黑曲霉吸附弱酸性艳蓝RAWL机理研究

考察了黑曲霉对染料吸附性能的pH响应模式,红外光谱表征了菌体表面的主要官能团组成,化学修饰定量研究了不同官能团的染料吸附贡献.结果显示,在低pH条件下,菌体表现出最优的染料吸附特性:随着pH值由2.0升至6.0,染料吸附量由39.6mg/g降至9.3mg/g.菌体表面含有氨基、羧基和磷酸根.高pH下,羧基和磷酸根电离导致菌体表面带负电并与染料发生静电斥力,使得染料吸附量下降;低pH下,氨基的质子化使得菌体带正电并通过静电吸引提高染料吸附.甲基化氨基在酸性条件下仍然可以质子化,故氨基甲基化修饰后染料吸附性能不变;乙酰化氨基在酸性体系中失去质子化能力,乙酰化修饰菌体染料吸附性能下降51.6%.氨基质子化引起的菌体正电性和染料负电性之间的静电引力是染料吸附的重要机制.图6参10     

不同底物和环境条件对两株铜绿假单胞菌接触烷烃方式及降解活性的影响

考察了不同烷烃底物和温度、酸度、盐度等环境条件对两株铜绿假单胞菌接触烷烃方式和降解活性的影响.结果表明,微生物接触烷烃的两种方式——直接接触方式和乳化接触方式同时存在于菌体降解烷烃过程中且受底物和环境条件的影响.底物烷烃碳数的增加对菌株两种接触方式降解烷烃都有利,而盐度增加对它们都不利;高温、偏碱性环境以及延长降解时间有利于菌体以乳化方式降解烷烃;低温、中性溶液环境有利于菌体以直接接触方式降解烷烃.     

染料化合物光催化氧化降解中氮元素行为分析

在含氮染料化合物的降解过程中,不同结构氮的降解过程是不同的,其中偶数结构与非偶氮结构存在很大差别。实验中发现,在相同的TiO2/UV条件下光解,非偶氮结构染料的降解体系很快有NH4^ 离子和NO3^-离子产生,而在偶氮结构染料的降解物中却没有二者生成。并通过实验证明,体系中产生的NH4^＋是染料降解的中间产物,而NO3^－则至少有两条生成途径。     

黄孢原毛平革菌对固体介质中染料的降解反应

用黄孢原毛平革菌(Phanerochaetechrysosporium)3品系在固体介质中建立染料的降解反应体系,分光光度法测定染料的脱色降解率。黄孢原毛平革菌在琼脂、沙子及土壤等固体介质中均能有效地降解偶氮染料、蒽醌染料及聚合染料;植物材料玉米芯和木屑可作为共代谢碳源被该菌利用;BKM F 1767菌种降解能力最强,对活性艳蓝KN R的进攻性优于对PolyR 478和比布列希猩红。     

不同活化过硫酸盐体系的机理分析及不同无机阴离子的作用:以两种有机染料为例

高级氧化技术（AOPs）广泛应用于不同的废水处理,并目前此类技术多以羟基自由基（OH·）的产生为主.近年来,基于硫酸根自由基（SO ₄^-·）的AOPs因其对有机污染物的高反应活性和对复杂环境基质的高选择性而备受关注.但是,在对各种活化方式的系统比较方面还存在一些不足,对降解途径和不同阴离子对体系的影响也缺乏研究.本文通过两种染料的降解对3种活化过硫酸盐体系进行了系统性的比较,并结合自由基捕获实验（甲醇,叔丁醇）和产物分析,研究了体系降解机制及路径.研究了4种阴离子（HCO₃^-、N O₃^-、Cl-、Br-）对3种不同活化过硫酸盐体系降解染料的影响.结果表明,SO ₄^-·与OH·在3种活化体系中对染料降解均有贡献.在热活化体系（heat-Na₂S₂O₈）中,对染料降解起到主导作用的活性物种为S O₄^-·;在光...     

