染料结构与其絮凝脱色效果关系的探讨

在对活性、酸性和碱性等 1 0种水溶性染料水样絮凝脱色和平衡渗析实验数据进行分析的基础上 ,初步探讨了染料结构与其絮凝脱色率之间的定性关系。PAN -DCD絮凝剂对 1 0种染料的最佳脱色pH范围 <5,尤其在pH值 <4更佳。在最佳pH条件下 ,絮凝剂加入量增加 ,脱色率升高。染料分子上磺酸基数目多者脱色效果好 ,分子中疏水性基团大则脱色率高 ,含蒽醌环的染料脱色率大于萘环者 ,也大于含苯环者。     

JAZ型絮凝剂对活性染料的絮凝效果

本文介绍了新近开发的ＪＡＺ絮凝凝剂地水样中活性艳红Ｋ－２ＢＰ，活性紫Ｈ－２Ｒ和活性黑Ｋ－ＢＲ染料的絮凝效果及ＰＨ值和投药比对脱色率的影响。在中性和弱酸性中絮凝效果好。投药比增大脱色率增加。对活性艳红和活性紫，起始浓度增加则达到８８．５％脱色率的投药比降低。对三种活性染料配水和活性 染料配水和活性黑染料生产水脱色率均可达到９９％，处理液残余色度在２０倍以下。     

金属离子协同马尾藻对水中偶氮染料分子脱色的研究

本文研究了多种金属离子对海藻处理不同结构的偶氮染料分子的影响，结果表明，金属离子的种类及浓度对海藻处理偶所染料都有重要的作用，偶氮染料的分子量和结构也影响该体系的脱色效果。适当浓度的金属离子和海藻的体系比单独海藻处理偶氮染料的脱色速度快，脱色率高。同时探讨了该体系处理不同结构染料分子的脱色差异。     

复极性固定床电解反应器对活性染料的降解

本文用复极性固定床电解反应器对１６种活性染料的脱色降解进行了试验研究。结果表明：染料脱色率在９９．６％以上,出水上清液ＣＯＤ去除率绝大部分在９０％以上,对活性翠蓝ＫＮ－Ｇ和活性深蓝ＫＭ－ＧＲ的铜去除率分别为９７．０％和９９．７％。     

Anaerobic decolorization of an azo dye by a mixed culture

Wool dyeing wastewater contains xenobiotic compounds that can be removed by biotechnological processes. Studies on various dyes showed that anaerobic processes are suitable to alter azo dyes as a first step of the biodegradation process. These compounds are reduced by anaerobic consortia to aromatic amines and its ultimate degradation can be achieved by a further aerobic treatment.

Studies on degradation rate of an wool acid dye were performed in batch systems inoculated with anaerobic biomass. A commercial diazo dye, Acid Red 73, was added to the synthetic medium in which glucose was used as sole carbon source.

Results indicated that the Acid Red 73 was partially degraded by a mixed culture of anaerobic bacteria and a decolorization of 90% was obtained. Kinetics studies on removal of the colour showed that the decolorization rate was several times faster than the degradation rate of glucose for a range of dye concentrations between 60 mg/L and 400 mg/L. A first order kinetic model was used for dye concentrations up to 200 mg/L. For higher concentrations a model similar to the Michaelis‐Menten equation was better fitted to the experimental data.     

Decolorization and degradation of acid dyes mediated by salt fractionated turnip ( Brassica rapa ) peroxidases

Peroxidases from turnip roots (524?U?g^?1 of vegetable) were highly effective in decolorizing acid dyes having wide spectrum chemical groups. Dye solutions, containing 40–170?mg?dye?L^?1, were treated by turnip peroxidases (TP) (specific activity of 122.0?U?mg^?1 proteins). These enzymes were able to decolorize most of the acid dyes in the presence of 2.0?mM 1-hydroxybenzotriazole (HOBT). Increasing concentration of enzyme and time in the absence of HOBT did not influence dye decolorization. The rate of decolorization was significantly enhanced when HOBT was added to the decolorizing solutions. The decolorization of all the used dyes was maximum at pH 5.0 and 40°C. Complex mixtures of dyes were significantly decolorized when treated with enzyme in the presence of HOBT (2.0?mM). Phytotoxicity test based on Allium cepa root growth inhibition has shown that majority of the TP-treated dye product were not more toxic than their parent dye. Kinetic parameters of the TP with various dyes showed that this enzyme has highest affinity for Acid Yellow 42. This study demonstrates that the peroxidase/mediator system was an effective biocatalyst for the treatment of industrial effluents from textile, dye manufacturing, dyeing and printing industries or complex mixtures of dyes.     

