Mg掺杂TiO_2光催化降解孔雀绿染料的研究

采用溶胶-凝胶法制备的Mg掺杂TiO2光催化剂降解孔雀石绿(MG)染料废水,考察了MG初始浓度、催化剂加入量等因素对其降解的影响。结果表明,Mg的掺杂显著提高了TiO2光催化降解孔雀石绿的活性,当催化剂用量为1.0 g/L,经120 min紫外光照射后,可使30 mg/L孔雀石绿溶液降解率达到84%,同时讨论了光催化机制。     

水溶液中孔雀石绿与SDS的缔合相互作用的研究

通过测量孔雀石绿在十二烷基硫酸钠水溶液紫外吸收光谱,我们发现在孔雀石绿与SDS之间存在着一种相互缔合的作用。通过建立适当热力学模型,测量孔雀石绿在一系列SDS水溶液中的吸光度,得到了孔雀石绿与SDS在水溶液缔合平衡常数K和热力学参数ΔrGm。     

α-SiW_（11）Ti/聚苯胺/TiO_2复合材料的光催化性能

以α-SiW11Ti/PANI/TiO2为光催化剂。在紫外灯辐射下,研究了模拟染料废水孔雀石绿溶液的光催化降解的反应,考察了催化剂投加量、底物浓度、pH值对孔雀石绿降解率的影响。结果表明,孔雀石绿溶液光催化降解的最佳条件为：pH=11,α-SiW11Ti/PANI/TiO2催化剂投加量为0.125 g.L-1,浓度为10 mg.L-1,经30 W紫外灯照射90 min后,其降解率为97.53%。     

Adsorption Studies of Methylene Blue and Malachite Green From Aqueous Solutions by Pretreated Lignocellulosic Materials

Lignocellullosic materials have been used as low-cost adsorbents for the removal of methylene blue (MB) and malachite green (MG) dyes from aqueous solutions. The organic compounds in the adsorbents that contribute to chemical oxygen demand (COD) have been removed through pretreatment of the adsorbents. The percentage of color removal and COD reduction of both MB and MG dyes were found relatively close in values. The adsorption process followed the Langmuir isotherm as well as the Freundlich isotherm and pseudo-second order kinetic model. The process was found to be endothermic in nature.     

微波增强TiO2光催化降解染料和水杨酸

引言 作为一种先进的氧化技术,多相光催化在有机污染物的降解中发挥着重要的作用,已成为环境科学领域最为活跃的研究方向之一.利用多相光催化氧化反应可以消除和降解水中多种有机污染物,如染料、杀虫剂、表面活性剂等[1-3].然而,在光催化反应中,大部分光生空穴和电子在被OH·或O2捕获之前已经重组,这样导致量子效率较低(小于5%),而低量子效率导致了光催化降解率较低,以致应用光催化时需要大的反应器和较长的反应时间.     

Imidazole modified acrylate-containing photocured hydrogels for the efficient removal of malachite green dye from aqueous solutions

In this work, we aimed to prepare a simple and an efficient adsorbent for the removal of toxic, cationic dye; malachite green (MG). We reviewed many previous studies and designed our adsorbent based on the rationale that (1) acidic groups containing monomers which are capable of making hydrogen bonds (or electrostatic interactions) with MG are very effective in adsorption and (2) π-π stacking enhances the adsorption capacity. We first synthesized an imidazole-acrylate adduct and used it for the preparation of photocured hydrogels. The imidazole-acrylate adduct was characterized by H NMR and FTIR spectroscopy. The effect of experimental conditions on the MG adsorption properties of the hydrogels such as the effect of pH, time and MG concentration were also investigated. Under the optimum conditions (pH = 6 and 220 min contact time) at room temperature, the maximum adsorption capacity was found as high as 714.28 mg/g. The results showed that the adsorption process of the optimum hydrogel, which can be used 4 times without a significant loss in its adsorption capacity, fits the Langmuir isotherm model. The hydrogel adsorbent displayed good selectivity and reusability.     

Evaluation of Adsorption Characteristics of Malachite Green onto Almond Shell (Prunus dulcis)

The potential usage of almond shell (P. dulcis), which is an agricultural waste product, in the removal of malachite green from aqueous solutions was evaluated with respect to various experimental parameters including contact time, initial malachite green concentration, temperature, adsorbent concentration, etc. The adsorption kinetics of malachite green fitted well the pseudo-second-order kinetic model. The monolayer adsorption capacity of almond shell was found to be 29.0 mg g^?1. The adsorption of malachite green onto almond shell increased with raising the temperature. From the experimental results, almond shell could be employed as a low cost and easily available adsorbent for removal of malachite green in wastewater treatment process.     

