水力空化强化二氧化氯降解苯酚废水研究

发布时间：2018-02-02 11:29

本文关键词： 水力空化苯酚二氧化氯降解率　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：苯酚是一种具有代表性的难降解有机物,对生态环境和人类健康可造成较大危害,传统的处理工艺无法将其彻底去除,且易造成二次污染。水力空化作为一种新型水处理技术,具有经济、高效、操作简单、不会产生二次污染等特点。本研究首次利用水力空化技术强化二氧化氯处理模拟苯酚废水,并取得了理想的降解效果,为难降解有机废水的处理提供了理论依据,具有重要的实际指导意义。本研究在阅读大量国内外文献的基础上,自行设计了多孔板和文丘里管空化发生器,并设计了一套水力空化装置。研究分别采用单独水力空化、单独二氧化氯及水力空化强化二氧化氯三种工艺处理苯酚模拟废水,探究了多种因素对苯酚降解效果的影响,确定了研究范围内的较优操作条件和最佳空化发生器。并利用高效液相色谱(HPLC)分析了水力空化强化二氧化氯降解苯酚反应的中间产物,揭示了苯酚的降解历程。同时,建立了水力空化强化二氧化氯降解苯酚的动力学模型,探讨了化学反应动力学规律。论文的主要研究成果如下:(1)研究了分别以多孔板和文丘里管作为空化发生器对苯酚降解效果的影响,结果表明,以多孔板作为空化发生器对苯酚的降解效果优于文丘里管,且以开孔率为0.0610,开孔为环状布孔的孔板作为空化发生器对苯酚的降解效果最好。在较优反应条件:入口压力为0.4 MPa,处理90min,苯酚的最大降解率可达27.6%。单独水力空化降解苯酚时,苯酚首先被氧化为苯醌,接着苯醌被降解为顺丁烯二酸;(2)单独二氧化氯氧化苯酚时,苯酚降解率随着二氧化氯浓度的增加逐渐增大。处理时间超过45min,随着处理时间的增加,苯酚降解率趋于稳定。当苯酚与ClO2的物质的量比为1:2,处理45min,苯酚的降解率为87.1%;单独Cl O2处理苯酚时,最终仅可将苯酚氧化为苯醌。(3)水力空化强化二氧化氯降解苯酚时,以开孔率为0.0610,开孔为环状布孔的孔板作为空化发生器,较优反应条件为:ClO2与苯酚的物质的量之比为1:1,处理时间为30min,苯酚的降解率最大可达92.1%,是相同条件下,单独水力空化(苯酚降解率为17.1%)和单独二氧化氯(苯酚降解率为47.9%)对苯酚降解率之和的1.4倍;(4)水力空化强化二氧化氯对苯酚的降解符合一级反应动力学规律,其反应速率常数为1.49×10-3s-1,半衰期约为8min。水力空化与二氧化氯联合降解时,存在较好的协同效应,增强因子为3.18.(5)通过对水力空化强化ClO2降解苯酚中间产物和途径的探讨,明确反应过程中首先生成苯醌,在自由基的作用下,中间产物苯醌被进一步氧化为乙二酸和顺丁烯二酸。
[Abstract]:Phenol is a representative refractory organic matter, which can cause great harm to the ecological environment and human health, and can not be completely removed by traditional treatment technology. As a new water treatment technology, hydraulic cavitation is economical, efficient and easy to operate. For the first time, the treatment of simulated phenol wastewater with chlorine dioxide was enhanced by hydraulic cavitation, and the ideal degradation effect was obtained. The treatment of refractory organic wastewater provides theoretical basis and has important practical significance. On the basis of reading a large number of domestic and foreign literature, a porous plate and Venturi tube cavitation generator was designed by ourselves. A set of hydraulic cavitation device was designed to treat phenol simulated wastewater by three processes: single hydraulic cavitation, single chlorine dioxide and enhanced chlorine dioxide by hydraulic cavitation. The effects of various factors on the degradation of phenol were investigated. The optimum operating conditions and the optimal cavitation generator were determined and the intermediate products of the hydro cavitation enhanced chlorine dioxide degradation of phenol were analyzed by high performance liquid chromatography (HPLC). The degradation process of phenol was revealed, and the kinetic model of degradation of phenol with enhanced chlorine dioxide by hydraulic cavitation was established. The main results of this paper are as follows: 1) the effect of porous plate and Venturi tube as cavitation generator on the degradation of phenol was studied. The degradation effect of phenol with porous plate as cavitation generator was better than that of Venturi tube, and the porosity was 0.0610. The porous plate with annular perforation was the best for phenol degradation. The optimum reaction conditions were as follows: the inlet pressure was 0.4 MPA and the treatment time was 90 min. The maximum degradation rate of phenol was 27.60.When phenol was degraded by hydraulic cavitation alone, phenol was first oxidized to benzoquinone, then benzoquinone was degraded to maleic acid. 2) when phenol was oxidized by chlorine dioxide alone, the degradation rate of phenol gradually increased with the increase of chlorine dioxide concentration, the treatment time was more than 45 min, and the treatment time increased with the increase of treatment time. The degradation rate of phenol tends to be stable. When the ratio of phenol to ClO2 is 1: 2, the degradation rate of phenol is 87.1 when treated for 45 min. Only phenol can be oxidized to benzoquinone. 3) when the phenol is degraded by hydro cavitation enhanced chlorine dioxide, the open porosity is 0.0610. The porous plate with annular holes was used as the cavitation generator. The optimum reaction conditions were as follows: the ratio of the mass of 1: ClO2 to phenol was 1: 1, and the treatment time was 30 min. The maximum degradation rate of phenol can reach 92.1g, which is under the same conditions. The total degradation rate of phenol by hydraulic cavitation alone (17.1%) and chlorine dioxide (47.9%) was 1.4 times higher than that of single chlorine dioxide (47.9%). (4) the degradation of phenol by hydro cavitation enhanced chlorine dioxide is in accordance with the first-order reaction kinetics, and its reaction rate constant is 1.49 脳 10 ~ (-3) s ~ (-1). The half-life is about 8 min.There is a good synergistic effect when the hydro cavitation is combined with the degradation of chlorine dioxide. The enhancement factor was 3.18. 5) by exploring the intermediate products and ways of degradation of phenol by ClO2 enhanced by hydraulic cavitation, it was clear that benzoquinone was first formed in the reaction process, under the action of free radical. The intermediate product benzoquinone was further oxidized to adipic acid and maleic acid.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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