Highly efficient removal of dyes from wastewater over a wide range of pH value by a self-adaption adsorbent

The study prepared a self-adaption adsorbent that was capable of removing anionic dye over a wide range of pH value and revealed its essential adsorption mechanism to the conventional dyes as target pollutants. Through a cross-linking/embedding method, MgO particles were successfully combined with magnetic substances and Chitosan, which created a novel magnetic adsorbent (named as MgO-MCS) that could be used to efficiently remove anionic dyes by self-adjusting its surface charge. A series of characterization techniques and adsorption experiments were conducted to reveal the properties and the adsorption mechanisms, whose results showed that MgO-MCS had a better adsorption effect, and wider application range than that of magnetic Chitosan (MCS). The enhancement of adsorption was attributed to the formed more micropores and mesopores on the surface of MgO-MCS, and the essential mechanism was mainly caused by the combined effects of van der Waals force, electrostatic interaction and hydrogen bond .