Active Carbon from Microwave Date Stones for Toxic Dye Removal: Setting the Design Capacity

The widely used toxic dye malachite green (MG) poses a significant risk to human health, having a mutagenic effect. Waste date stones were used to produce microwave-activated carbons and were applied to adsorb the highly toxic dye. The critically important task of selecting the correct design adsorption capacity for different effluent pollutant concentrations to meet effluent discharge limit standards is described and a novel design selection criteria approach is presented.     

Extraction and determination of malachite green from aquatic products based on molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) were synthesized using malachite green (MG) as template, and methacrylic acid/sodium methacrylate as composite monomers. The equilibrium dissociation constant and apparent maximum adsorption capacity of the MIPs reach 12.2 mg·L^?1 and 3.2 mg·g^?1, respectively. The MIPs demonstrate excellent recognition ability due to high-affinity sites constructed by the electrostatic interaction and hydrogen bonds between template and composite monomers. The MIPs were successfully employed for the detection of MG residue in aquatic products coupled with high-performance liquid chromatography (HPLC) with a detection limit of 0.57 μg·kg^?1.     

Enhanced Adsorption of Malachite Green by EDTAD-modified Sugarcane Bagasse

Abstract

Ethylenediaminetetraacetic dianhydride (EDTAD) modified sugarcane bagasse (SB) was prepared and characterized by Fourier transform infrared spectroscopy (FTIR). Due to the presence of a large number of carboxyl groups, the adsorption capacity of the EDTAD modified SB (EDTAD-SB) for malachite green (MG) showed a significant increase compared with SB. Increase in ion strength of solution-induced decline of MG sorption. The maximum adsorption capacities were 157.2 mg g^?1 for MG, according to the Langmuir equation. Kinetic studies showed better correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by a chemisorption process.     

Removal of Selected Basic Dyes using Activated Carbon from Tannery Wastes

Activated carbon prepared from tannery leather waste (TLW-AC) has been studied for its efficiency of removal of basic dyes, namely rhodamine B (RB), methylene blue (MB), and malachite green (MG) from aqueous solutions. Factors influencing dye adsorption such as the concentration of dye, pH, contact time, and temperature were investigated. The adsorption was found to be strongly dependent on the pH and temperature. The maximum sorption capacity of RB was obtained at pH 3 and for MB and MG was obtained at pH 11. Various thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated. The kinetic studies reveal that the adsorption process follows the pseudo second-order kinetic model. The equilibrium data have been well-described by the Langmuir and Freundlich models, and the data fitted well in both model equations. The study revealed that wastes from leather industry is an economically viable option for dye removal.     

In-situ synthesis of 3D CdMoO4@CdS core-shell structure for efficient photocatalytic degradation

3D CdMoO₄@CdS core-shell visible-light-driven photocatalyst was successfully synthesized by in-situ method. Various analytical techniques show that CdS dots are uniformly loaded on the surface of CdMoO₄ hollow microspheres constructing a 3D core-shell CdMoO4@CdS heterojunction. The photocatalytic activity of nanocomposites was studied by degrading malachite green (MG) under visible light irradiation. It was found that the composite material can effectively degrade MG under visible light irradiation. Furthermore, the enhanced photocatalytic efficiency for the composite material is due to the effective diffusion and separation of photogenerated carriers.     

Poly(malachite green) film: Electrosynthesis, characterization, and sensor application

Poly(malachite green) films were synthesized electrochemically on the glassy carbon electrode in the potentiodynamic mode. The characterization and growth mechanism of as-prepared films were studied with FT-IR spectroscopy, UV-vis spectroscopy, cyclic voltammetry, chronocoulometry, and electrochemical impedance spectroscopy. Charge transfer and ion transport of poly(malachite green) films were investigated in the aqueous solutions with different types of supporting electrolytes. The poly(malachite green) film coated glassy carbon electrode showed catalytic ability towards ascorbic acid and dopamine. The difference of the anodic peak potential of ascorbic acid on the poly(malachite green) film modified electrode from that of dopamine was 180 mV. Based on their voltammetric responses, the poly(malachite green) film coated glassy carbon electrode was utilized as an electrochemical sensor for the content determination of ascorbic acid and dopamine simultaneously and separately in pharmaceutical and injections.     

The use of nutshell firstly as a natural dye for cotton and wool and then as a natural adsorbent for colour removal of basic dye effluent

The aim of this study is to utilise nutshell, which is normally a waste. To this end, in the first part of our study we investigated the usability of nutshell extract solution as a natural dye for the coloration of cotton and wool fabrics. In order to optimise the fastness properties of dyed samples, mordant type was chosen as a variable in experiments and dyeings were carried out at 100 g l⁻¹ extract concentration. After extracting its dye, nutshell was used as adsorbent for colour removal of basic dye effluent. The effect of adsorbent dose, initial dye concentration, and contact time on the adsorption of malachite green (MG) onto nutshell was investigated. Adsorption isotherms and kinetics of MG adsorption onto nutshell were also studied.     

