Ultrafiltration purification of waters contaminated with bifunctional reactive dyes

The problem with the removal of textile dyes from waste waters is an important issue both from an ecological and technological point of view. Besides well known conventional methods, membrane techniques of separation are used more and more nowadays. The successful application of such a process depends on membrane type, process conditions and the behavior of the membrane under these conditions. Process effectivity can be improved by using both conventional and membrane processes.     

Catalytic wet oxidation of reactive dyes in water

In the presence of small amount of H₂ the Pd–Pt/Al₂O₃ bimetallic catalysts showed excellent activity toward wet oxidation of reactive dyes due to the combined roles of faster redox cycle and the formation of H₂O₂.     

二氧化钛光催化降解活性染料废水的研究进展

综述了二氧化钛光催化降解活性染料废水的研究成果,对影响二氧化钛光催化降解活性染料废水的各种因素(如催化剂的形态、溶液的pH值、光源与光照强度和溶液中其它物质等)及光催化降解动力学行为进行了讨论,并提出了今后的研究方向。     

Jet printing with reactive dyes

The history of ink jet printing on textile substrates is reviewed and the major projects currently under examination are examined. The development of Procion reactive dye formulations and associated application technology for the ink jet printing of cellulose fabrics is discussed in detail.     

Purification of polymeric dyes by ultrafiltration

Ultrafiltration has been evaluated as a method for the purification of of polymeric dyes. Transport data for solvent and solutes were obtained for several polymer-impurity mixtures and different membrane types. Relatively low molecular weight impurities were found to be significantly rejected by these membranes. A critical concentration of sodium chloride or sodium hydroxide was found to be necessary to effect efficient transport of these species. Gel permeation chromatography was used to monitor these separations and characterize the purity of the polymeric dyes produced. Impurity concentrations in the final product were typically less than 500 ppm.     

Printing of cationised cotton with reactive dyes

The printing properties of cationised cotton that had been pretreated with 2,3-epoxypropyltrimethylammonium chloride were examined. Fixation (steaming) time, colour yields, colorimetric properties, fastness properties, staining of the white grounds and penetration behaviour were evaluated for a number of reactive dyes with cationised cotton fabrics. The cationisation of cotton was found to be very effective in reducing steaming times and washing off processes, and in increasing colour yield. Fastness and other properties of the printings are also discussed.     

Ag2CO3@PVDF/氧化石墨烯超滤膜及其分离性能

以聚偏氟乙烯（PVDF）为聚合物,氧化石墨烯（GO）为添加剂,聚乙烯吡咯烷酮（PVP-K30）为致孔剂,N,N-二甲基乙酰胺（DMAc）为溶剂配制铸膜液,借助相转化法制备了PVDF/GO膜（PGM）,并通过原位共沉反应在PGM表面沉积Ag₂CO₃得到Ag₂CO₃@PVDF/GO复合膜（AgC-PGM）;使用扫描电镜（SEM）、傅里叶红外光谱（FTIR）、水接触角、纯水通量、BSA截留率和三维荧光光谱（3D-EEM）考察了膜材料的形貌、亲水性、水通量和分离性。结果表明,当添加GO为0.4%（质量）,AgNO₃（5.0 mmol·L^-1）与Na₂CO₃（2.5 mmol·L^-1）共沉反应3次得到AgC-PGM;与PVDF膜（132.8 L·m^-2·h^-1）相比,AgC-PGM呈现出较高的亲水性和纯水通量（237.4 L·m^-2·h^-1）,其纯水通量提高了78.8%,对BSA截留率稳定在75%以上;在过滤校区湖水时,AgC-PGM不仅凸显去除蛋白质污染的能力,且出水COD和UV₂₅₄达到自然水体一级标准。     

Development of novel reactive dyes with a mixed bifunctional reactive system

The advantages of the mixed bifunctional reactive system—vinylsulphone and monochlorotriazine—with respect to dyeing and fastness properties are discussed in detail.     

Continuous dyeing of cationised cotton with reactive dyes

Cotton fabrics pretreated with cationic starch have been dyed with reactive dyes by a continuous dyeing method and the pretreatment conditions influencing dyeability of the treated cotton investigated. Cationised cotton has been found to give level dyeing without the presence of salt and dye fixation is improved compared with untreated cotton. The dyeings show good wash and rub fastness.     

Degradation of reactive dyes by supercritical water oxidation in a batch reactor

The supercritical water oxidation of three reactive dyes in a batch reactor was studied with varying levels of hydrogen peroxide oxidant. The decolorisation of each dye was measured by absorbance spectrophotometry and quantitatively determined from calibration graphs for each of the three dyes. At the lowest excess oxidant concentration (zero excess), the extent of chromogen destruction was nominally lower for the red dye than for the blue and black dyes.     

