NaOH改性花生壳对亚甲基蓝染料吸附性能的研究

花生壳用5%的NaOH溶液改性作吸附剂处理亚甲基蓝染料废水,考察pH值、吸附剂投加量、染料浓度和温度及吸附时间对染料吸附性能的影响。结果表明,吸附最佳的工艺条件为:温度25℃,吸附剂投加量0.3 g,亚甲基蓝的初始浓度3.5 g/mL,反应时间135 min,pH值7。此时改性花生壳对亚甲基蓝的吸附率达99.57%。     

Removal of methylene blue from aqueous solution by adsorption onto zeolite synthesized from coal fly ash and its thermal regeneration

BACKGROUND: The removal of cationic dyes from wastewater is of great importance. Three zeolites synthesized from coal fly ashes (ZFAs) were investigated as adsorbents to remove methylene blue (MB), a cationic dye, from aqueous solutions. Experiments were conducted using the batch adsorption technique under different conditions of initial dye concentration, adsorbent dose, solution pH, and salt concentration. RESULTS: The adsorption isotherm data of MB on ZFAs were fitted well to the Langmuir model. The maximum adsorption capacities of MB by the three ZFAs, calculated using the Langmuir equation, ranged from 23.70 to 50.51 mg g^?1. The adsorption of MB by ZFA was essentially due to electrostatic forces. The measurement of zeta potential indicated that ZFA had a lower surface charge at alkaline pH, resulting in enhanced removal of MB with increasing pH. MB was highly competitive compared with Na⁺, leading to only a < 6% reduction in adsorption in the presence of NaCl up to 1.0 mol L^?1. Regeneration of used ZFA was achieved by thermal treatment. In this study, 90–105% adsorption capacity of fresh ZFA was recovered by heating at 450 °C for 2 h. CONCLUSION: The experimental results suggest that ZFA could be employed as an adsorbent in the removal of cationic dyes from wastewater, and the adsorptive ability of used ZFA can be recovered by thermal treatment. Copyright © 2010 Society of Chemical Industry     

Removal Of methylene blue dye from simulated wastewater by alginic acid fiber as adsorbent: Equilibrium,kinetic, and thermodynamic studies

Alginic acid fiber was used as a novel adsorbent to remove methylene blue from aqueous solution, and adsorption mechanisms were investigated. System variables, including contact time, pH, temperature, and initial concentration were examined to investigate the effect on adsorption in batch experiments. The results showed that equilibrium reached in less than 20 min and pH significantly influenced the equilibrium value. Langmuir, Freundlich, and Temkin isotherm models were employed to analyse the isotherm behaviours. It was found the isotherm behaviours conform to Freundlich and Temkin models well, indicating a chemisorption process. Pseudo‐first‐order, pseudo‐second‐order, and intraparticle diffusion models were employed to investigate kinetic behaviours. The kinetic behaviour is best described by pseudo‐second‐order model. Thermodynamic parameters indicate that the process is spontaneous and exothermic.     

Adsorption of heavy metals and methylene blue from aqueous solution with citric acid modified peach stone

Peach stones (PS) modified by citric acid (MPS) were used to remove heavy metals and methylene blue (MB) from wastewater. The effects of experimental factors such as pH, adsorbent dosage and contact time, etc. were conducted. Moreover, the adsorption kinetics and isotherm studies also were investigated. According to the Langmuir isotherm model, the maximum adsorption capacities of Pb²⁺, Cd²⁺, Cu²⁺ and MB were 118.76, 37.48, 32.22 and 178.25 mg/g, respectively. Finally, column experiments were also carried out to investigate the adsorption of Pb²⁺ and MB. All results indicated that PS has a good potential for the treatment of wastewater.     

芝麻叶对亚甲基蓝吸附的动力学与热力学研究

以天然芝麻叶为吸附剂,亚甲基蓝(MB)为吸附质,考察芝麻叶吸附亚甲基蓝的动力学、热力学以及溶液pH值、吸附剂投入量、温度等对吸附的影响.采用准一级、准二级、颗粒内扩散吸附动力模型及Langmuir,Freundlich及Dubinin-Radushkevich(D-R)等温模型分别对吸附动力学和吸附等温线进行分析.结果...     