UVC/过硫酸盐/乙腈反应体系的构建及对茜素类染料的降解

为探索水体环境中有机污染物在硫酸根自由基(·SO₄^-)作用下的迁移转化规律,构建了UVC/过硫酸盐(PDS)/非质子极性溶剂反应体系,模拟了茜素类染料在·SO₄^-作用下的降解动力学与反应机制.媒染橙1在不同溶剂体系中的降解动力学常数大小为:(90%乙腈(ACN)+10%水(H₂O))>100%H₂O>100%二甲基亚砜(DMSO)>100%二甲基甲酰胺(DMF).并且媒染橙1比茜素黄GG具有更高的降解反应速率. UVC/PDS/(90%ACN+10%H₂O)体系中PDS用量、底物浓度、反应温度和光照强度等因素对茜素类染料降解动力学均有明显的影响.高温和强的光强有利于茜素类染料的降解,而过高PDS用量和底物浓度降低了茜素类染料的反应速率.·SO₄^-对茜素类染料的降解占据主导作用.而茜素类染料的初始降解途径主要包括单电子转移反应导致的脱磺酸基和偶氮键断裂以及吸氢反应和取代反应等...     

蒽醌染料及中间体脱色优势菌的特性研究和基因定位

本文对分离到的两株蒽醌染料脱色优势菌的脱色能力及其基因定位进行了研究,结果表明,ＮＤ１,ＮＤ２均能有效脱除活性艳蓝ＫＮ－Ｒ及溴氨酸的色度;两株优势菌均含有质粒,其降解染料的能力是由质粒控制的;并考察了不同碳源、氧、温度、ｐＨ值等理化因素对菌株降解染料的影响。     

黄孢原毛平革菌对固体介质中染料的降解反应

用黄孢原毛平革菌(Phanerochaete chrysosporium)3品系在固体介质中建立染料的降解反应体系，分光光度法测定染料的脱色降解率。黄孢原毛平革菌在琼脂、沙子及土壤等固体介质中均能有效地降解偶氮染料、蒽醌染料及聚合染料；植物材料玉米芯和木屑可作为共代谢碳源被该菌利用；BKM-F-1767菌种降解能力最强，对活性艳蓝KN—R的进攻性优于对Poly R-478和比布列希猩红。     

重金属离子对酵母降解苯酚的影响

研究了铜、镉、锌和铅对酵母 (Pityrosporumsp .)降解苯酚的影响 .急性毒性试验表明 :Cu2 36h时对菌体生物量的毒性抑制微低于对苯酚降解的抑制 ;48h时对菌体生物量的毒性高于对苯酚降解的毒性 .受试时间段 ,Cd2 对菌体生物量的毒性均高于其对苯酚降解的毒性 .在 0— 36h内 ,Cu2 对菌体比增长速率的EC50 是 45 0nmol·l- 1 ,对苯酚降解速率的EC50 是 0 32nmol·l- 1 ;Cd2 相应的EC50 分别是 681nmol·l- 1 和 33 3nmol·l- 1 .Cu2 比Cd2 具有更高的毒性 .而锌和铅在低浓度时 ,对酵母降解苯酚过程中菌体生物量以及苯酚的降解均有促进作用 ,其促进作用随着金属离子浓度的增加而减弱 .     

负载型纳米Fe-Pd降解水溶性偶氮染料

采用阳离子交换树脂表面为载体,合成了负载型纳米Fe-Pd二元复合金属材料,采用扫描电子显微镜(SEM)和能谱分析对该材料进行表征,研究了其对一些水溶性偶氮染料的降解效果.实验表明,该材料对0.05 g.L-1甲基橙、日落黄、酸性橙8、金橙G和活性红2等偶氮染料有较好的降解效果,纳米双金属中Pd含量的增加有利于染料的降解;反应体系初始pH值对染料的降解率影响较大,本研究中,pH 4酸性条件下降解效果最佳;制备的材料在第10次活化后,仍有较好的降解效果;为环境中偶氮染料的降解提供了一种有效的方法.     

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.     

