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1.
不同环境条件下偶氮染料酸性大红GR的生物降解性能 总被引:1,自引:0,他引:1
为了考察不同环境条件下偶氮染料酸性大红GR生物降解性能,采用已驯化的混合菌群作为接种液进行偶氮染料酸性大红GR脱色试验。结果表明,微氧条件下(静置敞口培养),偶氮染料酸性大红GR脱色效果最佳,染料脱色主要发生在菌体的对数生长期。混合菌群对pH、温度适应范围较广,pH为3.32~9.18,温度在20℃~37℃范围内均可以获得较好脱色效果,脱色率均在80%以上。微氧条件下酸性大红GR降解历程表明,偶氮基整个共轭系统被破坏,生成了一种新的结构,使原有的某些精细结构在二阶导数光谱中得以表现,由此探讨其生物降解机理。 相似文献
2.
《应用与环境生物学报》2020,(2)
偶氮染料废水的排放会对水生环境及人类健康造成严重威胁.目前生物法处理偶氮染料的应用与研究居于首位,而混合菌群因具有多种微生物间的协同作用成为当前研究的热点.综述混合菌群的构建及偶氮染料脱色降解的影响因素,并重点阐述偶氮染料降解机理及降解酶系的相关研究.研究发现,混合菌群较单一菌株具有较好的脱色降解性能;其中碳氮源、温度、pH值、染料结构与浓度、溶氧量等因素对降解染料具有重要影响.细菌复合菌群是通过分泌一系列的酶如偶氮还原酶等使其偶氮双键断裂,产生的芳香胺类物质进一步被氧化成CO2和H2O,揭示了偶氮还原酶降解偶氮染料时的两种可能机制,即有无依赖氧化还原介质的偶氮染料降解.真菌复合菌群是通过生化反应来催化偶氮染料降解,阐述了漆酶降解染料的机理,即底物自由基中间体的产生和氧气还原成水.细菌与真菌复合菌群则是通过降解酶系统与生化反应相结合来降解染料.最后提出单一菌株存在着降解不彻底、效果不理想等问题,指出未来应根据废水中偶氮染料的种类、结构特点构建具有特异性、高效性且降解多种偶氮染料的混合菌群,并开展其生物降解的分子机制研究,进而为微生物降解偶氮染料的研发提供参考与理论支撑.(图2表3参96) 相似文献
3.
《应用与环境生物学报》2020,(4)
偶氮染料所造成的环境污染问题已成为近年来亟待解决的问题.以前期构建的嗜热偶氮染料降解复合菌群为研究对象,探究其在不同初始p H、培养温度、染料浓度及不同结构偶氮染料的脱色特性,并对不同浓度下染料的降解进行动力学分析;通过紫外-可见光扫描、红外光谱扫描及酶活性变化等分析偶氮染料的生物降解情况.此外,还将通过植物毒理性实验来验证偶氮染料降解后的脱毒情况.研究发现,该复合菌群在初始p H为8、温度为55℃的条件下脱色效果最佳,在含400 mg/L直接黑G的脱色培养基中静置培养48 h后,脱色率高达100%;且对直接黑G具有较高的耐受能力,在3 000 mg/L的条件下脱色率仍高达70%;对不同结构的偶氮染料均表现出较好的脱色性能;动力学分析发现其最佳脱色速率与浓度分别为40.597 3 mg g~(-1) h~(-1)、484.337 6 mg/L.通过紫外-可见光扫描及红外光谱扫描分析发现偶氮染料直接黑G在降解前后化学键及表面官能团发生了明显的变化;酶活性分析发现偶氮染料降解酶在降解后显著提高.此外,植物毒理性实验证明经复合菌群降解后的染料代谢产物对植物的毒性大幅度降低,可能被降解为其他低毒性物质.本研究结果表明该复合菌群具有较好的染料脱色降解性能,这将为偶氮染料的无污染化处理奠定理论基础.(图6表4参43) 相似文献
4.
《环境化学》2016,(3)
本实验利用溶剂热法合成了铋掺杂氧化铟催化剂,利用XRD、EDS和SEM对催化剂的结构和形貌进行了表征.研究表明,铋离子已经掺杂进氧化铟的晶格中.掺杂后的催化剂粒径为纳米级,且具有良好的球形形貌.本文以偶氮染料直接大红废水为目标降解物,分别考察了不同催化剂对该染料废水的降解性能以及铋掺杂氧化铟催化剂的投加量、染料的浓度、溶液的p H、超声频率和超声功率对该染料的降解性能.在本实验条件下,催化剂投加量为7.5 mg、染料浓度为10 mg·L~(-1)、pH值为6、超声频率为45 kHz、功率为100 W时,对染料废水的去除效果最优,总去除率可达83.7%,比空白实验的去除率提高将近5倍. 相似文献
5.