Removal of reactive blue 19 and reactive blue 49 textile dyes by citrus waste biomass from aqueous solution: Equilibrium and kinetic study

The purpose of this study was to establish the potential of inexpensive and locally available biomaterial, that is, lignocellulosic waste of Citrus sinensis as biosorbent to remove reactive anthraquinone dyes from aqueous solution. The effects of immobilisation and chemical treatment of biosorbent were also explored for the enhanced sorption of dyes. Biosorbent was chemically treated with organic and inorganic reagents of which acetic acid augmented the sorption capacities for Reactive blue 19 and Reactive blue 49 attaining equilibrium in 60 min. While immobilisation of biosorbent into calcium alginate beads reduced the sorption capacity and the time to achieve equilibrium was prolonged up to 120 min. Sorption of both reactive dyes was found to be dependent on pH of media and maximum removal was observed at pH 2. The sorption process was fast and the data followed pseudo‐second‐order kinetic rate equation (R² = 0.99). The equilibrium data were also fitted to Freundlich, Langmuir and Temkin isotherms. The mechanism of sorption was found to be physiosorption. FTIR analysis and SEM imaging of biosorbent were also carried out to study functional groups involved and morphological changes at the surface of biomass. © 2011 Canadian Society for Chemical Engineering     

亚甲基蓝溶液的光催化降解

采用三种不同方法对TiO2粉末进行改性,制得蒙脱土/TiO2、Ag/TiO2和SO42-/TiO2催化剂。以亚甲基水蓝溶液的脱色率为指标,采用XRD、SEM和XPS等手段分析考察了3种改性催化剂的活性及抗无机离子的干扰能力。结果显示,三种改性光催化剂在溶液中的活性顺序为：蒙脱土/TiO₂>SO₄^2-/TiO₂>Ag/TiO₂>TiO₂。其中,蒙脱土/TiO2活性提高最大,在温度30 ℃和催化剂用量1.0 g·L^-1条件下,1 h内使 5.0 mg·L^-1的亚甲基蓝溶液的脱色率达90%以上,Ag/TiO₂的抗无机离子干扰能力最强。     

石英砂负载氧化铁吸附去除溶液中亚甲蓝的研究

以石英砂为原料制得石英砂负载氧化铁(IOCS),考察了IOCS的性能、吸附条件对IOCS吸附亚甲蓝效果的影响及吸附柱的再生,并对吸附过程进行了动力学研究。结果表明,采用高温烧结法制备的IOCS吸附亚甲蓝效果较好;IOCS对溶液中亚甲蓝吸附的适宜条件:pH为13.5,亚甲蓝质量浓度约为6 mg/L,温度为293 K,上样液吸附流速为4 BV/h;IOCS对溶液中亚甲蓝的吸附动力学曲线可以用Weber-Morris曲线来拟合;Langmuir吸附等温方程和Freundlich方程都能较好地描述IOCS对溶液中亚甲蓝的吸附过程;0.01 mol/L的HCl对IOCS吸附柱的再生效果较好。     

Biosorption from aqueous solutions by eggshell membranes and Rhizopus oryzae: equilibrium and kinetic studies

This study assesses the use of eggshell membranes and Rhizopus oryzae as media for the biosorption of p‐chlorophenol (p‐CP), 2,4‐dichlorophenol (2,4‐DCP), 3,5‐dichlorophenol (3,5‐DCP), reactive dye and cadmium from aqueous solutions. The performance of the adsorbents was quantified by measuring the equilibrium uptake and the batch rate kinetics from solutions. The constants in the Freundlich, Langmuir and Redlich–Peterson isotherm models were calculated through the linearization of the equations and linear regression. The kinetics of the adsorption systems for cadmium and a reactive dye have been assessed in a batch stirred adsorber. The effect of the process parameters such as pH, adsorbate concentration, adsorbent dosage, adsorbent particle size, temperature and agitation speed are reported. The external mass transfer coefficients are reported for some different system conditions. Both materials are determined to be effective adsorbents and could find application in the treatment of contaminated wastestreams. © 2002 Society of Chemical Industry     

