Purification of starch and phosphorus wastewater using core-shell magnetic seeds prepared by sulfated roasting

Core-shell magnetic seeds with certain adsorption capacity that were prepared by sulfated roasting, served as the core of a magnetic separation technology for purification of starch wastewater. XRD and SEM results indicate that magnetite's surface transformed to be porous alpha-Fe2O3 structure. Compared with magnetite particles, the specific surface area was significantly improved to be 8.361 from 2.591 m(2)/g, with little decrease in specific susceptibility. Zeta potential, FT-IR and XPS experiments indicate that both phosphate and starch adsorbed on the surface of the core-shell magnetic seeds by chemical adsorption, which fits well with the Langmuir adsorption model. The porous surface structure of magnetic seeds significantly contributes to the adsorption of phosphate and starch species, which can be efficiently removed to be 1.51 mg/L (phosphate) and 9.51 mg/L (starch) using magnetic separation. (C) 2019 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.