Using shell-tunable mesoporous Fe3O4@HMS and magnetic separation to remove DDT from aqueous media

Abstract

a b s t r a c t 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) is of concern in water treatment because of its persistence and health effects. A new concept is proposed to synthesize hexagonal mesoporous silica (HMS) with magnetic functionalization for DDT removal from aqueous media. Fe 3 O 4 nanocrystals were synthesized by a low-temperature solvothermal process, and then encapsulated in mesoporous silica through a packing approach, forming core-shell structured Fe 3 O 4 @HMS microspheres. The synthesized materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen adsorption-desorption techniques. The results indicate that the silica shell conserves mesoporous structure after the removal of surfactant templates. Different from previous studies, the thickness, pore volume and surface area of silica shell can be controlled by adjusting the reaction condition. These Fe 3 O 4 @HMS materials show high adsorption capacity and fast adsorption rate for DDT. Because of the useful magnetic property and unique mesoporous structure, the synthesized materials provide a fast, convenient and highly efficient means to remove DDT from aqueous media.Crown

Magnetic Nanocomposites with Mesoporous Structures: Synthesis and Applications

“…Hollow mesoporous carbon spheres with magnetic cores are also good adsorbents for bilirubin, as its adsorption capacity can reach up to 146.5 mg g −1 170. Magnetic materials with Fe 3 O 4 cores and mesoporous silica shells have been tested for the removal of DDT from aqueous media 171…”

Tannic acid adsorption on amino-functionalized magnetic mesoporous silica

“…Previous researches on magnetic mesoporous silica adsorbents mainly focused on the removal of aqueous heavy metal [15,16], and only a few studies have been conducted on adsorption of organic pollutants in water. For example, Tian et al synthesized the magnetic hexagonal mesoporous which can remove DDT from aqueous solution [17]. Deng et al prepared a superparamagnetic microsphere with an Fe 3 O 4 @SiO 2 core and mesoporous SiO 2 shell and observed fast removal of microcystins in water [18].…”

Recent research progress on the preparation and application of magnetic nanospheres

“…Some factors including pH, temperature, initial concentration and coexisting common ions influence the adsorption of metal ions 134, 135. Also, based on affinity, mesoporous magnetic iron oxide nanospheres are promising for the effective release of Cr (VI),136 Ni(II),137 Cu(II), Cd(II)138 and 1‐bis(4‐chlorophenyl)‐2,2,2‐trichloroethane (DDT)139 from water in the presence of an external magnetic field. In this case, it is worth mentioning that the affinity plays an important role in ion exchange, and the size and surface of nanospheres affect the effectiveness of the wastewater treatment.…”