Advanced Magnetic Adsorbents Prepared from Emulsion Template for Water Treatment

Abstract

Adsorption technology regarded as an ideal method to remove water contaminants has been widely applied in practical applications, as the merit of the wide suitability and low cost. Among various adsorbents, magnetic recyclable adsorbents have gained more and more attention in recent years, which not only decrease the risk of secondary pollution but also realize the cyclic use of the adsorbent after being regenerated and even increase significantly the additional value for enriching the scattered metals and precious metals. Recently, more and more studies have concerned the morphological control, homogeneous size, and tuned porous structure of magnetic adsorbents except for the adsorption performance. Hence, the emulsion template technique is applied to construct the magnetic adsorbents based on the advantages of facilely controlling the size distribution, crystallinity, and porous structure of magnetic materials.Here, recent studies on the preparation of magnetic materials based on the emulsion template are reviewed, including magnetic nanoparticles, magnetic microspheres, and magnetic porous materials, and then the applications of the magnetic adsorbents for water treatment are summarized and discussed. The major points include the following aspects: (1) the emulsion template for preparation of the magnetic materials presents several advantages such as the confined reaction in the “microreactor,” controlled shape, particle size and distribution, high polymerization degree, high productivity, low reaction temperature, and sufficient and tuned porous structure. (2) The obtained magnetic adsorbents exhibit excellent adsorption performance to the various pollutants, including heavy metals, dyes, and other organic contaminants, as well as the oil-water separation. It is expected that this review could be regarded as an important reference for the design and fabrication of novel adsorbents.