分子印迹聚合物微球对亚甲基蓝的去除特性研究

以亚甲基蓝为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯（EGDMA）为交联剂,偶氮二异丁腈（AIBN）为引发剂．采用沉淀聚合法制备了亚甲基蓝分子印迹聚合物微球（MIP）。用扫描电镜表征了MIP的形貌,结果显示制备的MIP的粒径为1～3μm,粒径较为均匀。考察了MIP对亚甲基蓝的吸附性能,结果表明其吸附动力学过程可以用假二级吸附速率方程来描述,MIP对亚甲基蓝的最大吸附量为27．1mg／g,吸附效果较好,可以用于染料废水中亚甲基蓝的分离富集。     

A combined effect of adsorption and reduction potential of biochar derived from Mentha plant waste on removal of methylene blue dye from aqueous solution

ABSTRACT

Plant biochars were prepared by slow pyrolysis of Mentha plant waste to remove cationic dye methylene blue (MB) from aqueous solution. The biochars were characterized by X-Ray diffraction, IR-spectroscopy, thermogravimetric analysis, scanning electron microscope, cyclic voltammetry (CV), Brunauer-Emmett-Teller analysis, and zeta potential analyzer. Adsorption isotherms and kinetics applied on the MB dye removal by biochars showed monolayer chemisorption of MB dye. Present investigation revealed that removal of MB dye was due to synergistic action of chemisorption coupled with reductive electron transfer mechanisms. CV test showed a reversible, coupled redox reaction at interface of MB dye and biochar particles.     

四（对-磺酸基苯基）卟啉催化降解亚甲基蓝染料废水

详细介绍了利用四（对-磺酸基苯基）水溶性锰卟啉（Mn-TPPS4）作为催化剂氧化降解亚甲基蓝染料废水的研究结果。结果表明：Mn-TPPS4/H2O2体系有很好的氧化性且效率高,亚甲基蓝的初始浓度为4mg/L时,反应4h降解率可达97%。反应溶液酸性越强或碱性越强对反应越有利。     

p-Sulphonatocalix[8]arene functionalized silica resin for the enhanced removal of methylene blue from wastewater: equilibrium and kinetic study

ABSTRACT

The present investigation represents the synthesis of new p-sulphonatocalix[8]arene-based silica resin, p-SC8SR (5) and its application for the enhanced removal of methylene blue (MB) dye from contaminated water. The new p-SC8SR (5) resin was characterized by FT-IR, SEM, and EDX spectroscopy. The adsorption of MB on p-SC8SR (5) was investigated systematically by evaluating the effects of adsorbent dosage, initial pH, contact time, dye concentration, and ionic strength. Excellent adsorption (94%) of MB on p-SC8SR (5) was achieved at pH 9.5, contact time 10 min by using 0.2 mol L^?1 ionic strength and 2 × 10^?5 M initial MB dye concentration. Kinetic behavior of MB dye adsorption process on the newly synthesized p-SC8SR (5) adsorbent follows the pseudo-second-order rate model (R² = 0.998 and 0.999 for 2 × 10^?5 M and 1 × 10^?4 M, respectively). Adsorption isotherms were fitted well by the Freundlich model with excellent value of coefficient of determination (R²) = 0.995 which demonstrated that the adsorption of MB follows multilayer mechanism. Wastewater samples contaminated with MB were used to assess efficiency of the p-SC8SR (5) adsorbent. Results indicated that newly synthesized p-SC8SR (5) was found to be efficient adsorbent. During the removal process, the role of different functional groups’ cyclic structure was scrutinized and found that the ionic property as well as π–π interaction of host molecules played imperative role in the extent of adsorption.     

Biosorption of chromium (VI) from aqueous solution by seed powder of prickly pear (Opuntia ficus indica L.) fruits

ABSTRACT

The solid residue of the cold press oil extraction from prickly pear (Opuntia ficus indica L.) fruit seeds was evaluated as a low-cost biosorbent for biosorption of Cr(VI) from aqueous solutions. Batch experiments were conducted as a function of initial pH, contact time, biosorbent dose, initial Cr(VI) concentration, and temperature. Biosorption was highly pH-dependent and found to be maximum at pH 1.0. Langmuir and Freundlich equations fitted very well with experimental data. The maximum monolayer adsorption capacity was 19.61 mg/g at 298 K and pH 1.0. Biosorption kinetics was controlled by the pseudo-second-order model. Thermodynamic parameters indicated that biosorption of Cr(VI) was a spontaneous, favorable and endothermic process. The activation energy was found to be 40.68 kJ.mol^?1.     

