Biodegradability of Azo and Triphenylmethane dyes by Pseudomonas pseudomallei 13NA

Biodegradability of dyes by Pseudomonas pseudomallei 13NA was examined by spectrophotometric and thin layer chromatographic methods. The results are summarized as follows:

• (i) Pseudomonas pseudomallei 13NA intact cells were responsible for the decolorization of p–aminoazobenzene, C. I. Acid Orange 7, C. I. Acid Orange 12, C. I. Acid Orange 20, C. I. Acid Red 88, C. I. Direct Red 28, C. I. Direct Yellow 4, C. I. Basic Violet 1, C. I. Basic Violet 3 and C. I. Basic Orange 21.
• (ii) The half–decolorization time of the azo dyes used in this experiment showed good correlation with their molecular weights.
• (iiii) The detection of the reaction products of p–aminoazobenzene and C. I. Basic Violet 3 was examined by spectrophotometric and thin layer chromatographic methods. The results indicate the possibility of biodegradation of these dyes by Pseudomonas pseudomallei 13NA.

     

Biodegradation of p–Aminoazobenzene by Continuous Cultivation of Pseudomonas pseudomallei 13IMA

A continuous cultivation apparatus was constructed in order to improve the existing biological treatments for waste dye–liquor. The cleaning effect by Pseudomonas pseudomallei 13NA, an azo–assimilating bacteria, was examined. Using p–aminoazobenzene as a typical component of waste dye–liquor, it was found that the bacteria effectively removed it by biological degradation. For example, 80% of 10 ppm p–aminoazobenzene was removed by a three–stage continuous treatment.     

合成染料的生物降解

综述了合成染料的生物降解技术。染料废水处理技术多种多样,其中生物法以其经济、高效、无二次污染、对环境友好等优点而应用最为广泛。迄今为止,已经证明多种微生物对合成染料具有生物降解能力。将来,利用微生物降解外源性化学物质（包括合成染料）有望成为解决土壤和水污染等环境问题的一项绿色处理技术。     

Two-dimensional 1H-, 13C- and 15N-NMR Spectra of Azo Dyes Derived from J-Acid,H-Acid and Gamma Acid

The ¹H-, ¹³C- and ¹⁵N-NMR spectra of compounds prepared by coupling benzenediazonium chloride with J-acid, H-acid and Gamma acid under alkaline conditions have been measured. Two-dimensional H,H-COSY, NOESY, H,C-COSY and COLOC spectra and one-dimensional selective INEPT have been used in the assignment of the ¹H- and ¹³C-NMR signals. The results show that the above-mentioned aminohydroxynaphthalene-sulfonic acids undergo diazo coupling of benzenediazonium chloride ortho to the hydroxyl groups under alkaline conditions. Using δ(¹³C), δ(¹⁵N) and ¹J(¹⁵NH) it has been found that the coupling products exist, in hexadeuteriodimethyl sulfoxide solutions, as equilibrium mixtures of the azo and hydrazone tautomers with strongly prevailing naphthoquinone phenyl-hydrazone configurations.     

非诱变偶氮染料的研究进展(I)──偶氮染料诱变性研究方法及其致癌机理

主要讨论了偶氮染料诱变性能研究方法及其致癌机理。偶氮染料诱变性能研究方法多采用“Ａｍｅｓ／Ｓａｌｍｏｎｅｌｌａ”测试法,而其致癌机理,目前大多数专家认为主要是通过它在动物（或人）体内偶氮还原开裂形成的芳胺或其相关化合物特别是芳氮烯阳离子来实现的。     

Fenton法处理模拟偶氮染料废水的研究

采用Fenton法对模拟偶氮染料废水进行了处理。考察了废水初始pH值、H2O2和Fe2＋投加量、反应时间及反应温度等对模拟染料废水COD去除率的影响。实验结果表明,在甲基红的初始浓度为200mg.L-1,初始pH值为3.0,H2O2和Fe2＋投加量分别为20mmol.L-1和1mmol.L-1,反应温度为50℃,反应时间为60min的条件下,废水中COD的去除率可达83.5%。     

偶氮染料分子致癌机理探讨

对国外有关偶氮染料分子致癌的研究结果进行分析,总结出偶氮染料分子致癌的可能途径,为偶氮染料的安全使用和环境友好偶氮染料分子设计提供了理论指导。     

偶氮染料的光敏性研究

合成了单偶氮蒽醌、双偶氮蒽醌和双偶氮芴酮三个系列偶氮染料,并以此制成了功能分离型双层光电导体。蒽醌类单偶氮染料扩大取代基的共轭体系,可以提高光敏值,最大可由Ix.S2800提高到Ix.S62,含-NO_2的染料光敏性最高,最低为-OCH_3。蒽醌双偶氮类染料取代基对光敏性的影响与蒽醌单偶氮类染料相同,前者的光敏性高于取代基相同的后者。取代基对芴类双偶氮染料光敏性的影响与前两类不同,含-Cl取代时光敏性最高,含-NO_2最低。染料的光敏性排序为:芴酮类>双偶氮蒽醌类>单偶氮蒽醌类。     

