本文關鍵詞： 有機酸 羅硝唑 光催化 協(xié)同效應 降解機理　出處：《廣西大學》2017年碩士論文　論文類型：學位論文

【摘要】：硝基咪唑類藥物是一種廣泛用于禽畜和人類疾病預防和治療的抗生素藥物,過量使用硝基咪唑類藥物導致其在水體和食品中頻繁檢出。研究表明硝基咪唑類藥物具有基因毒性,且能致畸、致癌和致突變,嚴重威脅著人類健康。因此,對于廢水中硝基咪唑藥物進行有效的污染控制具有十分重要的意義。光催化技術是一種高效的高級氧化技術,具有反應條件溫和,無二次污染等優(yōu)點,被廣泛應用于有機污染物的去除。然而光催化過程中的光生空穴和電子對的快速復合降低了光催化反應效率,同時粉體TiO_2光催化劑難于回收且無法利用可見光限制了光催化技術的實際應用。本文以羅硝唑(RNZ)為硝基咪唑類藥物的代表物,系統(tǒng)開展以下研究:為了抑制TiO_2光生空穴和電子對的復合,提高光催化效率,通過在TiO_2體系中加入有機酸作為電子供體的方法有效促進了羅硝唑的降解效率。以紫外燈為光源,以P25為光催化劑,開展了不同有機酸對光催化降解羅硝唑的影響研究,并探討有機酸的增效機制。研究結果表明,羅硝唑的降解受草酸濃度、溶液pH、有機酸結構的影響。不同有機酸對光催化降解羅硝唑的協(xié)同增效作用順序為:乳酸灑石酸≈蘋果酸檸檬酸草酸,僅含有單一羧基或羥基的有機酸或醇作為電子供體不能促進羅硝唑的光催化降解效率。TiO_2+草酸體系中的主要活性物質(zhì)為(CO2·-和e-,羅硝唑在TiO_2+草酸體系中主要有2條降解途徑:一為氮雜環(huán)上的雙鍵斷裂形成脂肪族化合物;二為雜環(huán)支鏈上的硝基、氨基經(jīng)過轉換聚合生成偶氮化合物,而后C-O鍵斷裂。另外,為了有效解決粉體光催化劑難于回收的問題,且將催化劑的光響應范圍擴展至可見光區(qū)域,采用溶膠凝膠法制備了Fe2O3@TiO_2@HGMs催化劑,對其進行能譜分析(EDS)、X射線衍射(XRD)、X射線光電子能譜分析(XPS)和紫外可見漫反射(UV-Vis DRS)表征。以氙燈為光源,在有機酸存在下,詳細研究了降解條件對羅硝唑去除效率的影響,并對降解機理進行探討。研究結果表明,Fe和Ti成功地負載在空心玻璃微珠表面,并分別以Fe203和TiO_2的形態(tài)存在。Fe203@TiO_2@HGMs復合材料不僅提高了紫外光區(qū)域的吸收能力,還拓寬了光的吸收范圍。溶液初始pH值對羅硝唑降解的影響較大,隨著溶液pH值的升高,羅硝唑的降解速率明顯下降。有機酸存在對體系降解羅硝唑具有協(xié)同增效作用,則必須滿足以下2個條件:(1)所添加的有機酸能與Fe(Ⅲ)形成配合物;(2)Fe(Ⅲ)-有機酸必須在可見光條件下有光反應活性。在草酸和Fe2O3@TiO_2@HGMs體系中,·OH為主要的活性物質(zhì),CO2·-起輔助作用。研究發(fā)現(xiàn)此體系能自生成H202,同時發(fā)生光芬頓和光催化反應,有效提高了羅硝唑的去除效果。有機酸增效Fe2O3@TiO_2@HGMs去除羅硝唑主要有3條降解路徑:一為羅硝唑支鏈上的NH2與雜環(huán)上兩個N之間的C原子成鍵形成新的雜環(huán)產(chǎn)物(3-乙酰-2-惡唑烷酮);二為羅硝唑雜環(huán)上的碳氮雙鍵斷裂形成開環(huán)產(chǎn)物;三為雜環(huán)支鏈斷裂后生成聚合產(chǎn)物。最后中間產(chǎn)物進一步轉化生成CO2和H2O。
[Abstract]:Nitroimidazole is a kind of widely used antibiotics in livestock and human disease prevention and treatment, excessive use of nitroimidazole drugs lead to the frequently detected in water and food. The research showed that if nitroimidazole has genetic toxicity and teratogenic, carcinogenic and mutagenic, a serious threat to human health. Therefore, for nitroimidazole drug wastewater for effective pollution control has a very important significance. The photocatalytic technology is an efficient and advanced oxidation technology, has the advantages of mild reaction conditions, no two pollution, has been widely used in the removal of organic pollutants. However, the photocatalytic process of photogenerated electron and hole on the composite reduce the efficiency of photocatalytic reaction, and TiO_2 powder photocatalyst is difficult to recycle and use the actual application limit of visible light photocatalytic technology. This paper take the ornidazole (RNZ As the representative) nitroimidazoles, carried out the following studies: TiO_2 system in order to suppress the photogenerated electron and hole on the composite, improve the photocatalytic efficiency by adding organic acid in the TiO_2 system as the electron donor to effectively promote the degradation efficiency of ronidazole. Under UV light with P25 as a photocatalyst, carried out research on the influence of different organic acids on the photocatalytic degradation of ronidazole, and to investigate the synergistic mechanism of organic acids. The results show that the degradation of ronidazole by oxalic acid concentration, solution pH, influence of organic acid structure. The synergistic effect of different organic acids sequence on the photocatalytic degradation of ronidazole the lactic acid tartaric acid, malic acid and citric acid oxalic acid, organic acid or alcohol containing only a single carboxyl or hydroxyl groups as electron donor cannot promote the main active substances ronidazole the photocatalytic degradation efficiency of.TiO_2+ in oxalic acid system for (CO 2 - and e-, ronidazole has 2 main degradation pathway in TiO_2+ in oxalic acid system: one is breaking on the formation of heterocyclic aliphatic compounds; nitro heterocyclic branched chain amino 2, converted polymerized azo compounds, and the breaking of C-O bonds. In addition, in order to solve the difficulties in the recovery of powder photocatalyst the problem, and the catalyst light response extended to visible light region, Fe2O3@TiO_2@HGMs catalyst was prepared by sol-gel method, the energy spectrum analysis (EDS), X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV Vis diffuse reflectance (UV-Vis DRS) to characterize. Xenon lamp as light source, in the presence of organic acids, the effects of degradation conditions on the removal efficiency of ronidazole is studied in detail, and the degradation mechanism were discussed. The results show that the Fe and Ti successfully loaded on the surface of hollow glass bead, and using Fe203 and The morphology of TiO_2.Fe203@TiO_2@HGMs composite materials not only improves the ability to absorb ultraviolet region, broaden the range of light absorption. The initial pH value of the solution has great influence on the degradation of ronidazole, with the increasing of pH value, the degradation rate of ronidazole decreased significantly. The organic acid has synergistic effect on the degradation of Luo ornidazole, you must meet the following 2 conditions: (1) organic acid added with Fe (III) complexes; (2) Fe (III) - organic acid must be under visible light. The reaction activity of oxalic acid and Fe2O3@TiO_2@ HGMs system, OH is the main active material CO2, - play a supporting role. It was found that the system can self generate H202, Covington and the photocatalytic reaction occurred at the same time, effectively improve the removal effect of ronidazole. Organic acid enhanced Fe2O3@TiO_2@HGMs removal ronidazole has 3 main degradation paths: Luo nitrate NH2 and the heterocyclic triazole branched between two N C atoms form new heterocyclic products (3- acetyl -2- oxazolidinone); carbon nitrogen double bond fracture for ronidazole on the formation of heterocyclic ring opening products; three is generated after the polymerization product of heterocyclic side chain. Finally, the intermediate product was further transformed into CO2 and H2O.

