【摘要】 为了揭示菱铁矿对水中六价铬Cr(Ⅵ)阴离子的吸附-还原耦合固定去除特性，采用合成菱铁矿矿物材料开展铬的吸附等温线和动力学特征探究，着重考察溶液pH对铬去除效率的影响，并对铬反应前后菱铁矿样品进行表征与分析。结果表明：采用Langmuir等温吸附模型，能更好地描述合成菱铁矿对Cr(Ⅵ)的去除，而铬去除动力学则更符合伪二级吸附动力学模型。Cr(Ⅵ)可被菱铁矿表面Fe(Ⅱ)快速还原转化为Cr(Ⅲ)离子，但由于pH升高，Cr(Ⅵ)的氧化性能有所降低，因而导致铬的去除率明显下降。菱铁矿表面形成了Fe(Ⅲ)-Cr(Ⅲ)氢氧化物共沉淀，从而实现菱铁矿对六价铬离子的有效去除。更多还原

【Abstract】 A synthetic siderite mineral material was employed to explore the sorption isotherms and kinetics of Cr(Ⅵ), aiming to reveal the removal characteristics of siderite for aqueous chromate anion Cr(Ⅵ) from waters by its adsorptive-reductive coupling immobilization. Here, an emphasis was placed to investigate the effect of solution pH on the efficiency for Cr(Ⅵ) removal, then all the siderite samples before and after reacting with Cr(Ⅵ) were characterized and analyzed in-depth. The results showed that the reaction process for Cr(Ⅵ) removal by synthetic siderite were quite well fitted to the Langmuir adsorption isotherm model, and the removal kinetics just well followed the pseudo-second-order kinetic model. Cr(Ⅵ) can be rapidly reduced to Cr(Ⅲ) by Fe(Ⅱ) on siderite surface, but Cr(Ⅵ) oxidative ability is somewhat decreased as solution pH increases, thus leading to chromium removal rate to be decreased obviously at the higher pH. Fe(Ⅲ)-Cr(Ⅲ) hydroxide co-precipitation had formed on siderite surface, so that Cr(Ⅵ) anion could be effectively removed by siderite.更多还原