【作者】 张永利；

【导师】 胡筱敏；

【作者基本信息】 东北大学 ， 安全技术及工程， 2006， 博士

【摘要】 随着精细化工和印染技术的发展,印染废水中PVA染料、新型助剂等难生化有机物日益增多,致使其处理难度越来越大,传统的印染废水处理技术遇到了新的挑战。而湿式氧化技术被视为第二代有机废水处理高新技术,用于第一代常规技术难以解决或无法解决的难生化、有毒有害等有机废水的净化处理。开发印染废水的湿式氧化处理技术,研制新型、高效、价廉、稳定的催化剂,对有机废水治理及水资源保护具有重要意义。本研究以亚甲蓝水溶液作模拟印染废水,以COD去除率、脱色率、出水pH值和非均相研究中出水Cu溶出浓度作评价指标,对湿式氧化(WO)技术、均相催化湿式氧化(HCWO)技术和非均相催化湿式氧化(NHCWO)技术处理模拟印染废水及实际印染废水进行了系统的研究,得到一些重要结论。湿式氧化技术处理模拟印染废水,研究各因素对水样处理过程的影响,结果表明：COD去除率随氧分压、反应温度、进水pH值的升高而升高,搅拌速度存在最佳值880rpm,反应过程分快速期和慢速期两个阶段。通过湿式氧化过程中不同时刻水样的红外谱图(FT-IR),探讨了亚甲蓝降解的机制,研究表明：杂环上的-C-S-、-C=S-首先断键,其次是杂环上的-C-N-、-C＝N-断键,亚甲蓝转化为二甲基苯胺,继而是苯环上C与二甲氨基中N相联的-C-N-断键,二甲基苯胺降解为对苯醌和二甲胺。均相催化湿式氧化技术处理模拟印染废水,从18种可溶盐中筛选出较好的催化剂,其排序依次为：Cu(N03)2、CuSO4、Fe(NO3)3、FeSO4、Zr(NO3)4、Cr(NO3)3。按所含金属离子的质量比例,以CuSO4和FeSO4复配了双组分催化剂Cu1Fe3、 CulFe1、Cu3Fe1,实验发现Cu1Fe1对亚甲蓝的催化氧化效果最好,在50mg/L催化剂用量、温度120℃下,水样COD去除率比不加催化剂时提高约50%。接着,进行了Cu1Fe1在亚甲蓝湿式氧化中应用的系统研究,结果表明：COD去除率和脱色率随催化剂用量、氧分压、反应温度的提高而提高,在进水pH值5.25、催化剂用量150mg/L、氧分压1.0MPa、温度180℃下反应60min,水样COD由2000mg/L降低到130mg/L,去除率达到93.5%,而色度由30万倍降低到20倍,脱色率达到99.99%。关于Cu1Fe1在亚甲蓝湿式氧化中的作用机理,研究表明：Cu、Fe对亚甲蓝降解有主导性的催化作用,催化剂诱导自由基产生,发生氧化反应；此外,Fe(Ⅱ)盐被氧化为Fe(Ⅲ)盐,以各种羟基Fe(Ⅲ)离子及聚合物形式存在,对水样有混凝作用。非均相催化湿式氧化技术处理模拟印染废水,对4种载体FSC、AC、FSD及FSE的研究表明,FSC载体是最佳的选择。X射线衍射谱图(XRD)分析表明,此载体的主要成分为γ-Al2O3。在均相催化湿式氧化研究的基础上,以Cu(NO3)2作为活性组分,通过原子吸收、扫描电镜(SEM)、XRD等检测手段,对催化剂制备的浸渍状态、浸渍温度、浸渍时间、浸渍液浓度、焙烧温度、焙烧时间进行了系统的研究,结果表明：在浸渍液浓度为6wt%Cu、浸渍温度35℃时动态浸渍8h、焙烧温度和时间分别为650℃和5h的条件下制备的Cu/FSC催化剂,其用量为2g/L、温度150℃时,水样COD去除率比不加催化剂时提高近20%。Cu/FSC作为亚甲蓝湿式氧化的催化剂,可用Redox机理来解释。为了减少反应过程中催化剂的Cu溶出并提高催化剂活性,选用Ce(NO3)3作为助剂对Cu/FSC催化剂进行改性,优化了Cu-Ce/FSC催化剂的制备工艺：Cu(NO3)2与Ce(NO3)3共浸渍、金属离子总浓度为6wt%、Cu2+:Ce3+为1：1(wt)、35℃下动态浸渍8h、110℃下干燥10h、550℃下焙烧5h；改性的催化剂Cu-Ce/FSC与Cu/FSC对比,其活性略有提高,而稳定性大大加强；机理研究表明,Cu-Ce/FSC催化剂中,CeO2起到了结构助剂和电子助剂的双重作用。将Cu-Ce/FSC催化剂应用于模拟印染废水的湿式氧化,在进水pH值5.25、氧分压1.0MPa、反应温度180℃、催化剂用量10g/L的条件下反应60min,水样COD由2000mg/L降低到176mg/L,去除率达到91.2%；色度由30万倍降低到20倍,脱色率达到99.99%；水样pH值由5.25升高到7.5；出水Cu溶出浓度为1.92mg/L。实际印染废水处理的研究表明,在催化剂Cu1Fe1和Cu-Ce/FSC用量分别为150mg/L和10g/L、温度200℃、氧分压1.0MPa条件下反应90min,出水COD、BOD5均达到《污水综合排放标准》(GB8978-1996)三级标准,而色度和pH值均达到一级标准,非均相的Cu溶出浓度达到三级标准；印染废水的可生化性改善显著,BOD5/COD由处理前的0.021提高到处理后的0.423(均相)和0.307(非均相)。更多还原

【Abstract】 With the development of fine chemicals and printing and dyeing technologies, PVA dyestuffs, new-style doping agents and other hard-biodegradable organic matter in printing and dyeing wastewater have been increasing with each passing day, therefore, the wastewater treatment has become more and more difficult, and the conventional treatment technologies of printing and dyeing wastewater have been faced with challenges. Wet Oxidation (WO) is regarded as the second era technology for treating organic wastewater, and it has been used to treat wastewater that is nocuous and hard-biodegradable for the first era technology of wastewater treatment. It is important for the treatment of organic wastewater and for the protection of water resource that the WO technologies on printing and dyeing wastewater treatment are