Synthesis and characterization of carboxymethyl cellulose/organic montmorillonite nanocomposites and its adsorption behavior for Congo Red dye

A series of carboxymethyl cellulose/organic montmorillonite （CMC/OMMT） nanocomposites with different weight ratios of carboxymethyl cellulose （CMC） to organic montmorillonite （OMMT） were synthesized under different conditions. The nanocomposites were characterized by the Fourier transform infrared （FT-IR） spectrophotometer, X-ray diffraction （XRD） method, transmission electron microscope （TEM）, scanning electron microscope （SEM）, and thermal gravimetric （TG） analysis. The results showed that the introduction of CMC may have different influences on the physico-chemical properties of OMMT and intercalated-exfoliated nanostructures were formed in the nanocomposites. The effects of different reaction conditions on the adsorption capacity of samples for Congo Red （CR） dye were investigated by controlling the amount ofhexadecyl trimethyl ammonium bromide （CTAB）, the weight ratio of CMC to OMMT, the reaction time, and the reaction temperature. Results from the adsorption experiment showed that the adsorption capacity of the nanocomposites can reach 171.37 rag/g, with the amount of CTAB being 1.0 cation exchange capacity （CEC） of MMT, the weight ratio of CMC to OMMT being l：l, the reaction time being 6 h, and the reaction temperature being 60~C. The CMC/OMMT nanocomposite can be used as a potential adsorbent to remove CR dye from an aqueous solution.

Spectroscopic and calorimetric studies of congo red dye-amyloid peptide complexes

Thermodynamic properties of complexes of Con ?go Red (CR) dye with amyloid ? (A?) peptides were studied by both absorption spectroscopy and isothermal titration calorimetry (ITC). Based on the absorption spectrum for the formation of CRAβ complexes in phosphate buffered saline solution (pH 7.4), van’t Hoff plots over a temperature range of 10oC to 70oC were created for CRAβ140, Aβ1228, and Aβ142. The plot for CR Aβ1228 complex showed a relatively linear feature within the given temperature range with ?H = –10.1 ?0.6 kJ/mol and ?S = + 0.128 ? 0.002 kJ/(mol K). However, the plot for CRAβ140 and CRAβ142 complexes exhibited two distinct linear regions with opposite slopes centered at a specific temperature, Ts, which was 54.7 ? 0.2℃ and 34.8 ? 0.2℃, respectively. The ITC experiments conducted at 25℃in water exhibited quite a different situation from the above mentioned spectroscopic approach. The ITC studies yielded a ?H of –85.3 ? 0.2 kJ/mol for the CRAβ1228 complex with negative entropy change –0.152 kJ/mol K). For CRAβ140, the ITC studies indicated the presence of two binding sites with ?H1 = –81.8 ? 0.3 kJ/mol and ?H2 = –119.5 ? 0.2 kJ/mol with K1 = 5.5 ? 0.7 ? 106 M1 and K2 = 6.9 ? 2.4 ? 108 M1, respectively. These binding constants are consistent with the model suggested by several studies. Both binding sites showed negative entropy changes suggesting that the formation of the complex is enthalpically driven. The disagreement in thermochemical values between two different methods confirmed that the enthalpy and entropy are heavily dependent on temperature and buffer/salt environment, and may involve inherently different reaction paths.

Adsorption of Congo Red from Aqueous Solution Using CTAB-Kaolin from Bechar Algeria

Cetyltrimethylammonium bromide-modified kaolin (CTAB-kaolin or KC) was prepared and tested as an adsorbent for an anionic dye Congo red (CR) removal from aqueous solution in comparison with natural kaolin (K). The effect of various experimental parameters was investigated using a batch adsorption technique. In this manner, the adsorption isotherms and adsorption kinetics of CR on K and KC were examined. The isothermal data could be well described by the Langmuir equation and the dynamical data fit well with the pseudo-second-order kinetic model. The adsorption capacity of modified kaolin KC (24.46 mg/g) was found to be around 4 times higher than that of natural kaolin K (5.94 mg/g). The KC demonstrated the highest adsorption capacity by removing over 98% of CR after ten minutes of contact. These results indicate that CTAB-kaolin could be employed as low-cost alternative to activated carbon in wastewater treatment for the removal of colour which comes from industrial effluents of textile activities, tanning or printing.

