Extraction-spectrophotometric Determination of Dicyanoaurate(Ⅰ) with Crystal Violet

Extraction spectrophotometric determination of dicyanoaurate (Ⅰ) with Crystal Violet is described. At pH 2.6～10.7, dicyanoaurate (Ⅰ) can react with Crystal Violet and form a complex which can be extracted into isoamylacetate. The apparent molar absorptivity is 8.37×10 4 L·mol -1 ·cm -1 at 605 nm. Beer′s law is obeyed for 0～15 μg of Au(Ⅰ) per 5 ml of isoamylacetate. The interference from Ag(Ⅰ) and Cu(Ⅱ) can be eliminated with thiourea and EDTA. The method is applied to the determination of dicyanoaurate (Ⅰ) in sample solution with satisfactory results.

The ultratrace detection of crystal violet using surface enhanced Raman scattering on colloidal Ag nanoparticles prepared by electrolysis

Highly active, stable and affordable surface enhanced Raman scattering （SERS） substrates were obtained by electrolyzing a mixture of AgNO3 （4 × 10^-4 mol/L） and Na3C6H5OTH2O （6 × 10^-5 mol/L） for 1, 2, 3 and 4 h at 7 V. With crystal violet （CV） as a test molecule, a portable Raman spectrometer with 785 nm laser excitation was employed to carry out the SERS detection. Colloidal Ag nanoparticles prepared by electrolyzing for 3 h with the particle size of （65 ±17） nm is a perfect SERS substrate for the ultratrace detection of CV, which displayed an enhancement factor of ca. 1.3 × 10^8 and the detection limit of CV is down to ca. 10-15 mol/L （ca. 10^-4 ppb） with 10^-1 mol/L KBr as aggregating agent. Thus, this SERS substrate will provide a hopeful foreground in ultratrace detection. Meanwhile, it will provide a possibility to bring Raman analysis out of the laboratory to process in situ, real-time detection and identification.

Degradation of crystal violet using nanometer TiO_2 under the synergistic action of H_2O_2 and ultrasonic wave

TiO_2 nanoparticles with different phases are prepared by hydrolysis oftitanium tetrabutoxide in the presence of HC1. The composition and microstructure of the resultingsamples are studied by XRD and TEM. These results show that the range of particle size of TiO_2 isfrom 20 to 30 nm. The mechanism of TiO_2 photocatalysis reaction has been discussed extensively.Photocatalytic activities of nanometer TiO_2 are also evaluated by degradation of the crystal violetsolution. Experimental results indicate that the synergistic action of H_2O_2 and ultrasonic wavegreatly enhances photo-catalytic reaction of TiO_2.

Molecularly Imprinted Polymers for Selective Extraction of Crystal Violet from Natural Seawater coupled with HighPerformance Liquid Chromatographic Determination

Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

Laser action in methyl methacrylate （MMA） co-doped with sulforhodamine B and crystal violet dyes was investi- gated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd：YAG laser. Distributed feedback dye laser （DFDL） action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor-donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor-donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

FRACTAL STRUCTURE OF COLLOIDAL SILVER AND ITS EFFECTS ON SERS INTENSITIES OF CRYSTAL VIOLET

The surface-enhanced Raman spectra (SERS) of crystal violet on colloidal silver particles of different sizes and shapes were measured and the structural effect of the silver aggregates on the SEPS intensities was discussed in terms of fractal geometry. It is found that the SERS band intensities of crystal violet change significantly with the fractal dimension (D) of colloidal silver at 1.25<D<1.65, but remains nearly constant at D>1.8.

Kinetic Modeling of Methylene Blue and Crystal Violet Dyes Adsorption on Alginate-Fixed Water Hyacinth in Single and Binary Systems

Removal of Methylene Blue (MB) and Crystal Violet (CV) dyes from monocomponent and binary aqueous solutions by water hyacinth-E. Crassipes roots fixed on alginate (a low-cost adsorbent) has been investigated. The extent of adsorption was evaluated as a function of solution pH, initial dye concentration, and bead biomass loading. Kinetic sorption data were analysed by widely used models: pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The results showed that pseudo-second-order model better described the biosorption experimental data than the pseudo-first-order kinetic model for both dyes, whilst the Elovich model fitted the biosorption experimental data at lower dye concentrations. The intraparticle diffusion model indicated that sorption of CV and MB was characterized by rapid surface adsorption coupled with slow film diffusion process at higher initial dye concentration and at all initial bead biomass loading. The range of mean free energy values confirmed physical adsorption as the mechanism for dye removal from solution.

