首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 490 毫秒
1.
以月桂酸为阴离子表面活性剂,3-胺丙基三乙氧基硅烷(APTES)为共结构导向剂,合成了高含量氨基功能化介孔氧化硅材料(AFMS)。以AFMS为吸附剂对溶液中酸性橙7(AO7)进行吸附,对影响AO7吸附效率的相关因素进行了详细研究,结果表明,溶液pH值及温度影响较大。吸附动力学表明,本研究中合成的AFMS对AO7的吸附速率极快。Sips吸附模型对吸附等温线模拟效果最好,从中可知AO7在样品D(由3.0 mL正硅酸乙酯及1.4 mL APTES合成)上的最大吸附量为1.26 mmol·g-1,远远高于相关文献报道的值。此外,通过吸-脱附循环实验证明,样品D具有良好的稳定性。  相似文献   

2.
以月桂酸为阴离子表面活性剂,3-胺丙基三乙氧基硅烷(APTES)为共结构导向剂,合成了高含量氨基功能化介孔氧化硅材料(AFMS)。以AFMS为吸附剂对溶液中酸性橙7(AO7)进行吸附,对影响AO7吸附效率的相关因素进行了详细研究,结果表明,溶液p H值及温度影响较大。吸附动力学表明,本研究中合成的AFMS对AO7的吸附速率极快。Sips吸附模型对吸附等温线模拟效果最好,从中可知AO7在样品D(由3.0 m L正硅酸乙酯及1.4 m L APTES合成)上的最大吸附量为1.26 mmol·g-1,远远高于相关文献报道的值。此外,通过吸-脱附循环实验证明,样品D具有良好的稳定性。  相似文献   

3.
4.
用一步合成自组装法制备出了氢氧化钴与还原氧化石墨烯(Co(OH)2/rGO)的复合催化剂,并将其用于水中染料的催化降解实验.通过X射线衍射(XRD),激光拉曼(Raman)光谱,透射电镜(TEM),X射线能量色散谱(EDS)以及X射线光电子能谱(XPS)等一系列分析手段对催化剂的结构形貌进行了详细的表征,表征结果证实氢氧化钴很好地附着在还原石墨烯的表面.最后初步考察了催化剂催化单过硫酸钾(PMS)降解酸性橙(AO7)的性能.结果表明,催化剂显示出了高效的催化性能,酸性橙的色度可在12 min内完全去除,总有机碳(TOC)实验也表明染料降解的同时也可获得较高的矿化度.循环稳定性实验表明在进行到第三次实验时,催化剂仍能保持高的催化活性,将酸性橙在16 min内降解完毕.  相似文献   

5.
用一步合成自组装法制备出了氢氧化钴与还原氧化石墨烯(Co(OH)2/rGO)的复合催化剂,并将其用于水中染料的催化降解实验. 通过X射线衍射(XRD),激光拉曼(Raman)光谱,透射电镜(TEM),X射线能量色散谱(EDS)以及X射线光电子能谱(XPS)等一系列分析手段对催化剂的结构形貌进行了详细的表征,表征结果证实氢氧化钴很好地附着在还原石墨烯的表面. 最后初步考察了催化剂催化单过硫酸钾(PMS)降解酸性橙(AO7)的性能. 结果表明,催化剂显示出了高效的催化性能,酸性橙的色度可在12 min内完全去除,总有机碳(TOC)实验也表明染料降解的同时也可获得较高的矿化度. 循环稳定性实验表明在进行到第三次实验时,催化剂仍能保持高的催化活性,将酸性橙在16 min内降解完毕.  相似文献   

6.
乙二胺改性磁性壳聚糖纳米粒子对酸性染料的吸附特性   总被引:1,自引:0,他引:1  
利用乙二胺改性磁性壳聚糖纳米粒子(EMCN)吸附酸性橙7 (AO7)和酸性橙10 (AO10). EMCN制备时先通过在由环已烷/正已醇、壳聚糖和铁盐组成的反相微乳体系中加NaOH溶液沉淀剂, 得到磁性壳聚糖纳米粒子, 再经乙二胺改性以增加氨基含量和提高吸附容量. 透射电镜表明, EMCN分散良好, 粒径15-40 nm. 吸附实验表明, AO7和AO10最佳吸附分别在pH 4.0和pH 3.0. EMCN具有粒径小和高表面活性, 因此吸附速率快. 吸附平衡符合Langmuir模型, AO7和AO10的最大吸附容量分别为3.47和2.25 mmol·g-1. 热力学分析表明吸附过程放热, 且能自发进行. EMCN可用NH4OH/NH4Cl (pH 10.0)溶液再生并可重复使用.  相似文献   