【學位授予單位】：廣西大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：X703

【參考文獻】

相關期刊論文 前10條

1 楊旭;李小龍;胡彩花;沙作良;楊立斌;;以乙二醇為電子給體在CuO/TiO_2上光催化分解水制氫[J];無機化學學報;2015年11期

2 陳冬梅;喻澤斌;孫蕾;黃俊;高麗紅;李明潔;;TiO_2降解迪美唑的動力學及活性物質(zhì)分析[J];環(huán)境科學;2015年11期

3 鄭思燦;陳天虎;劉海波;鄒雪華;朱承駐;陳冬;;光助芬頓反應催化降解氣體中甲苯[J];環(huán)境科學;2015年10期

4 劉晴;喻澤斌;張睿涵;李明潔;陳穎;王莉;匡瑜;張搏;朱有慧;;鈀摻TiO_2光催化降解全氟辛酸[J];環(huán)境科學;2015年06期

5 孫艷;閆康平;;甘油為電子給體的TiO_2納米管光催化制氫[J];成都大學學報(自然科學版);2015年01期

6 高乃云;張晏晏;馬艷;;UV/TiO_2去除水中磺胺甲唑的動力學及影響因素分析[J];中國環(huán)境科學;2013年11期

7 劉子傳;鄭經(jīng)堂;趙東風;吳明鉑;;TiO_2禁帶寬度和光吸收系數(shù)對其光催化性能的影響[J];發(fā)光學報;2012年12期

8 彭壽;王蕓;彭程;彭小波;;空心玻璃微珠制備方法及應用研究進展[J];硅酸鹽通報;2012年06期

9 李瑛;吳振禹;周立祥;蘭葉青;;施氏礦物和有機酸共存體系中孔雀石綠的多相光催化降解[J];南京農(nóng)業(yè)大學學報;2012年03期

10 于化江;熊亮;熊中瓊;張國慶;;復合電沉積制備TiO_2/泡沫鎳光催化材料及其催化活性[J];化工進展;2011年09期

相關博士學位論文 前4條

1 王娜;環(huán)境中磺胺類抗生素及其抗性基因的污染特征及風險研究[D];南京大學;2014年

2 楊莉?qū)?硝基咪唑類有機藥物及其配合物的合成、表征和生物活性研究[D];西北大學;2012年

3 李春娟;芬頓法和類芬頓法對水中污染物的去除研究[D];哈爾濱工業(yè)大學;2009年

4 楊世迎;TiO_2光催化降解有機污染物的初始步驟機理研究[D];浙江大學;2005年

相關碩士學位論文 前5條

1 王琳;均相UV-Fenton體系中有機羧酸根配體對金橙Ⅱ染料降解的增效作用及機理研究[D];南昌大學;2016年

2 周婉媛;TiO_2光催化浮球的制備及其降解甲硝唑的性能研究[D];東華大學;2014年

3 江丹君;施氏礦物對小分子有機酸光化學還原Cr（Ⅵ）的催化作用研究[D];南京農(nóng)業(yè)大學;2012年

4 沈瑜瀟;有機酸協(xié)同黃鐵礦對Cr（Ⅵ）的還原作用研究[D];南京農(nóng)業(yè)大學;2010年

5 李金蓮;Fenton技術處理含聚丙烯酰胺廢水的研究[D];大慶石油學院;2005年

，

本文編號：1502788