禁用偶氮染料新动向和对策

20 0 2年 9月 11日 ,欧盟委员会发出了 2 0 0 2年第六十一号指令 ,禁止使用会在还原条件下分解产生2 2种致癌芳香胺的偶氮染料 ,并规定 2 0 0 3年 9月 11日之后 ,在欧盟 15个成员国的市场上销售的欧盟自行生产或从第三国进口的有关产品中所含有的会分解产生 2 2种致癌芳香胺的偶氮染料的含量不得超过 30ppm的限量 ;2 0 0 3年 1月 6日 ,欧盟委员会进一步发出 2 0 0 3年的第三号指令 ,规定在欧盟的纺织品、服装和皮革制品市场上禁止使用和销售含铬偶氮染料 ,并将于 2 0 0 4年 6月 30日生效。欧盟在不到半年的时间内连续二次发出了禁用部分偶氮染料和含铬偶氮染料的指令 ,不仅是其首次将禁用部分偶氮染料和含铬偶氮染料形成为欧盟所有成员国的统一行动 ,也反应了国际市场上不断竖起“绿色壁垒”的新动向。     

The Photofading of Mixtures of Azo Dyes and Mixtures of an Azo Dye and Oxygen in Aquous Solutions Containing d,l-Mandelic Acid

The reactions of the reducing species formed on photo-excitation of d, l-mandelic acid in aqueous solutions with azo dyes, oxygen, mixtures of azo dyes, and mixtures of azo dyes and oxygen have been investigated. The results indicate that all reactions can be described as reductions of the oxidising agents (azo dyes and/or oxygen) by the photochemically formed reducing species. The azo dyes used can be arranged in a sequence according to their electron affinities. The higher the electron affinity the more susceptible a dye is to reduction in d, l-mandelic acid on ultraviolet irradiation. The inhibition of the photoreduction of azo dyes in solution by oxygen is mainly caused by a competition of the azo dye present and oxygen for the reducing species. However, the rates of fading of the dyes in aerobic solutions are only partly determined by the electron affinities of dye and oxygen. Other factors, such as the relative rates of intermediate reactions and the occurrence of as yet unidentified side-reactions, determine to an important extent the sequence of stability of the azo dyes during irradiation in aerobic solutions.     

Formation of Hydrazyl Radicals and Hydrazo Compounds by Photoreduction of Azo Dyes

The photoreduction of eighteen different monoazo dyes in aqueous and ethanolic solutions, containing d, l -mandelic acid or acetone as hydrogen donors, to the corresponding amines has been investigated by flash-photolysis and rapid-flow techniques. The photoreduction of azo dyes proceeds in stages involving hydrazyl radicals and hydrazo compounds. The former are formed in a rapid reaction of the azo dyes with the active reducing agent produced upon absorption of light by the hydrogen donor. These radicals are unstable and disproportionate with formation of hydrazo compounds and regeneration of the original azo dye. The hydrazo compounds are also unstable and decompose with formation of amines and regeneration of the dye. The reaction schemes presented are supported by kinetic evidence and electron spin resonance measurements.     

高效液相色谱-串联质谱法同时测定食品非法添加的三种偶氮类工业染料

建立高效液相色谱-串联质谱法(HPLC-MS/MS)同时检测食品中所含碱性嫩黄O、酸性橙II和酸性金黄的检测方法。样品用经甲醇-50 mmol/L乙酸铵洗脱,经高效液相色谱-串联质谱法测定。结果表明3种组分在0.10~2.00 mg/L呈良好的线性关系,相关系数在0.999 3以上。样品回收率81.3%~110.5%,相对标准偏差(n=3)为2.0%~5.4%,定量限在1.0 mg/kg以下。该方法操作简单、灵敏度高、结果准确可靠,可应用于食品中3种偶氮类工业染料的定量及确证分析。     