7.
In this paper, the preparation conditions of antimony-doped SnO2 and PbO2 electrode were optimized for the degradation activity of AO7 dye solution. The results showed that when the doping content of Sb is 8 mol %(SnO2-Sb(0.08)), the SnO2 electrode exhibited best activities for the decolorization and mineralization of AO7. The concentration of NaF in electroplating solution had a noticeable effect on PbO2 electrode for the decolorization of AO7 solution, but little influence on the COD removal rate. The anodic stability tests showed that the electrode prepared in the solution containing 0.10 g l−1 NaF (PbO2-F(0.10)) was best for environmental application. The comparison of SnO2-Sb(0.08), PbO2-F(0.10) and Boron-doped Diamond (BDD) electrodes revealed that a more rapid decolorization rate was obtained on SnO2-Sb(0.08) and PbO2-F(0.10) electrodes in dilute AO7 solutions, while higher COD removal rate of concentrated AO7 solutions was on BDD and SnO2-Sb(0.08) electrodes. The effect of concentration of Na2SO4 on the degradation rate of AO7 was very notable on BDD electrode for its highest overpotential of oxygen evolution reaction. In the chloride-containing medium, the decolorization was accelerated greatly but the completed mineralization of AO7 was inhibited with the increasing of chloride ions concentration when these high-overvoltage anodes were used Published in Russian in Elektrokhimiya, 2008, vol. 44, No. 7, pp. 865–875. The text was submitted by the authors in English.  相似文献   

8.
In alkaline media, well‐characterized gelatin‐stabilized palladium (GPd) nanoparticles catalyze the reduction of the azo group containing pollutant dye, Acid Orange 7 (AO7) by sodium borohydride (NaBH4) to 1‐amino‐2‐napthol and sulfanilic acid. Kinetic observations and detailed FTIR studies suggests that the reaction follows Langmuir–Hinshelwood kinetic model, where during the reaction both AO7 and borohydride are adsorbed on the GPd surface. Plots of lnko versus ln[AO7] or ln[NaBH4] show that the order of reaction with respect to AO7 and NaBH4 remains almost same over different molar ratios of [NaBH4]/[AO7]. The catalyzed reaction shows an initial induction period (t0) due to a surface‐restructuring process of GPd nanoparticles, and (1/t0) can be defined as the rate of surface restructuring. The activation energy of the catalyzed reaction and energy of the surface‐restructuring process of GPd are estimated as 22 ± 3 and 25 ± 7 kJ M?1, respectively.  相似文献   

9.
《中国化学快报》2022,33(4):2125-2128
The difficulty in Fe(III)/Fe(II) conversion in the Fe(III)/peroxymonosulfate (PMS) process limits its efficiency and application. Herein, l-cysteine (Cys), a green natural organic ligand with reducing capability, was innovatively introduced into Fe(III)/PMS to construct an excellent Cys/Fe(III)/PMS process. The Cys/Fe(III)/PMS process, at room temperature, can degrade a variety of organic contaminants, including dyes, phenolic compounds, and pharmaceuticals. In subsequent experiments with acid orange 7 (AO7), the AO7 degradation efficiency followed pseudo-first-order kinetic which exhibited an initial “fast stage” and a second “slow stage”. The rate constant values ranged depending on the initial Cys, Fe(III), PMS, and AO7 concentrations, reaction temperature, and pH values. In addition, the presence of Cl?, NO3?, and SO42? had negligible impact while HCO3? and humic acid inhibited the degradation of AO7. Furthermore, radical scavenger experiments and methyl phenyl sulfoxide (PMSO) transformation assay indicated that sulfate radical, hydroxyl radical, and ferryl ion (Fe(IV)) were the dominant reactive species involved in the Cys/Fe(III)/PMS process. Finally, based on the results of gas chromatography-mass spectrometry, several AO7 degradation pathways, including N=N cleavage, hydroxylation, and ring opening were proposed. This study provided a new insight to improve the efficiency of Fe(III)/PMS process by accelerating Fe(III)/Fe(II) cycle with Cys.  相似文献   

