凹凸棒石/γ-Fe_2O_3/碳纳米复合材料的制备及其对苯酚的吸附作用

Preparation of Palygorskite/(γ-Fe_2O_3)/C and Adsorption Removal of Phenol from Aqueous System

为获得同时具有有机亲和性和磁分离特性的吸附材料,以凹凸棒石黏土和废活性白土为原材料,通过铁盐水解共沉淀和在氢气气氛下程序升温煅烧的方法,制备廉价的凹凸棒石/γ-Fe2O3/碳纳米复合材料。运用磁化率分析,红外吸收光谱,透射电镜,X射线衍射分析和碳含量分析对其进行了表征,并研究了复合材料吸附去除水中苯酚的动力学、吸附试验中pH的影响及同等条件下与其他吸附材料吸附性能的对比。结果表明,复合材料的磁化率值为2 769×10-8m3/kg,用磁分离工序即可把该吸附材料从溶液中快速分离出来;铁的磁性氧化物以γ-Fe2O3的形态负载到凹凸棒石表面,颗粒直径为1060 nm;碳以无定形的形态负载在凹凸棒石晶体表面;复合材料中的w（碳）为7.4%,材料中出现了有机官能团—CH3和—CH2—。对苯酚的吸附试验表明,复合材料对苯酚的去除率是凹凸棒石原矿的3倍。

Palygorskite and spent bleaching earth were used to prepare a nanocomposite named palygorskite/（γ-Fe2O3）/C by hydrolysis precipitation and calcination in the atmosphere of hydrogen.The nanocomposite was an adsorbent of organic affinity and had magnetic separation characteristics.The nanocomposite was characterized by magnetic susceptibility analysis,Fourier transform infrared spectrometry,transmission electron microscopy,X-ray diffraction analysis and carbon content analysis.Phenol adsorption kinetics,pH influence and the comparison of adsorption efficiency with other materials were studied.The results suggested that the magnetic susceptibility of the nanocomposite material was（2,769×）10^-8（m^3/kg）,and the nanocomposite could be subsequently separated simply by the magnetic separation method.The magnetic iron oxide（γ-Fe2O3） was loaded onto the surface of the palygorskite,with particle diameter from 10 to 60 nm.The carbon was loaded onto the palygorskite crystal surface in the form of amorphism,and the carbon content in the nanocomposite was 7.4%.Furthermore,functional groups（—CH3） and（—CH2—） were found in the nanocomposite.The efficiency of composite material for phenol removal was three times higher than that of palygorskite.