亚甲基蓝分光光度法测定水中硫化物影响因素的探讨

本文对亚甲基蓝分光光度法测定硫化物过程中容易忽视的环节,如测定用水和试剂、样品采集和保存、样品测试等能对测定产生影响的因素进行了探讨,规范了测试中的操作技术,提高了测试的准确度和精密度。     

掺锌纳米TiO_2光催化降解亚甲基蓝研究

选用掺杂锌的纳米TiO2作为光催化剂对亚甲基蓝进行降解研究。制备工艺参数对样品光催化降解亚甲基蓝的活性具有很大影响,焙烧温度为500℃,Zn2+掺入量为0.5%,催化剂的加入量为1 g/L时光催化剂对亚甲基蓝的降解效果最好;亚甲基蓝的初始浓度为5 mg/L降解速率较快。     

固定式填充复合床光催化反应器降解亚甲基蓝的研究

设计了一种固定式填充复合床光催化反应器,以普通玻璃片和玻璃螺旋圈为载体,用溶胶-凝胶法制备了负载型TiO2薄膜光催化剂。利用紫外光为光源,采用难降解物质亚甲基蓝在不同初始浓度、pH值和光强等因素下的光催化降解脱色反应速率考察了该反应器的工艺特性,试验结果表明:该种反应器的最佳操作条件为反应器中同时放置普通玻璃片TiO2薄膜光催化剂和玻璃螺旋圈TiO2薄膜光催化剂,溶液pH值为7.5,光源光强为650W,光照时间为180min。当进水亚甲基蓝的质量浓度为8.0mg/L时,在此条件下的降解脱色效率为93.83%,且其设计易于实现产业化。     

微波法制多孔石墨烯及对亚甲基蓝的吸附性能

以改进的Hummers法合成的氧化石墨烯为自组装原料,通过微波加热的方式制备三维多孔石墨烯材料.并采用场发射扫描电子显微镜、傅立叶红外光谱仪、X射线衍射仪对石墨、氧化石墨烯、三维多孔石墨的微观形貌和内部结构进行表征分析.以亚甲基蓝为吸附质、三维多孔石墨烯为吸附剂,研究其吸附性能.结果表明,三维多孔石墨烯材料的最大吸附量...     

Removal of methylene blue from coloured effluents by adsorption onto SBA‐15

Adsorption has been proven to be the most efficient method for quickly lowering the concentration of dissolved dyes in an effluent. In this regard, activated carbon is the most widely used adsorbent for removal of dyes from aqueous solution. However, the high cost of production and regeneration make it uneconomical. Therefore, inorganic adsorbents (e.g. zeolites) with high surface areas have been used as alternatives to carbon adsorbents. Microporous zeolites ZSM‐5, NH₄‐Beta, MCM‐22 and mesoporous materials MCM‐41 have been investigated for the removal of dyes from aqueous solutions and they show effective adsorption performance. SBA‐15 possesses a larger pore size and pore wall thickness than MCM‐41. As a result, SBA‐15 has greater potential for the adsorption of methylene blue with larger molecule size and higher hydrothermal stability than the M41S family. SBA‐15 is an excellent adsorbent for methylene blue (MB), exhibiting 280 mg g^?1 adsorption capacity and about 100% fading rate for MB. The adsorptive process is so fast that adsorption equilibrium is achieved in 5 min. In addition, SBA‐15 can be effectively recovered by calcination and reused 10 times without significant loss in removal of MB from aqueous solution. The efficient adsorption of MB molecules onto SBA‐15 was ascribed to MB adsorbed into the pore channels of SBA‐15, which was confirmed by nitrogen physisorption analysis of the adsorbent before and after adsorption. The long reuse life of the adsorbent suggests a high potential for application in industry. Copyright © 2010 Society of Chemical Industry