Synthesis of Nano-Titanium Tannate as an Adsorbent for Crystal Violet Dye, Kinetic and Equilibrium Isotherm Studies

The purpose of this study was to prepare nano-titanium tannate complex (TTC) and to investigate its adsorption capacity for removal of cationic dyes such as crystal violet (CV) dye. The morphology and the main elements of TTC adsorbent were characterized by scanning electron microscopy (SEM-EDS), while its crystal structure was characterized by X-ray diffraction (XRD). Also, FT-IR spectroscopy study structural aspects of TTC. A “cotton-ball”-like and porous surface structure of titanium tannate complex (TTC) with nanoparticle size of 16.18 nm show high capability for absorbing crystal violet dye. The effect of several parameters such as contact time, initial concentrations of CV, solution pH and the amount of TTC was investigated. Three different kinetic equations such as pseudo-first order, pseudo-second order and intraparticle diffusion were used to study the order and the mechanism of the adsorption process. The adsorption of CV dye followed pseudo- second order equation. Moreover, equilibrium data were tested with four adsorption isotherm models namely, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R). Langmuir was the best fit for the data with maximum capacity as 58.8 mg/g. The results of Separation factor, Surface coverage and standard free energy (ΔG°) indicated that adsorption of CV onto TTC was favorable with fast rate and spontaneous physical adsorption process.

Aminopropyl-containing ionic liquid based organosilica as a novel and efficient adsorbent for removal of crystal violet from wastewaters

Herein a novel aminopropyl-containing ionic liquid based organosilica(ILOS-NH_2) is prepared, characterized and applied as effective adsorbent for removal of crystal violet(CV) dye from wastewater. The ILOS-NH2 material was synthesized by hydrolysis and co-condensation of 1,3-bis-(3-trimethoxysilylpropyl)-imidazolium chloride(BTMSPIC) under acidic conditions followed by treatment with 3-aminopropyl-trimethoxysilane in toluene under reflux conditions. This material was characterized using scanning electron microscopy(SEM), diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS), thermal gravimetric analysis(TGA) and energy dispersive X-ray analysis(EDAX). The material was effectively used in the removal of crystal violet at ambient temperature and showed high capacity and stability under applied conditions. The efficacy of p H, contact time, adsorbent dose, initial dye concentration, temperature, and isotherm studies and the applicability of pseudo-first, second order and Elovich kinetic models have also been investigated.

Rapid Adsorption of Crystal Violet onto Magnetic Zeolite Synthesized from Fly Ash and Magnetite Nanoparticles

This work reports the adsorption of crystal violet (CV) dye onto magnetic zeolite (MZ) nanoparticles, synthesized by direct fusion of fly ash (FA) and magnetite particles. The synthesised MZ showed high capacity for CV dye adsorption, removing 95% of the dye at an equilibrium adsorption time of 10 min and 25℃. The effects of adsorbent dosage, dye concentration, and pH, on adsorption were evaluated. Adsorption data were best described by the Langmuir adsorption isotherm (R2 = 0.9986), while the adsorption kinetics was best fitted by the pseudo-second-order kinetic model (R2 = 0.9999). Application of the MZs synthesised from inexpensive resources such as FA could ensure the sustainability and cost effectiveness of treating industrial effluent containing basic dyes, especially effluent from the textile industries.

Preparation, characterization and photocatalytic activity of N-doped TiO_2 nanocrystals

N-doped TiO2 nanocrystals were prepared using titanium alkoxide as precipitant with different proportional materials. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-vis diffuse reflectance spectra. It is confirmed experimentally that the photocatalytic activity of N-doped TiO2 is much higher than that of Degussa P25, when used for the degradation of crystal violet. The degradation kinetics follows an apparent first-order reaction, which is consistent with a generally observed Langmuir-Hinshelwood mechanism. The doping of TiO2 with nitrogen significantly increases the absorption in the region of visible light. The energy of the band gap of N-doped TiO2 is 2.92 eV. The better performance of N-doped TiO2 can be explained by the fact that it is also excited with longer-wavelength light.

