克雷伯氏菌脱色偶氮染料废水的生化机理研究

发布时间：2018-01-04 00:37

本文关键词：克雷伯氏菌脱色偶氮染料废水的生化机理研究　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：偶氮染料广泛的应用于纺织、印染行业,其是一类含有偶氮键(—N=N—)和芳香基等有机化合物的典型染料;其中作为发色基团的偶氮键决定着废水的颜色,在其印染过程由于着色不完全产生的染料废水对动植物和人类均存在极大的危害;目前,吸附法、生物法和高级氧化法是偶氮染料废水应用较多的处理方法。高级氧化法多集中于·OH、·SO_4~(2-)催化剂的研究,生物法多集中于污泥法、新型细菌发酵研究等,吸附法对于新型碳质材料和合适的催化剂的研究较多,研究者们希望通过发现更多效果更好的催化剂和碳质材料以促进偶氮染料废水的脱色。相较于吸附法和高级氧化法的处理能力有限、耗能高,生物法脱色彻底、耗能低、产生的污染少,正逐渐成为近年来偶氮染料废水研究的热点。其中,微生物处理法因为胞外电子穿梭体的添加可以带来经济、高效的处理效果而备受人们的关注。其中,蒽氢醌-2,6-二磺酸钠(AHQDS)、蒽醌-2-磺酸钠(AQS)、腐殖酸(HA)作为醌类物质可以在细菌厌氧发酵脱色偶氮染料的过程中起到促进作用,这类物质可作为细菌厌氧发酵过程中的电子穿梭体,加快细菌代谢过程中的电子传递。除此之外,活性碳也可以作为催化剂促进染料分子的去除,论文中选择Klebsiella oxytoca GS-4-08作为脱色偶氮染料甲基橙的主体,考察了单独的活性炭活性炭与克雷伯氏菌复合,腐殖酸负载铁与细菌复合,以及AQS对偶氮染料的去除效果;也通过考察细菌对于AQS、GAC、Fe-HA的耐受性,选择AQS作为最佳电子穿梭体,考察其对于Klebsiella oxytoca GS-4-08厌氧发酵过程的影响。主要研究内容和结论如下:(1)在实验室的条件中,配置1.5g·L~(-1) HA,10000g离心20min去除不溶物,加入5 mmol·L~(-1) FeSO_4·7H_2O,快速搅拌,调节Ph=7,将悬浮液静置一周,再重复上述离心过程,收集沉淀物进行冷冻干燥,获得Fe-HA沉淀物,对Fe-HA与Klebsiella oxytoca GS-4-08复合降解偶氮染料甲基橙进行考察分析,发现在30h时,细菌在空白、Fe、FeHA复合情况下脱色甲基橙分别可以达到62%、11%、52%,说明Fe-HA对细菌的耐受性有一定的影响。(2)通过控制GAC的浓度,考察其对偶氮染料甲基橙的去除效果,结果发现在2、5、8、10 g·L~(-1)时,甲基橙的降解过程可以很好的与一级降解动力学方程拟合;甲基橙脱色效率随着GAC浓度的增加而随之增加,在2h内10g·L~(-1)GAC可脱色99%的甲基橙,8g·L~(-1) GAC可以在2.75h内脱色99%的甲基橙,5g·L~(-1)GAC可以在5h内脱色99%的甲基橙,2g·L~(-1)GAC可以在10.5h内脱色97%的甲基橙;2g·L~(-1)GAC与细菌复合前后脱色甲基橙的降解情况均符合二级降解动力学方程,而其脱色速率分别为0.175、0.17,两者差别不大,而在实验反应10h后,GAC与菌株复合反应的实验中出现菌株死亡现象,这说明GAC会影响菌株脱色甲基橙的耐受性。(3)通过投加AQS进入细菌厌氧发酵过程中,发现在未加AQS的情况下,25h细菌脱色MO只能达到60%,而0.08mmol·L~(-1)的AQS可以在10h内脱色MO达100%,且在AQS参与的细菌厌氧发酵过程中,菌株生长状况良好,且在厌氧发酵后期出现产氢情况,所以论文后期将重点放在AQS促进Klebsiella oxytoca GS-4-08厌氧发酵产氢上。(4)考察不同AQS浓度下,Klebsiella oxytoca GS-4-08利用蔗糖厌氧发酵产氢脱色甲基橙过程中,分析了甲基橙的脱色动力学、产氢动力学、蔗糖降解动力学、以及细菌生长情况,以及在厌氧发酵过程中,嗜温菌Klebsiella oxytoca GS-4-08作为单一菌株厌氧发酵,AQS作为电子穿梭体改变电子传递速率,对电子平衡和能源转换的影响。结果发现:最佳浓度为0.1 mmol·L~(-1)。在该浓度下,Klebsiella oxytoca GS-4-08可在10h内完全脱色MO,25h内降解蔗糖达到92%,同时产生23.3 mmol·L~(-1)乙醇和23.5mmol·L~(-1)乙酸,100.5 mL氢气;AQS浓度的电子得率最高为90.5%;通过对比降解过程中能源的转换,得到能源产量最高为802 kJ·mol蔗糖~(-1)以及Klebsiella oxytoca GS-4-08发酵过程可产生乙醇和氢气两种以上生物燃料。
[Abstract]:Azo dyes are widely used in textile, printing and dyeing industry, it is a kind of containing azo bond (N=N) typical dyes and aromatic organic compounds; the azo bond chromophore determines the color of wastewater in the dyeing process, due to incomplete colored dye wastewater has great harm the plants and animals and humans; at present, adsorption method, biological method and advanced oxidation process is a method of treating wastewater containing azo dye used. Advanced oxidation method focused on OH, SO_4~ (2-) catalysts, biological method focused on the research of new bacterial fermentation sludge, etc., there are many studies on adsorption method new carbonaceous material and a suitable catalyst, the researchers hope to promote the decolorization of azo dye wastewater through the discovery of more better catalysts and carbonaceous materials. Compared to the processing capacity of adsorption and advanced oxidation method Limited, high energy consumption, biological decolorization completely, low energy consumption, produce less pollution, it has become a hot research of azo dye wastewater in recent years. Among them, the microbial process for adding extracellular electron shuttle can bring economic, highly efficient processing and attracted much attention. Among them, anthrahydroquinone -2,6- two sodium sulfonate (AHQDS), anthraquinone -2- sulfonate (AQS), humic acid (HA) as quinones can play a role in the process of anaerobic fermentation of bacterial decolorization of azo dyes, this kind of material can be used as electronic anaerobic bacteria in the fermentation process of shuttle, accelerate the electron transfer during bacterial metabolism. In addition in addition, the activated carbon can be used as a catalyst to promote the removal of dye molecules, the choice of Klebsiella oxytoca GS-4-08 as the main body of the