Adsorptive Mass Transport of Dye on Rice Husk Ash

Experimentations have been carried out to characterize the adsorption of Methylene Blue (MB) and Congo Red (CR) dyes in the aqueous phase onto Rice Husk Ash (RHA). Theoretically analyses are also made for describing the sorption and diffusion processes. The effective pore diffusivities of the dye molecules studied in RHA are determined by a suitable global optimization technique. The depth of penetration, on the other hand, has been estimated for various initial concentrations of dyes. Theoretically predicted concentration pro-files are compared with the experimental values at different initial concentrations of these dyes. Such com-parative studies indicate that the predicted values are in excellent agreement with the experimental values.

海藻酸钠固定漆酶复合淀粉处理模拟印染废水的应用

采用固定漆酶的海藻酸钠-钙离子交联水凝胶球与阳离子淀粉按质量比1∶1形成新型复合吸附剂,用于对模拟刚果红染料废水的研究。考察如吸附剂投加量、反应时间、pH值等条件对模拟印染废水吸附效果的影响。结果表明,在体积50 mL、转速125 r·min^(-1)的条件下,吸附剂用量为0.6 g、吸附时间30 min、pH值在6~7、反应温度为30℃、刚果红溶液初始浓度为100 mg·L^(-1),脱色率达到96.11%,吸附量为164.2 mg·g^(-1)。对比Freundlich吸附等温方程(R^(2)=0.9899)和Langmuir吸附等温方程(R^(2)=0.9982),表明此处理过程等温拟合模型更符合Langmuir吸附模型,为单层吸附。

Synthesis, Characterization and Application of Mg/Al Layered Double Hydroxide for the Degradation of Congo Red in Aqueous Solution

The adsorption properties of layered double hydroxide (Mg/Al-CO3) for the removal of Congo Red (CR) dye from aqueous solution were studied. The layered double hydroxide was synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopic (FTIR) and Energy-Dispersive X-ray Spectroscopic (EDX). The effects of various experimental parameters such as contact time, dye concentrations and temperature variation were investigated. The results show that the amount of Congo Red adsorbed increases with increase in temperature but decreases with increase in initial dye concentration and contact time. The data were also fitted to several kinetic models: zero-order kinetic model, first-order kinetic model, second-order kinetic model, pseudo-second-order kinetic model and third-order kinetic model respectively. The adsorption process was best defined by zero-order-kinetic model (R2 = 1). Langmuir, Freundich, Temkin and Dubinin-kaganer-Radushkevich (DPK) adsorption isotherm models were applied to analyze adsorption data with Temkin isotherm being the most applicable to the adsorption process. Thermodynamic parameters e.g. △Go, △So, △Ho and △Hx of the adsorption process were found to be endothermic, spontaneous and feasible.

Design, Microwave Assisted Synthesis of Some Schiff Bases Derivatives of Congo Red and Conventional Preparation of Their Structurally Reversed Analogous Compounds

This work contributes to the improvement of the azo group which has outstanding electron donating capability and serves as excellent ligands in the field of coordination chemistry. The authors of this research deal with the microwave irradiation synthesis of some new Schiff bases derived from the biologically effective and photoactive Congo red [Ia-g]. The design and preparation of the structurally reversed analogous compounds to the above compounds [IIIa-d] were accomplished using the conventional chemical methods by keeping the benzidine moiety of Congo red as the nucleus of the synthesized compounds, doubling the number of the azo groups and inverting the way of their conjugation order with the azomethine groups. The structures of the newly prepared compounds were established on the basis of their FTIR and H1 NMR spectral data.

