Novel Fe3O4–poly(methacryloxyethyltrimethyl ammonium chloride) adsorbent for the ultrafast and efficient removal of anionic dyes

The removal of anionic dyes from wastewater has attracted global concern. In this work, a novel Fe3O4–poly(methacryloxyethyltrimethyl ammonium chloride) (Fe3O4–pDMC) adsorbent for the efficient removal of anionic dyes from wastewater was successfully synthesized by grafting methacryloxyethyltrimethyl ammonium chloride (DMC) on the surfaces of Fe3O4. Various characterization analyses confirmed that the obtained Fe3O4–pDMC possessed numerous functional groups on its surfaces and retained good magnetic separation properties. Fe3O4–pDMC showed ultrafast removal for acid orange 7 (AO7, 58.6%, 1 min) and direct blue 15 (DB15, 98.1%, 1 min), and the maximum adsorption capacity was high (266.8 and 336.5 mg g−1 for AO7 and DB15, respectively). In addition, the adsorption process was in accordance with pseudo-second-order kinetics and the Langmuir isotherm. The mechanism underlying the adsorption of Fe3O4–pDMC on anionic dyes was mainly dependent on electrostatic interaction. This study illustrated that Fe3O4–pDMC has great potential applications as an environmentally friendly, desirable adsorbent for the efficient removal of anionic dyes from wastewater.