【摘要】：粉煤灰是以煤為能源電廠發(fā)電產(chǎn)生的廢棄物,本課題以內(nèi)蒙古的粉煤灰為原料,通過對粉煤灰EDTA水熱改性后,共沉淀Fe制備復合催化劑,主要使用掃描電子顯微鏡(SEM)、比表面積(BET)、傅里葉轉(zhuǎn)換紅外光譜(FTIR)、熱重(TGA)、X射線光電子能譜分析(XPS)等手段對復合催化劑的形貌結(jié)構(gòu)、表面性質(zhì)、熱穩(wěn)定性等進行了表征。實驗室研究以2-氯酚模擬廢水中的苯系污染物,建立臭氧催化氧化體系進行廢水氧化降解研究。中試試驗應用到煤化工MTO汽提塔外排污水中,主要結(jié)論如下：(1)利用0.05 mol/L的EDTA對粉煤灰通過水浴加熱方法表面改性,Al、Si含量升高。活化改性后共沉淀Fe制備粉煤灰基復合催化劑,掃描電鏡SEM分析FA-A基復合催化劑具有不規(guī)則,多孔的表面,BET增大到200.3 m2/g；熱重TGA分析在600℃左右具有良好的熱穩(wěn)定性：紅外光譜FTIR分析FA-A基復合催化劑沒有明顯的基團變化；XPS分析載鐵FA-A基復合催化劑負載了一定量的鐵氧化物,其中含有二價和三價鐵。(2)載鐵粉煤灰基復合催化劑臭氧催化降解2-氯酚：①液固比為5：1(mL/g),2-氯酚的初始濃度為200 mg/L,在pH為9時,催化臭氧化降解2-氯酚的去除效率提高了40.57%-57.21%。②不同液固比下2：1、5：1、10：1(mL/g),液固比2：1的2-氯酚催化氧化的去除效率較好。③液固比為10:1 (mL/g),100mg/L、200 mg/L、 500 mg/L、1000mg/L的2-氯酚,100 mg/L的2-氯酚的去除效率較高,但測定的2-氯酚降解的量是逐漸降低的。④2-氯酚初始濃度為200 mg/L,液固比為10：1(mL/g),添加叔丁醇的量為5mmol/L,叔丁醇的添加更加明顯抑制了單獨臭氧過程中2-氯酚的去除效率,而對催化臭氧過程抑制效果的影響降低。⑤臭氧氧化降解2-氯酚的過程遵循準一級動力學模型,對于單獨臭氧、粉煤灰、載鐵FA-A基催化劑來說,臭氧氧化降解2-氯酚的動力學反應速率常數(shù)分別為0.03、0.05、0.1 min-1。2-氯酚通過臭氧催化氧化首先降解為鄰苯二醌；然后鄰苯二醌中間產(chǎn)物氧化開環(huán),轉(zhuǎn)化為己二烯二酸、馬來酸、草酸等中間產(chǎn)物；最后上述有機酸降解為二氧化碳的過程。(3)MTO汽提塔外排污水中試及載鐵復合催化劑機理研究：利用臭氧催化氧化與分離技術對MTO汽提塔外排污水進行處理,出水指標符合儀表沖洗水指標。載鐵FA-A基復合催化劑的加入,促進產(chǎn)生了更多的羥基自由基,吸附在催化劑表面上的有機物直接與臭氧發(fā)生氧化作用,也可以與羥基自由基發(fā)生間接的氧化作用。
[Abstract]:Fly ash is a kind of waste produced by coal-fired power plant. In this paper, fly ash from Inner Mongolia was used as raw material, after hydrothermal modification of fly ash EDTA, composite catalyst was prepared by coprecipitation of Fe. The morphology, surface properties and thermal stability of the composite catalysts were characterized by scanning electron microscopy (SEM), specific surface area (SEM), (BET), Fourier transform infrared spectroscopy (FTIR), (FTIR), thermogravimetric (TGA) (TGA) and X-ray photoelectron spectroscopy (XPS). In the laboratory, 2-chlorophenol was used to simulate benzene pollutants in wastewater, and ozone catalytic oxidation system was established to study the degradation of wastewater. The main conclusions are as follows: (1) the surface modification of fly ash by water bath heating method with EDTA of 0.05 mol/L is used to increase the content of MTO Si. The composite catalyst based on fly ash was prepared by co-precipitation of Fe after activation. SEM analysis showed that the composite catalyst based on FA-A was irregular and the porous surface increased to 200.3 m2 / g. The thermogravimetric TGA analysis shows good thermal stability at about 600 鈩，

本文編號：2221942