10.
Oxygen-functionalized porous carbon (PC-800) was fabricated through direct thermal treatment of biowaste under inert atmosphere. The PC-800 was systematically characterized and the results showed that the catalyst was extremely favorable for catalysis due to its high specific surface area (993 m2/g) and abundance active sites (ketonic groups). The results indicated that PC-800 can efficiently degrade acid orange 7 (AO7), and increasing the catalyst loading and PMS dosage have promotional effect on catalysis. The recyclability study showed that, while PC-800 can be reused for several cycles, the catalytic activity was partially deactivated due to the cannibalistic oxidation of PC-800 surface. Nevertheless, high mineralization extent (DOC removal = 70%) and ring opening of aromatic AO7 intermediates was achieved. It was also found that both radical and nonradical mechanisms were responsible for AO7 degradation. Overall, this study showed that biowaste can be facilely functionalized with oxygen functional groups for sustainable PMS activation.  相似文献   

11.
Fenton‐ and photo‐assisted Fenton advanced oxidation processes generate reactive oxygen species from hydrogen peroxide and are candidates for the remediation of dye wastewaters. The purpose of this study was to investigate interactions of iron (III) with hydroxyazo dyes. The o‐hydroxyazo dyes Acid Orange 7 (AO7; 4‐[(2‐hydroxynaphthalen‐1‐yl)azo]benzenesulfonic acid sodium salt) and Acid Orange 10 (AO10; 7‐hydroxy‐8‐(phenylazo)naphthalene‐1,3‐disulfonic acid disodium salt) represent dyes allegedly able to chelate FeIII through the chromophore. The p‐hydroxyazo dye Acid Orange 20 (AO20; 4‐[(4‐hydroxynaphthalen‐1‐yl)azo]benzenesulfonic acid sodium salt) represents an analogous structure that is unable to chelate FeIII due to the position of the OH group. Reactions were carried out at pH 2 – 3 in perchlorate or chloride media in the absence of peroxide. No evidence was found by UV/VIS spectroscopy for complexation of FeIII by the o‐hydroxyazo chromophore. Instead, FeIII apparently coordinated or formed an ion pair with the sulfonate group, and, when only one sulfonate group was present (i.e., AO7), the dye formed a co‐precipitate with iron(III) hydrous oxides and perchlorate ion. Dye precipitation was seeded by colloidal iron hydrolysis product nuclei. By contrast, the p‐hydroxyazo dye (AO20) was rapidly oxidized by iron(III). The net Fe2+/oxidized AO20 ratio was 2 : 1, and a minor yield of 1,4‐naphthoquinone was obtained. The major initial oxidation product, which was not identified, formed a reversible complex with Fe2+. Results of this study indicate that the effectiveness of Fenton‐based methods for treating certain azo dyes that form insoluble ferric salts may be compromised by removal of the catalyst from solution. However, the degradation of certain other azo dyes might be assisted by direct thermal oxidation by iron(III).  相似文献   

12.
The aim of this research was the simultaneous removal of heavy metal and dye pollutants from water by a clinoptilolite–TiO2 nanocomposite. The nanocomposite was prepared by the synthesis of TiO2 nanoparticles on clinoptilolite. The structure and morphology of the clinoptilolite–TiO2 nanocomposite were studied by XRD, SEM, EDS and FTIR. The TiO2 synthesis and loading on clinoptilolite were confirmed by EDS, XRD and FTIR analysis. The TiO2 particle size was estimated by SEM images and XRD analysis to be less than 80 nm. The photocatalytic performance of the nanocomposite was evaluated for acid orange 7 (AO7) photodegradation under UV light irradiation in the presence of Pb2+. The removal of Pb2+ ions was investigated at the same time and the effect of the initial solution pH, the effect of AO7 and Pb2+ concentration were examined. The results indicated that the nanocomposite can simultaneously remove 77% of metal and 85% of dye from wastewater containing 500 ppm Pb2+ and 40 ppm AO7. The removal of Pb2+ ions was investigated at the same time and the effect of the initial solution pH, the effect of AO7 and Pb2+ concentration were examined. The results indicated that the nanocomposite can be used for the simultaneous photodegradation of AO7 and the removal of Pb2+ from water several times without a noticeable reduction in their efficiency. Also, the presence of the dye molecules led to a 10% increase in the removal efficiency of Pb2+ compared to when just Pb2+ was present.  相似文献   

