Removal of basic dyes from aqueous solutions by crosslinked‐acrylic acid/acrylamidopropane sulfonic acid hydrogels

In this study, Acrylic acid (AA)/2‐acrylamido‐2‐methlypropane sulfonic acid (AMPS) hydrogels were prepared by free radical polymerization in aqueous solutions of AA, AMPS, and N,N‐methylenebisacrylamide (NMBA) as crosslinker. Potassium persulfate (PPS)/potassium bisulfide (PBS) were used as initiator and accelerator pair. The water absorption capacities and dye adsorption properties of the hydrogels were investigated. Adsorption properties of the hydrogels were evaluated by depending on different adsorption conditions such as different initial dye concentration and contact time. The concentrations of the dyes were determined using UV/Vis Spectrophotometer at wavelength 530 nm for safranine T (ST) and 622 nm for brilliant cresyl blue (BCB). Adsorption kinetic studies showed that pseudo‐first order kinetic model is suitable to explain the adsorption kinetic data of the hydrogels. Langmuir and Freundlich isotherm models were used to describe adsorption data. The result revealed that the adsorption of basic dyes onto hydrogels fit very well both Langmuir and Freundlich isotherms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Xanthene dyes/amine as photoinitiators of radical polymerization: A comparative and photochemical study in aqueous medium

The efficiency of several xanthene dyes as photoinitiators of the free radical polymerization in aqueous medium was evaluated. These results show that dyes with triplet quantum yield higher than 0.1 present similar efficiencies, independently of their different chemical structure. A detailed study of the photophysics of the dyes under the polymerization conditions was carried out using laser time-resolved spectroscopies. These studies show that the active radicals are those which formed in the interaction of excited triplet state of the dye with the amine through an electron transfer process. In spite of this, the photoinitiation efficiency is not correlated with the triplet quantum yield. Also, the photophysics studies show that the quantum yield of the different pathways of the decomposition of the charge transfer intermediate is an important parameter to predict the efficiency of these photoinitiator systems. The experimentally measured active radical formation is well correlated with that calculated from the polymerization rate. The presence of heavy atoms in the xanthene ring increases the triplet quantum yield, but decreases the active radical yield, and then the polymerization rate.     

Application of ozone on the decolorization of reactive dyes — Orange-13 and Blue-19

This study investigated the feasibility of applying ozone (O₃) to reduce the color content of wastewater caused by two commercial reactive dyes (Blue-19 and Orange-13). In the bench-scale experiment, experimental parameters including pH, ozone dosage, and reaction time were evaluated in a 14-L reactor to obtain the optimal operating conditions. Results show that ozone dosage and pH dominated the effectiveness of the decolorization process. The color content could be reduced from 2000 to 200 ADMI (American Dye Manufacture Institute) values within a reaction time of 30 min with the ozone input rate of 2.66 g/h. The pH values of 3 and 10 favored decolorization of Blue-19 and Orange-13, respectively. This was due to the effects that reactive and oxidizing species of molecular ozone and hydroxyl radicals were predominant at low and high pH, respectively. Moreover, molecular ozone was more selective to certain dye structures during the oxidation process. Kinetic analyses show that decolorization of Orange-13 and Blue-19 followed first-order kinetics. The degree of decolorization was primarily proportional to the ozone dosage. Results from this study provide insights into the characteristics and mechanisms of decolorization by the O₃ technique. Results will also aid in designing a system for practical application.     

Biosorption of a reactive textile dye from aqueous solutions utilizing an agro-waste

In the present study a low-cost waste biomass derived from canned food plant, was tested for its ability to remove reactive textile dye from aqueous solutions. The batch biosorption experiments were carried out at various pH, biosorbent dosage, contact time and temperature. Optimum decolorization was observed at pH 2.0 and 1.6 g dm^− 3 of biomass dosage within 20 min. The first-order and the pseudo-second-order kinetics were investigated for the biosorption system. The applicability of the Langmuir and Freundlich isotherm models was examined. The thermodynamic parameters for the biosorption were also calculated. The experimental results in this study indicated that this low-cost biomaterial was an attractive candidate for the removal of textile dye Reactive Red 198 (RR198) from aqueous solutions.     