响应面法优化一株链霉菌对偶氮染料AR30的降解脱色条件 总被引:1,自引:0,他引:1
以一株对偶氮染料红30(AR30)具有较强降解脱色作用的菌株Streptomyces sp.FX649为研究对象,在单因素实验基础上,选择染料初始浓度、培养时间、pH与培养温度为主要因素,采用Box-Benhnken组合实验和响应面分析法对降解条件进行了精确优化.经实验修正,获得了最佳降解脱色条件,即在染料浓度110 mg.L-1、培养时间36 h、pH 7.3与培养温度31.3℃时该菌对染料AR30的降解脱色率为95.1%. 相似文献
6.
植物油改性纳米铁修复硝基苯污染地下水的研究 总被引:1,自引:0,他引:1
实验室条件下,液相还原法FeSO4·7H2O和KBH4反应制备纳米铁,用XRD、TEM对其性能进行表征,结果表明该纳米铁平均粒径为50 nm,主要成分为α-Fe0。实验室进一步制备植物油改性纳米铁,TEM表明油膜均匀包覆在纳米铁颗粒表面,且纳米铁粒子分布均匀,分散较好。厌氧条件下,纳米铁与硝基苯反应,研究纳米铁和植物油改性纳米铁对硝基苯的降解性能,以及不同初始铁投加量、植物油质量分数、初始 pH 对硝基苯降解的影响。研究表明,纳米铁和植物油改性纳米铁均对硝基苯有较强的降解能力,理论摩尔比下,1 h内纳米铁和改性纳米铁对硝基苯的降解率达99.85%和56.74%;油膜质量分数为1%和2%的改性纳米铁降解硝基苯效果较好;随着初始纳米铁投加量的增加,硝基苯的降解越快;初始pH对改性纳米铁降解硝基苯有一定影响,酸性条件有利于改性纳米铁降解硝基苯。 相似文献
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8.
纳米TiO2催化声化学降解酸性红B的研究 总被引:1,自引:0,他引:1
以经过高温活化处理的锐钛型纳米TiO2为催化剂,考察了各种因素对酸性红B溶液超声降解反应的影响。结果表明:锐钛型纳米TiO2对酸性红B溶液超声降解反应具有明显的催化作用,其降解效果明显好于单纯使用超声波降解。超声频率40 kHz,输出功率50 W,催化剂用量0.5 g/L,pH=3.0,酸性红B溶液的初始浓度20 mg/L的条件下,60 min降解率即可达80%左右,120 min基本降解完全。因此,纳米锐钛型TiO2催化超声降解偶氮染料的方法切实可行,而且具有良好的应用前景。 相似文献
9.
偶氮染料分子结构特征与其生物降解性的关系 总被引:6,自引:4,他引:6
本文研究了偶氮染料分子结构特征对其藻菌共生系统降解作用的影响。实验结果表明,藻菌共生系统对大多数偶氮染料有较强的降解作用,且这种降解作用的强弱与其分子结构特征有密切的关系。染料芳香环上取代基团的种类、数量、位置以及染料分子量的大小都能影响其降解的效果。 相似文献
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11.
G. Gaßner 《Environmental Sciences Europe》1993,5(2):76-81
The adsorption behavior of three anionic azo dyes (Acid Orange 6, Acid Orange 10 andAcid Orange 12) on different soil/sediment components (quartz sand, clay and organic matter) was investigated with a flow-through method using a simplified HPLC apparatus. Organic matter had the highest adsorption capacity for all three dyes, followed by clay and sand. The adsorption on different components in mixtures was not additive. The adsorption of similar aniomic azo dyes decreased with increasing negative charge. The affinity of equally charged dye molecules to the adsorbents was also strongly influenced by the remaining chemical structure. While adsorption on organic matter could always be described by Freundlich isotherms, S-shaped isotherms were often measured with quartz sand and clay. For that reason one must assume different adsorption mechanisms for organic matter and mineral adsorbens. Lower pH values always led to stronger adsorption of the anionic azo dyes. On the other hand, ionic strength effects cannot be characterized so clearly. Adsorption was generally lowered by decreasing ionic strengths but sometimes the opposite effect was observed. Moreover, there were some unusual cases of partly irreversible adsorption on quartz sand and organic matter when the dyes were not dissolved in an aqueous solution containing additional inorganic ions but in double distilled water. The adsorption of anionic azo dyes on soil and sediment materials turned out to be a very complex process. Although some interesting coherences could be pointed out, much more research is required to recognize general principles, concerning for example the influence of the chemical structure or the surrounding aqueous solution. 相似文献
12.
Degradation of azo dyes in water by Electro-Fenton process 总被引:19,自引:0,他引:19
The degradation of the azo dyes azobenzene, p-methyl red and methyl orange in aqueous solution at room temperature has been studied by an advanced electrochemical oxidation
process (AEOPs) under potential-controlled electrolysis conditions, using a Pt anode and a carbon felt cathode. The electrochemical
production of Fenton's reagent (H2O2, Fe2+) allows a controlled in situ generation of hydroxyl radicals (·OH) by simultaneous reduction of dioxygen and ferrous ions on the carbon felt electrode. In turn, hydroxyl radicals react
with azo dyes, thus leading to their mineralization into CO2 and H2O. The chemical composition of the azo dyes and their degradation products during electrolysis were monitored by high performance
liquid chromatography (HPLC). The following degradation products were identified: hydroquinone, 1,4-benzoquinone, pyrocatechol,
4-nitrocatechol, 1,3,5-trihydroxynitrobenzene and p-nitrophenol. Degradation of the initial azo dyes was assessed by the measurement of the chemical oxygen demand (COD). Kinetic
analysis of these data showed a pseudo-first order degradation reaction for all azo dyes. A pathway of degradation of azo
dyes is proposed. Specifically, the degradation of dyes and intermediates proceeds by oxidation of azo bonds and aromatic
ring by hydroxyl radicals. The results display the efficiency of the Electro-Fenton process to degrade organic matter.
