RESUMO
Blast furnace slag loaded with sulfide nano zero valent iron (S-nZVI@BFS) was applied to remove oxytetracycline (OTC) from water. S-nZVI@BFS was synthesized via liquid reduction and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer, Emmett and Teller (BET) theory. The effect of reaction time, initial concentration of OTC, initial pH, and coexisting hexavalent chromium[Cr(â ¥)] were investigated. The results show that Fe and S were successfully immobilized on the surface of S-nZVI@BFS, the specific surface area and pore volume of which increased to 141.986 m2·g-1 and 0.388 cm3·g-1, respectively, following the loading of nZVI and sulfurization. The utilization rate of the surface active sites of S-nZVI@BFS was improved with an increase of the initial concentration of OTC; the removal rate increased from 20.12 mg·g-1 to 202.74 mg·g-1 when the initial concentration of OTC was increased from 10 mg·L-1 to 100 mg·L-1. The removal rate decreased with pH, declining from 99.78 mg·g-1 to 41.12 mg·g-1 when pH was increased from 3 to 11 due to the switch from Fendon oxidation to electrostatic adsorption. There was notable competition between OTC and Cr(â ¥) meaning that Cr(â ¥) can inhibit the removal of OTC, which is dose dependent.