17 Scope of Conventional Versus Advanced Technologies …
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17.3.4 Clay Minerals
Clay is another material which has found application as an adsorbent in removal
of ECs. The characteristics of clay as an adsorbent material govern the efficiency
of the removal process, through adsorption. Similar types of clays have different
removal efficiencies, and this depends on the presence of specific amount of iron or
other minerals and nitrogen content (Rahardjo et al. 2011). The above fact has been
proven by the studies undertaken by Wu et al. (2010 and 2012a, b), in which 35%
and 100% removal of ciprofloxacin has been reported by the use of montmorillonite
(MMT) clay as an adsorbent. This difference in removal efficiency was attributed to
the source of the clay material. The cation exchange capacity (CEC) of adsorbent
materials also plays an important role in their adsorption capacity, and these (CEC)
values can be modified by impregnating with different ions to enhance the performance and selectivity of the clays (Parolo et al. 2012 and Zhao et al. 2012). The
use of such approaches can demonstrate promising results, but need further thorough investigations as the fate of the contaminants and mechanisms involved in their
remains is largely unknown.
17.3.5 New Adsorbents
Several other new adsorbent materials have been developed for removing of ECs
from contaminated waters. These include microporous materials, resins, oxides of
metals, zeolites, etc. (Ahmed et al. 2015 and Hou et al. 2010). The structure of
these adsorbent materials produces a significant effect on the adsorption/removal
efficiency of the adsorbents. An example of this is the study conducted by Liu et al.
2012 for the removal of tetracycline antibiotic by the use of binary oxides of Fe–
Mn. Both the metal oxides were tested individually, and it was found that Mn oxide
could remove >98% of the tetracycline, whereas Fe oxide could remove only 30%
of the antibiotic. However, by increasing the content of Mn in the binary oxide
formulation, there was a considerable decrease in removal of EC. In a similar manner, the combination of CNTs with aluminum oxide in a ratio of 1:1 increased the
removal of carbamazepine EC from 0 to 70%. The chemical nature of the pollutant also plays a significant role on the efficiency of the adsorbent material. Some
other examples are of pumice or zeolite which have been utilized for removal of
ciprofloxacin (Ji et al. 2010a, b), use of alum oxide for adsorption of different antibiotics gave different removal results ranging from 43 to 90% (Rahardjo et al. 2011).
The application of varied nature of adsorbents and molecularly imprinted polymer materials has been utilized for the removal of a variety of pharmaceuticals of
(Genç and Dogan 2015; Avisar et al. 2010).
Besides the above technologies, some more recent technologies have been
proposed for removal of ECs.
397
17.3.4 Clay Minerals
Clay is another material which has found application as an adsorbent in removal
of ECs. The characteristics of clay as an adsorbent material govern the efficiency
of the removal process, through adsorption. Similar types of clays have different
removal efficiencies, and this depends on the presence of specific amount of iron or
other minerals and nitrogen content (Rahardjo et al. 2011). The above fact has been
proven by the studies undertaken by Wu et al. (2010 and 2012a, b), in which 35%
and 100% removal of ciprofloxacin has been reported by the use of montmorillonite
(MMT) clay as an adsorbent. This difference in removal efficiency was attributed to
the source of the clay material. The cation exchange capacity (CEC) of adsorbent
materials also plays an important role in their adsorption capacity, and these (CEC)
values can be modified by impregnating with different ions to enhance the performance and selectivity of the clays (Parolo et al. 2012 and Zhao et al. 2012). The
use of such approaches can demonstrate promising results, but need further thorough investigations as the fate of the contaminants and mechanisms involved in their
remains is largely unknown.
17.3.5 New Adsorbents
Several other new adsorbent materials have been developed for removing of ECs
from contaminated waters. These include microporous materials, resins, oxides of
metals, zeolites, etc. (Ahmed et al. 2015 and Hou et al. 2010). The structure of
these adsorbent materials produces a significant effect on the adsorption/removal
efficiency of the adsorbents. An example of this is the study conducted by Liu et al.
2012 for the removal of tetracycline antibiotic by the use of binary oxides of Fe–
Mn. Both the metal oxides were tested individually, and it was found that Mn oxide
could remove >98% of the tetracycline, whereas Fe oxide could remove only 30%
of the antibiotic. However, by increasing the content of Mn in the binary oxide
formulation, there was a considerable decrease in removal of EC. In a similar manner, the combination of CNTs with aluminum oxide in a ratio of 1:1 increased the
removal of carbamazepine EC from 0 to 70%. The chemical nature of the pollutant also plays a significant role on the efficiency of the adsorbent material. Some
other examples are of pumice or zeolite which have been utilized for removal of
ciprofloxacin (Ji et al. 2010a, b), use of alum oxide for adsorption of different antibiotics gave different removal results ranging from 43 to 90% (Rahardjo et al. 2011).
The application of varied nature of adsorbents and molecularly imprinted polymer materials has been utilized for the removal of a variety of pharmaceuticals of
(Genç and Dogan 2015; Avisar et al. 2010).
Besides the above technologies, some more recent technologies have been
proposed for removal of ECs.