developed and the new-style, high-effect, low-cost and steady catalysts are prepared.Methylene blue (MB) watery solution with the COD value of2000mg/L was selected as printing and dyeing simulant wastewater, and COD removal rate, color removal rate, effluent pH and Cu concentration in solution of nonhomogeneous CWO were selected as evaluation standards. Printing and dyeing simulant and actual wastewater was treated with the technologies of WO, homogeneous catalytic wet oxidation (HCWO) and nonhomogeneous catalytic wet oxidation (NHCWO), then some important conclusions have been acquired.The results on the treatment of printing and dyeing simulant wastewater with WO technology showed that COD removal rates of MB increased with the increase of oxygen pressure, reaction temperature and influent pH values. The best value of stirring speed was880rpm, and the reaction comprised quick reaction course and slow reaction course. MB degradation mechanism was investigated by the FT-IR spectra of different moments, and the results showed that:firstly,-C-S-、-C=S-secondly,-C-N-、-C=N-in heterocyclic broke off, then the-C-N-of the carbon in benzene ring and the nitrogen in (CH3)2N-broke off, so xylidine was degraded,1,4-benzoquinone and (CH3)2NH were come into being. Printing and dyeing simulant wastewater was treated with HCWO technology, and18dissolvable metals were filtrated, according to their catalytic activity, the better catalysts of them were Cu(NO3)2, CuSO4, Fe(NO3)3, FeSO4, Zr(NO3)4, Cr(NO3)3. CuSO4and FeSO4were selected to compound CulFe3, CulFel and Cu3Fel according to the mass proportion of metal ion. The results indicated that Cu1Fel took on the most excellent catalytic activity. With the catalyst dosage of50mg/L, and the reaction temperature of120℃, COD removal rate enhanced about50percents than that of the course without any catalyst. Then the application of Cu1Fel was investigated in the course of MB oxidation. The results indicated that the COD and color removal rates increased with the increase of the catalyst dosage, the oxygen pressure and the reaction temperature. With the following conditions, the influent pH of5.25, the catalyst dosage of150mg/L, the oxygen pressure of1.0MPa, the reaction temperature of180℃, and reaction time of60minutes, the water sample COD dropped to130mg/L from2000mg/L, and COD removal rate was93.5%; The water sample chromaticity dropped to20from300thousands, and color removal rate was99.99%. The effect mechanism of Cu1Fe1in the course of MB wet oxidation was researched:For one thing, Cu and Fe behaved dominant catalysis, and puissant oxidant radicle induced organic matter to oxidize. For another, Fe(Ⅱ) was oxidized to Fe(Ⅲ), so Fe(Ⅲ) and its polymers agglomerated water sample.Printing and dyeing simulant wastewater was treated with NHCWO technology. Among4types of support materials:FSC, AC, FSD and FSE, FSC was selected as the support material of the catalysts,and