【作者】 安婧；

【导师】 何星存；

【作者基本信息】 广西师范大学 ， 应用化学， 2006， 硕士

【摘要】 染料废水成分复杂、色度高、COD高且难生物降解,对环境造成较大污染。本文采用镀铜铁屑增强型内电解—光催化协同作用处理染料废水。主要的研究内容和得到的结论如下:1.静态实验研究镀铜铁屑增强型内电解协同光催化作用对染料废水的处理效果,并与使用铁屑时的处理效果进行比较;对镀铜铁屑协同光催化作用处理染料废水过程的影响因素进行研究,结果表明:(1)与铁屑相比,镀铜铁屑扩大了原电池的两极电位差,使更多的有机物质得到了还原,加快了染料的降解速度,提升了染料废水的处理效果。(2)利用内电解反应生成的内源性物质Fe(Ⅲ)-OH络合物以及镀层中的Cu2O等物质的光化学性质,在内电解反应过程中协同光催化作用,加快了染料的脱色速度,提高了染料COD的去除率。反应30min后,染料的脱色率均达到95%以上,COD的去除率也提升了10%-20 %左右。(3)增加反应时间、镀铜铁屑投加量以及振荡速度均能够加强染料废水的去除效果。但是当三种因素的量增加到一定程度后,对COD和色度去除率的影响减弱。(4)降低pH可以使内电解反应的电位差增大。因此无论使用镀铜铁屑还是铁屑,降低pH均可提升染料废水的去除效果。与传统的铁屑内电解法相比,由于镀铜铁屑扩大了原电池的两极电位差,所以其对于一些pH为6.0-9.0的染料废水也具有较好的处理效果。如对pH=9.0的活性翠蓝和活性黄的脱色率均在95%以上。(5)将铁屑镀铜后,改变了原铁屑的表面结构和性质,放宽了对铁屑粒径的要求,减缓了结块、钝化等现象,增加了催化剂的重复使用次数。2.自制流动反应装置,分别以活性黑废水、银海集团实际废水和混合染料废水为研究对象,研究了停留时间、曝气量等因素对染料废水处理效果的影响;对流动反应柱的运行稳定性进行了研究,结果表明:(1)增加停留时间、曝气量可以提高染料的脱色率和COD去除率。但是当停留时间和曝气量增加到一定程度后,染料去除率的变化已不十分明显了。(2)流动反应装置处理混合染料废水,运行30天后染料的脱色率由96.2%下降至92.2%,COD的去除率由87.5%降低至84.4%。去除效果变化不大,流动反应柱的运行情况良好。3.用现代分析方法对镀铜铁屑进行表征:(1)用扫描电镜(SEM)对铁屑镀铜前后以及镀铜铁屑反应前后的表面进行分析,结果表明:铁屑镀铜前表面清洁,镀铜后表面结构发生变化。随着反应的进行,镀铜铁屑表面生长出类似葡萄状的物质。(2)对镀铜铁屑表层剥落物进行X-衍射分析(XRD),结果表明:红褐色的剥落物质为铜及其氧化物的混合物。4.探讨了镀铜铁屑增强型内电解—光催化协同作用处理染料废水的作用机理。在实验中我们用荧光法检测出内电解过程中有氢氧自由基生成,它的强氧化性质可以更好的降解复杂的染料分子。此外,还有其他的作用机理,如氢的氧化还原作用,铁的还原作用,电场作用,铁离子的络合混凝作用以及内源反应产物Fe(Ⅲ)-OH络合物和镀层中的Cu2O的光化学作用等。更多还原

【Abstract】 The composition of dyestuff wastewater is complicated. Its chromaticity is high; COD is high and hard to be degraded by biochemical treatment. That is why it causes serious pollution to the environment. In this dissertation, a combined process of copper-plating iron chips intensive inner electrolysis - photocatalysis was used to treat dyestuff wastewater. The main contents and results were presented as follows:1. Compared with iron chips, the effects of the dyestuff wastewater by copper-plating iron chips intensive inner electrolysis - photocatalysis was studied by static experiments. The affecting factors of treatment were also studied. The results were as follows: (1) compared with iron chips, copper-plating iron chips magnified the potential difference between anode (Fe) and cathode (promoter), so that more organic compounds could be reduced. As a result, the degradation of dyestuff was accelerated. (2) Because of photochemical characteristic of Fe(Ⅲ)-OH complex system which was produced from inner electrolysis and Cu2O which was the component of the plating zone, the decoloration ratio and the COD removal ratio of dyestuff wastewater could be promoted by sunlight. Reacting 30 min, the decoloration ratio was over 95% and the COD removal ratio was increased about 10%-20%. (3) Increasing the reaction time, the quantity of copper-plating iron chips and the oscillation rate could intensify the removal effects of dyestuff wastewater. But the effects would be unnoticeable when the quantity of these factors exceeded the specific quantity. (4) When pH value was cut down, the hydrogen potential difference between anode and cathode can be magnified. No matter used copper-plating iron chips or iron chips, reducing the pH value could intensify the removal ratio of dyestuff. Compared with traditional iron inner electrolysis, the decoloration ratio and COD removal ratio of dyestuff wastewater whose pH value was from 6.0-9.0 were also high, when the wastewater was treated by copper-plating iron chips. For example, decoloration ratio of reactive turquoise blue and reactive yellow was over 95%, when their pH value was about 9.0. (5) When iron chips were plated with copper, constructions and characteristics of their surface were changed. So the limit about the gain size was shrinking, and the phenomenon about agglomeration and rust was ameliorated. In addition, copper-plating iron chips could be used more times than iron chips.2. The flow-equipment was made by our own. The factors such as residence time and quantity of aerating affecting the treatment effect of reactive black, the wastewater of YinHai Corporation and the mixed dyestuff wastewater were studied. We also studied the running stabilization of the flow-equipment. The results were as follows: (1) the decoloration ratio and COD removal ratio of these three kinds of dyestuff wastewater were increased with the increment of residence time and the quantity of aerating. But the treatment effects of these three wastewater improved inconspicuousness when the residence time and quantity of aerating exceeded specific quantity. (2) Using the flow-equipment to treat the mixed dyestuff wastewater, the removal ratio of the wastewater did not reduce so much after 30 days. The decoloration ratio was from 96.2% to 92.2% and the COD removal ratio was from 87.5% to 84.4%.3. Modern analysis methods were used to characterize the surface of copper-plating iron chips. (1) Scanning electron microscopy (SEM) was employed to explore the changes between iron chips surface and copper-plating iron chips surface, and the changes on copper-plating iron chips surface in the process treating dyestuff wastewater. Although iron surface was clean, copper-plating iron chips surface was different with iron surface. After reaction, there were things whose shapes liked grape generated from copper-plating iron chips surface. (2) X-ray diffraction (XRD) was used to explore the component of plating zone. The plating zone of copper-plating iron chips was mainly composed of copper and oxides of copper.4. The mechanism of copper-plating iron chips intensive inner electrolysis -photocatalysis in treatment of dyestuff wastewater was researched. Hydroxyl radical(·OH) was determinated in the process of inner electrolysis by fluorimetry. The oxidation value of·OH was so high that it can degrade dyestuff more effectively. It also contented oxido-reduction of hydrogen, reducing action of iron, electric field action, complexation-concrete action of iron, and the photochemical characteristic of Fe(Ⅲ)-OH and Cu2O.更多还原