絮凝剂PAN-DCD的结构和性质研究

以聚丙烯腈（ＰＡＮ）和双腈双胺（ＤＣＤ）为原料,合成了有机絮凝剂ＰＡＮ－ＤＣＤ。用ＩＲ、１ＨＮＭＲ和１３ＣＮＭＲ等方法对其结构进行了表征,探讨了ＰＡＮ－ＤＣＤ溶解度随ｐＨ值变化的规律,研究了ＰＡＮ－ＤＣＤ对活性染料的絮凝脱色和去除ＣＯＤＣｒ的性能。结果表明,ＰＡＮ－ＤＣＤ是侧链带有多种极性基团的聚合物;在酸性条件下溶解度较小,碱性条件下溶解度较大;在加入量较少的情况下使活性染料的脱色率接近１００％,并对ＣＯＤＣｒ的去除有较大贡献。     

水中直接染料的多相催化脱色的试验条件研究

实验结果表明，金属氧化物催化剂与活性炭和过氧化氢配合使用，对直接染料有很高的催化脱色率。反应进行迅速，以直接耐酸大红4BS和直接红棕RN为代表的正交实验表明影响催化脱色作用的主要因素为催化剂，其次是活性炭和过氧化氢。直接深蓝L－3RB，直接铜蓝2R，直接黑L－3BQ，直接耐晒黄RS，直接青莲RB等的最大脱色率为92.9%-99.5%。     

Sol-gel immobilisation of methyl parathion degrading bacteria isolated from agricultural areas of Pakistan

The following areas are discussed in this paper: immobilisation of bacterial consortium in sol-gel; methyl parathion degradation and bioremediation applications; evaluation of indigenous bacterial isolates of contaminated soils. Bacterial strains were isolated from agricultural areas of Pakistan which were contaminated with methyl parathion. A bacterial consortium of seven (out of 64) Enterobacteriaceae isolates including Citrobacter, Enterobacter and Proteus vulgaris capable of degrading methyl parathion (enzyme activity ranging 410–675 mU mL^?1 for individual isolates and 982 mU/mL for consortium) was selected and subsequently immobilised in tetraethyl orthosilicate (TEOS) and sodium-silicate-based sol-gel matrices. Cell viability of suspended and immobilised bacterial consortium was monitored using a minimal salt medium supplemented with methyl parathion. The results indicate that sol-gel immobilisation can be helpful to increase the shelf life of methyl parathion degrading bacterial strains along with preservation of biological activity for bioremediation applications in field.     

酸性染料的臭氧降解与中间产物

以酸性金黄G模拟染料废水为研究对象,观察臭氧氧化过程中染料溶液吸光度和TOC的变化,利用离子色谱仪、红外光谱仪和GC/MS对染料的降解过程进行了分析,并用发光细菌法检测了溶液急性毒性的变化,结果表明,臭氧对染料的降解符合一级反应动力学,反应40 min后染料溶液的脱色率达到99.3%,TOC去除率为35.7%;染料分子中的S有97.8%被转化为SO2-4,分子中的仲胺基部分转化成酰胺基,水解后生成NH+4,最终氧化成NO-3,溶液中有草酸产生;溶液在臭氧化前期由于生成了醛类和酚类物质,使急性毒性首先呈上升趋势,25min后随着氧化的深入,溶液毒性开始逐渐下降,     

新生MnO2对直接染料废水的脱色作用

以化学法合成的新生MnO2作吸附剂，对直接桃红12B（Direct red 12B)，直接大红4B（Direct reb 4B)，直接耐晒蓝B2RL（Direct Fast blue B2RL)染料废水进行脱色研究，探讨了影响吸附的因素，结果表明：新生MnO2对三种染料的吸附符合Langmuir吸附等温式，吸附速率大，在适宜条件下对直接桃红，直接大红，直接耐晒蓝的脱色率分别为95．5％，96．2％和98．9％。     

Decolorization of azo dyes by a salt-tolerant Staphylococcus cohnii strain isolated from textile wastewater

The salt-tolerant Staphylococcus cohnii strain, isolated from textile wastewater, has been found effective on decolorizing several kinds of azo dyes with different structures. The optimal conditions for azo dye acid red B (ARB) decolorization by S. cohnii were determined to be pH = 7.0 and 30°C. The decolorization efficiency increased with the increase of the salinity concentration, and around 90% of ARB (100 mg·L^?1) could be decolorized in 24 h when the salinity concentration was up to 50 g·L^?1. Moreover, the strain could still decolorize 19% of ARB in 24 h even when the NaCl concentration was increased to 150 g·L^?1. Meanwhile, the dependence of the specific decolorization rate by S. cohnii on the ARB concentration could be described with Michaelis-Menten kinetics (K _m = 585.7mg·L^?1, V _max = 109.8 mg·g cell^?1·h^?1). The addition of quinone redox mediator, named 2-hydroxy-1,4-naphthoquinone and anthraquinone-2,6-disulfonate, significantly accelerated the decolorization performance of S. cohnii. Furtherly, the activities of azoreductase (0.55 ??mol·mg protein^?1·min^?1) and Nicotineamide adenine dinucleotide-dichlorophenol indophenol (NADH-DCIP) reductase (8.9 ??mol·mg protein^?1·min^?1) have been observed in the crude cell extracts of S. cohnii. The decolorization products of ARB were analyzed by HPLC-MS, and the results indicated the reductive pathway was responsible for azo dye decolorization by S. cohnii.     

