iCWPO与光催化工艺处理染料废水及其协同作用的实验研究

发布时间：2018-01-08 12:30

本文关键词：iCWPO与光催化工艺处理染料废水及其协同作用的实验研究　出处：《陕西师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：印染废水是我国主要有害、难降解的工业废水之一。随着新型助剂、染料等在印染行业中的大量使用,使染料废水中的底物不断向抗光解、抗氧化、抗生物降解方向发展。目前,处理印染废水的可行方法包括生物、化学和物理化学技术,但传统的生物化学法难以得到理想的结果。近年来,多相催化湿式氧化法因其高效性和稳定性具有广阔的发展前景,但存在处理成本高、反应条件苛刻的缺点。为增强其有效性及实用性,使发生条件温和,研究者添加具有强氧化能力的H2O2作为氧化剂增强处理效果,即催化湿式过氧化氢氧化技术。催化剂中负载的活性金属能够加速反应的进行,提高其催化活性、稳定性和特定的吸附性能,提高反应效率。可将两种或两种以上金属溶液混合浸渍,制备复合金属氧化物,使催化活性明显提高,加速催化反应的进行。磁性或导电材料受到外加高频交变磁场作用时会感应发热,铁磁材料在交变磁场中能够迅速升温。我们对非均相反应体系的染料废水处理进行改进,采用具有较好感应热性能的铁磁材料或制备具有感应内核的催化剂,外加全场分布的高频交变磁场使材料感应产热。通过对分散的催化剂颗粒增设感应特性,使外部输入的电磁能量只在颗粒表面实现热能转换而不作用于水相,能量的转换更集中于实际的微观反应位点。本文以碳包覆海绵铁(SI-C)为载体负载金属,制备具有感应磁核的多金属复合催化剂,实现感应热反应器CWPO(iCWPO)处理低浓度难降解污染物,并结合紫外光助芬顿反应协同处理高浓度染料废水。主要结论如下：(1)以SI-C为载体,Ni的硝酸盐为前驱物,采用混合浸渍焙烧法制备了SI-C表层负载型复合金属催化剂(Mn-Ni/C、Mn-La/C、Ni-La/C、Mn-Ni-La/C)。对催化材料及其前躯体的形貌和结构表征,海绵铁的主要成分是铁及铁的氧化物,具有良好的磁热效应；SI-C表层原子排布紧密,海绵铁原有的孔隙结构被活性炭层覆盖,为载体负载活性金属提供了条件；负载型多金属催化剂表面有光泽,具有明显分层现象,孔隙分布均匀,有利于进行物质和能量交换。(2)用Fe/C比4：1反复包覆海绵铁3次可实现较好包覆。0.02 mol/L的La、Mn、Ni硝酸盐金属浸渍液以体积比1：1：1均匀混合,并在300。C焙烧2h制得的Mn-Ni-La/C多金属复合催化剂具有良好的磁热效应和催化氧化性能。(3)在常温常压iCWPO处理低浓度染料废水工艺中,对直接蓝D-3GL的去除率达98.39%,对直接紫D-BL的去除率达97.56%,对直接大红D-GLN的去除率达92.18%。表明Mn-Ni-La/C在常温常压iCWPO工艺中有较好的催化活性,且反应条件温和,明显降低了反应器液相温度,促进非均相催化反应的进行。(4)研究了常温常压下UV/Mn2+-Fe3+/H2O2光催化均相反应体系处理低浓度偶氮染料废水的特性,紫外光、H202以及金属离子在均相反应体系中具有良好的协同催化作用。金属离子在反应中起激发和传递作用,使链反应持续进行直至耗尽H2O2。在20 w紫外光源照射下,Mn2+-Fe3+投加量均为3 mmol,且H2O2投加量为10 ml/L时,直接大红D-GLN在反应20 min时,脱色率就已达到90%以上。(5)将iCWPO与UV/Mn2+-Fe3+/H2O2反应体系结合,协同处理高浓度难降解污染物,彻底破坏了染料分子的共轭发色基团,并提高废水的可生化性。在4 w紫外灯照射下,Mn2+-Fe3+投加量均为1 mmol, H2O2投加量为5 ml/L时,600 mg/L的偶氮染料模拟废水在经过光催化反应60 min后,通过iCWPO作用,对直接紫D-BL的脱色率和COD去除率分别为90.46%和80.14%,对直接蓝D-3GL的处理效率可达到94.83%和87.53%,对直接大红D-GLN的脱色率和COD去除率分别91.35%、82.47%。UV/Mn2+-Fe3+/H2O2反应体系与感应热体系的协同催化作用有效促进了非均相催化反应的进行,使活性金属高效催化分解H2O2引发链式自由基反应,破坏染料分子共轭结构,实现高效降解。
[Abstract]:Printing and dyeing wastewater is the main harmful, one of the industrial wastewater is difficult to degrade. With the extensive use of new additives, dyes in the dyeing industry, the dye wastewater substrate to anti photolysis, anti-oxidation, anti biodegradation direction. At present, the methods of dyeing wastewater treatment including biological, chemical and physical chemistry technology, but it is difficult for the traditional biochemical method to get the ideal results. In recent years, multi phase catalytic wet oxidation method for its high efficiency and stability and has broad prospects for development, but there are high cost, harsh reaction conditions and shortcomings. In order to enhance their effectiveness and practicability, the occurrence of mild conditions, the researchers add with the strong oxidation ability of H2O2 as oxidant to enhance the treatment effect, namely the catalytic wet peroxide oxidation technology. The load active metal catalyst can accelerate the reaction, improve its catalytic activity, Stability and specific adsorption performance, improve the reaction efficiency. Can be two or more than two kinds of metal solution impregnation, preparation of composite metal oxides, the catalytic activity increased significantly, to accelerate the catalytic reaction. The magnetic or conductive materials by high frequency alternating magnetic field during induction heating, the ferromagnetic materials can be rapidly warming in the alternating magnetic field. The heterogeneous reaction system in dye wastewater treatment was improved, the catalyst has good thermal properties of ferromagnetic materials of induction or preparation of magnetic core, and the high frequency alternating magnetic field distribution of the material induced heat production. Through the addition of catalyst particle dispersion characteristics of the