一株耐盐菌的鉴定及其高盐条件下喹啉降解性能研究

从山西某焦化废水厂的活性污泥中筛选分离出一株耐盐菌株LV4,对其进行鉴定和高盐条件下的喹啉降解性能的研究。通过菌体形态和16S rDNA序列同源性分析鉴定菌株LV4归属于红球菌属(Rhodococcus sp.)。耐盐菌株LV4可在盐度为4%的高盐条件下以喹啉为唯一碳氮源进行生长,并可完全降解初始浓度不高于200 mg/L的喹啉,对应的TOC降解率不低于83.26%,表明菌株LV4在高盐环境中对喹啉具有良好的矿化降解效果。单因素实验结果表明耐盐菌株LV4在高盐条件下降解喹啉的适宜温度为30℃、pH为7～8、转速为120r/min。在高盐环境中耐盐菌株LV4能同时降解喹啉和吡啶,并且吡啶的共存加速了LV4对喹啉的降解,这为高盐废水生物强化处理提供了良好的菌种资源。     

喹啉的生物降解动力学

喹啉是一种典型的氮杂环化合物,在化工、医药及农药生产中经常用作溶剂和原材料．喹啉又是一种毒性大、致变性和致癌性强的物质,对人类、水生生物及植物有着很大的危害．因此随着工业废水特别是焦化废水的排放,使喹啉成为水中常见的污染物．喹啉的结构为许多人工合成化合物的基本结构,而人工合成化合物一般不易被自然界中固有的微生物识别,所以多数为难以生物降解的化合物,研究喹啉的生物降解能为研究其他人工合成化合物的生物降解提供有益的启示．人们对喹啉的降解途径进行了有益的探索［１ -３］,对喹啉降解的动力学也进行了研究［…     

The use of bacteria immobilized in tubular membrane reactors for heavy metal recovery and degradation of chlorinated aromatics

Microbial treatments of waste water can be done in membrane reactors. A membrane installed outside the reactor is used to separate bacteria from the treated effluent.

A new membrane reactor concept is presented. The separation membrane is introduced in the reactor and not outside as in a normal one. The membrane plays the role of a separator of two streams and is used at the same time as the immobilizing support for the bacteria.

The reactor keeps the bacteria active via a specific nutrient stream that is provided on one side of the membrane. The bacteria grow in and on the membrane where they form an active biofilm. The bacteria can treat the effluent on one side and can be kept active via the nutrient stream at the other side without contamination of the effluent by the nutrient.

In this work, the performance of the BICMER (Bacteria Immobilized Composite MEmbrane Reactor) is demonstrated via treatments of effluents containing heavy metals or organic xenobiotics.

For heavy metal removal Alcaligenes eutrophus CH34 bacteria were used. These bacteria induce a metal bioprecipitation process that results in the formation of crystalline metal carbonates, which are recovered on a separate column in the reactor. In this way metals can be recovered without disturbing the biofilm on the membrane. Metals such as Cd, Zn, Cu, Pb and Y can be reduced to less than 50 ppb. The metals Co, Ni, Pd and Ge are reduced to below 100 ppb.

For organic xenobiotics Alcaligenes eutrophus AE1308 bacteria or other strains (depending on the xenobiotic to be degraded) were used. This strain degrades the xenobiotic 3-chlorobenzoate (Cba) and 2,4-dichlorophenoxyacetic acid to CO₂, H₂O and chloride). Concentrations of 3 mM Cba could be reduced to less than 0.1 mM. For other toxic organic compounds, different biodegrading strains need to be used.     

固定化细菌去除苯甲酸类化合物的研究

用富集培养法,从工业废水中分离到能以苯甲酸类化合物为唯一碳源和能源而生长的细菌不动杆菌ＢＪ１和产碱杆菌ＳＢ１。用海藻酸钙共固定化的ＢＪ１和ＳＢ１菌株于３０℃培养７２ｈ以后,模拟工业废水中１ｇ／Ｌ的苯甲酸,邻羟基苯甲酸,间羟基苯甲酸,以羟基苯甲酸,邻苯二甲酸和苯乙酸的去除率分别为８９％,９８％,９７％,１００％,９０％和６１％。     

Enhanced biodegradation of thiocyanate by immobilized Bacillus brevis

Biodegradation of Thiocyanate by Free and Immobilized Bacillus brevis was explored. Lignite carbon and Alginate beads have been used as immobilization matrices to study the degradation of thiocyanate with immobilized cells. The rate of thiocyanate degradation is found to be higher by immobilized cells. Cells on lignite carbon matrix are more efficient than cells on alginate beads. The tolerance of the bacteria to the toxic chemical increases by immobilization. Degradation of 100 ppm of thiocyanate was achieved in 20 h by immobilized Bacillus brevis onto lignite carbon. Reduced cost and simplicity make this technique very useful for wastewater treatment.     

