铁系氧化物催化臭氧化降解模拟苯酚废水的研究
发布时间：2019-06-13 14:53
【摘要】：采用铁系氧化物作为催化剂,催化臭氧化处理苯酚模拟废水,对比纳米颗粒催化剂羟基氧化铁(FeOOH NPs)、三氧化二铁(Fe2O3NPs)和四氧化三铁(Fe3O4 NPs)及相对应的非纳米颗粒催化剂FeOOH、Fe2O3和Fe3O4对苯酚降解效果。通过X射线衍射(XRD)、比表面积-孔径分布(BET)和扫描电子显微镜(SEM)手段对催化剂进行表征。研究结果表明:Fe3O4 NPs催化剂存在情况下对溶液TOC去除率最高,初始浓度1.0 mmol/L,pH为3.0,催化剂投量1.0 g/L,O3/O2流量200 ml/min(混合气体中的O3浓度42.38 mg/L),反应180min后,TOC去除率达80.0%。进一步测定反应液(无苯酚添加)中溶铁(Fe2+)变化,结果表明Fe3O4 NPs,Fe2O3 NPs和Fe3O4溶出的Fe2+浓度会随着时间的推移逐渐增加,240 min后分别达4.49 mg/L,0.9 mg/L和0.78 mg/L,而其它铁系催化剂存在的溶液中Fe2+浓度非常低且几乎不随时间增加。在Fe2+存在条件下,铁系氧化物催化臭氧化降解模拟废水中的苯酚遵循以下反应动力学模型:-d[TOC]/dt=[TOC]t/(a+bt),并在一定条件下可简化成拟一级反应动力学,实验结果显示,其动力学可分别拟合成两段,分别由诱导期和快速降解期构成。结果显示Fe3O4 NPs两段的反应速率常数均较其他催化剂大,分别为3.3×10-3 min-1和8.82×10-3 min-1,从而说明了Fe3O4 NPs的优越的催化能力。本实验以Fe3O4 NPs为催化剂,以苯酚模拟废水为研究对象,以总有机碳(TOC)降解率为目标参数,研究了反应体系操作条件(O3/O2流量、Fe3O4 NPs投量和反应温度)对催化剂性能的影响。研究结果表明,在本实验条件范围内,TOC去除率分别随着臭氧量、Fe3O4 NPs投量和反应温度增加而增加,最佳条件为O3/O2流量200 ml/min,Fe3O4 NPs投量1.0 g/L和反应温度25℃,反应180min后,TOC去除率可达80.0%。采用GC-MS对苯酚降解的中间产物进行分析,并假设·OH为主要活性物种,从而提出Fe3O4 NPs作为催化剂,苯酚催化臭氧氧化的可能降解途径。
[Abstract]:Phenol simulated wastewater was treated by catalytic ozonation with iron oxides as catalysts. The degradation effects of hydroxyl iron oxide (FeOOH NPs), iron trioxide (Fe2O3NPs) and iron tetrooxide (Fe3O4 NPs) and corresponding non-nanoparticles catalysts FeOOH,Fe2O3 and Fe3O4 on phenol degradation were compared. The catalysts were characterized by X-ray diffraction (XRD), specific surface area pore size distribution (BET) and scanning electron microscope (SEM). The results show that in the presence of Fe3O4 NPs catalyst, the removal rate of TOC in solution is the highest, the initial concentration is 1.0 mmol/L,pH, the amount of catalyst is 1.0 g / L, the flow rate of O _ 3 鈮，
本文编号：2498597
[Abstract]:Phenol simulated wastewater was treated by catalytic ozonation with iron oxides as catalysts. The degradation effects of hydroxyl iron oxide (FeOOH NPs), iron trioxide (Fe2O3NPs) and iron tetrooxide (Fe3O4 NPs) and corresponding non-nanoparticles catalysts FeOOH,Fe2O3 and Fe3O4 on phenol degradation were compared. The catalysts were characterized by X-ray diffraction (XRD), specific surface area pore size distribution (BET) and scanning electron microscope (SEM). The results show that in the presence of Fe3O4 NPs catalyst, the removal rate of TOC in solution is the highest, the initial concentration is 1.0 mmol/L,pH, the amount of catalyst is 1.0 g / L, the flow rate of O _ 3 鈮，
本文编号：2498597
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