摘要
Nano zero-valent manganese(nZVMn,Mn^0)was prepared through a borohydride reduction method and coupled with different oxidants(persulfate(S2O8^2-),hypochlorite(CIO^-),or hydrogen peroxide(H2O2))to remove thallium(TI)from wastewater.The surface of Mn°was readily oxidized to form a core-shell composite(MnOx@Mn°),which consists of Mn°as the inner core and MnOr(MnO,M112O3,and Mn3O4)as the outer layer.When Mn^0 was added alone,effective T1(I)removal was achieved at high pH levels(>12).The Mn-H2O2 system was only effective in T1(I)removal at high pH(>12),while the Mn^0-S2O8^0or Mn0-ClO^-system had excellent T1(I)removal(>96%)over a broad pH range(4-12).The Mn-S2O8 oxidation system provided the best resistance to interference from an external organic matrix.The isotherm of T1(I)removal through the Mn°-S2O8^2-system followed the Freundlich model.The Mn°nanomaterials can activate persulfate to produce sulfate radicals and hydroxyl radicals.Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy suggested that oxidation-induced precipitation,surface adsorption,and electrostatic attraction are the main mechanisms for T1(I)removal resulting from the combination of Mn^0 and oxidants.Mn^0coupled with S2O8^2-/ClO^-is a novel and effective technique for T1(I)removal,and its application in other fields is worthy of further investigation.
基金
the National Natural Science Foundation of China(Grant Nos.51808144,51678562,and 41830753)
the Science and Technology Program of Guangzhou(Nos.201906010037 and 201804010281)
the Guangdong Natural Science Foundation(No.2018A0303130265).
