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

【摘要】：染料廢水成分復(fù)雜、色度高、有機(jī)物含量高、可生化性差,屬于典型的難降解有機(jī)廢水,對(duì)環(huán)境的危害極大,因而尋求一種經(jīng)濟(jì)有效的處理方法是水污染處理的一個(gè)難題。高級(jí)氧化技術(shù)中的Fenton反應(yīng)具有氧化性強(qiáng)、反應(yīng)速度快等優(yōu)點(diǎn),因而廣泛用于染料廢水處理中。但傳統(tǒng)Fenton反應(yīng)需在較強(qiáng)酸性條件下進(jìn)行,且H202利用率不高,反應(yīng)后會(huì)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(yīng)在一定程度上可解決傳統(tǒng)均相Fenton反應(yīng)存在的問題,同時(shí)可實(shí)現(xiàn)催化劑回收利用,具有良好的應(yīng)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(yīng)體系,具有反應(yīng)條件溫和、操作簡(jiǎn)單、自由基利用率較高等優(yōu)點(diǎn),可進(jìn)一步解決傳統(tǒng)Fenton反應(yīng)存在的問題,因而成為類Fenton體系研究的又一熱點(diǎn)。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(duì)所制備催化劑進(jìn)行表征。實(shí)驗(yàn)考察了反應(yīng)影響因素對(duì)催化降解性能的影響,對(duì)催化劑穩(wěn)定性進(jìn)行分析,初步探討了催化劑催化機(jī)理,以期對(duì)染料廢水的有效處理提供一種新的理論依據(jù)和技術(shù)支持。考察焙燒溫度和焙燒時(shí)間對(duì)CuFe2O4催化活性的影響,確定其焙燒溫度400℃,焙燒時(shí)間2h,在此溫度下得到CuO和Fe203的最佳焙燒時(shí)間為2h. XRD和EDS結(jié)果表明,所制備催化劑確為CuFe2O4、CuO和Fe2O3、SEM和BET分析可知,實(shí)驗(yàn)制備CuFe2O4、CuO和Fe203平均粒徑較小,依次分別為52nm、67nm、139nm。實(shí)驗(yàn)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(dāng)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(yīng)180min后,三個(gè)反應(yīng)體系對(duì)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(duì)CuO/K2S2O8和CuFe2O4/K2S2O8反應(yīng)體系的催化降解機(jī)理進(jìn)行研究,得出反應(yīng)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(shí),以非均相催化為主；CuFe2O4用作催化劑,在各pH范圍內(nèi)以非均相催化為主,增大反應(yīng)pH時(shí),催化效果更好。自由基捕獲實(shí)驗(yàn)得出反應(yīng)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(shí)驗(yàn)制備催化劑用到K2S2O8反應(yīng)體系時(shí),CuFe2O4的催化活性和穩(wěn)定性最好,CuO次之,Fe2O3最差,表明實(shí)驗(yàn)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(hào)：1619193