1710 / 2019-08-27 17:01:13

The synthesis of ferrihydrite/manganese dioxide composites and their adsorptive removal of Cd(II) and As(V)

3、环境科学 > 专题5：砷的环境地球化学

Ferrihydrite/manganese dioxide composites (FH-M) was synthesized from ferrihydrite (FH) and manganese compounds by ex-situ synthesis and characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy in the present work. The influences of experimental parameters such as solution pH value and initial concentration of adsorbate on the adsorption uptake of Cd(II) / As(V) was systematically investigated. The adsorption kinetics was analyzed by fitting quasi-first-order and quasi-second-order kinetic equations. The results showed that with increasing the pH value the adsorption rate of Cd(II) increased, while that of As(V) increased at first and then decreased. For the kinetic adsorption process, the adsorption performance of FH-M to As(V) was better than that to Cd(II). The quasi-second-order kinetic equation was more suitable to describe the adsorption kinetics of Cd(II) / As(V). The ligand exchange of Cd(II) / As(V) with the -OH in the composites was obtained by analyzing the characterization results of X-ray photoelectron spectroscopy. The high adsorption ability of the FH-M makes it a potentially attractive adsorbent for the removal to Cd(II) and As(V) with a good application prospect.