Optimization of porous structure of superparamagnetic nanoparticle adsorbents for higher and faster removal of emerging organic contaminants and PAHs

Abstract

a Superparamagnetic permanently confined micelle array (Mag-PCMAs) nanoparticle adsorbents have been successfully synthesized with a core/shell structure of a silica/surfactant mesostructured hybrid layer on negatively charged maghemite nanoparticles. A micelle swelling agent, 1,3,5-trimethyl benzene, was introduced during the synthesis and removed afterward to optimize the porous structure of Mag-PCMAs to achieve larger surface area and higher pore volume. The isotherms and kinetics of three representative EOCs (methyl orange, sulfamethoxazole and gemfibrozil) and two PAHs (acenaphthene and phenanthrene) onto Mag-PCMAs were determined, and the regeneration and reusability of Mag-PCMAs for methyl orange removal was also investigated. With the optimization of porous structure, the sorption kinetics and capacities of EOCs and PAHs were significantly improved. All of the results showed that Mag-PCMAs can provide fast, effective and sustainable approach for EOCs and PAHs remediation.

Recent advances on iron oxide magnetic nanoparticles as sorbents of organic pollutants in water and wastewater treatment

“…(30, 31) A silica porous layer is used to confine the cationic surfactant micelles into the mesopores preventing loss during subsequent use. Huang et al (32) demonstrated high adsorption rate and capacity for three different industrial effluents and PPCPs (methyl orange, sulfamethoxazole and gemfibrozil) as well as two different PAHs (acenaphthene and phenanrtene). By adding a micelle swelling agent during synthesis and then removing it (28), Huang et al were able to increase the pore volume and surface area of the Mag-PCMAs, thus increasing their sorption capacity and diffusion rate.…”

Isothermal titration microcalorimetry to determine the thermodynamics of metal ion removal by magnetic nanoparticle sorbents

“…range of pH and water hardness) as well as shown good regenerability and reusability. Though magnetic nanoparticle sorbents have successfully been applied to remove heavy metal ions, 10,[18][19][20][21][22] hydrophobic compounds, [23][24][25] pesticides, 26,27 natural organic matter, 22,28,29 oxyanions 30,31 and emerging organic contaminants, 25,32,33 those studies focused on the synthesis and characterization of physicochemical properties of these engineered nanomaterials, as well as their environmental application. However, the key quantitative thermodynamic data (e.g.…”

Nanomaterials with Tailored Magnetic Properties as Adsorbents of Organic Pollutants from Wastewaters

“…Furthermore, the adsorption equilibrium was achieved within a relatively short period of time (20 min), because of the high surface area and short adsorption path of mesoporous solid. Another approach is the work of Keller's group [52] in which the surfactant 3-(trimethoxysilyl)propyl-octadecyldimethyl-ammonium chloride (TPODAC) was used as a templating agent to prepare permanently confined micelle array core-shell nanoparticles. Maghemite cores were surrounded by TPODAC and TMB as a micelle-swelling agent, and then TEOS was added to covalently bind the surfactant onto the magnetic cores.…”