【摘要】 采用氧化还原法合成3个不同氧化度的碱性水钠锰矿,并表征其晶体结构、比表面积和表面化学性质,探讨其对Cr(Ⅲ)的氧化及影响因素。研究表明:随着合成反应的n(Mn7+)/n(Mn2+)逐渐减小,合成碱性水钠锰矿的氧化度和比表面积逐渐减小,其PZC逐渐升高。反应时间和反应条件(p H、Cr(Ⅲ)浓度和矿物用量)均影响碱性水钠锰矿对Cr(Ⅲ)的氧化。在低p H值范围内Cr(Ⅲ)氧化率随着p H的增加逐渐增加,但在高p H值范围内氧化率随着p H的升高而减小。此外,Cr(Ⅲ)的氧化率随着Cr(Ⅲ)浓度的升高逐渐降低,但随着氧化度的提高显著增加。更多还原

【Abstract】 Alkaline birnessite had been synthesized by an oxidation-reduction method,and its crystal structure,specific surface area and surface chemical property were characterized. The influencing factors of Cr( Ⅲ) oxidation by alkaline birnessite was also studied. The results indicated with decrease of Mn7 +/ Mn2 +in synthetic method,the AOS and specific surface area of synthetic birnessite decreased,but the PZC of synthetic birnessite increased. The effect of reaction conditions( p H,concentration of Cr( Ⅲ),birnessite loadings and AOS) was studied. The oxidation rate of Cr( Ⅲ) increased with the increase of p H in the low p H range,but it decreased with the increase of p H in high p H range. In addition,the oxidation rate of Cr( Ⅲ) decreased with the increase of concentration of Cr( Ⅲ),but it increased with the increase of birnessite loadings and AOS respectively.更多还原