沸石咪唑酯骨架-8的制备及其对刚果红的吸附性能

为制备印染废水的吸附材料,以六水合硝酸锌和2-甲基咪唑为原材料,以去离子水作溶剂,采用水溶剂法制备沸石咪唑酯骨架-8(ZIF-8)材料。借助扫描电子显微镜、红外光谱仪、X射线衍射仪等探究ZIF-8材料的结构,测试其对阴离子刚果红染料的吸附性能,并分析其吸附机制。结果表明:ZIF-8颗粒大小均匀,表面光滑,呈多面体结构;其热裂解温度为258℃,具有良好的热稳定性;ZIF-8对刚果红的吸附更符合准二级动力学模型和Langmuir吸附等温线模型,即以化学吸附为主且吸附位点等效;吸附过程为自发进行的放热反应,低温有利于吸附;在温度为20℃、pH值为7的条件下,ZIF-8对95 mg/L的刚果红溶液的吸附效果最佳,吸附量可达671.41 mg/g。

掺杂型三维多孔纳米镍催化偶氮染料脱色性能

偶氮染料是纺织印染工业废水中的主要污染物,其大量排放会严重危害生物健康。为了开发一类有效的纳米催化剂对废水中的偶氮染料进行脱色,本文采用简单的水热合成法将Fe、Co元素掺杂到镍纳米材料中形成了具有三维网状多孔结构的三元金属纳米材料(Fe-Co-Ni NPs)。所制备的三元合金纳米材料为三维网状结构,少量的Fe、Co元素掺杂获得了更高的饱和磁化率,而未改变镍的多晶结构。在硼氢化钠存在条件下,由于多种金属元素之间的相互作用,Fe-Co-Ni NPs对刚果红的还原降解具有非常高的催化活性,2 min即可完全脱色,表观速率常数为1.24 min^(−1),明显优于二元Fe-Ni(1.00 min^(−1))、Co-Ni(0.96 min^(−1))及单金属Ni(0.83 min^(−1))纳米晶。Fe-Co-Ni NPs对其它偶氮染料甲基橙、直接红80及硝基苯酚类物质的还原降解也表现出较佳的催化性能。总之,该三元金属催化剂易于合成、成本低,对偶氮染料脱色效果好、稳定性高且可重复使用,非常适合工业偶氮废水的前期脱色处理。

羧基酯化改性花生壳对染料废水的吸附

通过甲醇酯化法制备改性花生壳,用于吸附刚果红、次甲基蓝染料废水。考察了吸附时间、溶液pH值、初始浓度对吸附的影响及改性花生壳的再生。结果表明,在室温、刚果红在pH值4.16、次甲基蓝在7.45时,吸附效果最佳,经搅拌吸附120 min达到平衡,两染料最大吸附率分别为82.30%和90.84%,饱和吸附量分别为10.88 mg/g和11.82 mg/g。吸附符合一级动力学过程和Langmuir等温吸附模型。改性花生壳吸附效果较未改性花生壳明显提高,且可经0.5 moL/L NaOH溶液再生重复使用。

光电催化氧化法脱色处理刚果红染料废水

采用阴极还原法制备了泡沫镍负载纳米ZnO(ZnO/Ni)电极,采用SEM和XRD技术对ZnO/Ni电极进行了表征。以高压汞灯为光源,ZnO/Ni电极为阳极,铂电极为阴极,对模拟刚果红染料废水进行了光电催化脱色处理。考察了催化工艺、电解质种类及浓度、初始废水pH和反应温度等因素对刚果红降解率的影响。表征结果显示,制备的纳米Zn O呈六方晶系结构,平均粒径为23.6 nm。实验结果表明,当外加电流为1.0 m A时,在初始刚果红质量浓度为30 mg/L、电解质Na2SO4浓度为0.050mol/L、初始废水p H为5、反应温度为50℃的条件下,光电催化反应60 min后,刚果红降解率为86.36%,COD和色度的去除率分别达到70.56%和92.86%。

