双酚A在不同铁矿物上的吸附行为研究

发布时间：2018-03-27 12:07

  本文选题：双酚A　切入点：铁矿物　出处：《中国地质大学(北京)》2016年硕士论文

【摘要】：双酚A是一种典型的环境内分泌干扰物,在工业生产和日常生活中应用广泛。近年来,在各类环境介质中的检出日益频繁,由于其具有生物致毒效应,受到越来越多的关注。本文选取了三种土壤常见矿物水铁矿(包括含Si水铁矿)、针铁矿和菱铁矿,通过静态吸附批实验,辅以各种表征手段(XRD、Raman、SEM/TEM-EDX、BET-BJH、XPS、FTIR、TGA),旨在研究双酚A在不同类型含铁矿物上的吸附行为。实验结果表明:(1)水铁矿、针铁矿和菱铁矿对双酚A的去除率分别为54%、16%、2%,这是因为,同针铁矿和菱铁矿相比,水铁矿具有更大的比表面积、更小的颗粒尺寸和孔径,可提供更多的活性吸附位。双酚A与水铁矿、针铁矿和菱铁矿的动力学过程均符合准二级动力学方程,反应平衡时间分别为12、6、6h;反应溶液初始pH的改变对反应体系的影响并不明显。(2)双酚A与水铁矿、针铁矿和菱铁矿的等温吸附实验均可用Freundlich模型拟合。其中,菱铁矿的等温吸附结果更加符合Henry线性模型,表明其吸附过程为物理吸附。而双酚A与水铁矿、针铁矿的作用过程则是物理吸附和表面化学吸附共同作用的结果。(3)溶液中Fe(Ⅱ)的存在,对水铁矿反应体系影响不大,而对针铁矿组和菱铁矿组有较为明显的促进作用;而Fe(Ⅲ)的存在,对水铁矿组具有明显的抑制作用,对针铁矿和菱铁矿组影响不大(微弱促进作用)。这可能是与铁的存在状态有关。(4)双酚A与三种不同比例含Si水铁矿(5SiFh、10SiFh和20SiFh)的动力学过程均符合准二级动力学方程,平衡时间分别为12、6、6h,且其作用过程不仅与其比表面积、颗粒大小等物理因素有关,还受到含Si水铁矿化学组成的影响。随着Si含量的增加,SiFh吸附双酚A的量逐渐减少。(5)由于水铁矿本身具有较好的缓冲能力,反应初始pH值并不是影响双酚A与SiFh的反应过程的主要因素;共存离子(Na~+、Ca~(2+))含量的增加,均会抑制反应的进行,且Ca~(2+)抑制作用强于Na~+。
[Abstract]:Bisphenol A (BPA) is a typical environmental endocrine disruptor, which is widely used in industrial production and daily life. In recent years, bisphenol A has been detected more and more frequently in various environmental media, because of its biological toxic effect. More and more attention has been paid to it. In this paper, three common minerals in soil, including Si-bearing water ore, goethite and siderite, were selected, and the static adsorption batch experiments were carried out. A variety of characterization methods are used to study the adsorption behavior of bisphenol A on different types of iron bearing minerals. The experimental results show that the removal rates of bisphenol A from water ore, goethite and siderite are 544,16162.This is because, Compared with goethite and siderite, water ore has larger specific surface area, smaller particle size and pore size, and can provide more active adsorption sites. The kinetic processes of goethite and siderite are in accordance with the quasi second-order kinetic equation, the equilibrium time of the reaction is 12 ~ 6 ~ 6 h, respectively, and the effect of the initial pH of the reaction solution on the reaction system is not obvious. The isothermal adsorption experiments of goethite and siderite can be fitted by Freundlich model. The isothermal adsorption results of siderite are more consistent with Henry linear model, indicating that the adsorption process is physical adsorption. The process of action of goethite is the result of physical adsorption and surface chemisorption. The existence of Fe (鈪，

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