湿式过氧化氢氧化活性艳蓝KN-R的实验研究及机理分析

发布时间：2018-12-25 12:06

【摘要】：随着印染行业的发展,染料废水对水体的污染日益严重。由于染料废水中含有大量的、难以被微生物降解的有毒有害物质,使印染废水的污染治理成为人们关注的焦点。在所有染料中,蒽醌染料的使用量仅次于偶氮染料。由于其具有十分稳定的蒽醌结构,不易被生物降解,因而在环境中残留时间长。活性艳蓝KN-R是一种典型的蒽醌类染料。为了有效地处理印染废水,本论文采用了湿式过氧化氢氧化法(Wet Peroxide Oxidation,简称WPO)降解活性艳蓝KN-R。通过筛选反应因子,获得最佳的条件是:H_2O_2的添加剂量为20.4μL,即反应体系中H_2O_2的溶度为0.01 mol/L,反应温度为150°C,反应时间为4 h,反应压强为0.5 MPa,p H为6.8。在最佳的条件下处理后,活性艳蓝KN-R模拟废水的颜色由深蓝色变为无色。当初始浓度为200 mg/L时,在最优条件下,活性艳蓝KN-R的脱色率和TOC去除率分别为100%和68.54%。在120~150°C范围内考察了该反应的动力学,结果表明活性艳蓝KN-R的湿式过氧化氢氧化反应符合准一级动力学方程,并且通过计算得到了反应活化能为73.9 k J/mol(R2=0.96)。对活性艳蓝KN-R经WPO法降解后的产物,利用气相色谱/质谱联用仪(GC-MS)进行鉴定。结果表明其降解产物主要为小分子有机酸,如丁二酸、已二酸、邻苯二甲酸,而这种小分子酸都是可生化的,这说明经过WPO降解后,活性艳蓝KN-R的可生化性有所提高。通过添加自由基捕获剂(叔丁醇)研究了自由基反应机理,结果显示,自由基捕获剂的存在对WPO法降解活性艳蓝KN-R有负面影响。150°C,0.5 MPa氧气压力,加入叔丁醇,反应4 h后,溶液在596 nm处的吸光度从0.00725增加到0.40696,因此H_2O_2在反应过程中产生了羟基自由基,并且高反应活性的羟基自由基也参与了WPO法降解活性艳蓝KN-R的反应机制。
[Abstract]:With the development of printing and dyeing industry, dye wastewater pollution to water is becoming more and more serious. Because dye wastewater contains a lot of toxic and harmful substances which are difficult to be degraded by microorganisms, the pollution treatment of printing and dyeing wastewater has become the focus of attention. Of all the dyes, anthraquinone dyes are used second only to azo dyes. Because of its stable anthraquinone structure, it is difficult to biodegrade, so it remains in the environment for a long time. Reactive brilliant blue KN-R is a typical anthraquinone dye. In order to deal with printing and dyeing wastewater effectively, wet hydrogen peroxide oxidation (Wet Peroxide Oxidation,) method was used to degrade reactive brilliant blue KN-R. (WPO). By screening the reaction factors, the optimum conditions were obtained as follows: the amount of H_2O_2 was 20.4 渭 L, that is, the solubility of H_2O_2 in the reaction system was 0. 01 mol/L, the reaction temperature was 150 掳C, the reaction time was 4 h. The reaction pressure is 0. 5 MPa,p H is 6. 8. After treatment under the best conditions, the color of reactive brilliant blue KN-R simulated wastewater changed from dark blue to colorless. When the initial concentration was 200 mg/L, the decolorization and TOC removal rates of reactive brilliant blue KN-R were 100% and 68.54%, respectively. The kinetics of the reaction was investigated in the range of 120 掳C. The results show that the wet hydrogen peroxide oxidation reaction of reactive brilliant blue KN-R accords with the quasi first-order kinetic equation, and the activation energy of the reaction is 73.9 k J/mol (R20.96). The products of reactive brilliant blue KN-R degraded by WPO were identified by gas chromatography / mass spectrometry (GC-MS). The results showed that the degradation products were mainly small molecular organic acids, such as succinic acid, adipic acid and phthalic acid, which were biodegradable, which indicated that the biodegradability of reactive brilliant blue KN-R was improved after WPO degradation. The mechanism of free radical reaction was studied by adding free radical trapping agent (tert-butanol). The results showed that the existence of free radical trapping agent had a negative effect on the degradation of reactive brilliant blue KN-R by WPO method. After 4 h reaction, the absorbance of the solution at 596 nm increased from 0.00725 to 0.40696, so H_2O_2 produced hydroxyl radical during the reaction. The hydroxyl radical with high reactive activity also participated in the degradation mechanism of reactive brilliant blue KN-R by WPO method.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

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