive materials. Conca and Wright (2006) used a new material as a PRB filler
called Apatite (II) Ca 10−x Na x (PO4) 6−x (CO 3 ) x (OH) 2 where x < 1, and this material
is derived from fishbone waste and has been found to be better than the phosphate
rocks, cow bones, various zeolites, ZVI filing, manures, etc. Conca (1997). The
change in concentration in entering and exiting the PRB was quite noticeable, and
the PRB has concealed over 45 kg of Cd, 91 kg of Pb, 4550 kg of Zn over five
years. Indraratna et al. (2014) studied the remediation of acidic groundwater with
the help of PRB in Shoalhaven floodplain at Sydney, Australia. Here, they used
recycled concrete aggregates as PRB filler. This was the first study to the real-time
monitoring and evaluation of PRB in the remediation of acidic groundwater. The
governing equations used were encapsulated with the software like MODFLOW.
Loss in hydraulic conductivity was observed at the entrance of the PRB due to the
formation of metal precipitates. Twenty-two full-scale PRB projects were running
197
boiled for 10 min, after the mixture of immobilised biochars with SRM was used as
PRB filler.
The development in the field of reactive materials synthesis is continuously taking
path ahead. The reactive fillers are now composed of layers of different adsorbent
materials, composites of multiple compounds and so on. There have been many new
green materials and green technologies which are and will continue to remediate
the contaminants from groundwater (Kumari et al. 2017). Several of these materials
tested at batch scale are i) removal of Cr by Mn powder from battery waste solution
(Kumari et al. 2018b) ii) remediation of E. Coli. by Ag nanoparticles by corn cob silica, and to name few technologies i) vermicomposting for Cu and Zn removal (Gogoi
et al. 2015) ii) fouling control with the help of pre-oxidation combined with coagulation (Deka et al. 2020). The given Table (8.4) shows different PRB materials for
different contaminants found in the groundwater, both geogenic and anthropogenic.
8.9 Case Studies and Economic Viability
The case studies are very limited in developing countries than the developed ones.
McGovern et al. (2002) designed and built a funnel and gate PRB for remediating
the petroleum hydrocarbon (toluene, ethylbenzene, xylene, alkanes) in southeastern
Australia. After an operation period of ten months, ‘peat’ was proved to be effective
reactive material with a removal efficiency of 72% overall. Germany was among the
few countries which adopted PRBs without any further delay between years 1998–
2001 (Birke et al. 2003) which also includes world’s largest funnel and gate system
PRB installed at Edenkoben with six gates with the length being approximately
450 m. Wantanaphong et al. (2005) studied a wide range of reactive materials both
natural and waste materials including (i) clinoptilolite (ii) calcified seaweed granules
(iii) crushed cocoa shell iv) chitin shells (v) fly ash, and the surface area was found
to be maximum in flash powder. The order of the efficiency of these materials in
removing the metals Pb, Cd, Zn and Cu was fly ash > chitin > clinoptilolite > calcified
seaweed > clay soil > cocoa shell. Several new materials are also making their way
to reactive materials. Conca and Wright (2006) used a new material as a PRB filler
called Apatite (II) Ca 10−x Na x (PO4) 6−x (CO 3 ) x (OH) 2 where x < 1, and this material
is derived from fishbone waste and has been found to be better than the phosphate
rocks, cow bones, various zeolites, ZVI filing, manures, etc. Conca (1997). The
change in concentration in entering and exiting the PRB was quite noticeable, and
the PRB has concealed over 45 kg of Cd, 91 kg of Pb, 4550 kg of Zn over five
years. Indraratna et al. (2014) studied the remediation of acidic groundwater with
the help of PRB in Shoalhaven floodplain at Sydney, Australia. Here, they used
recycled concrete aggregates as PRB filler. This was the first study to the real-time
monitoring and evaluation of PRB in the remediation of acidic groundwater. The
governing equations used were encapsulated with the software like MODFLOW.
Loss in hydraulic conductivity was observed at the entrance of the PRB due to the
formation of metal precipitates. Twenty-two full-scale PRB projects were running