活性艳红X-3B水溶液的光化学与光催化协同脱色反应

 对影响活性艳红X－3B水溶液光化学与光催化协同脱色反应的各种条件（如溶液的pH值,紫外光照强度,空气流量,催化剂用量及溶液的初始浓度等）进行了考察．结果表明,降解率随着紫外光照强度的增强而加快,随着X－3B初始浓度的增大而减慢;催化剂最佳用量为4g／L,空气最佳流量为4．3L／h．在X－3B水溶液的光催化脱色过程中,存在有光解反应,但它远不如光催化反应重要．因此,活性艳红X－3B水溶液的降解是光化学与光催化的协同脱色反应．     

催化褪色光度法测定痕量亚硝酸根

用吸收光谱法研究了在磷酸介质中,亚硝酸根催化甲基绿被溴酸钾氧化而褪色的反应。在紫外可见光谱区,甲基绿的三个吸收峰出现在632．6,421．4和313．4nm。根据亚硝酸根的催化褪色反应在632．6nm产生的吸光度差或在三个吸收峰产生的吸光度差的总和,与亚硝酸根的浓度呈线性关系,建立了催化褪色光度法测定痕量亚硝酸盐的方法。     

Process development for the decoloration of Panax notoginseng extracts: A design space approach

A systematic, yet simple method for the decoloration of Panax notoginseng extracts has been developed by static adsorption tests and response surface methodology. Through static adsorption experiment screening, acidic alumina was selected because of its high decoloration ratio and saponin recovery ratios. Using response surface methodology, the correlation between the process parameters (i.e., sample volume and flow rate) and decoloration performance was modeled. A design space of the decoloration process was subsequently established through the proposed models. The verification experimental values were in good agreement with the predicted values. The design space was proven reliable, because all the verification experimental results attained the criteria for design space development. Moreover, most of the saponins adsorbed by the acidic alumina could be recovered through dynamic desorption using water and ethanol. The method developed in the current study is highly efficient, flexible, and easy to control, thus providing a promising approach for the decoloration of Panax notoginseng extracts with consistent decoloration performance.     

辉光放电等离子体处理阳离子染料结晶紫废水

用辉光放电等离子体技术对结晶紫进行了降解脱色处理,考察了多种因素对结晶紫降解效果的影响。实验发现,提高电解质浓度和增加电压均可提高结晶紫的脱色效果,考虑到电极损耗,辉光放电最佳条件为:电解质浓度为2 g/L Na2SO4,电压为600 V。当改变溶液的初始pH值时,结晶紫的脱色率随溶液的初始pH值升高而增加,加入一定量H2O2能明显地提高结晶紫的脱色效率;若加入0.4 mmol/L Fe2 ,5 min时结晶紫的脱色率由原来的13.64%增加到91.36%。结果表明,辉光放电产生的.OH对结晶紫的降解起重要作用。最佳条件下,40 min内的脱色率达到93%,降解率为74%。     

离子交换纤维对亚硫酸法糖汁脱色性能研究

研究了强碱性阴离子交换纤维对亚硫酸法清净糖汁的脱色性能.对沉清工段清汁的脱色效果和影响因素进行了研究.结果表明,阴离子交换纤维对沉清汁的脱色效果明显,脱色后清汁色值低于30 oSt.再生液洗脱再生反复使用90次后,脱色效果达84%.与717强碱性苯乙烯系阴离子交换树脂相比具有脱色容量高、脱色速度快、再生速度快和抗污染能力强等优点.通过离子交换纤维的脱色处理,亚硫酸法清净糖汁可以达到制备优质糖的要求.     

