Synthesis of iron-based magnetic nanocomposites and applications in adsorption processes for water treatment: a review

摘要

Rising worldwide concern about the quantity and quality of water available to living beings calls for efficient technologies of water treatment. Nanomaterials are promising adsorbents to remove contamination from aqueous solution, and magnetic nanomaterials based on iron have attracted attention because magnetic materials are easy to separate. Here, we review iron magnetic nanomaterials applied for water and wastewater treatment, with focus on toxic elements, pharmaceuticals and pesticides. Major advances are: coprecipitation is the most used method for synthesis of iron magnetic nanoparticles, followed by solvothermal and hydrothermal methods. Magnetite is the most common magnetic nanoparticles applied as magnetic adsorbent. In general, magnetic nanocomposites are superparamagnetic, and the highest magnetization is sought for core-shell structures, reaching 65 emu/g. Most reports focus on removal of toxic metals. Adsorption is explained by the Langmuir isothermal model, kinetic patterns being correlated with pseudo-second-order equations. Overall, iron-based magnetic nanocomposites display promising performances for pollutant removal, yet few investigations report the toxic impacts of magnetic nanoparticles on the environment.