【摘要】：磁性納米顆粒因其具有良好的吸附性能以及磁分離、磁場中定向移動等特性,在環(huán)境污染治理和納米藥物載體等領域展現(xiàn)出良好的潛在應用前景。從磁性納米顆粒在水污染處理領域的應用出發(fā),設計合成了一系列具有良好吸附性能的多孔磁性氧化物。以所合成的多孔磁性氧化物為吸附劑,研究了其對偶氮染料及重金屬離子等一系列污染物的吸附性能。探討了影響吸附量的若干重要因素,如吸附時間、p H、離子強度、溫度等。并根據(jù)吸附過程中的熱、動力學數(shù)據(jù),提出了相應的吸附機理。論文的主要內容包括:(1)通過簡單的兩步反應合成了磁分離型鐵氧體Ni0.6Fe2.4O4以及Co0.6Fe2.4O4納米顆粒。研究了Ni0.6Fe2.4O4對剛果紅,Co0.6Fe2.4O4對Pb2+的吸附性能,結果顯示所得材料對水體污染物具有良好的移除能力。研究了p H值、離子強度、溫度和吸附時間等因素對吸附性能的影響。結果表明,剛果紅在Ni0.6Fe2.4O4以及Pb2+在Co0.6Fe2.4O4上的動力學過程,符合準二級吸附動力學過程。剛果紅在Ni0.6Fe2.4O4上的吸附隨著溫度的增加而降低,而Pb2+在Co0.6Fe2.4O4上的吸附隨著溫度的升高而增大。通過對熱力學參數(shù)(ΔH°,ΔS°,ΔG°)進行計算可知剛果紅在Ni0.6Fe2.4O4上的吸附以及Pb2+在Co0.6Fe2.4O4上的吸附都是熱力學自發(fā)過程。剛果紅在Ni0.6Fe2.4O4吸附作用機制為靜電引力,而Pb2+在Co0.6Fe2.4O4上的吸附作用機制屬于離子交換。(2)以α-Fe2O3為起始原料,通過簡單的碳熱反應,制備了C/Fe3O4復合材料。與磁性氧化鐵相比,α-Fe2O3是一種更加容易得到的原料。我們利用海藻酸鈉輔助法,以具有不同形貌的α-Fe2O3為原料,合成了兩種具有不同形貌的C/Fe3O4復合吸附劑。該方法具有普適性,利用市售的α-Fe2O3作為原料,通過該方法同樣可以得到C/Fe3O4復合吸附劑。對該系列吸附劑的形貌、尺寸以及比表面積等微觀結構進行了表征。研究了溫度和吸附時間等因素對幾種磁分離型吸附劑移除亞甲基藍性能的影響。結果表明,亞甲基藍在這三種不同形貌的復合吸附劑上吸附的動力學過程,均符合準二級吸附動力學過程。此外,該吸附過程的速率控制步驟(RDS)為表面擴散過程。
[Abstract]:Due to their good adsorption properties, magnetic separation and directional movement in magnetic field, magnetic nanoparticles have shown good potential applications in the field of environmental pollution control and nano-drug carriers. Based on the application of magnetic nanoparticles in water pollution treatment, a series of porous magnetic oxides with good adsorption properties were designed and synthesized. The adsorption properties of porous magnetic oxides for a series of pollutants such as azo dyes and heavy metal ions were studied. Some important factors affecting adsorption amount, such as adsorption time, p H, ion strength and temperature, were discussed. According to the data of heat and kinetics in the adsorption process, the adsorption mechanism was put forward. The main contents of this paper are as follows: (1) Ni0.6Fe2.4O4 and Co0.6Fe2.4O4 nanoparticles were synthesized by simple two-step reaction. The adsorption properties of Ni0.6Fe2.4O4 to Congo red and Co0.6Fe2.4O4 to Pb2 were studied. The results show that the obtained materials have good removal ability to water pollutants. The effects of pH, ionic strength, temperature and adsorption time on the adsorption properties were studied. The results show that the kinetic processes of Congo red on Ni0.6Fe2.4O4 and Pb2 on Co0.6Fe2.4O4 are in accordance with the quasi-second-order adsorption kinetic process. The adsorption of Congo red on Ni0.6Fe2.4O4 decreases with the increase of temperature, while the adsorption of Pb2 on Co0.6Fe2.4O4 increases with the increase of temperature. The calculation of thermodynamic parameters (螖 H 擄, 螖 S 擄, 螖 G 擄) shows that the adsorption of Congo red on Ni0.6Fe2.4O4 and the adsorption of Pb2 on Co0.6Fe2.4O4 are thermodynamic spontaneous processes. The adsorption mechanism of Congo red on Ni0.6Fe2.4O4 is electrostatic force, while the adsorption mechanism of Pb2 on Co0.6Fe2.4O4 belongs to ion exchange. (2) 偽-Fe2O3 is used as the starting material through a simple carbothermal reaction. C/Fe3O4 composites were prepared. 偽-Fe2O3 is a more readily available raw material than magnetic ferric oxide. Two kinds of C/Fe3O4 composite adsorbents with different morphologies were synthesized from 偽-Fe2O3 with different morphologies by sodium alginate assisted method. The method is universal. Using 偽-Fe2O3 as raw material, the C/Fe3O4 composite adsorbent can also be obtained by this method. The morphology, size and specific surface area of the adsorbent were characterized. The effects of temperature and adsorption time on the removal of methylene blue by magnetic separation adsorbents were studied. The results show that the kinetic process of methylene blue adsorption on the three kinds of composite adsorbents with different morphology is in accordance with the quasi-second-order adsorption kinetic process. In addition, the rate control step of the adsorption process, (RDS), is a surface diffusion process.
【學位授予單位】：聊城大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TQ424;TB383.1

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相關期刊論文 前1條

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本文編號：2392626