光辐射对水溶性偶氮染料还原脱色反应的影响

以硼氢化物和硫酸盐混合物为还原脱色剂，对17个水溶性阴离子偶氮染料进行光还原脱色降解，考察求灯辐射光对其还原脱色反应的影响，并运用紫外可见光谱法进行分析。结果表明，辐射光对水溶性偶氮染料的还原脱色反应具有明显的促进作用，6种目标染料在光辐射下的脱色率也明显高于室内条件下的脱色率，两者之间的差距随着反应时间的延长而增加，尤其以直接染料的表现更为突出。紫外可见光谱显示，在光还原脱色反应中，染料分子中的共轭体系和芳香环结构均遭到破坏。     

复配兔毛蛋白脱色剂在印染废水脱色中的应用

介绍了兔毛蛋白脱色剂及其复配聚硅酸.硫酸铝脱色剂的制备方法,并模拟印染废水进行脱色。分析了兔毛蛋白脱色剂用量、pH值,以及复配脱色剂脱色时对pH值、聚硅酸.硫酸铝用量、兔毛蛋白脱色剂用量、脱色时间与染料浓度、染料类型对脱色效果的影响。优化得出复配脱色剂对活性艳红K-2BP模拟废水的的最佳脱色条件:兔毛蛋白脱色剂用量400mL/L,聚硅酸.硫酸铝用量4mL/L,pH值小于12,在室温(25℃)下用磁力搅拌器快速搅拌大于5min,且研究表明,该复配脱色剂对直接染料、酸性染料、分散染料脱色效果均较好。     

改性鸡毛角蛋白脱色剂对印染废水絮凝脱色性能的研究

用十六烷基三甲基苄基溴化铵对鸡毛角蛋白脱色剂进行改性处理,制备出改性的鸡毛角蛋白脱色剂.探讨了制备改性鸡毛角蛋白脱色剂的配方,评价了改性鸡毛角蛋白脱色剂的脱色效果,并研究了脱色回用水的再利用.结果表明:制备改性鸡毛角蛋白脱色剂的最佳配方为鸡毛角蛋白脱色剂0.1 g/L、十六烷基三甲基苄基溴化铵0.05 g/L;该改性鸡毛角蛋白脱色剂在碱性条件下对染料废水的脱色效果较好,脱色适用性较广;染料废水中的NaCl对其絮凝脱色效果影响不大;当废水中存在渗透剂JFC时,其絮凝脱色性能显著降低;脱色回用水可重新用于染色.     

新型复合混凝脱色剂处理印染废水

讨论了钠离子质量浓度对印染废水絮凝沉降的影响,并根据其影响规律通过无机絮凝剂与脱色剂的复配研制出一种新型混凝脱色剂。采用新研制的混凝剂对染料溶液、实际印染废水进行COD去除和脱色研究,并讨论了投料量、pH等的影响。结果表明,絮凝剂对不同离子浓度的染料溶液均有显著的COD去除及脱色效果。     

铁改性腈纶纤维催化剂在偶氮染料降解反应中的应用

使用水合肼和盐酸羟胺对腈纶纤维进行表面改性,然后将其与铁离子反应制得铁改性腈纶纤维催化剂（PAN-Fe）。在过氧化氢存在条件下将PAN-Fe催化剂应用于2种水溶性阴离子偶氮染料的光催化氧化降解反应中,考察了催化剂添加量、催化剂表面铁离子含量、染料浓度和pH值对染料降解反应的影响。结果表明,尽管PAN-Fe催化剂在暗态能催化染料降解反应,但是光辐射可促进其催化作用的提高;催化剂添加量及其表面铁离子含量的增加能够明显提高染料的脱色率。在PAN-Fe催化剂存在下染料降解反应可在碱性条件下进行,但是染料浓度的增加会使其脱色率降低。     

纳米银粒子对偶氮染料的催化还原降解的研究

为了探索纳米银粒子对染料的催化还原降解,选用单偶氮和双偶氮染料为目标降解物,以硼氢化钠为还原剂,研究纳米银粒子的催化性能及偶氮染料催化还原降解的机理。经试验讨论得知:在不加入纳米银催化剂的条件下,硼氢化钠还原剂对单偶氮染料(酸性橙7和弱酸性红B)就具有一定的还原性能;在同时加入纳米银催化剂和还原剂的情况下,酸性橙7和弱酸性红B染料的还原降解反应的反应速率得到了大幅度的提升。酸性橙7和弱酸性红B染料的还原降解反应主要是发生在偶氮基上的加氢还原,造成染料分子偶氮键的断裂并生成相应的有机物,最终实现单偶氮染料分子结构的破坏。对于双偶氮染料而言(刚果红和酸性黑1),在不加入纳米银的条件下硼氢化钠对染料的还原降解能力非常有限,特征吸收峰的下降幅度很小;在同时加入纳米银和还原剂的条件下,两种双偶氮染料才发生了有效的还原催化降解。     