国内外活性染料的进展

两个三聚氯氰取代基分别在染料母体两端,藏青色染料结构如下[42]:     

Dyeing cotton with reactive dyes under neutral conditions

This paper describes a new method to dye cotton with selected reactive dyes by long-liquor – or so-called 'exhaustion'– processes under neutral conditions. Particularly promising results were obtained with reactive dyes containing free vinyl sulphone residues. Although there are dyes on the market that contain free vinyl sulphone groups, for example, the Novacron C (Huntsman) range of dyes, many of this class contain 'blocked' vinyl sulphone residues; examples include sulphatoethylsulphone or chloroethylsulphone precursor groups, and these may be preactivated to the highly reactive vinyl sulphone form simply by a mild alkali treatment. After this activation, neutral, long-liquor dyeings can be carried out at the boil in the presence of electrolyte. This new dyeing method gave very good results in terms of overall fixation efficiency values, without the need for alkali additions.     

超滤法提取大蒜超氧化物歧化酶的工艺研究

在热处理除去部分杂蛋白的基础上,利用相对分子质量为5×104的聚醚砜膜对大蒜超氧化物歧化酶(SOD)进行了分离和纯化,考察了蛋白质溶液性质(pH、离子强度)和溶液流体力学性质(流速、搅拌速率)对SOD透过率的影响.在最优分离条件下,SOD纯度可高达90.6%,比活性为712.49 U/mg.     

Technological evaluation of reactive cyclodextrin in cotton printing with reactive and natural dyes

The chemical modification of cotton fabric with reactive cyclodextrin (R‐CD) at different concentrations was carried out to enhance the printability of cotton fabric. The extent of the modification reaction was expressed as %N. Reactive and natural dyes were used to print cotton fabric before and after modification. Printing pastes were applied immediately after preparation or after 24 h of storage. Printing fixation was performed through either steaming or thermal treatment. The effect of the incorporation of R‐CD in the printing paste of unmodified cotton was also studied. The results reveal that the extent of the modification reaction increased with increasing R‐CD concentration and so did the color strength (K/S) of the printed sample regardless of the dye used. The results also revealed that K/S of the R‐CD modified cottons were higher than that of the corresponding unmodified samples regardless of the method of fixation or the time elapsed before printing. On the other hand, the incorporation of R‐CD in the printing pastes of reactive dyes, namely, Cibacron Brown 6R‐P or Remazol Brilliant Red GG, had adverse effects, most probability due to the (a) increasing viscosity of the paste and/or (b) interaction of the reactive dye with R‐CD hydroxyls. The opposite held true when a natural dye was used. Further, the incorporation of R‐CD in the printing pastes had no effect on the rheological type of the pastes or the on overall fastness properties of the prints. Nevertheless, such an incorporation of R‐CD was accompanied by a remarkable increase in the magnitude of the apparent viscosity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 338–347, 2006     

膜分离法提纯L-苏氨酸的研究

采用超滤膜分离系统一步截留不经预处理的L-苏氨酸发酵液中的菌丝体、蛋白质和悬浮的固体颗粒等杂质.在实验中确定了膜的最佳操作方式和清洗方式,滤液澄清透明、质量高,过滤收率高达96%以上,系统的平均膜通量最高可达86L/(m2·h).另外,对污染膜的清洗研究表明,NaOH和HNO3溶液对于膜的恢复有很好的效果.     

Diffusion with simultaneous reaction of reactive dyes in cellulose

The theoretical equations which described the concentration profile of immobilized species of reactive dyes in the substrate were derived from the diffusion equation with the chemical reaction of first-order or pseudofirst-order. The theoretical profiles in the substrate described by the equations were discussed. The larger the diffusion coefficient D of active species and the smaller the reaction rate constant k, the deeper is the penetration of the immobilized and active species of reactive dyes into the substrate. The method of estimating D and k from the diffusion profiles of both species obtained by means of the method of the cylindrical cellophane film roll was described. The diffusion coefficients of the hydrolyzed species of C.I. Reactive Orange 1 and Red 1 were nearly constant in all the pH values examined. The concentration profiles of both the species of Orange 1 at pH 8.8 were identical with the theoretical ones; while the profiles of immobilized species of Red 1 at pH 10 and of Orange 1 at pH 12 agreed with the theoretical ones and those of active species did not because of the hydrolysis. The diffusion coefficients of active species of these dyes at these pH ranges were smaller than those of the hydrolyzed species.     

Dyeing of N-modified viscose rayon fibres with reactive dyes

Modified viscose rayon fibres were produced by incorporation of different doses of a polydiallyldimethylammonium chloride based additive in the viscose dope prior to spinning. On dyeing the modified fibres with different reactive dyes, excellent dye exhaustion and total dye fixation above 90% were obtained without the use of electrolyte and with low salt concentration. Exhaustion and total dye fixation showed an exponential relationship. The wash fastness properties of the dyed fibres were excellent and the light fastness showed a slight drop in the modified fibres. The presence of the amino groups along with low density and crystallinity of the modified fibres may be responsible for the enhanced dyeability.