聚乙二醇对聚醚砜微孔膜致孔作用的研究

以聚醚砜聚乙二醇溶剂为铸膜液体系、采用干湿相转化法制备微孔滤膜,研究了各种制膜条件对膜孔径结构的影响.实验发现聚乙二醇在体系中起到分散稳定的作用,只有到浓度大于70%时,才会对铸膜液的粘度产生明显影响,聚合物在铸膜液中的溶解状态也随之改变,进而影响膜的结构.不同溶剂NMP、DMF、DMAc、DMSO等极性溶剂或固体溶剂己内酰胺均可制得开孔率较高的微孔膜,但对膜的结构和性能影响差别不大.在本研究体系中,膜的结构取决于聚乙二醇、溶剂的浓度比例关系.     

Viscoelastic phase separation in polyethersulfone modified bismaleimide resin

The polymerization-induced phase separation process of polyethersulfone (PES) modified bismaleimide resin, 4,4′-bismaleimidodiphenylmethane (BDM), was investigated by time resolved light scattering (TRLS) and scanning electronic microscopes (SEM). At the blends with 10 wt% and 12.5 wt% PES, a phase inversion structure was found by SEM. TRLS results displayed clearly the spinodal decomposition (SD) mechanism and the exponential decay procedure of scattering vector q_m, which followed Maxwell-type relaxation equation. The characteristic relaxation time τ for the blends can be described by the Williams-Landel-Ferry equation. It demonstrated experimentally that the phase separation behaviors in these PES modified bismaleimide blends were affected by viscoelastic effect.     

Revision of the structure of the compound obtained by the reaction of 2-hydrazino-4-methylquinoline and acetylacetone

Condensation of 2-hydrazino-4-methylquinoline (1) and acetylacetone gives a compoundA, which has the structure of 3,5-dimethyl-1-(4-methylquinolino)-pyrazole (2) and not of 4-methylquinolino-(2,3—c)-3,5-dimethyl-1H-1,2-diazepine (3) assigned earlier. The structure2 was confirmed on the basis of¹H-NMR,¹³C-NMR, IR spectral data and its unambiguous synthesis.

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Revision der Struktur einer Verbindung aus der Reaktion von 2-Hydrazino-4-methylchinolin und Acetylaceton

Zusammenfassung Die Kondensation von 2-Hydrazino-4-methylchinolin (1) mit Acetylaceton ergibt eine Verbindung mit der Struktur eines 3,5-Dimethyl-1-(4-methylchinolin)pyrazols (2) und nicht eines 4-Methylchinolino-(2,3—c)-3,5-dimethyl-1H-1,2-diazepins (3) gemäß einer früheren Zuordnung. Die Struktur von2 wurde auf Grund von¹H-NMR,¹³C-NMR, IR und einer eindeutigen Synthese bewiesen.

     

基于含羟基聚芳醚砜的有机-无机杂化材料的制备

聚芳醚砜类材料作为全芳香无定形耐高温工程塑料一直备受关注,在航空、航天、信息及能源等领域得到了广泛的应用~([1]).以脂肪族聚合物为基体的杂化材料往往不具备良好的热、化学与辐射稳定性.人们希望通过将无机粒子引入芳香性耐高温聚合物中,使其既具有理想的性能,又满足苛刻的运行环境.通过简单物理掺杂和共混的方法很难精确控制材料的微观形态与性能.利用溶胶-凝胶法将无机相引入聚合物体系中~([2]),通过调节有机与无机的组分比可以实现对材料的"剪裁",达到有机-无机两相最优组合的目的.     

A synthesis of the tetracyclic carboskeleton of isaindigotidione

An efficient synthesis of the unique indolizino[7,6-c]quinoline carboskeleton of isaindigotidione has been achieved. This strategy employed l-proline and isatin as the main building blocks in the construction of the framework. Four transformations occurred in a one-pot operation to furnish the tetracyclic nucleus.     

Palladium-catalyzed amination of quinaldine-5-triflate

Palladium-catalyzed amination reactions of quinoline triflate and the effect of a Pd catalyst, its ligands, solvents, bases, and temperature were studied. This method facilitated an easier pathway for the preparation of aminoquinoline derivatives as potential precursors of new serotoninerg agents.      

Selective direct fluorination of quinoline derivatives

Direct fluorination of various quinoline derivatives in acidic reaction media gives fluorinated quinoline products arising from selective, efficient electrophilic substitution processes.     