微电解法处理三种红色染料废水的研究

以模拟染料废水为研究对象,用铁碳微电解法处理高色度的3种红色染料废水。分别考察了铁碳比、反应时间、氢氧化钙的投加量对原废水去除效果的影响;比较了微电解法与其他方法的去除效果,探索了微电解法处理染料废水的机理。实验结果表明,微电解法对染料废水有明显的去除效果,固定废水pH值为5.8左右,反应时间分别为25,30,20 min,铁碳比分别为1∶1.5,1.5∶1,2.5∶1,氢氧化钙投加量分别为0.02,0.06,0.05 g时,活性红的去除率为92.7%,直接红的去除率为91.8%,酸性红的去除率为98.9%。     

过氧化钛配合物(PTC)体系在柔性染料敏化太阳能电池中的应用

本文利用水性过氧化钛配合物(peoxotitanium complex:PTC)前驱体可低温合成锐钛矿TiO2溶胶的特性,将其用作柔性染料敏化太阳能电池(DSSC)中的光阳极材料的成膜助剂.研究发现:加入基于PTC制得的TiO2溶胶可以明显提高DSSC的光电转换性能,在制备DSSC的浆料中加入10%(体积分数)的基于PTC制得的TiO2溶胶后,电池的光电效率可以提升50%.我们进一步研究了光电转换效率的影响因素,结果表明,溶胶的加入量和反应时间均有一最佳值,当基于PTC的TiO2溶胶添加量为10%,反应时间为9h,所得到电池的光电性能最好.     

热敏打印技术及热敏染料在彩色影像输出中的应用

全彩色热敏打印由于具有影像质量高、使用方便、利于环保等优点,成为彩色影像输出技术领域的发展方向。荧烷化合物具有在熔点下从无色到有色的互变结构,可通过变换取代基,得到黄、品、青系列染料,成为应用在热敏彩色影像输出技术中的主要染料类型。     

微波辐射-吸附催化法处理孔雀石绿染料废水的研究

采用微波辐射-活性炭吸附催化法,研究其处理孔雀石绿染料废水的可行性及其影响处理过程的因素和规律。结果表明:微波辐射-吸附催化法对孔雀石绿染料废水具有较好的处理效果,当孔雀石绿染料废水的质量浓度为250 mg/L,活性炭的投加量为36 g/L,辐射电压为165 V,辐射时间为20 min时,脱色率可达83%;增加活性炭用量、处理时间和染料废水浓度均能提高微波-吸附催化法处理孔雀石绿染料废水的脱色率;微波辐射可加快活性炭吸附催化孔雀石绿的速率,具有加速孔雀石绿裂解和氧化速率的作用。     

磺酰胺类染料中间体的合成与表征

以乙酰苯胺、间苯二胺为主要原料,经磺酰化、酰胺化、脱乙酰基,合成了替代致癌染料中间体N,N'-1,3-苯基二-(4-氨基)苯磺酰胺,并优化了酰胺化反应条件。产物分别经元素分析、红外、质谱和核磁表征确证了结构。     

锦/棉织物一浴法染色工艺探讨

本文对活性染料染锦/棉交织物的染色工艺进行了系统研究。根据活性染料的染色特征值SERF值从大到小的顺序筛选了三组活性染料,分别对先酸后碱工艺和应用pH值调节剂A工艺的染色效果作了比较研究。结果表明:SERF值中等的染料适用于上述两种工艺。先酸后碱工艺的固色率可达70%,摩擦牢度和皂洗牢度分别为4～5级,同色性较好。应用pH值调节剂A的工艺固色率可达80%,摩擦牢度和皂洗牢度分别为4～5级,且同色性较好。