改性钨酸铋催化降解有机废水性能研究

发布时间：2018-11-12 09:22

【摘要】：由于有机废水水质的复杂性,使其难以被常规水处理技术有效且彻底地降解。其大量的不达标排放使污染物在环境中富集,从而对生态环境和人类健康带来了极大的危害。因此,研究开发新型的水处理技术已迫在眉睫。本文分别采用溶剂热法和水热法一步合成两种不同形貌的掺铁钨酸铋光催化剂,并使用X-射线衍射(XRD)、X-射线能量色散谱(EDS)及场发射扫描电镜(FESEM)等表征方法对掺铁钨酸铋样品的物化性质及形貌进行了相关测试分析。测试结果表明,合成的样品均为斜方晶型钨酸铋微米级半导体材料,并由EDS分析可知铁离子成功地掺杂进入到钨酸铋晶格当中,且铁元素的掺杂并未对样品的形貌和尺寸产生明显的影响,其分别呈微米球状和花状结构。印染废水的水质特点在较难处理的有机废水中最具代表性。故本实验以直接大红染料溶液作为模拟废水,以合成的两种不同掺铁钨酸铋半导体材料为催化剂,研究了超声空化协同光催化剂处理直接大红模拟染料废水的催化降解效果,并在最佳实验条件下,对催化反应的不同影响因素进行了反应动力学模型的拟合。研究结果表明:1)超声协同改性钨酸铋催化剂的降解性能优于单一超声作用,且掺铁钨酸铋的降解性能优于未掺杂的,说明铁离子的掺杂提高了催化剂的催化活性;2)直接大红染料废水的超声降解效果会受到铁掺杂量、催化剂投加量、溶液初始浓度和pH值、超声频率与功率等不同因素的影响,并在循环实验中表明催化剂具有较好的稳定性;3)在动力学研究中,各拟合直线均具有极高的线性相关性,拟合相似度R2均高于0.96,故超声催化反应的过程符合一级反应动力学模型。
[Abstract]:Because of the complexity of organic wastewater, it is difficult to degrade it effectively and thoroughly by conventional water treatment technology. Its large amount of substandard discharge makes pollutants enriched in the environment, which brings great harm to the ecological environment and human health. Therefore, it is urgent to develop new water treatment technology. In this paper, two kinds of bismuth ferrate doped tungstate photocatalysts with different morphology were synthesized by solvothermal method and hydrothermal method, respectively. The X-ray diffraction (XRD),) method was used to prepare two kinds of bismuth ferrate doped catalysts. X-ray energy dispersive spectroscopy (EDS) and field emission scanning electron microscopy (FESEM) were used to characterize the physical and chemical properties and morphology of bismuth ferric tungstate doped samples. The results show that the synthesized samples are obliquely square type bismuth tungstate semiconductor materials, and the EDS analysis shows that iron ions have been successfully doped into bismuth tungstate lattice. And the doping of Fe had no obvious influence on the morphology and size of the samples, which were spherical and flower-like in micron structure, respectively. The water quality of printing and dyeing wastewater is the most representative in the organic wastewater which is difficult to treat. In this experiment, direct scarlet dye solution was used as simulated wastewater, and two kinds of different ferric bismuth tungstate doped semiconductor materials were used as catalysts to study the catalytic degradation effect of ultrasonic cavitation and photocatalyst for treating direct red simulated dye wastewater. Under the optimum experimental conditions, the kinetic model of the reaction was fitted to the different factors affecting the catalytic reaction. The results show that: 1) the degradation of bismuth tungstate modified by ultrasound is superior to that of single ultrasonic, and the degradation performance of Fe doped bismuth tungstate is better than that of unadulterated bismuth tungstate, which indicates that the doping of iron ion improves the catalytic activity of the catalyst; 2) the ultrasonic degradation effect of direct scarlet dye wastewater will be affected by different factors, such as iron doping, catalyst dosage, solution initial concentration and pH value, ultrasonic frequency and power, etc. The results show that the catalyst has good stability. 3) in the kinetic study, all fitting lines have very high linear correlation, and the fitting similarity R2 is higher than 0.96, so the process of ultrasonic catalytic reaction accords with the first-order reaction kinetic model.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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