Silylation and sulfonation of structured supported catalysts active in the decoloration of azo-dyes under visible light

Structured silica woven fabrics have been derivatized with functional groups able to anchor by exchange of Fe³⁺-ions and TiO₂ showing a stable performance during the visible light induced decoloration of the Orange II azo-dye. The kinetics and efficiency of the decoloration mediated by the catalytic loaded silica fabrics with Fe³⁺-ions were seen to be much higher than found with homogeneous Fenton reagents (Fe³⁺/H₂O₂) with the equivalent Fe³⁺ content. The same was observed for derivatized membranes where TiO₂ has been anchored as the active catalyst surface species. In the case of the silica Fe³⁺-ions loaded fabrics, the decoloration was studied as a function of the amount of H₂O₂ oxidant added in solution, the intensity of the applied visible light and the concentration of the initial Orange II. In the case of the silica-TiO₂ fabrics the decoloration kinetics was observed to be a function of the O₂ present in solution. In the case of the derivatized Fe³⁺ and TiO₂ loaded silica fabrics, the decoloration process presented three common features: (a) the decoloration process was observed only in the presence of light pointing to a photo-induced process in both cases, (b) the decoloration was also observed to be truly catalytical following repetitive cycles for Orange II, and finally (c) the decoloration processes were limited by the mass transfer kinetics taking place at the surface of both derivatized fabric catalyst and proceeded with about the same kinetics in both cases. The numerical values for the diffusion distance of the radicals species OH√ and HO₂√ as well as the decrease in the concentration of radicals away from the silica fabric during the photodegradation of Orange II is estimated by the Smoluchowski diffusion equation.     

Mechanism of decoloration by solvent of thermally degraded poly(vinyl chloride)

The mechanism of decoloration of thermally degraded poly(vinyl chloride (PVC)) by solvents has been investigated systematically. The main results obtained are as follows. Good solvents for PVC, especially tetrahydrofuran, methyl ethyl ketone, and dioxane are effective for decoloration. The solvent peroxide which is formed by autoxidation of solvent contributes to decoloration. The number of double bonds in degraded PVC decreases as the decoloration proceeds and at the same time the solvent peroxide existing in solvent is consumed. Moreover, the existence of solvent fragments in decolored PVC is recognized. From these results, it is most reasonable to conclude that the decoloration mechanism is as follows: the solvent partially is changed to a solvent peroxide by autoxidation, and the solvent peroxide reacts with polyene double bonds of degraded PVC and breaks down conjugated double bonds, and consequently degraded PVC is decolored.     

可用于光催化研究的脉冲放电流光光源

利用针板形式的电极系统、正极性纳秒级脉冲电压供电、在空气和水混合条件下产生脉冲放电流光,研究了脉冲放电流光与电气参数、溶液电导率、鼓泡空气流量的变化关系,利用脉冲放电流光和纳米颗粒的半导体TiO2结合对酸性橙染料(AO7)溶液进行脱色效果的实验研究。结果表明,脉冲放电流光可以诱导TiO2发生光催化活性,在脉冲放电等离子体处理效果的基础上,提高AO7的脱色效果。     

Online LC-MS-MS process monitoring for optimization of biological treatment of wastewater containing azo dye concentrates

A biological high-performance treatment process comprising two 40-L reactor compartments has been developed for purification and decoloration of concentrated textile wastewater containing up to 15 g L⁻¹ reactive dyestuff. The decoloration rate of 95% meets the requirements of German legislation for textile wastewater treatment. Successful process development and optimization was achieved by use of high-performance liquid chromatography, with diode-array and electrospray tandem mass spectrometric (LC-ESI-MS-MS) detection, coupled with inline microfiltration membrane-sampling devices, applied online to bioreactors as a process analytical tool for the first time. The optimum process performance was found by correlation of dye and decoloration product-specific concentrations with summary properties such as redox potential and dissolved oxygen content. Details of the degradation and decoloration mechanism for the azo dye reactive black 5 was revealed by using mass spectrometry for structure elucidation.     