4例肝淀粉样变性的临床特点和分析

目的对已确诊病例的临床特点进行总结和分析,以提高对本病的认识,减少误诊率。方法经肝、肾组织学检查及特异性组织学染色明确诊断为肝淀粉样变性的4例住院患者。住院期间检测肝功、血脂、尿常规等化验,腹部彩超、腹部CT或腹部核磁,肝脏、肾脏的活体组织病理检查及特异性组织学染色(刚果红染色)。结果患者均有肝大,肝功生化检查AKP及r-GT明显增高,低蛋白血症,高脂血症。肝脏彩超和CT显示肝脏增大,肝密度低,回声细密,类似脂肪肝的表现。肝穿及肾穿病理见大量粉红色淀粉样物质沉积,刚果红染色(+),病理结论为肝、肾淀粉样变性。结论对临床上高度怀疑为肝淀粉样变性的患者,作肝肾活体组织检查及特异性组织学染色(刚果红染色),可证实为肝淀粉样变性。

功能化锌金属有机骨架对刚果红染料的吸附

为了提高染料废水中刚果红的吸附量和脱色率,从而减少其对环境的污染,以锌金属有机骨架(MOF-5)和功能化锌金属有机骨架(EDA/MOF-5)作为吸附材料,探讨其对刚果红的吸附性能;研究染料浓度、温度、pH值、吸附时间和离子强度对吸附性能的影响,用Langmuir和Freundlich模型对其吸附行为进行描述,并对其吸附动力学进行了探究.结果表明:EDA/MOF-5较于MOF-5对刚果红的吸附量和脱色率分别提升了13.19 mg/g和14%;金属有机骨架MOF-5在弱碱性的条件下更容易吸附水中的刚果红染料,EDA/MOF-5受pH值的影响较小;在试验范围内,随着刚果红初始浓度和温度的升高,EDA/MOF-5对刚果红的吸附量也随之增大,当刚果红浓度为80 mg/L时,EDA/MOF-5对其吸附量和脱色率分别达到78.36 mg/g和98%;由于其他离子的加入,其与染料分子相互竞争吸附位点,对于刚果红的吸附有一定的抑制作用;研究表明Freundlich模型更适合描述该吸附过程;该吸附过程更符合拟二级动力学方程.

磁性壳聚糖微球的制备及其吸附行为研究

采用乳化交联法,以戊二醛为交联剂,制得磁性壳聚糖微球(MCTS),研究其对刚果红染料的吸附行为。考察戊二醛用量、反应温度和反应时间对刚果红染料吸附效果的影响。并通过正交试验确定最佳吸附条件及主要影响因素。结果表明:在最佳吸附条件下,刚果红染料的脱色率可达95.68%。磁性壳聚糖微球对刚果红染料的吸附遵循Langmuir等温吸附式。磁性壳聚糖微球可再生使用,再生4次后,脱色率仍高于90%。

深海盐单胞菌产生的微生物絮凝剂HBF-3对刚果红模拟染料废水脱色的研究

以深海盐单胞菌V3a′(Halomonas sp.V3a′)合成的新型微生物絮凝剂HBF-3对刚果红模拟染料废水进行脱色试验,探讨HBF-3加入量、溶液pH、温度对脱色效果的影响,并与活性炭和壳聚糖对刚果红染料的脱色效果进行对比。结果表明:增加HBF-3的加入量可以提高对刚果红溶液的脱色效果,HBF-3质量浓度为100mg/L时对200mg/L刚果红的去除率达83.7%;HBF-3对染料废水脱色效果受pH值的影响大,pH值在5.0～6.0时,HBF-3对刚果红溶液的脱色效果较弱,为41.1%左右;pH值在7.0～9.0之间变化时,脱色率稳定在88.7%左右;在10～70℃范围内絮凝率随温度变化而改变的幅度小。

纳米ZnO/Ni电极的制备及光电催化性能研究

采用阴极电沉积法制备泡沫镍负载纳米氧化锌电极,并用扫描SEM和XRD分析其晶粒形貌和物相结构。以刚果红染料为模拟污染物,ZnO/Ni为工作电极,铂丝电极为对电极,对刚果红染料废水进行了光电结合催化降解的试验研究。考察了外加偏压、氯离子浓度和溶液初始pH对刚果红染料废水光电催化降解效率的影响,同时在最优条件下比较了光催化降解、电解与光电结合催化降解对刚果红染料废水的降解效果的差异。结果表明,在相同条件下,光电结合催化降解刚果红染料废水的速率比单纯的光催化降解速率和单纯的电解速率快。在外加偏压为1.2 V,支持电解液浓度为0.20 mol.L-1,溶液pH为6时对40 mg.L-1的刚果红光电催化降解120 min时的降解率、色度和COD去除率分别达到82.57%、94.00%和68.72%。

