本文選題：芬頓 + 亞甲基藍��； 參考：《成都理工大學(xué)》2017年碩士論文

【摘要】：據(jù)統(tǒng)計,1噸染料廢水的排放,將造成20噸水體的污染,染料廢水因生物難降解性和“三致”毒性,會對湖泊、江河等水體造成巨大危害。針對該類廢水的處理,芬頓技術(shù)是目前研究最為集中且極具前景的高級氧化技術(shù)之一。芬頓氧化法具有高降解率、化學(xué)反應(yīng)過程友好、成本低和應(yīng)用廣泛等特點,但傳統(tǒng)芬頓體系存在出水色度高、鐵流失量大,反應(yīng)體系呈酸性等缺點。研究發(fā)現(xiàn),制備不溶于水的催化劑,能改善傳統(tǒng)芬頓的缺點。本文以硅藻土為載體,采用直接蒸發(fā)法制備一種新型負載型非均相催化劑,優(yōu)化了D-Fe_2O_3的制備條件,并對其進行了SEM、XRD等表征;考察了各反應(yīng)因素對催化降解的影響;初步探討了氧化亞甲基藍的過程以及各因素的反應(yīng)動力學(xué);分析了D-Fe_2O_3的穩(wěn)定性,并利用非均相芬頓流化床對D-Fe_2O_3的實用性進行評價。經(jīng)實驗可知制備過程中鐵離子濃度和固液比對D-Fe_2O_3的催化性能存在影響,其制備的最優(yōu)鐵離子濃度和固液比分別為0.5 mol/L和1:15;SEM、EDS和XRD的結(jié)果表明,在改性硅藻土表面上負載了致密的、不定型的Fe_2O_3。又建立了非均相芬頓體系(D-Fe_2O_3/H2O2),在相同的反應(yīng)條件下,該體系相較于傳統(tǒng)芬頓體系對亞甲基藍的脫色速率提升了3.5倍。通過正交實驗可知各因素對脫色效果的影響程度各不相同,其中初始pH反應(yīng)溫度D-Fe_2O_3投加量雙氧水投加量。經(jīng)過單因子實驗結(jié)果表明,當(dāng)雙氧水投加量120 mmol/L、D-Fe_2O_3投加量12 g/L、反應(yīng)溫度55℃、初始pH 3和初始濃度50 mg/L時對亞甲基藍的脫色效果最佳,反應(yīng)20 min脫色率可達99%以上。通過UV-vis分析和文獻可知,在降解過程中顯色基團(巰基,-S-)的N,S雙烯環(huán)及其兩側(cè)連接的苯環(huán)發(fā)生分解,中間產(chǎn)物不斷地進行脫甲基化和脫氨基化,直至降解為CO2、H2O和無機鹽離子(Cl-、NO3-和SO42-)。降解反應(yīng)符合一級反應(yīng),其線性相關(guān)度均達到0.950以上。對D-Fe_2O_3穩(wěn)定性分析可知,在強酸和強堿環(huán)境中溶出鐵量分別為5.31 mg/L和0.05 mg/L,耐酸堿性能良好;D-Fe_2O_3經(jīng)過5次連續(xù)重復(fù)使用后,仍能保持在90 min內(nèi)達到99%以上的脫色率;在非均相芬頓流化床小試實驗中,反應(yīng)器出水澄清,色度能達到污水排放標(biāo)準(zhǔn);反應(yīng)器出水COD、脫色率和溶出鐵量分別達到50 mg/L、99%和18 mg/L以上。因此D-Fe_2O_3有運用于實際的可能性,是一種很有潛力的非均相芬頓催化劑。
[Abstract]:According to statistics, the discharge of 1 ton dye wastewater will cause 20 tons of water pollution. Because of biodegradability and "three causes" toxicity, dye wastewater will cause great harm to lakes, rivers and other water bodies. Fenton technology is one of the most concentrated and promising advanced oxidation technologies for the treatment of this kind of wastewater. Fenton oxidation is characterized by high degradation rate, friendly chemical reaction process, low cost and wide application. However, the traditional Fenton system has the disadvantages of high chroma of effluent, large amount of iron loss and acidic reaction system. It has been found that the preparation of insoluble catalysts can improve the shortcomings of traditional Fenton. In this paper, a novel supported heterogeneous catalyst was prepared by direct evaporation with diatomite as the carrier. The preparation conditions of D-Fe2O3 were optimized and characterized by SEMMA-XRD, and the effects of various reaction factors on the catalytic degradation were investigated. The process of methylene blue oxidation and the reaction kinetics of various factors were discussed, the stability of D-Fe2O3 was analyzed, and the practicability of D-Fe2O3 was evaluated by using a non-homogeneous Fenton fluidized bed. The experimental results show that the concentration of iron ion and the ratio of solid to liquid have influence on the catalytic performance of D-Fe2O3. The optimum concentration of iron ion and the ratio of solid to liquid are 0.5 mol / L and 1: 15% SEMEDS and XRD, respectively. The results show that the modified diatomite is loaded on the surface of the modified diatomite, and the results of XRD show that the optimum concentration of iron ion and the ratio of solid to liquid are 0.5 mol / L and 1: 15 respectively. Unshaped Fe2O3s. Furthermore, a heterogeneous Fenton system was established. Under the same reaction conditions, the decolorization rate of methylene blue in this system was 3.5 times higher than that in the traditional Fenton system. The orthogonal experiment shows that the influence of various factors on the decolorization effect is different, among which the initial pH reaction temperature D-Fe2O3 dosage of hydrogen peroxide is different. The results of single factor experiment show that the decolorization efficiency of methylene blue is the best when the dosage of hydrogen peroxide is 120 mmol / L, the dosage of D-Fe2O3 is 12 g / L, the reaction temperature is 55 鈩，

本文編號：2040798