Selection of poly(R)-3-hydroxybutyric acid utilising bacteria by enrichment,optimisation and compatibility testing for consortia development

Bacterial strains with poly-3-hydroxybutyrate (PHB) degradation potential were isolated from waste yard soil samples of selected industrial sites in Uttarakhand, India, and two microbial consortia were developed, i.e. Consortium I comprises Pseudomonas sp. strain Rb10, Pseudomonas sp. strain Rb11 and Bacillus sp. strain Rb18, and Consortium II is composed of Lysinibacillus sp. strain Rb1, Pseudomonas sp. strain Rb13 and Pseudomonas sp. strain Rb19. The current study involved enrichment selection via liquid and semi-solid media, followed by isolation and screening of bacterial strains using PHB pellets and films. Furthermore, the identification and characterisation was done by triphasic approach. The utilisation of PHB by the characterised strains was confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the minimum inhibitory concentration of solubilised PHB was found to be 2.5?mg/mL, which was detected through ‘clear zone assay’. Further, the selection and biocompatibility testing of potential isolates were performed for the formation of bacterial consortia. Thus, the present work would provide direct and standardised protocol for screening and selection of potential microbiomes for biodegradation of polymers by overcoming the negative effect of organic solvents. Moreover, indigenously developed consortia would be evaluated for their in situ biodegradation potential against various bioplastic films.     

Color removal efficiency of dyes using nanozerovalent iron treatment

In this study, zerovalent iron nanoparticles (Fe⁰) were synthesized by chemical reduction method using ferric chloride hexahydrate (FeCl₃?·?6H₂O) as a starting material. Sodium borohydride (NaBH₄) was used as a reducer. The synthesized nanozerovalent iron (NZVI) was separated using magnets. The X-ray diffraction pattern of iron (Fe) nanoparticles showed that the presence of intensive diffraction peak at 2θ value of 45.33° from the lattice plane of face-centered cubic Fe unequivocally indicates that the particles are made of pure Fe. The size of the synthesized NZVI was found to be 16.64?nm. The scanning electron micrograph revealed that the particles have a hexagonal and spherical shape in nature. EDX showed the surface atomic distribution and chemical composition of NZVI. The decolorization efficiency rose with increasing concentration of nanoparticles as well as with time. Maximal color removal efficiency was 90.72% when using 0.5?g/100?mL Fe nanoparticle for acridine orange. Data revealed that the function of NZVI on color removal efficiency was statistically significant. The correlation coefficient between NZVI concentration and time showed a strong negative correlation for dyes used in the experiment.     

Chitosan-polypropylene imine dendrimer hybrid: a new ecological biomordant for cochineal dyeing of wool

The classical use of synthetic dyes is causing issues of environmental pollution and heath risk. As a consequence natural dyes are gaining interest, but the use of natural dyes still includes toxic reagents such as metals as mordants and acids to enhance color and yield. Therefore, we designed a new chitosan-polypropylene imine dendrimer hybrid at 0–2000 mg/L to treat wool before dyeing with cochineal. We compared dye exhaustion, color depth, color characteristics, and color fastness of the new process with dyed pristine and metal mordanted wool. Results show that wool pretreatment improved dye exhaustion from 48 to 88 %, shifted saturation point toward lower dye concentration from 3000 to 1000 mg/L, and improved color depth from 13.68 for pristine wool and 15.17 for metal mordanted wool to 23.89 for the new process.     

Determination of growth kinetics of microorganisms linked with 1,4-dioxane degradation in a consortium based on two improved methods

● Evaluated three methods for determining the consortia’s growth kinetics. ● Conventional method is flawed since it relies on the total biomass concentration. ● Considering only selected bacterial taxa improved the accuracy. ● Considering oligotrophs and copiotrophs further improved the accuracy. The conventional method for determining growth kinetics of microbial consortia relies on the total biomass concentration. This may be inaccurate for substrates that are uncommon in nature and can only be degraded by a small portion of the microbial community. 1,4-dioxane, an emerging contaminant, is an example of such substrates. In this work, we evaluated an improved method for determining the growth kinetics of a 1,4-dioxane-degrading microbial consortium. In the improved method, we considered only bacterial taxa whose concentration increase correlated to 1,4-dioxane concentration decrease in duplicate microcosm tests. Using PEST (Parameter Estimation), a model-independent parameter estimator, the kinetic constants were estimated by fitting the Monod kinetics-based simulation results to the experimental data that consisted of the concentrations of 1,4-dioxane and the considered bacterial taxa. The estimated kinetic constants were evaluated by comparing the simulation results with experimental results from another set of microcosm tests. The evaluation was quantified by the sum of squared relative residual, which was four orders of magnitude lower for the improved method than the conventional method. By further dividing the considered bacterial taxa into oligotrophs and copiotrophs, the sum of squared relative residual further decreased.     