不同形貌CaO_(2)的制备及其降解水中结晶紫的研究

为探究不同形貌过氧化钙对染料降解去除效果的差异性,采用钙盐法在不同条件下制备不同形貌的过氧化钙,并将其用于处理结晶紫模拟的染料废水。通过X射线衍射、扫描电子显微镜和傅里叶变换红外光谱对制得的过氧化钙进行了形貌表征,证明合成了四方晶状过氧化钙和球状纳米过氧化钙,并考察了两种过氧化钙在不同条件下对模拟染料废水中结晶紫的去除效果。结果表明,在模拟染料废水初始pH为6.0,结晶紫初始浓度为10 mg/L,四方晶状过氧化钙投加量为18.0 mg,球型纳米过氧化钙投加量为30.0 mg时,结晶紫的去除率分别可以达到94.14%和85.49%。准一级动力学方程可以描述两种过氧化钙对结晶紫的降解机制,球状纳米过氧化钙对结晶紫的降解过程与准一级动力学模型的吻合度更高。

白云石/三聚氰胺复合材料制备及吸附结晶紫性能研究

以白云石和三聚氰胺为原料,热聚合制备白云石/三聚氰胺复合吸附材料,以结晶紫的吸附率为评介指标探讨复合材料对结晶紫的最佳吸附条件。结果显示复合材料对结晶紫最佳吸附条件是:复合材料投加量为0.75 g、结晶紫溶液初始浓度300 mg/L、反应时间100 min,对结晶紫吸附率达97.3%。动力学拟合发现吸附反应符合准二级动力学方程和Langmuir等温方程模型,即吸附材料对结晶紫的吸附过程以单分子层的化学吸附为主。

双交联淀粉凝胶的制备及对结晶紫的吸附

实验选取红薯淀粉和高直链玉米淀粉、ECH为交联剂制备淀粉凝胶,再以硼砂、明胶及PEG2000为添加剂与淀粉进行二次交联制备双交联淀粉凝胶。并测试了凝胶的吸水性及对结晶紫(CV)的吸附性能。结果表明,双交联淀粉凝胶制备的最佳反应条件为:淀粉质量分数为10%,ECH与淀粉及碱与淀粉物质的量比分别为2:1和1:1,40℃下反应60 min得淀粉凝胶,再添加2%硼砂得到双交联淀粉凝胶。凝胶的吸水率最高可达330.2%;当CV初始浓度在10~100 mg/L时,凝胶对CV吸附率先增大后减小,50 mg/L时吸附率最高,为93.48%;100 mg/L时吸附量最大,为30.79 mg/g。

羧基化改性海带渣对结晶紫的吸附性能研究

采用丁二酸酐(SA)对海带渣(LJR)进行羧基化修饰。利用红外光谱、扫描电镜、能量色散光谱对LJR和改性海带渣(CLJR)进行表征,对比改性前后LJR对结晶紫(CV)的吸附性能,并确定CLJR的最优吸附条件。结果发现:CLJR在1728 cm^(-1)处出现羧基的特征峰,孔隙结构明显增多,羧基化改性增强了LJR对CV的吸附性能。CLJR的最优吸附条件为初始质量浓度100 mg/L、吸附剂投加量0.8 g/L、初始pH 5~11;升高温度对LJR和CLJR的吸附过程有利。

钴锌铁氧体改性生物炭对水中结晶紫的吸附性能研究

染料在生产和生活中广泛使用,导致环境中染料污染问题频发,尤其是水体,对生态系统和人体健康带来潜在危害。生物炭具有来源广泛且符合“双碳”的要求,被广泛用于环境污染治理。但由于原始生物炭的吸附能力差,且缺乏选择性。因此,对生物炭改性是最常用的方法。为了提高生物炭对染料结晶紫(CV)的吸附效果,研究以橙子皮为原料,通过共沉淀-热解法制备钴锌铁氧体改性的磁性生物炭(Co_(0.5)Zn_(0.5)Fe_(2)O_(4)@BC)。采用X射线衍射(XRD)、电子扫描显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、比表面积及孔径分析仪(BET)、Zeta电位仪对改性前后的生物炭进行详细表征。实验结果表明,改性后产生介孔结构,显著增加了材料的比表面积,而且增加了材料的表面正电荷,提高材料的pH适应性,从而促进生物炭对CV的吸附效果。通过批处理实验考察不同实验条件对Co_(0.5)Zn_(0.5)Fe_(2)O_(4)@BC吸附CV的影响,并对吸附动力学和吸附等温线进行拟合,发现Co_(0.5)Zn_(0.5)Fe_(2)O_(4)@BC对CV的吸附性能显著提高,去除率可达到99.64%,相较于单独的BC(41.94%)和Co0.5Zn0.5Fe2O4(26.78%)吸附能力显著增强。一级动力学和Langmuir模型更好地拟合吸附过程和吸附等温线。吸附过程是单层吸附,以物理吸附为主,最大吸附量为227.59 mg/g。Co_(0.5)Zn_(0.5)Fe_(2)O_(4)@BC在pH 5~11都能有效地吸附CV。常见的共存阴阳离子稍微促进Co_(0.5)Zn_(0.5)Fe_(2)O_(4)@BC对CV的吸附。在自来水和长江水中,吸附效果比纯水中好。这说明该材料具有很好的抗干扰能力。经过5次循环后对CV的去除率仍能达到69.75%。研究为CV污染水体的处理提供一种潜在材料,也为生物炭改性对染料废水的吸附提供一种新思路。