2-巯基喹啉包裹的金纳米颗粒的制备及其电化学性质

纳米材料特有的尺寸效应、量子效应和表面效应使其具有许多异于常规材料的性质 ,在催化、生物传感器、微电子器件和磁性材料等诸多领域都有广泛的应用前景 [1] .已有专家预言 ,与纳米材料相关的技术将在新世纪经济发展中起主导作用 ,对其研究是目前科学研究中的热点 .金纳米颗粒是目前研究得最多的金属纳米材料体系 .传统的金纳米颗粒的制备方法以溶胶 -凝胶法为主 [2～ 4 ] ,所制备的金纳米颗粒的粒径较大 (一般大于 1 0 nm) ,粒径分布不均匀 ,易于团聚 ,因而限制了其应用 .为了解决上述问题 ,Brust等 [5]将硫醇化合物在金属表面的自组装…     

Metal-free synthesis of 2-difluoromethylated quinolines via DBU-promoted cascade michael addition / cyclization of methyl 4,4-difluorobut-2-ynoate with 2-aminobenzonitriles

A facile synthesis of 2-difluoromethylated quinolines via DBU-promoted cascade Michael addition/cyclization between functionalized 2-aminobenzonitriles and methyl 4,4-difluorobut-2-ynoate has been developed. Various highly functionalized quinolines were assembled in moderate to good yields under mild metal-free reaction conditions.     

Correlation between macrovoid formation and the ternary phase diagram for polyethersulfone membranes prepared from two nearly similar solvents

The morphological structure of membranes prepared from two nearly similar systems consisting of water/N,N-dimethylacetamide (DMAc)/polyethersulfone (PES) and water/N-methyl-2-pyrrolidone (NMP)/polyethersulfone (PES) has been studied. The morphology of the prepared membranes showed that both systems exhibit an instantaneous liquid–liquid demixing that leads to the formation of macrovoids in the resulting structures. Nevertheless, the resulting macrovoid structures were contrary to the generally accepted concepts concerning macrovoid formation. The membranes morphologies showed that in spite of better miscibility between water and DMAc, which must promote the formation of channel- and finger-like structures, more sponge-like structures were observed in membranes prepared from the water/DMAc/PES system compared to those prepared from the water/NMP/PES system. To find the source of this unexpected phenomenon, the complete ternary phase diagrams consisting of theoretical binodal curves, vitrification boundaries, and gelation boundaries were constructed for both systems and it was shown that gelation process occurs earlier in the water/DMAc/PES system compared to the other system, which inhibits the growth of macrovoids in this system.     

Improved protein-adsorption-resistant property of PES/SPC blend membrane by adjustment of coagulation bath composition

To improve surface protein-adsorption-resistant property of polyethersulfone (PES) membranes, soybean phosphatidylcholine (SPC) was added to PES casting solution. The blend membranes were prepared by a phase inversion method in a wet process. The surface of PES/SPC blend membranes was characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). XPS data revealed that the phosphorylcholine (PC) groups were concentrated at the surface by changing the composition of coagulation bath. Addition of N,N-dimethylformamide (DMF) in coagulation bath could prolong coagulation time and facilitate the migration of SPC from polymer bulk to membrane surface. The PES/SPC blend membranes dramatically reduced BSA and fibrinogen adsorption compared to PES control membrane due to effective immobilization of PC groups at the surface of PES/SPC blend membranes.     

Synthesis of substituted quinoline via copper-catalyzed one-pot cascade reactions of 2-bromobenzaldehydes with aryl methyl ketones and aqueous ammonia

In this Letter, a new version of the Friedländer synthesis of quinoline derivatives starting from 2-bromobenzaldehydes, aryl methyl ketones, and aqueous ammonia with copper-catalyzed amination as a key step is presented. Remarkable advantages of this new quinoline synthesis include commercially available and economical starting materials, simple operational process, and excellent efficiency.     

Synthesis,characterization and antimicrobial screening of quinoline based quinazolinone-4-thiazolidinone heterocycles

In an attempt to find new pharmacologically active molecules, we report here the synthesis and in vitro antimicrobial activity of various 2-(2-chloro-6-methyl(3-quinolyl))-3-[2-(4-chlorophenyl)-4-oxo(3-hydroquinazolin-3-yl)]-5-[(aryl)methylene]-1,3-thiazolidin-4-ones. In vitro antimicrobial activity of the title compounds are screened against two Gram positive bacteria (Staphylococcus aureus, Streptococcus pyogenes), two Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and three strains of fungi (Candida albicans, Aspergillus niger, Aspergillus clavatus) using broth micro dilution method. Some derivatives bearing chloro or hydroxy group exhibited very good antimicrobial activity.