Environmental Engineering Reference
In-Depth Information
AT P
St/CuBr,bpy
ATP
H
N
H
N
Br
Br
n
O
O
AS
AT-Br
DVB/CuBr/bpy
N
AT P
Br
n
m
O
ASD
H
N
AN,AIBN/DMF
AT P
Br
x
n
m-x
O
ASDN
P
N
NH
2
OH HCl/Na
2
CO
3
H
N
AT P
Br
n
x
m-x
O
P
ASDO
NOH
H
2
N
figure 16.17
scheme of the preparation procedure of AsdO.
several advantages, several difficulties or drawbacks are still underlying, which have to be addressed in future for wider/
practical applications.
The adsorption capacity of clay minerals without being exfoliated into the nanoscale is limited due to their small
surface area. The development of innovative organo-nanoparticles of layered silicates and similar nanocomposites with
large specific surface area merits attention for environmental remediation studies; it needs to be studied in-depth. However,
nanoscaled adsorbents are difficult to be separated from the water treating system, although they usually exhibit much
higher adsorption capacity. so the adsorption capacity and the practical maneuverability should be comprehensively con-
sidered for future work.
The organo-modification of clays via noncovalent interactions seems easier than those with covalent interactions. However,
the stability and reusability of the organo-modification of clays via noncovalent interactions might be of concern. The modified
organic molecules might fall off from the clays, decreasing their adsorption capacity. moreover, the dropped organic molecules
might become a secondary pollutant.
The studies conducted till now were mostly based on laboratory experiments. Wastewaters containing several cations/anions
as well as organic molecules may likely hamper the removal efficiency. Hence, more comprehensive works concerning selec-
tivity are likely to be conducted.
Before organo-modification of clay minerals, they are usually activated with acids. Handling acidic solutions containing a
large amount of metal ions produced in the acid-activated process may be another problem to solve.