白腐菌对3种含氯二(噁)(口英)类物质的降解作用

探讨了白腐菌射脉侧菌Phlebia radiateI-5-6对3种含氯量不同的二类物质———二苯并呋喃(DF)、2,7-二氯二苯并二(2,7-diCDD)和八氯二苯并呋喃(OCDF)的降解情况,并研究了不同培养条件对二降解的影响.在液体混合培养基中,在培养期内P.radiataI-5-6对3种二类物质的降解量分别为:DF>2,7-diCDD>OCDF;在培养的初始阶段,白腐菌对珠江江水/CEH漂白废水的加入需要一个适应期,然后开始降解这些污染物质.实验表明,在江水/CEH漂白废水处于一定浓度时,污染底物有更大的降解量;选择适当的培养基,可影响白腐菌对二类污染物的降解量.图3表3参17     

Electrochemical degradation of Acid Red I dye and its treatment by UV light

Degradation of Acid Red I (ARI) dye by electrochemical treatment and UV light irradiation was studied in this work. The effect of the current density and the concentration of NaCl and dye on the decoloration and degradation efficiency were studied and optimized. The UV irradiation was monitored by UV-Vis spectrophotometry and chemical oxygen demand. The kinetic constants for decoloration and degradation were calculated. Degradation of 86% was achieved in 160?min and the first-order kinetic constant was 0.013?min^?1. Degradation products were identified by gas chromatography/mass spectrometry. The mechanism for the degradation of ARI was proposed.     

Preparation and characterization of a new TiO2/SiO2 composite catalyst for photocatalytic degradation of indigo carmin

The TiO₂/SiO₂ composite was prepared by means of the SiO₂-particle-entrapment method. The FTIR data showed the presence of Si–O–Ti stretching vibration band at 970 cm⁻¹ in the TiO₂/SiO₂ composite, suggesting a reaction between TiO₂ and silica on the TiO₂ particle surface during the silicagel formation around the TiO₂ particles. The photocatalytic efficiency of TiO₂ immobilized in silicagel was compared with that of the conventional TiO₂ Degussa P25 catalyst. For this purpose, the degradation of indigo carmin (IC) dye was used as model molecule in the tests. The effect of operational parameters such as catalyst loading and dye concentration on the photocatalytic degradation of the model dye was investigated. The rate of degradation increased with increasing catalyst loading, and when the concentration of the dye decreases.     

石漠化地区豆科植物根瘤菌降解碳酸钙、镁能力研究

微生物对岩溶地区岩石风化、成土具有明显的促进作用,为了筛选出能够促进碳酸盐岩风化、加快成土速率的优势根瘤菌菌株,将其与豆科植物建立共生体系,进行石漠化地区修复与治理,实验以分离自云南石漠化地区的9株豆科植物根瘤菌为研究对象,将9株根瘤菌接种于加有难溶性碳酸钙或碳酸镁的液体培养液中,28.5℃、160 r·min-1摇床培养15 d,于0、1、3、6、10、15 d取样2 mL,每个样3个平行;将样品加入到10 mL体积比5∶1的硝酸高氯酸消化液中浸泡过夜,放在电热板上缓慢加热至溶液澄清透明,分别用含La3＋2%的盐酸溶液定容至10 mL,空白用同样方法处理;最后采用原子火焰吸收方法测定样品中Ca2＋和Mg2＋含量,筛选出对碳酸盐岩主要成分碳酸钙和碳酸镁具有强降解作用的根瘤菌菌株。结果表明：热带根瘤菌Rhizobium tropici （SWFU09）和根瘤菌Rhizobium sp.（SWFU02）对碳酸钙降解作用最强;对碳酸镁降解作用最好的菌株为根瘤菌Rhizobiumsp.（SWFU03）、热带根瘤菌Rhizobium tropici（SWFU05）和慢生根瘤菌Bradyrhizobium sp.（SWFU01）。溶液pH值对碳酸镁降解作用具重要的影响,对碳酸钙降解作用影响不大,说明根瘤菌代谢产生的酸性物质（有机酸、氨基酸）对碳酸钙和碳酸镁降解作用有一定影响,但不是唯一影响因素;也可能是微生物代谢产生的有机配体（基）吸附碳酸钙和碳酸镁表面,与水体中的成分形成复合物,改变溶解的平衡,置换出Ca2＋和Mg2＋。     