the analysis of XRD spectra showed that the central ingredient of FSC was γ-Al2O3. Based on the research of homogeneous CWO, Cu(NO3)2was selected as active component. The impregnating state, the impregnating temperature, the impregnating time, the impregnating concentration, the calcination temperature and time were researched systematically, by atom absorption, SEM, XRD, and so on. Considering the activity and stability of catalyst, the preparation process of Cu/FSC were optimized:the impregnating temperature of35℃, the impregnating state of dynamic, the impregnating time of8hours, the impregnating liquid concentration of6wt%Cu, the calcination temperature and time were650℃and5hours, respectively. With the Cu/FSC dosage of2g/L, and the reaction temperature of150℃, COD removal rate of simulant wastewater enhanced about20percents than that of WO course. The effect mechanism of Cu/FSC as a catalyst of oxidation reaction could be explained by redox mechanism.In order to decrease the leaching of Cu and promote the catalytic activity and stability of Cu/FSC, Ce(NO3)3was selected as doping agent. The preparation conditions of Cu-Ce/FSC catalyst were as follows:Cu(NO3)2and Ce(NO3)3were impregnated together, the total metal ions concentration of6wt%, the Cu:Ce ratio of1:1, the impregnating temperature of35℃, the impregnating time of8hours, the impregnating state of dynamic, the dryness temperature and time of110℃and10hours, respectively, the calcination temperature and time of550℃and5hours, respectively. Compared with Cu/FSC, the catalyst activity of Cu-Ce/FSC improved slightly, but its stability promoted greatly. The mechanism research indicated that CeO2behaved the function of configuration doping agent and electron doping agent in Cu-Ce/FSC catalyst. Cu-Ce/FSC catalyst was applied to treat simulant wastewater, the operational conditions were as follows:the influent pH of5.25, the oxygen pressure of1.0MPa, the reaction temperature of180℃, the catalyst dosage of10g/L, and the reaction time of60minutes. With these conditions, the water sample COD dropped to176mg/L from2000mg/L, and COD removal rate was91.2%; The water sample chromaticity dropped to20from300thousands, and color removal rate was99.99%. Effluent pH value promoted from5.25to7.5, and Cu concentration in solution was1.92mg/L.Printing and dyeing actual wastewater was treated with CWO technology. With these conditions:Cu1Fel dosage of150mg/L, Cu-Ce/FSC dosage of10g/L, the reaction temperature of200℃, the oxygen pressure of1.0MPa, and the reaction time of90minutes, COD and BOD5could make third grade standard of "sewerage synthesis letting standard"(GB8978-1996), chromaticity and pH made first grade standard, and Cu concentration in effluent water made third grade standard. The biodegradability of actual printing and dyeing improved greatly, its BOD5/COD increased to0.423(HCWO) and0.307(NHCWO) after treatment from original0.021.更多还原