Ag/Zn改性桑叶生物质碳及其光催化降解染料性能

通过在桑叶表面原位生长Zn基有机金属框架材料ZIF-8,再通过Ag改性、热解,制得一种新型的双金属Ag/Zn改性桑叶生物质碳材料(Ag/Zn@CL)。采用扫描电镜、X射线衍射、X射线光电子能谱、N_(2)吸附-脱附、紫外可见漫反射等手段对Ag/Zn@CL的组成与形貌结构进行了分析表征,并在可见光照射下研究了该材料对于有机染料结晶紫(CV)的光催化降解性能,分析了光催化脱色机理。实验结果表明,金属Ag成功负载在了ZIF-8复合桑叶的表面,制得的Ag/Zn@CL具有较窄的带隙能(2.71 eV),在可见光照射下可以产生大量e^(-)并进行后续的自由基反应,表现出优异的光催化降解活性。通过对桑叶与ZIF-8质量比、Ag的添加量、焙烧温度、焙烧时间等条件优化后,当CV初始质量浓度为300 mg/L,添加20 mg AgNO_(3),桑叶与硝酸锌质量比为1∶2,600℃下碳化3 h,暗反应30 min,光反应1 h后,CV的脱除率可达到97%。经过5次吸附-光催化循环测试,该材料对CV的降解率能保持在80%左右。利用废弃桑叶制得的Ag/Zn@CL能够快速、高效降解水体中的有机染料,同时具有较好的循环稳定性,在有机废水处理领域具有广泛的应用前景。

碱改性餐厨垃圾生物炭的制备及其对结晶紫染料废水的处理研究

以餐厨垃圾作为原始生物质材料,采用一步热解法和KOH共热解法分别制备了餐厨垃圾生物炭NKB和KOH活化改性餐厨垃圾生物炭MKB,并对比研究了两种材料对结晶紫染料的吸附性能。结果表明,对初始质量浓度为50 mg/L的结晶紫溶液,生物炭投加量为1 g/L、pH为9.0的条件下吸附平衡后,NKB吸附率可达64.22%,MKB吸附率可达95.06%;两种生物炭的吸附过程均符合伪二级动力学模型和Freundlich模型,活化后餐厨生物炭的最大吸附容量为196.08 mg/g,相较于原始生物碳材料吸附容量有显著提升。

污水中十二烷基磺酸钠快速检测试纸的研制

基于结晶紫与十二烷基磺酸钠在pH为7.00的缓冲溶液下发生反应,建立了一种十二烷基磺酸钠的快速检测试纸来判断污水中是否含有阴离子表面活性剂。结果发现,当浸渍1 mg/L结晶紫溶液的试纸和pH为7.00的缓冲溶液混合时(结晶紫溶液与缓冲溶体积比是3∶1)显色更明显;十二烷基磺酸钠浓度与显色深浅呈正比。该十二烷基磺酸钠检测试纸的检测最低值为0.05 mg/L,最高值为2 mg/L。配制样品测定结果的相对误差范围为1.167%~4.233%,表明该方法具有良好的准确性。

高比表面多孔碳酸钙用于高效吸附结晶紫研究

以石灰石为原料,采用碳化法+模板法制备石灰石基多孔碳酸钙,所得碳酸钙颗粒表面粗糙,呈孔状结构,比表面积高达60.17m^(2)·g^(-1)。该多孔碳酸钙对结晶紫的吸附实验结果显示,多孔碳酸钙对结晶紫的吸附去除率达到93.36%、吸附量816.89mg·g^(-1)。多孔碳酸钙吸附结晶紫前后的红外光谱图表明结晶紫成功被吸附在多孔碳酸钙上。采用等温吸附模型拟合发现,多孔碳酸钙吸附结晶紫过程遵循Langmuir模型,属于非均匀的单分子层吸附。同时,动力学拟合与准二级吸附模型吻合,表明吸附过程以化学吸附为主。