The effect of molecular structure on the secondary transitions and their influence on the decoloration kinetics of photochromic dyes in co‐polycarbonates

Photochromic dyes have restricted use in rigid polycarbonates because of slow coloration and decoloration kinetics. In this study, it is shown that the decoloration kinetics of two photochromic dyes can be controlled by tuning the chain stiffness and free volume of the host matrix. The introduction of flexible moieties in rigid BPA‐based polycarbonate chain accelerates the decoloration of these dyes whereas a rigid co‐monomer delays the decoloration kinetics. Although T_g might be used as a parameter to improve photochromism in polymer matrices, dynamic mechanical analysis demonstrates that the decoloration kinetics of the dyes in host polymer matrices having similar T_g depends primarily on the secondary relaxations and, thus, on the polymer architecture. The effect of the co‐monomer type on the characteristic ratio is also discussed underlining the potential relationship between the free volume and chain stiffness. These results open the possibility to develop transparent or semitransparent photochromic materials based on tailor‐made co‐polycarbonates. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1593–1601     

磁载光催化剂TiO2/SiO2/Ni0.5Fe2.5O4的制备及其催化氧化性能

采用固相反应法制备磁载体(SiO₂/Ni_0.5Fe_2.5O₄),溶胶-凝胶法得到易于磁分离回收的磁载光催化剂TiO₂/SiO₂/Ni_0.5Fe_2.5O₄。用XRD、SEM、IR和UV-Vis等进行表征。研究了太阳光下催化剂对亚甲基蓝溶液的脱色性能。结果表明,在太阳光下,磁载光催化剂TiO₂/SiO₂/Ni_0.5Fe_2.5O₄可使亚甲基蓝溶液迅速脱色；3次循环使用后脱色率仍为95%以上,回收率为98.8%。     

High energy induced decoloration and mineralization of Reactive Red 120 dye in aqueous solution: A steady state and pulse radiolysis study

Gamma radiation induced decoloration and degradation of aqueous solution of Reactive Red 120 dye (RR-120) have been investigated under different experimental conditions. Rate constants for the reaction of hydrated electron and hydroxyl radical with RR-120 were determined to be 1.2×10¹⁰ and 7.9×10⁹ mol^?1 dm³ s^?1, respectively, by pulse radiolysis technique. The decoloration and degradation efficiency were measured in terms of % decoloration and % TOC, respectively. Decoloration was observed to be most efficient under reducing condition, where the radiolytic yield for the decoloration of dye was determined to be 0.14 μmol/J. The extent of decoloration for both aerated and oxygen saturated solution was almost identical, whereas it decreased in N₂O saturated solution as well as N₂ saturated solution. For a solution having 10.56 μg/ml total organic carbon (TOC) at a dose of 3 kGy, 48% mineralization takes place in oxygen saturated solution whereas under aerated condition same was observed to be lowered to 38%.     

Photochromism of spirofluorenylindolizines

The decoloration kinetics of three spirofluorenylindolizines have been followed in solution and in polymer matrix. They are the 5′-methyl-spiro[9H-fluorene-9.1′(1′H)-indolizine]-2′-3′-bis-methoxycarbonyl ( I ), its methacryloyl oxymethyl ( II ) derivative, and the copolymers of ( II ) with ethyl acrylate. In solution the reactions follow first-order kinetics and show pronounced negative solvatochromism. In solid polymer film, the incorporation of the photochrome as side group of polyethylacrylate affects strongly the decoloration below T_g of the film. Above T_g the decoloration was interpreted on the basis of the WLF equation.     

活性艳红X-3B水溶液的光催化脱色及矿化过程研究

对染料活性艳红X-3B水溶液的光催化反应过程进行了初步研究.首先,利用紫外-可见吸收光谱、高效液相色谱和质谱对反应过程中溶液组成的变化进行了测试,并用重铬酸盐法测定了各反应时刻溶液的COD值;其次,使用红外吸收光谱对反应过程中催化剂表面的吸附物种进行了考察.研究结果表明,在本实验条件下,活性艳红X-3B水溶液的光催化脱色和矿化过程是同时进行的,脱色反应完成后,溶液中生成了难以降解的中间产物,致使矿化过程难以继续进行.     