菜籽磷脂脱色的动力学研究

以过氧化氢为脱色剂,对菜籽磷脂进行脱色,获得了有关动力学参数。研究结果表明,过氧化氢浓度对脱色效果的反应级数为0.6199,色素浓度对脱色效果的反应级数为0.3329,脱色反应的活化能为52.88kJ/mol。     

Pycnoporus sp. SYBC-L3漆酶催化偶氮染料脱色

为考察 Pycnoporus sp. SYBC-L3漆酶Lac-L对偶氮染料的脱色、解毒效果,探究最佳的脱色反应条件,采用单因素分析方法研究了不同的反应条件对Lac-L催化3种偶氮染料（AR1、RB5、RV5R）脱色的影响,得到最佳处理条件,并通过比较被漆酶降解前后的染料对小麦和水稻发芽率及根、芽生长的影响,分析其毒性变化。结果表明：在以HBT为介体、反应温度50 ℃、pH分别为4.0（AR1,RV5R）和5.0（RB5）、漆酶用量1 U/mL、染料初始质量浓度分别为30 mg/L（AR1）和50 mg/L（RB5、RV5R）条件下,漆酶对3种偶氮染料的脱色效率最高,AR1和RV5R几乎完全降解,脱色率达到96.1%和97.8%,而RB5也有83.8%的脱色率。植物毒理实验表明,3种偶氮染料经漆酶降解后对小麦和水稻发芽率没有影响,对胚芽和根生长的抑制作用也有所降低。     

联苯胺系统结构染料的纸色层鉴别法

一、基本原理联苯胺系统结构的偶氮染料,一股是以联苯胺系中间体作为重氮组分,所以在鉴别时,首先将此类染料还原裂解,以使偶氮键断开,然后用纸色层方法选用适当的展开剂,将还原裂解后各组分的混合物进行分离,在纸上展开后将重氮组分重新重氮化(某些偶氮组分也可以重氮化),再喷NW酸,在氨熏条件下,使其重新偶合。对于联苯胺系统结构的重氮组分则能生成一特征的蓝——紫色染料,因此在纸上某一位置呈现一特征的蓝紫色斑点,这个斑点的位置、颜色视展开剂组成、联苯胺苯核上基团的种类、位置及     

新型非均相Fenton反应催化剂在染料降解中的应用

使用自制的微球型非均相光催化剂和过氧化氢溶液对几种不同结构的染料进行非均相光催化氧化脱色反应,重点研究了催化剂数量、过氧化氢浓度、染料浓度和无机盐对其脱色反应的影响。结果表明,催化剂数量和过氧化氢浓度的增加能够明显提高染料的脱色率,染料浓度的增加使染料的最终脱色率降低,无机盐对染料的脱色降解也有影响。     

偶氮染料分子结构与氧化脱色性能的定量关系

基于草酸铁(Ⅲ)/过氧化氢光催化氧化体系,对35种水溶性阴离子偶氮染料进行脱色降解研究,通过选择分子结构描述符和计算机多元线性回归分析方法考察了其脱色率及其分子结构之间的定量关系。结果表明,在染料分子结构描述符与脱色率之间存在着较好的线性相关性,其中MW/S值和偶氮基数目对脱色率的贡献最为显著,得到的分子结构和脱色率之间的定量关系方程可用于计算染料的理论脱色率。     

Effect of light and sweeteners on color in an amaretto-type liqueur

Studies on the color loss in an amaretto-type liqueur under controlled light conditions showed a clear dependence of the decoloration rate on the light intensity, and complete color stability in the absence of light. The principal sweetener used in the preparation of the liqueur strongly affected the rate of color loss under irradiation, color stability being much greater for the formulations containing sucrose or no added sweetener instead of fructose 42. These differences were more pronounced in experiments conducted with chemically well-defined mixtures that contained either of the 2 azo dyes used in the coloration of the amaretto, tartrazine, and Allura Red, and various alternative sweeteners, in 28% (v/v) ethanol solution: D-fructose and, to a lesser extent, D-glucose, at concentrations of 14% (w/v), were effective in bringing about photodecoloration, while no color loss was detected in the presence of sucrose, or in the absence of any added sugar. The results are interpreted in terms of a redox reaction of reducing sugars with the diarylazo compounds, the function of the light being the conversion of the azo compound from the predominant trans configuration to the cis configuration, which on geometric grounds lends itself better to a concerted, cyclical redox reaction with the reducing sugar.     

An Automated Flow Injection Analysis Procedure for the Determination of Reducing Sugars by DNSA Method

A nonenzymatic spectrophotometric method, coupled to an automatic system of standard additions, based on the reaction with 3,5‐dinitrosalicylic acid (DNSA) is described. In a system based on an exhaustive reaction, sample volumes are introduced together with calibration solutions, thus the calibration is performed in a nonsegmented flow system. Homogenization of the sample/standard/carrier takes place in the calibration loop. Later, it is injected in the flow injection analysis system, where the reaction with DNSA occurs, to obtain 3,5‐diaminosalicylic acid which is measured spectrophotometrically. With the proposed method, it is possible to eliminate the Rochelle salt, sodium and potassium tartrate, phenol and sodium bisulfite of the principal reagent. Sample throughput was 11 samples/h and precision, expressed as relative standard deviation, was 2.3%.     

