印染废水处理技术研究进展探析

印染废水的主要特点是色度、BOD、COD、pH值、温度和浊度高,分子量大,生物降解性低,且废水成分复杂,含有有机高分子化合物和助凝剂等.综述了印染废水处理技术的研究及应用现状,介绍了印染废水中常用的物理处理法、化学处理法和生物法,分析了不同处理方法的研究及应用效果及优缺点,提出了各处理方法的技术缺陷及存在的问题,并对印染废水处理未来的研究方向进行了展望,不同处理方法间的组合可以较好地发挥它们各自的优点,是未来可靠处理印染废水的有效方法.     

TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi₅O₇NO₃) surface was synthesized via a precipitation method using TiO₂ and Ag as modified agents. The synthesized product was characterized by different analytical techniques. The removal efficiency was evaluated using mono-and di-sulphonated azo dyes as model pollutants. Different kinetic, isotherm and diffusion models were chosen to describe the adsorption process. X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi₅O₇NO₃;however, the presence of hydrophilic centres such as TiO₂ and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes. Dyes removal was found to be a function of adsorbent dosage, initial dye concentration, solution pH and temperature. The reduction of Langmuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent. Mass transfer can be described by intra-particle diffusion at a certain stage, but it was not the rate limiting step that controlled the adsorption process. Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.     

Enhanced anaerobic fermentation with azo dye as electron acceptor： Simultaneous acceleration of organics decomposition and azo decolorization

Accumulation of hydrogen during anaerobic processes usually results in low decomposition of volatile organic acids（VFAs）. On the other hand, hydrogen is a good electron donor for dye reduction, which would help the acetogenic conversion in keeping low hydrogen concentration. The main objective of the study was to accelerate VFA composition through using azo dye as electron acceptor. The results indicated that the azo dye serving as an electron acceptor could avoid H2 accumulation and accelerate anaerobic digestion of VFAs. After adding the azo dye, propionate decreased from 2400.0 to 689.5 mg/L and acetate production increased from 180.0 to 519.5 mg/L. It meant that the conversion of propionate into acetate was enhanced. Fluorescence in situ hybridization analysis showed that the abundance of propionate-utilizing acetogens with the presence of azo dye was greater than that in a reference without azo dye. The experiments via using glucose as the substrate further demonstrated that the VFA decomposition and the chemical oxygen demand（COD） removal increased by 319.7 mg/L and 23.3% respectively after adding the azo dye. Therefore, adding moderate azo dye might be a way to recover anaerobic system from deterioration due to the accumulation of H2 or VFAs.     

Detection of intermediates in the TiO2-assisted photodegradation of Rhodamine B under visible light irradiation

The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra （IR spectra）, ^1H nuclear magnetic resonance （^1HNMR） spectra, and gas chromatography-mass spectroscopy （GC-MS）. The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems （TiO2 nanostfipe or P25 and Rhodamine B systems）. GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway（s） for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.     

柱撑酸化膨润土对染料废水的处理实验研究

目前国内外对柱撑酸化膨润土的实验研究少有报道。将钙基膨润土酸性活化,用其处理染料废水其一次性COD去除率可达62%,色度去除率可达83%。若再对其进行无机柱撑,COD的去除率可达81%以上,色度去除率可达98%以上。其处理后的染料废水达到国家工业废水排放标准。     

印染工业废水处理工程设计要点

结合印染工业废水处理工程现状，提出应重视印染废水处理工程的工艺设汁，分析讨论了在印染工业废水处理工程设汁中要引起注意的三个方面问题。     

凤眼莲(Eichhornia crassipes Solms)对染料色水脱色作用的初步研究

经凤眼莲对染料色水的脱色作用静态试验表明,凤眼莲对阳离子、活性、直接、还原和酸性等染料有显著的脱色作用,其中对阳离子染料的脱色尤为有效,脱色率最高可达98％。还进行了小型动态实验,并建立了一个反映脱色率与进水色度、色水停留时间和凤眼莲生物量等参数间相关关系的数学模型。试验结果表明,凤眼莲的脱色作用具有酶促反应的若干特点,Ca~(2+)、Mn~(2+)等离子的存在可使脱色率显著提高。     

Photocatalytic decolorization of dispersol dyes

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活性艳蓝KN-R在ACF电极上成对电解脱色的影响因素

分别以活性炭纤维（ACF）为阳极和阴极，在无隔膜电解槽中研究了利用成对电解降解蒽醌染料活性艳蓝KN-R脱色过程的影响因素。考察了染料初始浓度、支持电解质Na2SO4、pH及温度诸条件对脱色性能的作用。结果表明：适当增加染料初始浓度和支持电解质浓度，酸性和中性条件以及适中的温度均对成对电解脱色性能有利。当染料初始浓度为251mg／L，在合适的处理条件下，脱色率达到95％，脱除单位质量染料电耗仅为1．22kWh／kg染料。     

Application of recording films of solar radiation for environmental and ecological research

Global solar radiation is recorded by fading of the colored film into which azo-dye is impregnated with use of organic solvent. Oil Red O, Sudan I, Sudan IV and Pyridylazonaphthol are used as the azo dye. These films can be applied to measure the solar radiation in many kinds of environmental or ecological conditions. The merits of the film compared with usual measurements are to be: unnecessary of any electric sources; cheap and mass-productive easily; suitable to integrate solar radiation for long time; easy dealing in out-door or underwater conditions; possible to use on leaves of any plants because of light weight; possible to use in a lot of points at the same time.