本文選題：高級氧化技術(shù) + 過一硫酸鹽　； 參考：《哈爾濱工業(yè)大學(xué)》2017年碩士論文

【摘要】：近年來,隨著工業(yè)的快速發(fā)展,環(huán)境污染問題日益嚴(yán)重,對人類的身心健康造成了極大的危害。一種基于羥基自由基的芬頓(Fenton)技術(shù)由于其較高的氧化活性,被逐漸的應(yīng)用到該領(lǐng)域中來,但其較低的催化效率以及較窄的pH范圍也制約了該技術(shù)的發(fā)展。因此,過硫酸鹽作為硫酸根自由基的來源受到了廣泛的關(guān)注,利用紫外光照射、過渡金屬離子活化等作用,形成硫酸根自由基,進而對有機物進行降解。本課題制備了一種具有較高電化學(xué)活性的金屬氧化物材料——鉬酸鈷,并首次將其應(yīng)用于過一硫酸鹽(PMS)的活化過程中,探究其催化性能以及催化氧化過程的影響因素,同時總結(jié)催化過程反應(yīng)機理。本課題選用水熱法制備鉬酸鈷前驅(qū)體粒子,并對其進行表征測試。測試結(jié)果表明材料具有均勻的微觀形貌以及較高的催化活性,對前驅(qū)體進行煅燒,制得一系列金屬氧化物催化劑,測試幾組樣品的催化活性,并選用性能最佳的一組進行后續(xù)實驗。500°C煅燒后的樣品結(jié)晶度較好,對應(yīng)著β-CoMoO4晶型,具有較為均一的花狀微觀形貌,其比表面積為61.9 m2/g,較大的比表面積為樣品提供了優(yōu)異的催化活性。選擇亞甲基藍(lán)(MB)為目標(biāo)污染物,本課題制備的CoMoO4在40 min內(nèi)對MB的去除率就可達(dá)到100%,催化活性明顯高于相同投加量的Co3O4以及CoFe2O4。同時,使用過后的催化劑仍具有較高的催化活性,可以循環(huán)利用。在CoMoO4/PMS體系催化氧化的過程中,PMS的初始濃度、催化劑的投入量、反應(yīng)體系的溫度、反應(yīng)體系初始pH值對催化過程均會產(chǎn)生影響。同時,重碳酸鹽、鹵素、金屬離子、天然有機物等存在也會對催化體系產(chǎn)生影響。這些離子的存在,主要是通過影響活性自由基的生成,或?qū)ζ溥M行消耗從而影響體系的催化性能。在本課題探究過程中,在以地表水、自來水為背景水體的實驗中,CoMoO4活化PMS的過程有一定的影響,但催化劑仍能展現(xiàn)出良好的降解性能。選取幾種不同類型的染料對催化劑的普適性進行評估,結(jié)果表明催化劑對幾種染料均具有優(yōu)異降解性能,尤其對于陰離子染料,展現(xiàn)出很高的活性。自由基競爭動力學(xué)實驗表明,硫酸根自由基和羥自由基均為CoMoO4活化PMS氧化有機物的主要活性物種,在活化PMS的過程中,電子轉(zhuǎn)移過程主要發(fā)生在Co原子上,與Mo原子無關(guān),即電子在CoMoO4表面的Co(II)上發(fā)生轉(zhuǎn)移,活化PMS產(chǎn)生自由基,進而降解有機物。
[Abstract]:In recent years, with the rapid development of industry, the problem of environmental pollution is becoming more and more serious, which has caused great harm to the physical and mental health of human beings. A Fenton technology based on hydroxyl radical is gradually applied in this field because of its high oxidation activity, but its low catalytic efficiency and narrow pH range also restrict the development of the technology. Therefore, persulfate, as the source of sulfate radical, has been paid more and more attention. By ultraviolet irradiation and transition metal ion activation, sulfate radical is formed, and then organic matter is degraded. In this paper, a metal oxide material with high electrochemical activity, cobalt molybdate, was prepared and used for the first time in the activation process of PMSs. At the same time, the reaction mechanism of catalytic process is summarized. In this paper, cobalt molybdate precursor particles were prepared by hydrothermal method and characterized. The results showed that the materials had uniform microstructure and high catalytic activity. A series of metal oxide catalysts were prepared by calcination of the precursor, and the catalytic activity of several groups of samples was tested. The crystallinity of the samples calcined at 500 擄C was better, corresponding to the 尾 -CoMoO _ 4 crystal form, and had a more uniform flower-like micromorphology. Its specific surface area is 61.9 m2 / g, and the larger specific surface area provides excellent catalytic activity for the sample. When methylene blue (MBB) was selected as the target pollutant, the removal rate of MB by CoMoO4 was 100 in 40 min, and the catalytic activity was obviously higher than that of Co3O4 and Cofe _ 2O _ 4 with the same dosage. At the same time, after the use of the catalyst still has a higher catalytic activity, can be recycled. The initial concentration of CoMoO4/PMS, the amount of catalyst input, the temperature of the reaction system and the initial pH value of the reaction system all affect the catalytic process. At the same time, the presence of bicarbonate, halogen, metal ions and natural organic compounds will also affect the catalytic system. The existence of these ions mainly affects the catalytic performance of the system by affecting the formation of active free radicals or consuming them. In the course of this research, in the experiment of surface water and tap water as the background water, the activation of PMS by CoMoO4 has a certain effect, but the catalyst can still show good degradation performance. Several kinds of dyes were selected to evaluate the universality of the catalysts. The results showed that the catalysts had excellent degradation performance for several dyes, especially for anionic dyes. The experimental results of free radical competition kinetics show that both sulfate radical and hydroxyl radical are the main active species of PMS oxidizing organic compounds activated by CoMoO4. In the process of activating PMS, the electron transfer process mainly takes place on Co atom, which is independent of Mo atom. In other words, electrons are transferred on the surface of CoMoO4, which activates PMS to produce free radicals and then degrades organic matter.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X703;O643.36

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本文編號：1790913