Electronic Publication 相似文献
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14.
Karla Ili&cacute &Dstrok ur&dstrok i&cacute Raluca Ostafe Olivera Prodanovi&cacute Aleksandra &Dstrok ur&dstrok evi&cacute &Dstrok elma Nikolina Popovi&cacute Rainer Fischer Stefan Schillberg Radivoje Prodanovi&cacute 《Frontiers of Environmental Science & Engineering》2021,15(2):19
15.
Three metallised azo dyes were investigated under TiO2‐photocatalytic and photosensitised conditions in aqueous buffering solutions. The degradation follows apparent first‐order kinetics. The size and strength of intramolecular conjugation determine the light‐fastness of the investigated dyes. Compared with 1O2 produced in photosensitised process, the more powerful *OH radicals in TiCO2 photocatalytic process are highly reactive towards the investigated azo dyes. And as a result, the TiO2‐photocatalysis makes little less distinction in the degradation kinetic data of the azo dyes compared with the photosensitised degradation of them. 相似文献
16.
Huilong Wang Shuqin Liu Hui Wang Wenfeng Jiang 《Frontiers of Environmental Science & Engineering》2010,4(3):311-320
Multi-walled carbon nanotubes (MWCNTs)/TiO2 composite photocatalysts with high photoactivity were prepared by sol-gel process and further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and UV-vis absorption spectra. Compared to pure TiO2, the combination of MWCNTs with titania could cause a significant absorption shift toward the visible region. The photocatalytic performances of the MWCNTs/TiO2 composite catalysts were evaluated for the decomposition of Reactive light yellow K-6G (K-6G) and Mordant black 7 (MB 7) azo dyes solution under solar light irradiation. The results showed that the addition of MWCNTs enhanced the adsorption and photocatalytic activity of TiO2 for the degradation of azo dyes K-6G and MB 7. The effect of MWCNTs content, catalyst dosage, pH, and initial dye concentration were examined as operational parameters. The kinetics of photocatalytic degradation of two dyes was found to follow a pseudo-first-order rate law. The photocatalyst was used for seven cycles with photocatalytic degradation efficiency still higher than 98%. A plausible mechanism is also proposed and discussed on the basis of experimental results. 相似文献
17.
Yinghui Mo Liping Sun Lu Zhang Jianxin Li Jixiang Li Xiuru Chu Liang Wang 《Frontiers of Environmental Science & Engineering》2023,17(4):49
18.
细菌偶氮还原研究进展 总被引:11,自引:0,他引:11
细菌偶氮还原是在细菌偶氮还原酶作用下偶氮复合物分解为芳香氨的过程,多种细菌都具有偶氮还原功能.有氧条件下细菌的偶氮还原是在特异性的偶氮还原酶作用下完成的,对氧气不敏感.而厌氧菌和兼性厌氧菌的偶氮还原是在厌氧或兼性厌氧条件下由一些氧化还原中间体作为电子穿梭体与偶氮复合物作用的非特性的还原过程.电子穿梭体与偶氮复合物作用是一个纯化学氧化还原过程,其中偶氮复合物作为电子受体接受电子.厌氧偶氮还原是细菌偶氮还原的主要形式.偶氮还原在厌氧-好氧染料废水处理系统和偶氮水溶胶聚合物作为结肠靶向给药载体的研究中有重要应用.图2表1参45 相似文献
19.
Wool dyeing wastewater contains xenobiotic compounds that can be removed by biotechnological processes. Studies on various dyes showed that anaerobic processes are suitable to alter azo dyes as a first step of the biodegradation process. These compounds are reduced by anaerobic consortia to aromatic amines and its ultimate degradation can be achieved by a further aerobic treatment. Studies on degradation rate of an wool acid dye were performed in batch systems inoculated with anaerobic biomass. A commercial diazo dye, Acid Red 73, was added to the synthetic medium in which glucose was used as sole carbon source. Results indicated that the Acid Red 73 was partially degraded by a mixed culture of anaerobic bacteria and a decolorization of 90% was obtained. Kinetics studies on removal of the colour showed that the decolorization rate was several times faster than the degradation rate of glucose for a range of dye concentrations between 60 mg/L and 400 mg/L. A first order kinetic model was used for dye concentrations up to 200 mg/L. For higher concentrations a model similar to the Michaelis‐Menten equation was better fitted to the experimental data. 相似文献
20.
Yanan Bai Xiuning Wang Fang Zhang Raymond Jianxiong Zeng 《Frontiers of Environmental Science & Engineering》2022,16(3):34