偶氮染料废水厌氧生物脱色强化

针对偶氮染料废水的生物降解难题,通过对比投加不同浓度的电子供体（葡萄糖）和氧化还原介体（RM）蒽醌-2,6-二磺酸钠盐和活性炭对偶氮染料的厌氧生物脱色效果的影响,探究增强偶氮染料厌氧生物脱色的条件。结果表明,投加电子供体或RM均可有效强化偶氮染料废水厌氧生物脱色：投加300 mg/L葡萄糖时脱色率可高达53.35%,投加200 mmol/L蒽醌-2,6-二磺酸钠盐时脱色率为34.59%,与投加0.6 g/L的活性炭的脱色率（35.26%）相当;投加葡萄糖时0~24 h的脱色速率最快为1.47%/h,36 h脱色效率接近最大值为46.49%;投加蒽醌-2,6-二磺酸钠盐时0~12 h的脱色速率最快为1.03%/h,60h脱色效率接近最大值为33.30%;投加活性炭时0~30 h的脱色速率最快为0.79%/h,60 h脱色效率接近最大值为33.65%。     

Fenton degradation of organic compounds promoted by dyes under visible irradiation

The influence of dyes on the Fenton reaction of organic compounds under visible irradiation (lambda > 450 nm) was examined. It was found that the presence of dyes could accelerate greatly the Fenton reaction of organic compounds such as salicylic acid, sodium benzenesulfonate, benzyltrimethylammonium chloride, and trichloroacetic acid under visible irradiation and that a complete mineralization of those compounds could also be achieved. The dyes such as Alizarin Violet 3B which has an anthraquinone structure unit showed much more significant effect on the reaction than the dyes such as malachite green without the quinone unit. A reaction mechanism of dye AV as a cocatalyst in the photo-Fenton reaction of organic compounds under visible irradiation is proposed based on the cycle of Fe(3+)/Fe(2+) catalyzed by quinone species and an electron transfer from the excited dye molecule to Fe3+.     

Analysis of Aldehydes and Ketones in the Headspace of Heated Pork Fat

Volatile chemicals in the headspace above heated pork fat were purged into aqueous solutions of cysteamine, sodium bisulfite, or methylhydrazine to trap aldehydes and ketones. Nine aldehydes and four ketones were determined as thiazolidine derivatives in traps containing aqueous cysteamine or aqueous sodium bisulfite. The major compounds produced were hexanal, heptanal, and pentanal. In general, aqueous cysteamine was more efficient at trapping carbonyl compounds than was aqueous sodium bisulfite. However, formalydehyde and acetaldehyde were trapped better by sodium bisulfite solution than by cysteamine solution. Acrolein and malonaldehyde were determined as l-methyl-2-pyrazoline and 1-methylpyrazole, respectively, from the trap containing methylhydrazine. This represents the first time that malonaldehyde has been determined in the vapor phase.     

铁盐媒介对靛蓝电化学还原体系的影响

针对当前电化学染色过程中染料还原率低、染色深度差问题,选择不同价态的铁盐溶液作为媒介与葡萄糖酸钠和Abal B配体形成协同络合体系,对靛蓝染料进行电化学还原。通过染液还原电位、染料还原率、亚铁离子转化率研究不同铁盐媒介的电化学还原能力。结合试验和极差分析探究还原液浓度、电压、通电时间对靛蓝间接电化学还原体系性能的影响,并对其染色工艺进行优化。试验得到的优化还原工艺为:靛蓝染料、FeSO₄·7H₂O、葡萄糖酸钠、Abal B、NaOH质量浓度分别为2.5、15、12、10.5、37.5 g/L,工作电压为10 V,时间为40 min。在此条件下,染料还原率达到89.95%,染色后棉织物染色深度值比传统方法提高4.5%,色光偏红,染色牢度与传统染色相当。     

Aspergillus flavus growth in the presence of chemical preservatives and naturally occurring antimicrobial compounds

The combined effects of water activity ([a(w)] 0.99 or 0.95), pH (4.5 or 3.5) and antimicrobial agent (potassium sorbate, sodium benzoate, sodium bisulfite, carvacrol, citral, eugenol, thymol, or vanillin) concentration (0, 100, 200 up to 1800 ppm) on the growth of Aspergillus flavus were evaluated in potato dextrose agar (PDA). Mold spore germination time and radial growth rates (RGR) were significantly (p<0.05) affected by the variables. For equal antimicrobial concentration, reduction in pH or a(w) had important effects, lowering RGR and delaying germination time. Depending on a(w) and pH, increase in antimicrobial concentration slightly reduced RGR until a critical concentration where RGR was drastically reduced or mold growth was inhibited. Germination time increased as antimicrobial agent concentration increased and when a(w) and pH decreased. Important antimicrobial differences were observed, being, in general, the natural antimicrobials less pH-dependent than chemical preservatives. A. flavus exhibited higher sensitivity to thymol, eugenol, carvacrol, potassium sorbate, sodium bisulfite, and sodium benzoate (at pH 3.5) than to vanillin or citral.