Anaerobic degradation kinetics of reactive dye with different carbon sources

This study aims to investigate the anaerobic degradation kinetics of reactive dye, C.I. Reactive Red 141 (Evercion Red H-E7B) by partially granulated anaerobic mixed culture using three carbon sources, namely modified starch (MS), polyvinyl alcohol (PVA) and acrylic size (AS) during batch incubation. There is a first-order kinetics reaction in the decolorization processes using MS and PVA as carbon sources, while a zero-order kinetics relationship describes the decolorization process for the AS carbon source. The k values and color removal rate of decolorization with MS carbon source was higher than those of PVA and AS carbon sources. This is because the MS carbon source was well degraded in comparison to AS and PVA, respectively This study also found dye reduction could be enhanced through the addition of MS as a carbon source. The decolorization rates increased with decrease in dye concentrations of RR 141. In contrast, the decolorization rates increased with increase in COD concentration.     

白腐菌Trametes hirsute对六氯苯的降解及其条件优化

在液体体系下,筛选了5株白腐菌,对六氯苯进行了降解研究,并优化了白腐菌Trametes hirsute TH对六氯苯的降解条件.结果表明,不同白腐菌均能降解六氯苯,其中白腐菌Trametes sp.TR对六氯苯降解率最高,达90.21%;而白腐菌T.hirsute TH对六氯苯降解率为87.08%,但生物量最高,达3.33 g/L.通过响应面法优化白腐菌T.hirsute TH降解六氯苯的条件,结果显示,转速、接种量和培养时间是影响六氯苯降解的主要因素.优化后的最佳条件为:转速125 r/min,菌丝接种量8%(V/V),培养时间2 d,温度28 ℃,pH为7.在优化条件下,2 d内白腐菌T.hirsute TH对浓度为10 mg/L的六氯苯降解率和降解量分别可达91.52%和2.288 mg L-1 d-1.图2表7参17     

Visible light sensitive activated carbon-metal oxide (TiO2, WO3, NiO,and SnO) nano-catalysts for photo-degradation of methylene blue: a comparative study

Four composites of metal oxide doped with activated carbon with a metal oxide weight of 20% were prepared using mechano-mixing method. The nano-catalysts were characterized by N₂-adsorption–desorption, X-ray diffraction analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV-diffuse reflectance, and photoluminescence spectroscopy. Photo-catalytic degradation of methylene blue dye under UV 254 nm and visible light was examined. In general, prepared catalysts are more active for degradation of dye under visible light than UV, reaching 96% within 180?min irradiation using the SnO catalyst. Photo-degradation of methylene blue followed pseudo first order reaction mechanism with a rate constant of 14.8?×?10^?3?min^?1, and the time required for removal of 50% of dye was 47?min.     

Biodegradation of phenylurea herbicide diuron by microorganisms from long-term-treated sugarcane-cultivated soils in Kenya

The phenylurea herbicide diuron [N-(3,4-dichlorophenyl)-N,N-dimethylurea] is widely used alone or in a broad range of herbicide formulations. Its degradation in sugarcane-cultivated soils which have been impacted by the herbicide through repeated applications was studied. Liquid culture experiments with diuron as the only carbon source led to the isolation of different bacterial strains capable of degrading diuron. The bacterial species belonging to the genera Bacillus, Vagococcus, and Burkholderia, identified through biochemical and molecular characterization, degraded diuron to different extents. The isolated Bacillus cereus, Vagococcus fluvialis, Burkholderia ambifaria, and Bacillus spp1 degraded diuron by 21%, 25%, 22%, and 19% of the initially applied concentration of 40?mg?L^?1, respectively, after 35 days of incubation in liquid culture media. Small amounts of 3,4-dichloroaniline and the de-methylated metabolite N-(3,4-dichlorophenyl)-N-methylurea were detected in liquid culture media. The combination of V. fluvialis and B. ambifaria showed an enhanced degradation of up to 30% of the initially applied concentration of 40?mg?L^?1. Degradation by pure isolates was low (18–25%) compared to the capacities of diuron degradation shown by the bacterial communities (58–74%). This study showed the presence of diuron degraders in sugarcane-cultivated soils impacted by diuron due to repeated applications.