Convenient separation from treated water is the other necessity
of a promising adsorbent. The traditional adsorbents, such as
activated carbon, ion exchange activated alumina, natural porous
minerals and the recently developed functionalized mesoporous
adsorbents, are difficult to be separated after water treatment.
Conventional methods such as centrifugation, precipitation, filtration
and chromatography are not only usually labor-consumptive
and uneconomical, but also accessible to malformation such as
deformation and inactivation. Therefore, convenient and effective
separation methods are in urgent demand. Magnetic materials can
be easily and rapidly separated from aqueous solutions under an
external magnetic field due to their magnetic property and have
the advantages of simplicity, high efficiency and sensitivity as well
as low costs. Therefore, introducing Fe3O4 which features superparamagnetism
into the prepared adsorbent is a good way to
resolve the problem of separation. There have been a few reports on
preparation of different types of mesoporous adsorbents with magnetic
nanocomposites incorporated into the pores [22]. However,
magnetic nanoparticles dispersed in the pores of the mesoporous
materials could block the pore, and lead to high mass transfer resistance.