表面增强拉曼光谱法快速检测水产品中的孔雀石绿

基于表面增强拉曼光谱技术的便携式拉曼光谱仪运用于水产品养殖、运输过程水样中孔雀石绿的快速测定进行了研究.利用孔雀石绿位于432-437 cm-1,1166-1170 cm-1,1613-1617cm-1的拉曼光谱特征峰及其强度,对孔雀石绿进行定性及半定量的快速测定.检测限为5.0μg/L,常见含氮化合物尿素、亚硝酸钠以...     

Adsorption Performances of Cationic Dyes from Aqueous Solution on Pyromellitic Dianhydride Modified Sugarcane Bagasse

In this study, pyromellitic dianhydride (PMDA) modified waste sugarcane bagasse (SCB) was prepared through a simple method to remove two cationic dyes: methylene blue (MB) and malachite green (MG) from aqueous solution. Adsorption performances of MB and MG on the modified sorbent were investigated in details. The adsorption capacities of the modified SCB for MB and MG were 571.4 and 377.4 mg g^?1, respectively, which were 10 and 12 times than that obtained on the unmodified SCB. Adsorption kinetics study showed equilibriums were obtained after adsorption for 13 hours for both dyes. The modified SCB could be used repeatedly after regeneration. FTIR results showed that carboxyl and hydroxyl groups on the modified SCB involved in adsorption process.     

Ca2+/H2O2降解水中孔雀石绿

在中性条件下,研究了Ca2++H2O2降解水中孔雀石绿(MG)过程. 结果表明,加入Ca2+明显促进了MG降解,可使其脱色率由20%升至98%. 随着H2O2加入量的增加,MG的脱色率在最初的10 min内显著上升,当H2O2/Ca2+(摩尔比)>5时,2 h后Ca2++H2O2降解MG脱色率均能达到98%. 随着温度的升高,MG的脱色率显著上升. 抗氧化剂(抗坏血酸)的加入抑制了Ca2++H2O2降解MG,当抗坏血酸浓度达到1 mg/L时,降解率为0,说明在Ca2++H2O2降解MG体系中存在着氧化作用. 在避光和光助条件下,加入Ca2+均能明显缩短MG的降解时间,说明Ca2+对其降解有催化作用.     

Enhanced adsorption of malachite green onto carbon nanotube/polyaniline composites

To enhance adsorption of organic dyes like malachite green (MG) onto polymeric absorbents, we prepared carbon nanotube (CNT) filled polyaniline (PANI) composites with large surface areas by simply using entangled CNTs as porous frameworks during PANI polymerization. Adsorption behavior of the CNT/PANI composites in MG solutions was experimentally investigated and theoretically analyzed. The CNT/PANI composites exhibit much higher equilibrium adsorption capacity of 13.95 mg g^?1 at an initial MG concentration of 16 mg L^?1, increasing by 15% than the neat PANI, which is mainly attributed to large surface areas and strong CNT‐PANI interactions of the composites. In addition, theoretical analyses indicate that the adsorption kinetics and the isothermal process of the composites can be well explained by using the Ho pseudosecond‐order model and the Langmuir model, respectively. In light of their high MG adsorption and easy operation, the CNT/PANI composites have great potential as high‐efficiency adsorbents for removal of dyes from wastewater. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

钢渣/焦炭吸附-微波降解法处理孔雀石绿染料废水的研究

利用钢渣和焦炭对孔雀石绿的吸附特性以及焦炭吸收微波产生高温的性能,提出了一种吸附-微波辐照降解处理孔雀石绿染料废水的新方法.考察了钢渣颗粒度大小、溶液pH值、固液比等因素对吸附的影响以及吸附剂的再生效果.结果表明:钢渣对孔雀石绿有很强的吸附能力,吸附量可高达1.28 g/g.染料的微波降解快速,吸附剂的再生效率高.该方法简单有效,成本低廉,具有良好的应用前景.     

海泡石负载Bi_2O_3对孔雀石绿光催化降解性能研究

以海泡石为载体,采用化学沉淀法制备了负载型Bi_2O_3光催化剂。通过XRD、SEM、TEM、UV-vis对光催化剂进行了表征。以孔雀石绿为模型降解物考察了光催化剂的光催化活性,重点研究了光催化剂投加量、孔雀石绿溶液初始pH及溶液初始浓度对降解效果的影响。结果表明:当光催化剂投加量为1.0 g/L,孔雀石绿溶液初始pH为7,溶液初始质量浓度为50 mg/L,光照30 min,孔雀石绿的降解率达到95.7%,孔雀石绿溶液初始浓度越高,越不容易被降解,但光照60 min,所有浓度的孔雀石绿基本降解完毕,通过重复实验发现,该负载型Bi2O3的稳定性较高。