부산대학교 도서관

Abstract This study investigated the efficient removal of As(V) from contaminated water using enhanced coagulation by Fe-Mn bimetal nano-oxides in combination with poly-ferric chloride (PFC) and poly-aluminum chloride (PAC). The effects of coagulant dose, initial pH, initial As(V) concentration, Fe-Mn nano-oxide dose and flocs properties were investigated. The results showed that the combination of coagulants and nano-oxides significantly increased the As(V) removal efficiency in the optimal coagulants doses (25 mg/L). The As(V) removal efficiencies for PAC and PFC were 82.93% and 88.22% and for PFC + Fe-Mn and PAC + Fe-Mn were increased to 96.83% and 98.26%, respectively. The residual As(V) concentration was decreased to ˂10 μg/L in the presence of Fe-Mn nano-oxides. The best removal efficiencies for PAC + Fe-Mn and PFC + Fe-Mn were in pH 7 and 9, respectively. Based on FESEM - EDX analysis, the combined floc formation by coagulants - nano-oxides and the existence of Fe, Mn and As elements in the precipitated flocs was confirmed, and the PFC + Fe-Mn flocs were more uniform and bigger than PAC + Fe-Mn flocs. Total Fe and Al residual concentrations in optimum dose of PAC + Fe-Mn and PFC + Fe-Mn were 0.15 and 0.25 mg/L and Cl− residue concentrations were 6.87 and 4.72 mg/L, respectively. Therefore, the combination of Fe-Mn bimetal nano-oxides with PFC and PAC coagulants can be a suitable option to improve the removal of As(V) from the contaminated water resources. Graphical abstract Image 1 Highlights • Efficient As(V) removal investigated by enhanced coagulation with Fe-Mn nano-oxide. • ≥96% As(V) was removed by combination of PFC + Fe-Mn and PAC + Fe-Mn. • Residual As(V) concentration decreased to <10 μg/L in the presence of nano-oxides. • Combined flocs formation by coagulants – nano-oxides was confirmed by FESEM – EDX. [ABSTRACT FROM AUTHOR]