微波辅助湿式催化氧化反应系统的构建及对煤化工废水处理
发布时间：2018-09-05 07:17
【摘要】：生化法对实际煤化工废水中的难降解有机污染物降解效果差,使得生化出水水质很难达标。因而,一种可靠的深度处理方法对煤化工生化二级出水进行再处理是十分必要的。湿式H2O2催化氧化技术(Catalytic Wet Peroxide Oxidation,CWPO)作为一种深度处理方法,微波技术作为一项成熟的高效低成本能量供给技术,二者结合所形成的微波辅助催化湿式双氧水氧化工艺(MWCWPO),给深度处理难降解工业废水提供了新思路。本研究以铜镍为活性组分,颗粒活性炭为载体,分别以浸渍法和沉淀法制备了CuOx-NiO/AC负载型催化剂,通过MWCWPO体系对喹啉的降解实验优化和比较了两种方法制备负载型催化剂的催化性能,并通过一系列表征手段进一步研究了催化剂制备方法对催化剂结构的影响。实验结果显示,沉淀法制备的催化剂对污染物降解效果更好,并确定了沉淀法制备负载型催化剂的最佳条件为:浸渍液硝酸铜和硝酸镍的混合浓度为0.2 mol/L,沉淀剂氨水的浓度为0.25 mol/L,硝酸铜和硝酸镍活性组分配比为4:1,沉淀剂投加方式为逆加法,焙烧温度为300℃,焙烧时间为4 h。对负载型催化剂进行表征分析后,发现由沉淀法制备的负载型催化剂活性组分晶粒更小,晶粒在颗粒活性炭中分布更加均匀,催化剂比表面积更大,表面化学吸附氧更多,是导致沉淀法制备负载型催化剂催化性能更好的主要原因。通过HFSS电磁模拟仿真软件对不同的微波腔体结构形式进行了微波分布均匀性分析,并对微波反应器腔体进行结构优化。研究表明负载水中微波均匀性大小的腔体结构为圆柱形微波腔体八面体微波腔体矩形微波腔体,优化后微波装置对污染物的去除效果更优。研究证明了MWCWPO工艺的优越性,发现反应温度和有效水力停留时间为MWCWPO工艺的主要控制条件,得到最佳反应温度和有效水力停留时间分别为60℃和1.12 min,微波功率(200~600 W)和催化剂投加量(50~200 g)在一定范围内对MWCWPO体系影响不大,处理后出水COD值为34 mg/L,满足《污水综合排放标准》(GB8978-1996)一级标准。催化剂在连续流实验中铜镍离子溶出量远低于排放标准,连续使用7次后,体系对TOC的去除率下降5%,催化剂稳定性高。为了提高MWCWPO反应器对废水的处理量,设计处理量为10 t/d的微波反应器,并对微波反应器的直径、高度、微波源的数目、微波腔体尺寸进行了模拟优化,构建出了微波反应器系统,为工业微波催化氧化中试装置提供参考。
[Abstract]:The biochemistry method has a poor effect on the degradation of organic pollutants in actual coal chemical wastewater, which makes the quality of biochemical effluent difficult to reach the standard. Therefore, it is necessary to retreat the secondary effluent from coal chemical industry by a reliable advanced treatment method. Wet H2O2 catalytic oxidation technology (Catalytic Wet Peroxide Oxidation,CWPO) as an advanced treatment method, microwave technology as a mature high efficiency and low cost energy supply technology, The microwave-assisted catalytic wet hydrogen peroxide oxidation process (MWCWPO),) formed by the combination of the two provides a new idea for advanced treatment of refractory industrial wastewater. In this study, CuOx-NiO/AC supported catalysts were prepared by impregnation method and precipitation method using copper and nickel as active component and granular activated carbon as carrier, respectively. The catalytic properties of the supported catalysts prepared by MWCWPO system were optimized and compared by the degradation experiments of quinoline. The influence of the preparation methods on the structure of the catalysts was further studied by a series of characterization methods. The results showed that the catalyst prepared by precipitation method had better degradation effect on pollutants. The optimum conditions for the preparation of supported catalyst by precipitation method were determined as follows: the mixed concentration of copper nitrate and nickel nitrate was 0. 2 mol/L, the concentration of ammonia water was 0. 25 mol/L, the distribution ratio of copper nitrate and nickel nitrate was 4: 1, and the precipitation agent was added. The way of addition is inverse addition, The calcination temperature is 300 鈩，
本文编号：2223572
[Abstract]:The biochemistry method has a poor effect on the degradation of organic pollutants in actual coal chemical wastewater, which makes the quality of biochemical effluent difficult to reach the standard. Therefore, it is necessary to retreat the secondary effluent from coal chemical industry by a reliable advanced treatment method. Wet H2O2 catalytic oxidation technology (Catalytic Wet Peroxide Oxidation,CWPO) as an advanced treatment method, microwave technology as a mature high efficiency and low cost energy supply technology, The microwave-assisted catalytic wet hydrogen peroxide oxidation process (MWCWPO),) formed by the combination of the two provides a new idea for advanced treatment of refractory industrial wastewater. In this study, CuOx-NiO/AC supported catalysts were prepared by impregnation method and precipitation method using copper and nickel as active component and granular activated carbon as carrier, respectively. The catalytic properties of the supported catalysts prepared by MWCWPO system were optimized and compared by the degradation experiments of quinoline. The influence of the preparation methods on the structure of the catalysts was further studied by a series of characterization methods. The results showed that the catalyst prepared by precipitation method had better degradation effect on pollutants. The optimum conditions for the preparation of supported catalyst by precipitation method were determined as follows: the mixed concentration of copper nitrate and nickel nitrate was 0. 2 mol/L, the concentration of ammonia water was 0. 25 mol/L, the distribution ratio of copper nitrate and nickel nitrate was 4: 1, and the precipitation agent was added. The way of addition is inverse addition, The calcination temperature is 300 鈩，
本文编号：2223572
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