13.
可用于光催化研究的脉冲放电流光光源   总被引:3,自引:0,他引:3  
利用针板形式的电极系统、正极性纳秒级脉冲电压供电、在空气和水混合条件下产生脉冲放电流光,研究了脉冲放电流光与电气参数、溶液电导率、鼓泡空气流量的变化关系,利用脉冲放电流光和纳米颗粒的半导体TiO2结合对酸性橙染料(AO7)溶液进行脱色效果的实验研究。结果表明,脉冲放电流光可以诱导TiO2发生光催化活性,在脉冲放电等离子体处理效果的基础上,提高AO7的脱色效果。  相似文献   

14.
A crude preparation of horseradish roots was used as a low-purity source of horseradish peroxidase (HRP) in dye decolorization experiments. The technical feasibility of the process was studied in bench scale for enzymatic removal of acid orange 7 (AO7), a synthetic dye. Further studies were carried out to understand the effects of process parameters such as pH value, H(2)O(2) level, concentrations of the synthetic dye, and HRP during enzyme-mediated dye degradation. Experimental data revealed that the concentration of AO7, pH of the aqueous phase, amount of the enzyme, and H(2)O(2) level played significant roles on the overall enzymatic reaction. Polyethylene glycol, as an anti-inactivation of HRP, in various concentrations showed no significant effect on the decolorization. The experimental data of initial reaction rates were fitted using an analytical equation proposed by Michaelis-Menten. The acute toxicity tests using Daphnia magna exhibited that the enzymatic treatment significantly decreased the toxicity of the dye solution.  相似文献   

15.
Lee MH  Chuang MT  Hou WC 《Electrophoresis》2002,23(15):2369-2372
Plasma amine oxidase (plasma AO, EC 1.4.3.6) is a copper-containing AO which converts benzylamine (BZ) to benzaldehyde, generating hydrogen peroxide and ammonia. The peroxidase was used as an ancillary enzyme to couple hydrogen peroxide to 3-amino-9-ethylcarbazole (AEC) to achieve plasma AO activity after electrophoresis on native polyacrylamide gels. It was confirmed that plasma AO is inhibited by semicarbazide but neither by clorgyline nor by deprenyl. We also used plasma AO activity staining for the screening of natural inhibitors. This fast and sensitive method can be used in the process of plasma AO purification, characterization, and inhibitor screening.  相似文献   

16.
The erosion effects of atomic oxygen (AO) in different incidence direction on carbon nanotube (CNT) arrays have been studied by ground‐based AO simulation facility. The surface morphologies and the molecular structures of CNT arrays before and after AO experiments have been characterized by scanning electron microscopy and Raman spectroscopy. It is shown that the morphologies of CNT arrays are quite different from those before AO experiments. It is presented that both bombardment effect and the oxidation effect of AO will contribute to the erosion effects on CNT arrays. Carbon nanotube arrays will be etched away in AO environment, but the AO erosion yield of CNT arrays is different with different AO incidence direction. It is proposed that the density of CNT‐based material may also affect the erosion yield.  相似文献   

17.
Microwave-assisted photocatalytic degradation of dyes is one of the emerging technologies for waste water remediation. Microwave effectively accelerates photocatalytic degradation, when microwave electrodeless lamp (MEL) substitutes traditional UV lamp as light source. This setup can be extremely simplified if MEL and photocatalyst can be replaced by a catalyst which can work under microwave irradiation in the absence of any light source. The present work reports for the first time degradation of acid orange 7 (AO) under microwave irradiation using polyaniline (PANI) as catalyst in the absence of any UV lamp as light source. The degradation/decolourization was carried out in neutral acidic and basic media and was monitored spectrophotometrically to evaluate the ability of microwave irradiation to degrade AO. Microwave irradiation showed excellent performance as it completely decolourizes AO dye solution in 10 min. With the advantages of low cost and rapid processing, this novel catalyst is expected to gain promising application in the treatment of various dyestuff wastewaters on a large scale.  相似文献   

