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.

Synthesis of photocatalytic La_(1–x)A_xTiO_(3.5–δ)(A=Ba, Sr, Ca) nano perovskites and their application for photocatalytic oxidation of congo red dye in aqueous solution

A-site substituted La0.8A0.2TiO3.5–δ（A=Ba, Sr, Ca） nano perovskites were prepared by sol-gel method and characterized using thermogravimetry/differential thermal analysis（TGA/DTA）, X-ray diffraction（XRD）, ultraviolet-visible（UV-Vis） spectroscopy and transmission electron microscopy（TEM）. XRD analysis showed that the La0.8A0.2TiO3.5–δ（A=Ba, Sr, Ca） nano perovskites derived after calcination at 800 oC were in single phase with orthorhombic structure. The particle size of all nano perovskites was found to be ~20 nm. The synthesized nano perovskites were tested for the photocatalytic decomposition of an azo dye, Congo red. The sequential behavior of La0.8A0.2TiO3.5–δ（A=Ba, Sr, Ca） nanoperovskites for photocatalytic decomposition of congo red in aqueous solution by visible light at room temperature was studied at various time intervals and the efficiency of degradation of the nanoperovskites was compared. Among all the A-site substituted La0.8A0.2TiO3.5–δ（A=Ba, Sr, Ca） nano perovskites, Ba substituted compound showed the highest dye degradation.

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.

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.

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。

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。

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.

基于刚果红的高分子染料制备及pH响应变色性能

为开发pH响应变色智能纺织品,以异佛尔酮二异氰酸酯为硬段、聚乙二醇1000为软段、1,4-丁二醇为扩链剂、刚果红为发色体,制备了具有pH响应变色功能的水性聚氨酯高分子染料,并将其用于棉织物涂层。通过傅里叶红外光谱、紫外-可见光光谱等表征该高分子染料的结构及颜色特征,并详细探讨了该高分子染料及其涂层织物的pH响应变色性能。结果表明,刚果红高分子化后的最大吸收波长存在12 nm的红移。随着pH值降低,由于刚果红中氨基质子化并转变为醌式结构,高分子染料溶液的最大吸收波长由510 nm迁移至605 nm,吸收峰峰形变宽,颜色由红色变成蓝紫色。另外,该高分子染料涂层棉织物在pH值小于3的环境中逐渐变成蓝色,呈现出显著的pH响应变色行为、较高的变色灵敏度、良好的可逆性及pH响应长期稳定性,且能够循环使用于染色废水检测。

聚硅酸钛铁锌的优化制备及其对偶氮染料废水的絮凝性能

以硅酸钠、硫酸钛、硫酸铁、硫酸锌为原料制备复合絮凝剂聚硅酸钛铁锌(PTFSZ)。以50 mg/L刚果红染料废水为处理对象,通过单因素实验与响应面实验优化PTFSZ的制备条件,探讨了优化条件下制备的絮凝剂对染料废水的絮凝性能。结果表明,PTFSZ的最佳制备条件为n(Si)∶n(Fe)=1,n(Si)∶n(Zn)=1∶0.33,n(Si)∶n(Ti)=1∶0.61,聚合pH=5,聚合时间1.23 h;PTFSZ对偶氮类染料废水处理效果好,当絮凝剂投加量为0.175 mmol/L时,刚果红去除率高达99.16%;在一定范围内,原水浊度对废水中偶氮染料的去除有一定的促进作用;PTFSZ可用于偶氮染料废水的处理。

聚硅酸铝钛改性纤维素复合絮凝剂的制备及其絮凝性能研究

絮凝法以简便、廉价的优势在染料废水处理中有着广泛的应用,将阳离子基团引入到絮凝剂中可以提高对染料的去除性能以加快絮体的沉降速度。采用阳离子醚化剂3-氯-2-羟丙基三甲基氯化铵(CHTPAC)对纤维素进行改性得到两性纤维素(CMCCTA);以硅酸钠、硫酸铝、硫酸钛为原料与两性纤维素进行复合,制备了聚硅酸铝钛-两性纤维素复合絮凝剂。通过单因素实验探究了两性纤维素的最佳合成条件与复合絮凝剂的制备及应用的最佳条件,对刚果红的去除率可达到95%。通过傅里叶变换红外光谱、X射线衍射仪、扫描电镜对其进行表征分析,结果表明两性纤维素与聚硅酸成功复合。制备的两性絮凝剂具有环保高效的特点,金属离子与两性纤维素的引入,提高了絮凝效果,增强了聚硅酸盐的稳定性,具有良好的应用前景。

超声辅助改性辣椒秸秆吸附刚果红性能研究

针对处理印染废水问题,以辣椒秸秆为原料,柠檬酸为改性剂,探索在超声辅助条件下,辣椒秸秆对刚果红的吸附情况。结果表明:最佳吸附条件是温度为65℃,用0.3g改性辣椒秸秆,刚果红溶液初始浓度为200mg/L刚果红溶液、超声时间110min。经对比发现,该吸附过程更符合准二级动力学方程(R^(2)=0.99248),为化学吸附,吸附过程符合Freundlich等温方程(R^(2)=0.82733)。经正交实验极差和方差分析得出最佳吸附组合为:投加量0.3g,染料的初始浓度240mg/L,吸附温度55℃,吸附时间90min,其中吸附剂用量对吸附效果的影响最为显著。

SiO_(2)-MgO复合材料的制备及其吸附性能研究

以黄磷炉渣为硅源制得SiO_(2)基体材料,将MgO负载在SiO_(2)基体材料表面制备了SiO_(2)-MgO复合材料,用于吸附刚果红染料废水。考察了吸附时间、吸附温度、刚果红染料废水初始质量浓度对吸附效果的影响。研究表明:当刚果红质量初始浓度为50mg/L、吸附剂用量为0.1g、吸附温度为25℃、吸附时间为10min时,吸附率可达99.73%,吸附量为49.87mg/g。SiO_(2)-MgO复合材料吸附性能好,且实验方法操作简单、经济效益高。

超声辅助改性玉米秆吸附刚果红性能研究

为了将废弃生物质应用于染料污水的治理,以玉米秆为原料,氢氧化钠为改性剂,探究了超声辅助条件下,改性玉米秆对刚果红的吸附情况。实验结果表明:玉米秆1.0 g、吸附温度55℃、超声时间30 min、染料刚果红200 mg/L、超声功率50%吸附效果最佳。正交试验表明:吸附效果影响因素的主次顺序是吸附剂用量>吸附温度>吸附时间,其中改性玉米秆投加量对吸附效果的影响最为显著。通过动力学模型和吸附等温线分析,该吸附过程符合准二级吸附动力学方程(R 2=0.9946),属于化学吸附;拟合等温Langmuir方程能更好地描述该吸附过程(R 2=0.9932),表明是在其表面进行的均匀的单分子层吸附。

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.

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。

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%。