醌基陶粒强化偶氮染料化学脱色的特性研究

采用吸附/共价耦合的方法将氧化还原介体蒽醌-2-磺酸(AQS)固定在无机陶粒表面(醌基陶粒),并对其在无氧条件下强化偶氮染料的化学脱色特性进行了研究。研究结果表明,AQS能够被固定在无机陶粒上,其浓度为2.3μmol g 1;在无氧条件下,醌基陶粒强化酸性金黄G化学脱色的最佳条件为:Na2S浓度为3.2 mmol L 1,pH为6.0;整个反应过程遵循假一级反应动力学,并且随着固定化AQS浓度的增加,酸性金黄G的假一阶动力学常数明显增大。当加入60μmol L 1固态醌时,酸性金黄G、活性艳红X-3B、苋菜红和酸性橙7的假一阶动力学常数分别提高2.9、5.3、9.9和6.0倍,并且重复实验表明,醌基陶粒介导的偶氮染料脱色速率能够保持为最初的98%。由此可见,此种新型的固定化介体材料醌基陶粒在偶氮染料废水处理方面具有潜在的应用价值。     

聚氨酯泡沫固定化蒽醌强化偶氮染料生物脱色的研究

研究了聚氨酯泡沫固定化蒽醌对偶氮染料生物脱色的强化作用。结果表明,蒽醌作为氧化还原介体,其加速苋菜红生物脱色的最适条件为:葡萄糖浓度为2g·L-1,pH值为8.0~9.0,蒽醌浓度为90mg·L-1。采用吸附方法固定蒽醌,所需聚氨酯泡沫块为2个。固定化蒽醌可以提高偶氮染料的厌氧生物脱色速率1~3倍,其加速作用与悬浮态的蒽醌作用相当。固定蒽醌的聚氨酯泡沫经10次循环使用后,偶氮染料的生物脱色速率仍保持在90%以上。可见,将蒽醌固定在聚氨酯泡沫上具有潜在的应用价值。     

Ozonation of Two Acidic Azo Dyes with Different Substituents

The ozonation of two differently substituted azo dyes (Schwarz GRS and Orange Acid 8) in water media is studied. The influence of pH on the effectiveness of the ozonation at various initial concentrations of each dye is explored. It was found out that the rates of decolorization for amino-group substituted dyes reflect the considerable influence by the widely varying initial pH from 4.5 to 10. Specifically, the highest effect of decolorization of this dye was obtained at the highest pH studied (pH 10) for all initial concentrations of the solutions. Considering the dye without an amino-group substitute, the rates of color disappearance in ozonation reflected to a lower degree the variations of the initial pH. Pseudo-first-order trends of decolorization were observed in all the experimental runs. Regarding the kinetic results obtained, an attempt to explain the different dyes reactivity was made based on the absolute electronegativity (E_lumo + E_homo) of both dyes. The COD/BOD analysis shows that the ozonation of both azo dyes can reduce the sample COD but it could not improve the biodegradability ratio (BOD₅/COD). BOD decrease with ozonation time indicates that the intermediates of the ozonation are of lower biodegradability. Oxalic acid was found as the final product of ozonation of both dyes.     

Photofading of Some Azo Disperse Dyes on Nylon Film

The photofading of nine azo disperse dyes on nylon 6 film has been investigated at 254 nm in the presence and in the absence of air. A reductive pathway is involved, which is confirmed by the presence of amines arising from the reduction of the azo group. Zero-order and first-order kinetics have been found to operate, depending on the dye structure. The reaction mechanisms are briefly discussed.     

微通道反应器中偶氮染料连续化制备技术研究

对微通道反应器中偶氮染料连续化制备技术进行研究,以C.I.酸性红54为模型底物,考察微通道反应器中反应物流速、停留时间、管道内径和反应温度对反应的影响,得较优工艺条件为:重氮组份、偶合组份的摩尔比为1∶1,反应物流速ν=0.18 m/s,停留时间τ=11.11 s,管道内径D=1.0 mm,室温下进行(20℃),产率为96.80%。以C.I.酸性红54较优工艺条件为基础,固定反应物流速ν=0.18 m/s,管道内径D=1.0mm,对不同色系的酸性偶氮染料和活性偶氮染料在微通道反应器中的反应情况进行初步研究,产率均大于80%。该工艺具有连续化、高效、条件温和等优点,具有很好的广泛实用性。     

假单胞菌代谢尼古丁研究进展

假单胞菌和节杆菌是两种最重要的尼古丁降解菌,目前节杆菌降解尼古丁的代谢途径、代谢相关基因和酶学机制都已经研究清楚,但是对假单胞菌降解尼古丁的研究尚不完善。本文将主要针对假单胞菌,从目前分离到的假单胞菌属微生物的菌株种类、代谢途径、代谢相关基因和酶学机制等方面阐述假单胞菌属微生物降解尼古丁的研究进展。