High removal rate and selectivity of Hg(II) ions using the magnetic composite adsorbent based on starch/polyethyleneimine

In this work, we developed a cheap and effective magnetic composite adsorbent (MSP) by introducing starch/polyethyleneimine to the surface of magnetic mesoporous silica. The prepared material was characterized by FT-IR, TG, XRD, SEM and TEM to determine its composition and morphology. Adsorption experiment showed that the removal rate of mercury(II) and adsorption capacity could reach 97.87% and 244.87 mg/g after 150 min. The kinetic study indicated that the adsorption data fitted well with the pseudo-second-order model, and the adsorption equilibrium data belonged to the Langmuir model. Meanwhile, the study of coexisting ions showed that MSP had a highly selective adsorption of mercury(II), and the adsorption capacity of the adsorbent after five times accounted for 91.27% of the initial adsorption capacity, which indicated magnetic nanomaterial manifested excellent selectivity and reutilization for mercury(II) adsorption. All in all, a feasible methods and cheap materials were implied to prepare a new magnetic composite adsorbent, and it will be a candidate for uptake of mercury(II) ions from industrial wastewater.