本文選題：非均相類Fenton　切入點：CuFe_2O_4　出處：《浙江大學》2015年碩士論文　論文類型：學位論文

【摘要】：染料廢水成分復雜、色度高、有機物含量高、可生化性差,屬于典型的難降解有機廢水,對環(huán)境的危害極大,因而尋求一種經(jīng)濟有效的處理方法是水污染處理的一個難題。高級氧化技術中的Fenton反應具有氧化性強、反應速度快等優(yōu)點,因而廣泛用于染料廢水處理中。但傳統(tǒng)Fenton反應需在較強酸性條件下進行,且H202利用率不高,反應后會產(chǎn)生大量鐵泥,出水顏色發(fā)黃,從而引發(fā)二次污染等問題。研究發(fā)現(xiàn),非均相Fenton反應在一定程度上可解決傳統(tǒng)均相Fenton反應存在的問題,同時可實現(xiàn)催化劑回收利用,具有良好的應用前景。基于SO4·-的過硫酸鹽活化是近年發(fā)展起來的一種類Fenton反應體系,具有反應條件溫和、操作簡單、自由基利用率較高等優(yōu)點,可進一步解決傳統(tǒng)Fenton反應存在的問題,因而成為類Fenton體系研究的又一熱點。本文采用檸檬酸輔助溶膠-凝膠法制備了CuFe2O4、CuO和Fe203三種非均相催化劑,在常溫常壓條件下催化K2S208氧化降解橙黃Ⅱ。優(yōu)化催化劑制備條件,并對所制備催化劑進行表征。實驗考察了反應影響因素對催化降解性能的影響,對催化劑穩(wěn)定性進行分析,初步探討了催化劑催化機理,以期對染料廢水的有效處理提供一種新的理論依據(jù)和技術支持。考察焙燒溫度和焙燒時間對CuFe2O4催化活性的影響,確定其焙燒溫度400℃,焙燒時間2h,在此溫度下得到CuO和Fe203的最佳焙燒時間為2h. XRD和EDS結果表明,所制備催化劑確為CuFe2O4、CuO和Fe2O3、SEM和BET分析可知,實驗制備CuFe2O4、CuO和Fe203平均粒徑較小,依次分別為52nm、67nm、139nm。實驗得到溶液初始pH值、K2S208投加量和橙黃Ⅱ初始濃度是影響催化降解效果的重要因素。其中,CuFe2O4的催化降解效果最好,CuO次之,Fe203最差。當橙黃Ⅱ初始濃度20mg/L,催化劑濃度均1g/L, K2S2O8濃度均0.5g/L,初始pH均5.3,反應180min后,三個反應體系對橙黃Ⅱ的色度去除率和TOC去除率依次分別為98%和62%、97%和50%、24%和21%。對CuO/K2S2O8和CuFe2O4/K2S2O8反應體系的催化降解機理進行研究,得出反應體系中起催化作用的主要是Cu。CuO用作催化劑,酸性條件下以Cu2+的均相催化為主,輔以非均相催化,增大pH至弱酸性或堿性時,以非均相催化為主；CuFe2O4用作催化劑,在各pH范圍內以非均相催化為主,增大反應pH時,催化效果更好。自由基捕獲實驗得出反應體系中主要活性中間體為SO4·-和HO·,酸性條件以S04.-為主,堿性條件以HO·為主。催化劑穩(wěn)定性分析可知,實驗制備催化劑用到K2S2O8反應體系時,CuFe2O4的催化活性和穩(wěn)定性最好,CuO次之,Fe2O3最差,表明實驗制備CuFe2O4是一種很有潛能的非均相類Fenton催化劑。
[Abstract]:Dye wastewater is a typical refractory organic wastewater with complex composition, high chromaticity, high organic content and poor biodegradability, which is harmful to the environment. Therefore, it is a difficult problem for water pollution treatment to seek an economical and effective treatment method. The Fenton reaction in advanced oxidation technology has the advantages of strong oxidation, fast reaction speed, and so on. So it is widely used in dye wastewater treatment, but the traditional Fenton reaction needs to be carried out under the condition of strong acidity, and the utilization ratio of H202 is not high. After the reaction, a large amount of iron sludge will be produced and the effluent color will turn yellow, thus causing secondary pollution and so on. The heterogeneous Fenton reaction can solve the problem of traditional homogeneous Fenton reaction to some extent, and can realize the recovery of catalyst at the same time. Persulfate activation based on SO4 路- is a kind of Fenton reaction system developed in recent years. It has the advantages of mild reaction conditions, simple operation, high free radical utilization rate and so on. It can further solve the problem of traditional Fenton reaction and become another hotspot in the study of Fenton like system. In this paper, three kinds of heterogeneous catalysts, CuFe2O4CuO and Fe203, were prepared by citric acid assisted sol-gel method. The oxidation degradation of orange by K2S208 was studied under normal temperature and atmospheric pressure. The preparation conditions of the catalyst were optimized, and the catalyst was characterized. The influence of reaction factors on the catalytic degradation performance was investigated experimentally, and the stability of the catalyst was analyzed. The catalytic mechanism of catalyst was preliminarily discussed in order to provide a new theoretical basis and technical support for the effective treatment of dye wastewater. The effects of calcination temperature and time on the catalytic activity of CuFe2O4 were investigated, and the calcination temperature was determined at 400 鈩，

本文編號：1619193