Decomposition and decoloration of a direct dye by electron beam radiation

The wastewaters released by textile industries to the environment contain hazardous compounds like toxic refractory dye stuff at high concentration. In this study, electron beam irradiation-induced decoloration and decomposition of C.I. Direct Black 22 aqueous solutions were investigated. The influences of absorbed doses and initial dye concentration on the percent of decoloration, COD and pH of the solutions are described. The results show that the direct dye solutions can be effectively degraded by electron beam irradiation.     

检测土壤中全碘的硫氰酸铁-亚硝酸钠-碘催化比色法

在稀硝酸溶液中 ,硫氰酸铁的褪色反应与体系中碘的含量、体系温度和反应时间有关 ,硫氰酸铁的质量浓度随时间的变化而减小 ,给检测带来较大误差。作者在体系反应一定时间之后加入颜色固定剂 ,使体系的吸光度在数小时内保持不变 ,提高了检测的准确度。     

立方状和球状氧化亚铜的制备及其光催化性质

利用室温液相还原法和低温水热法制备了立方状和球状氧化亚铜,通过X射线衍射、场发射扫描电子显微镜对合成产物进行了表征。 以合成产物光催化降解偶氮染料甲基橙为模型,研究了不同形貌Cu2O的光催化性能,结果表明,球状氧化亚铜对甲基橙的脱色率达89.0%,球状氧化亚铜/Fenton复合体系中甲基橙的脱色率达98.2%。 初步探讨了Cu2O粉体催化降解甲基橙的过程和机理。     

硅胶负载壳聚糖对水溶性染料脱色的正交试验

通过正交试验方法,用硅胶负载壳聚糖对直接耐晒兰、直接大红、直接艳红、直接深蓝、直接嫩黄五种水溶性染料进行脱色实验.对脱色的影响因素,如处理剂用量、pH值、搅拌时间、静置时间、染料颜色进行了探讨 确定了影响脱色效果的主次因素顺序,并绘制出硅胶负载壳聚糖对五种直接染料的吸附等温线,吸附等温线符合弗里德利希方程式 对直接耐晒兰的吸附方程式为:Γ=0.05·C0.36     

Polymeric siloxanes with a substituent and the spirobenzopyran moiety: Effect of polar substituent on the photochromic properties

Oligomeric polysiloxanes having the spirobenzopyran moiety and various substituents were prepared. The polymers were photochromic; the color changed from colorless to red on UV irradiation and the color faded on visible irradiation or on standing in the dark. The thermal decoloration was depressed by the polar substituents. However, the effect of the bulky substituent, which had been observed in the rigid siloxane resins, was not detected. In the inorganic/organic hybrid siloxane gels, the silica/(spirobenzopyran-bonding polysiloxane) system and the (spirobenzopyran-bonding silica)/polysiloxane system, the thermal decoloration was also affected by the polar substituent introduced into the polysiloxane portion. The effect was larger in the first case than in the second. The result can be interpreted by the term of the preferential diffusion of polar spirobenzopyran to the vicinity of the polar substituents during the gelation.     

Decoloration and mineralization of reactive dyes using electron beam irradiation,Part I: Effect of the dye structure,concentration and absorbed dose (single,binary and ternary systems)

In this study, three different reactive dyes (C.I. Reactive Red 4, C.I. Reactive Blue 2 and C.I. Reactive Yellow 4) and their blend solutions were irradiated with 10 MeV electron beam. Effect of absorbed dose, dye structure and primary solution concentrations on the pH value changes, degree of decoloration and chemical oxygen demand (COD) removal of solutions were investigated. Results show that this method is effective in decomposition and decoloration of the dyes solutions. This method can be applied in mineralization of wastewater containing different dyes.