electromagnetic induction, external energy input only in thermal energy conversion to achieve particle surface rather than the aqueous phase, micro reaction sites of energy conversion is more focused on practical. The carbon coated sponge iron (SI-C) for supported metal, multi metal catalyst preparation with magnetic core, the induction heat CWPO reactor (iCWPO) treating low concentration of refractory pollutants, combined with UV and Fenton reaction synergistic treatment of high concentration dye wastewater. The main conclusions are as follows: (1) based on SI-C and nitrate Ni as the precursor, SI-C surface supported composite catalysts were prepared by impregnation method mixed (Mn-Ni/C, Mn-La/C, Ni-La/C, Mn-Ni-La/C). The morphology and structure characterization of catalytic materials and its precursors, the main component of sponge iron is iron and iron oxide, has good magnetocaloric effect; SI-C surface atomic arrangement close the pore structure of the sponge iron original activated carbon layer, provides conditions for the carrier to load active metal supported multi metal catalyst; surface luster, has obvious stratification phenomenon, uniform pore distribution is Conducive to the exchange of material and energy. (2) by Fe/C 4:1 coated sponge iron 3 times repeatedly can achieve better.0.02 mol/L coated La, Mn, Ni metal nitrate solution with the volume ratio of 1:1:1 mixture, and has the magnetocaloric effect and good catalytic performance in 300.C roasting 2H prepared Mn-Ni-La/C multi metal composite catalyst. (3) in normal temperature treatment of low concentration iCWPO dye wastewater, the removal rate of 98.39% direct blue D-3GL, direct violet D-BL on the removal rate of 97.56%, the direct red D-GLN and the removal rate of 92.18%. showed that Mn-Ni-La/C had good catalytic activity in normal temperature and pressure in the iCWPO process, and mild reaction conditions, significantly reduces the temperature of the liquid phase reactor, promote heterogeneous catalytic reaction. (4) studied under normal temperature and pressure UV/Mn2+-Fe3+/H2O2 photocatalytic characteristics of homogeneous reaction system for treatment of low concentration of azo dye wastewater, UV, H202 and metal ions in a homogeneous reaction system has good synergistic catalytic effect. Metal ion excitation and transfer function in the reaction, the chain reaction continues until exhausted by H2O2. in 20 W under irradiation of ultraviolet light, Mn2+-Fe3+ dosage was 3 mmol, and the dosage of H2O2 is 10 ml/L when the direct red D-GLN in the reaction of 20 min, the decolorization rate reached above 90%. (5) the combination of iCWPO and UV/Mn2+-Fe3+/H2O2 reaction system, CO treatment of high concentration refractory pollutants, completely destroyed the conjugate dye molecules chromophore, and improve the biodegradability of waste water. In 4 W UV lamp under the irradiation of Mn2+-Fe3+ dosage was 1 mmol, H2O2 dosage is 5 ml/L, 600 mg/L of azo dye wastewater after photocatalytic reaction after 60 min, the iCWPO effect on direct violet D-BL decolorization and COD removal rates were 90.46% and 80.14%, the The treatment efficiency of direct blue D-3GL can reach 94.83% and 87.53%, of direct red D-GLN decolorization rate and COD removal rate of 91.35%, the synergistic catalytic effect of 82.47%.UV/Mn2+-Fe3+/H2O2 reaction system and induction heat system effectively promoted by heterogeneous catalytic reaction, the catalytic decomposition of H2O2 active metal, initiate free radical chain reaction, destroy the conjugation the structure of dye molecules, achieve high efficiency degradation.

【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

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