稻草活性炭加速偶氮染料厌氧降解机理研究
发布时间：2017-12-30 21:32
本文关键词：稻草活性炭加速偶氮染料厌氧降解机理研究 出处：《苏州科技大学》2017年硕士论文 论文类型：学位论文
更多相关文章： 偶氮染料 稻草活性炭 氧化还原介体 电子转移 机理
【摘要】：偶氮染料废水因其具有成分复杂、毒害大、水量大等特点,在传统的生物处理工艺中降解缓慢。碳材料具有发达的孔隙结构和比表面积,且结构中含有较多的官能团,使其具有优异的物理和化学特性,一直都是广大学者研究的热点。本研究利用稻草秸秆制备了稻草活性炭(SAC)和改性稻草活性炭(SAC_M)两种材料,有针对性的去除模拟染料废水中的金橙G(OG)物质,研究了SAC和SAC_M在促进Na_2S化学降解OG和厌氧颗粒污泥生物降解OG过程中的影响因素以及其在UASB连续流工艺中实际应用的可能性。首先通过表征手段对(NH_4)_2HPO_4作为活化剂制备的SAC和酚类物质改性制得SAC_M的物理和化学性质进行了分析,其中SEM结果表明,SAC和SAC_M均具有发达的孔隙结构和比表面积,内部孔隙大多是微孔结构,经过对苯二酚改性后的SACHQ-1.0和苯邻二酚改性后的SAC_(CT-1.0)比表面积明显下降,而苯酚改性后的SAC_(CT-1.0)比表面积明显上升;红外光谱结果显示了,SAC和SAC_M的结构中有大量官能团存在,且酚类改性后的SAC_M结构中的含氧官能团明显增多;拉曼光谱结果表明SAC和SAC_M结构中的无序碳原子或结构缺陷较少;采用漂移法测定SAC_3与SAC_(PH-1.0)的pH_(pzc),得出SAC_3和SAC_(PH-1.0)的pH_(pzc)分别为2.62和2.21。然后研究了在OG的化学还原降解过程,发现单独Na_2S对OG的还原降解效率较低,当Na_2S浓度为10mmol/L、温度为37℃和反应初始pH为7.2的条件下,OG的脱色率仅为49%;其中反应初始pH值对OG的降解影响较大,pH值在7.2~8.4范围内,OG降解效果较好,pH8.4后,OG降解效果明显变差,而pH值下降到6时,OG基本没有降解。而投加SAC和SAC_M后Na_2S还原降解OG的速率显著上升,且投加SAC_M的效果要好于SAC;在研究SAC促进Na_2S还原降解OG的过程中,发现30%(Wt)的(NH_4)_2HPO_4浸渍后制备的SAC_3效果最好,当SAC_3投加量为0.3g/L、Na_2S浓度为10mmol/L、温度为37℃和反应初始pH为7.2的条件下,仅需90min后OG的脱色率就达到了100%,在SAC_3/Na_2S体系还原降解OG的过程中,OG的降解速率与SAC_3投加量、Na_2S浓度、温度等成正相关,与pH成负相关。在SAC_M促进Na_2S还原降解OG的过程中,发现苯酚浓度为1.0mmol/L时制备的SAC_(PH-1.0)效果最佳,当SAC_(PH-1.0)投加量为0.3g/L、Na_2S浓度为10mmol/L、温度为37℃和反应初始pH为7.2的条件下,仅需30min后OG的脱色率就达到了100%,OG的降解速率与SACPH=1.0投加量、Na_2S浓度、温度等成正相关,与pH成负相关。通过TOC和UV-Vis光谱分析,得出SAC_3/Na_2S和SAC_(PH-1.0)/Na_2S体系中OG的矿化率分别为22.8%和34.2%,且OG结构中的偶氮键和萘环结构特征吸收峰随着反应的进行不断下降,最后完全消失。最后研究了OG的生物降解过程,发现单独AGS体系降解OG的效率较低,当AGS浓度为30mmol/L、温度为37℃和反应初始pH为7.2的条件下,48h内OG的脱色率仅为53.7%;远小于投加SAC_3(0.3g/L)和SAC_(PH-1.0)(0.2g/L)后的72.2%和90%;SAC_3/Na_2S和SAC_(PH-1.0)/Na_2S体系对OG的降解速率与SAC_3和SAC_(PH-1.0)投加量、AGS浓度、温度、营养液浓度成正相关,与pH成负相关。在单独UASB连续流系统中,当进水OG的浓度提高到150mg/L时,60d后系统出水的OG浓度达到46mg/L左右;而投加碳材料后连续运行40天,SAC_3/UASB和SAC_(PH-1.0)/UASB连续流系统出水中OG浓度分别降低至25mg/L和16mg/L左右且保持稳定;说明SAC_3和SAC_(PH-1.0)不仅在加速AGS降解OG的血清瓶实验中效果优异,而且在接近实际偶氮染料污水处理工艺的UASB连续流模型中,同样发挥出较好的效果,使得这种环境友好型材料的实际应用成为可能。综上可知,SAC_3和SAC_(PH-1.0)作为氧化还原介体(Redox Mediators)具有更大的比表面积,且其结构中的含氧官能团也较多,对Na_2S或者AGS与OG之间的电子转移起到了加速的作用,SAC_3和SAC_(PH-1.0)作为RM转移电子的速率主要跟自身物理和化学性质有关,可总结为一下两点:(1)SAC_3和SAC_(PH-1.0)吸附性能;(2)SAC_3和SAC_(PH-1.0)表面含氧官能团含量。并通过GC-MS对OG化学和生物降解的产物和途径进行了分析。
[Abstract]:Azo dye wastewater because of its complicated composition, high toxicity, high quantity, in the traditional biological treatment process. The slow degradation of carbon materials has developed the pore structure and surface area, and the functional groups contain more structure, which has excellent physical and chemical properties, has been the research focus of scholars this study. Straw activated carbon prepared by straw straw (SAC) and rice straw modified activated carbon (SAC_M) of two kinds of materials, targeted removal of dye wastewater in orange G (OG) material, study the influence factors of SAC and SAC_M in promoting Na_2S chemical degradation of OG and anaerobic granules sludgebiodegradation OG process and the possibility of its application in UASB continuous process. Firstly, through the characterization of (NH_4) _2HPO_4 as activator of SAC prepared and modified phenolic compounds prepared by physical and chemical properties of SAC_M The analysis results show that the SEM, SAC and SAC_M have developed pore structure and specific surface area, pore is mostly microporous structure after hydroquinone modified SACHQ-1.0 and benzene two adjacent phenol modified SAC_ (CT-1.0) significantly decreased the specific surface area, and phenol modified SAC_ (CT-1.0) significantly increased the specific surface area; infrared spectroscopy results show that, there are a large number of functional groups present structure of SAC and SAC_M, and the modified phenolic oxygen containing groups of SAC_M structure after the obviously increased; the Raman spectra results show that disordered carbon atoms or less structural defects SAC and SAC_M structure; Determination of SAC_3 and SAC_ by drift method (PH-1.0) pH_ (PZC), the SAC_3 and SAC_ (PH-1.0) pH_ (PZC) 2.62 and 2.21. respectively and then studied the reductive degradation process in OG chemistry, found that Na_2S alone reducing the degradation rate of OG is low, when the Na_2S concentration is 10mmol/L, temperature 搴︿负37鈩冨拰鍙嶅簲鍒濆pH涓，
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