decolorization of azo dye methyl orange, the effect of carbon activated carbon alone with Klebsiella complex Together, humic acid and bacterial load of iron compound, and AQS of azo dye removal effect; also through the investigation of bacteria for AQS, GAC, Fe-HA tolerance, AQS was selected as the best electron shuttle, to investigate its effects on Klebsiella oxytoca GS-4-08 anaerobic fermentation process. The main research contents and conclusions are as follows: (1) in laboratory conditions, configuration of 1.5g L~ (-1) HA, 10000g 20min centrifugation to remove insoluble matter, adding 5 mmol - L~ (-1) FeSO_4 - 7H_2O, rapid mixing, adjusting Ph=7, suspension static one week, and then repeat the centrifugal process, the precipitate was collected by freeze drying, Fe-HA precipitates investigation and analysis of Fe-HA, Klebsiella and oxytoca GS-4-08 composite degradation of azo dye methyl orange, found in 30h, Fe, FeHA of bacteria in the blank, composite under the condition of decoloration of methyl orange can respectively reach 62%, 11%, 52%, indicating that tolerance to bacteria is Fe-HA The effect of (2). By controlling the concentration of GAC, the removal of azo dye methyl orange, were found in the 2,5,8,10 g L~ (-1), the degradation process of methyl orange can be very good with the first-order reaction kinetics equation; the decolorization efficiency increases with the increase of GAC concentration in 2H 10g L~ (-1) GAC 99% 8g, the decolorization of methyl orange, L~ (-1) GAC in 2.75h 99% 5g, the decolorization of methyl orange, L~ (-1) GAC in 5h 99% 2G, the decolorization of methyl orange, L~ (-1) GAC in 10.5h 97% 2G the decolorization of methyl orange; L~ (-1) and bacterial degradation of GAC composite before and after decolorization of methyl orange were consistent with two degradation kinetic equation, and the decolorization rate was 0.175,0.17, the difference is small, while in the experimental reaction after 10h strain death phenomenon of complex reaction GAC and strain experiment, indicating that the GAC strains will affect the decolorization of methyl The tolerance of orange. (3) by adding AQS into the bacterial anaerobic fermentation process, found in the case of AQS without 25h, the decolorization MO can reach 60%, and 0.08mmol L~ (-1) AQS in 10h MO was up to 100%, and the bacteria in the anaerobic fermentation process in AQS strain, good growth status, and hydrogen production in anaerobic fermentation stage, so at the end of the paper will focus on the promotion of AQS Klebsiella oxytoca GS-4-08 of fermentative hydrogen production. (4) the effects of different concentrations of AQS, Klebsiella oxytoca GS-4-08 using sucrose fermentative hydrogen production in the process of decolorization of methyl orange, methyl orange decolorization kinetics analysis hydrogen production, kinetics, sucrose degradation kinetics, and bacterial growth, and in the process of anaerobic digestion, mesophilic bacteria Klebsiella oxytoca GS-4-08 as a single strain of anaerobic fermentation, AQS as electron shuttle change electron transfer rate, Effect of electronic balance and energy conversion. The results showed that the optimum concentration of 0.1 mmol L~ (-1). The concentration of Klebsiella, oxytoca and GS-4-08 completely within the 10h MO 25h the decolorization, degradation of sucrose reached 92%, while producing 23.3 mmol - L~ (-1) and 23.5mmol L~ ethanol (-1) acetic acid 100.5, mL electronic hydrogen; AQS concentration was the highest rate of 90.5%; through the conversion of energy contrast in the degradation process, obtained the highest yield energy was 802 kJ - mol ~ (-1) and Klebsiella sucrose oxytoca GS-4-08 fermentation process of ethanol and hydrogen can produce more than two kinds of bio fuels.

【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X791

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