18.
利用吸收光谱和荧光光谱方法,研究了吖啶橙(AO)与质粒DNA水溶液、以及含胶束介质的吖啶橙与质粒DNA溶液体系的相互结合作用及减色效应。结果表明:吖啶橙对质粒DNA的吸收光谱有减色效应;含十二烷基硫酸钠(SDS)的AO水溶液体系中,随着SDS浓度的增加,其光谱结果表现为由凝聚态向单体的转化。而在含十二烷基硫酸钠(SDS)的AO与质粒DNA溶液体系中,吖啶橙凝聚态随SDS浓度的增加,对AO与质粒DNA相互结合产生协同的减色效应,使质粒DNA空间结构发生缩拢。进一步采用电泳法研究了AO凝聚态可能对质粒DNA构象的影响,结果表明:在AO与质粒DNA溶液体系中,AO浓度的增加对质粒DNA构象未产生影响;而在含有SDS的AO与质粒DNA的溶液体系中,由于SDS对AO凝聚态的解聚作用,以及SDS对质粒DNA减色效应的协同作用,使得质粒DNA的构象发生变化,诱导质粒DNA形成超螺旋构象  相似文献   

19.
Rhizoma Atractylodes Macrocephala (RAM) is an important traditional Chinese medicinal herb that is used for treatment of dyspepsia and anorexia. The active ingredients, atractylenolide I (AO‐I) and atractylenolide III (AO‐III), were identified by direct‐injection ion trap‐mass spectrometry (IT‐MS) for collecting MSn spectra. The major fragment ions of AO‐I and AO‐III were confirmed by MSn both in negative ion mode and in positive ion mode. The possible main cleavage pathway of fragment ions was studied. The determinations of AO‐I and AO‐III were accomplished by liquid chromatography (LC) with UV and MS. The analytes provided good signals corresponding to the protonated molecular ions [M + H]+ and product ions. The precursor ions and product ions for quantification of AO‐III and AO‐I were m/z 249 → 231 and m/z 233 → 215, respectively, using selected ion monitoring by LC‐IT‐MS. Two methods were evaluated for a number of validation characteristics (repeatability, limit of detection, calibration range, and recovery). MS provides a high selectivity and sensitivity for determination of AO‐III and AO‐I in positive mode. After optimization of the methods, separation, identification and quantification of the two components in RAM were comprehensively tested by HPLC with UV and MS. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

20.
Photocatalytic degradation of water pollutants using nanometersized semiconductor colloids is an emerging area of environmental remediation. The synthesis of semiconductor nanocrystals (NCs), however, can be costly and result in low product yields. For large-scale photocatalytic application in environmental remediation, cost-effective production of the semiconductor NCs would be ideal. Demonstrated in this report is the efficient photocatalytic degradation of p-nitrophenol (pNP) and Acid Orange 7 (AO7) using ZnS nanocrystals (3 to 5 nm diameter) produced in gram quantities with >50% product yield. The pNP half-life in ZnS nanocrystal photocatalyzed reactions was about 1.95 to 2.45 min, whereas in comparable TiO2 reactions, the pNP half-lives were in the range of 12 to 15 min. Absorption spectra of the photocatalysis reactions suggested the decolorization of pNP without any noticeable formation of phenolic intermediates, implying a mechanism that involves a pNP ring opening via a radical mediated attack. Likewise, the degradation of AO7 was suggested to occur via an oxidative pathway involving hydroxyl radicals formed at the photocatalyst/liquid interface. Optimum conditions for AO7 degradation such as pH, photocatalyst-to-AO7 ratio, and photocatalyst surface passivation were similar to those for pNP. By demonstrating efficient mineralization of these model pollutants using mass-produced ZnS nanocrystals, we hope to lay the foundations necessary for development of large-scale, field-applicable systems.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号