【作者】 宋浩；

【导师】 庆承松；

【作者基本信息】 合肥工业大学 ， 环境科学， 2009， 硕士

【摘要】 本文利用凹凸棒石特殊晶体形态、优良吸附性能、表面化学活性以及对晶体成核和生长的控制作用,通过铁盐水解与热处理,在凹凸棒石表面负载纳米磁赤铁矿和炭,通过调控凹凸棒石/磁赤铁矿/炭复合材料组成、粒径,调控复合材料孔径分布和性能,制备具有超顺磁性、优良吸附性能的廉价多功能纳米复合材料。目的是通过改性凹凸棒石高效吸附和复合材料磁分离介质的作用去除水中溶解性微量有机污染物,通过复合材料超顺磁特性实现吸附剂磁选回收,通过各种表征技术着重研究复合材料制备方法及制备条件对复合材料相组成、微结构、表面性质、吸附性能、磁学特性、磁分离效果的影响以及污染物在复合材料上吸附性能、机理。结果表明,复合材料的磁化率值为2769×10^-8·m³/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的形态负载到了凹凸棒石表面,颗粒直径为10～60纳米;炭以无定形的形态负载在凹凸棒石晶体表面;复合材料中的含炭量为7.4%,并且材料中出现了有机官能团-CH₃、-CH₂-和-C=O。对苯酚的吸附实验表明,复合材料对有机污染物苯酚的去除率是凹凸棒石原矿的3倍。在298k～328k温度范围内,吸附热力学参数焓变值ΔH（-20.35kJ/mol）、熵变值ΔS（-71.88 J/K·mol）、自由能变值ΔG均为负值,说明复合材料对苯酚的吸附是一个自发、放热、熵增的过程。在研究的浓度、转速和温度的范围内,在凹凸棒石/γ-Fe₂O₃/炭复合材料对苯酚的吸附动力学数据能够较好地符合准二级动力学方程。凹凸棒石/γ-Fe₂O₃/炭复合材料对苯酚的吸附活化能为11.92 kJ/mol,说明此吸附并不是由单一的化学吸附为速率控制步骤,是由化学吸附和液膜扩散共同控制的吸附过程。成果对水深度处理、饮用安全保障技术研究具有重要意义,对环境矿物学、环境地球化学、地质微生物学、环境工程等学科研究具有重要意义。更多还原

【Abstract】 Using the special crystal form, excellent absorption properties, surface chemical activity, as well as crystal nucleation and growth control of attapulgite, through molysite hydrolysis and heat treatment, hematite and magnetic nano-carbon load in the surface of it; by controlling the composition and the size of palygorskite/γFe₂O₃ / carbon composites, control size distribution and performance, prepared a superparamagnetic iron, excellent absorption properties of low-cost multi-functional nanocomposites. In order to through the action of modified attapulgite’high adsorption and magnetic separation to remove the trace organic pollutants and suspended solids that dissolved in the water. using the superparamagnetic characteristic to achieve magnetic recovery of adsorbent; through biodegradable absorbent to achieve regeneration, solving the absorbent clay minerals solid-liquid separation and recycling problem.Simulate to using each kind of attribute technology to research the influence of the compound materials’preparation method and condition which affects on the composition, the microstructure, the surface properties, the adsorption performance, magnetism characteristic as well as the effect of magnetism separation, the biology - mineral correlation that pollutants affect on the adsorption performance, mechanism and absorbent regeneration of the compound materials. The results suggested that the nanocomposite could be subsequently removed from the water by a simple magnetic procedure. The magnetic iron oxides in the form ofγ-Fe₂O₃ were loaded onto the surface of the palygorskite, with particle diameter from 10 to 60 nm. The carbon in the form of amorphous was loaded onto palygorskite crystal surface and the content of carbon in the composite material was 7.4%. Furthermore, functional group -CH₃, -CH₂- and -C=O were found in the nanocomposite material. The efficiency of composite material for phenol removal was three times higher than that of palygorskite, which was suggested by the adsorption comparative test. Over the temperature range of 298k-328k, the thermodynamics parameters including Gibb’s free energy changes （ΔG）, enthalpy（ΔH）, and entropy changes （ΔS） were : -20.35（kJ/mol）, 71.88 （J/K·mol） respondingly. These indicates that adsorption thermodynamics of phone on palygorskite/γFe₂O₃ / carbon nanocomposite materials were a spontaneous and exothermic process. The achievement has the important meaning on water advanced treatment and potable water safety control technology, also in study of environment mineralogy, environment geochemistry ,Geological microbiology, environment engineering and so on.更多还原