7例肝淀粉样变性的临床分析

目的通过对已确诊肝淀粉样变性病例的临床特点进行总结和分析,以提高对本病的认识,减少误诊率。方法对7例经肝、肾组织学检查及特异性组织学染色明确诊断为肝淀粉样变性的住院患者的临床表现、实验室检查、超声心动图、B超、CT、MRI等影像学检查和病理检查及特异性的组织染色(刚果红染色)等进行了回顾性分析。住院期间检测肝功、血脂、尿常规等化验,腹部彩超、腹部CT或腹部MRI。结果 7例均有腹胀、纳差、乏力、体质量减轻(消瘦)、肝肿大,伴有碱性磷酸酶及γ-谷氨酰基转移酶明显升高、低蛋白血症、蛋白尿、高脂血症。肝穿及肾穿病理见大量粉红色淀粉样物质沉积,刚果红染色(+),病理结论为肝、肾淀粉样变性。结论肝淀粉样变性临床罕见,表现多样化且大多为非特异性,容易误诊,对临床表现高度怀疑为肝淀粉样变性的患者,肝、肾穿刺活体组织检查及特异性组织学染色(刚果红染色),可帮助确诊肝淀粉样变性。

超声强化铋掺杂氧化铟降解偶氮染料废水

本实验利用溶剂热法合成了铋掺杂氧化铟催化剂,利用XRD、EDS和SEM对催化剂的结构和形貌进行了表征.研究表明,铋离子已经掺杂进氧化铟的晶格中.掺杂后的催化剂粒径为纳米级,且具有良好的球形形貌.本文以偶氮染料直接大红废水为目标降解物,分别考察了不同催化剂对该染料废水的降解性能以及铋掺杂氧化铟催化剂的投加量、染料的浓度、溶液的p H、超声频率和超声功率对该染料的降解性能.在本实验条件下,催化剂投加量为7.5 mg、染料浓度为10 mg·L^(-1)、pH值为6、超声频率为45 kHz、功率为100 W时,对染料废水的去除效果最优,总去除率可达83.7%,比空白实验的去除率提高将近5倍.

改性δ-MnO_2对刚果红溶液吸附脱色的动力学和机理

研究了改性δ-MnO2对刚果红溶液的脱色动力学和有关限速步骤的机理。考察了振荡频率、MnO2投量、温度、pH值和刚果红初始浓度对脱色速率的影响。结果表明:脱色符合表观二级动力学方程,活化能为5·1kJ·mol-1。吸附过程的限速步骤为内部微孔扩散。较大的吸附容量和较快的吸附速率使改性δ-MnO2具有潜在的印染废水脱色能力。

磁性Fe_3O_4/碳纳米管复合材料光催化处理刚果红染料废水

采用共沉淀法制备了一种磁性Fe3O4/CNTs(碳纳米管复合物),采用XRD、SEM、VSM等对Fe3O4/CNTs复合材料的晶相、颗粒大小和磁性能进行了表征。以刚果红染料废水处理为例,研究了不同处理工艺、催化剂投加量、溶液p H、催化剂重复使用等因素对Fe3O4/CNTs材料光催化脱色刚果红染料废水效果的影响。结果表明,当刚果红染料起始质量浓度为10 mg/L,用量为0.2 g/L,3%的H2O20.2 m L,光照50 min后,Fe3O4/CNTs对刚果红溶液的脱色率达到97.0%。催化剂重复使用第4次,对刚果红染料的脱色率仍可达87%以上。此外,Fe3O4纳米粒子的存在使Fe3O4/CNTs材料具有较强的磁性,且可通过外加磁场将其从处理后的水体中快速分离回收。