Extracellular polymeric substances (EPS) from cyanobacterial mats: characterisation and isolation method optimisation

Extracellular polymeric substances (EPS) play an important role in bacterial mat formation and sediment stabilisation of coastal zones. The analysis of these secretion products on a molecular level is a prerequisite to understand their formation mechanisms and ecological function in microbial consortia. The present study focuses on the optimisation of EPS isolation and characterisation from cohesive cyanobacterial mats. Extracted EPS were analysed for quantity, content of total organic carbon and nitrogen, and bulk contents of neutral sugars, uronic acids, and proteins. These criteria are strongly influenced by the extraction conditions applied and therefore, the effects of different extraction media (NaCl or artificial seawater), addition of EDTA, centrifugal force, and purification via repeated ethanol precipitation on extraction success were determined. From this an optimised extraction procedure for EPS resulted. When using fresh mat samples, the yield of EPS amounted to 3.3 ± 0.8 mg g⁻¹ mat (dw). The isolated EPS were composed of nearly equal amounts of proteins and uronic acids (12.7 ± 1.5 and 11.8 ± 1.1%, respectively) and the bulk content of neutral sugars was 30.5 ± 2.6%. High contents of TOC and TN indicated relatively pure EPS and only a low contribution of inorganic compounds. Furthermore, low contents of 2-keto-3-deoxyoctonate and the small protein/polysaccharide-ratio in the EPS extracted by our method, signified low contaminations by intracellular polymers and hence a low rupture of cells. Our method provides an useful tool to evaluate further investigations of the composition, characteristics and properties of EPS on a sound basis.     

Nanosized magnetite in low cost materials for remediation of water polluted with toxic metals,azo- and antraquinonic dyes

Nanosized magnetite has emerged as an adsorbent of pollutants in water remediation. Nanoadsorbents include magnetic iron oxide and its modifiers/stabilizers, such as carbon, silica, clay, organic moieties (polymers, aminoacids, and fatty acids) and other inorganic oxides. This review is focused on the recent developments on the synthesis and use of magnetic nanoparticles and nanocomposites in the treatment of contaminated water. The emphasis is on the influence of the iron oxide modifiers on some properties of interest such as size, BET area, and magnetization. The characteristics of these nanomaterials are related to their ability to eliminate heavy metal ions and dyes from wastewater. Comparative analysis of the actual literature was performed aiming to present the magnetic material, its preparation methodology and performance in the elimination of the selected pollutants. Vast information has been properly summarized according to the materials, their properties and preferential affinity for selected contaminants. The mechanisms governing nanomaterial’s formation as well as the interactions with heavy metals and dyes have been carefully analyzed and associated to their efficiency.     

On the consortium of the tintinnid <Emphasis Type="Italic">Eutintinnus</Emphasis> and the diatom <Emphasis Type="Italic">Chaetoceros</Emphasis> in the Pacific Ocean

The morphology and distribution of the diatoms Chaetoceros tetrastichon and Ch. dadayi as epiphytes on the loricae of the tintinnids Eutintinnus apertus and E. pinguis investigated in the open waters of the Pacific Ocean. The Eutintinnus–Chaetoceros consortia was encountered in 38 of the 52 sampling stations from 34°N to 33°S, and together were among represented the most wide-spread species. The abundance was low with a maximum of 32 consortia l⁻¹ and E. apertus was often the most abundant species of the genus. The free-living Eutintinnus congeneric species showed a wider vertical distribution, whereas E. apertus–Chaetoceros tended to be near the surface. The success of E. apertus in consortium with Chaetoceros may be due to increase of the clearance rate and/or the lower susceptibility to predation. Chaetoceros modifies its morphology to adapt the epiphytic life, especially Ch. dadayi. The shorter curved setae may facilitate the transfer to the lorica of the daughter tintinnid after the cell division. The free-living Ch. tetrastichon and Ch. dadayi are very rare and Chaetoceros remained attached to empty loricae or encysted tintinnid cells. This suggests that the Eutintinnus–Chaetoceros consortium is obligate for the success of the diatom and renders the tintinnid more competitive versus congeneric species.     

高锰酸钾对染料废水的脱色研究

研究了影响高锰酸钾对染料废水脱色的有关因素,结果表明,脱色反应的最佳ＰＨ值应小于１．５,高锰酸钾的浓度对脱色效果显著。