H6P2W18O62/MIL-101(Fe)材料的制备及其吸附性能

采用溶剂热合成法在制备MIL-101(Fe)的过程中引入杂多酸H_6P_2W_(18)O_(62),制备出吸附剂H_6P_2W_(18)O_(62)/MIL-101(Fe),并测试了其对亚甲基蓝(MB)的吸附性能。考察了H_6P_2W_(18)O_(62)的负载量、MB质量浓度、溶液pH、温度等对材料的吸附性能。通过XRD、SEM、FTIR、N2吸附-脱附等手段对材料进行表征。结果表明:吸附平衡前,吸附量随MB质量浓度的增加而增加,在溶液pH=4、H_6P_2W_(18)O_(62)负载量相对于复合物质量分数为35%的条件下,吸附剂H_6P_2W_(18)O_(62)/MIL-101(Fe)对亚甲基蓝溶液吸附效果最佳,在303K下H_6P_2W_(18)O_(62)/MIL-101(Fe)对MB的最大吸附量可达148.1 mg/g。通过动力学和热力学分析,该吸附过程符合拟二级动力学与Langmuir等温吸附模型,同时是一个吸热、自发的过程。     

磺化聚醚醚酮纳米纤维膜的制备及其吸附性能

通过静电纺丝法制备了不同磺化度的磺化聚醚醚酮(SPEEK)纳米纤维膜,运用扫描电镜、热重分析仪分别对纤维的形貌和热性能进行了分析,并利用紫外-可见分光光度计研究了纤维膜对亚甲基蓝染料的吸附行为。结果表明:随着磺化度的增加,纺丝束流的稳定性得到改善,纤维直径减小;纤维膜对亚甲基蓝具有良好的吸附能力,在p H值=7时其对亚甲基蓝的去除率最大,平衡吸附时间约为90min;热力学分析表明,使用Freundlich模型描述SPEEK纳米纤维膜对亚甲基蓝的吸附行为更加合理;动力学分析表明,SPEEK纳米纤维膜对亚甲基蓝的吸附遵循准二级动力学模型。     

碱性钙基膨润土对亚甲基蓝和刚果红的吸附去除

该文研究了碱性钙基膨润土(ACB)对水体中的亚甲基蓝(MB)和刚果红(CR)染料的吸附性能,考察了吸附剂用量、吸附时间及温度、pH及盐等因素对吸附效果的影响,同时进行了两种染料在碱性钙基膨润土上的吸附等温模型、吸附动力学模型研究。结果表明,ACB对MB、CR的脱色率随着吸附剂用量的增加而增加,在实验条件下,50 mg/L MB和100 mg/L CR的最佳吸附剂质量浓度分别为1.0 g/L和2.0 g/L;升高温度可以加快吸附速率,但对最终的脱色率影响很小;50 mg/L MB的吸附平衡时间在60 min左右,100 mg/L CR的吸附平衡时间在120 min左右;在pH=3～12时,ACB对MB的脱色率都稳定在99%左右,而适宜ACB吸附CR的pH=3～7,对CR的脱色率保持在90%左右;NaCl的加入对MB的吸附效果影响很小,对CR的吸附则有很强的抑制作用;ACB对MB的吸附同时符合Langmuir和Freundlich模型,而ACB对CR的吸附则更符合Langmuir模型;ACB对两种染料的吸附过程均符合准二级动力学模型,颗粒内扩散模型的拟合结果说明吸附过程存在颗粒内扩散作用。     

Adsorption of cationic dye from aqueous solutions by activated carbon

Batch sorption experiments were carried out to remove a cationic dye, methylene blue (MB), from its aqueous solutions using a commercial activated carbon as an adsorbent. Operating variables studied were pH, stirring speed, initial methylene blue concentration and temperature. Adsorption process was attained to the equilibrium within 5 min. The adsorbed amount MB dye on activated carbon slightly changed with increasing pH, and temperature, indicating an endothermic process. The adsorption capacity of methylene blue did not significantly change with increasing stirring speed. The experimental data were analyzed by various isotherm models, and found that the isotherm data were reasonably well correlated by Langmuir isotherm. Adsorption measurements showed that the process was very fast and physical in nature. Thermodynamic parameters such as the adsorption entropy (ΔS^o) and adsorption enthalpy (ΔH^o) were also calculated as 0.165 kJ mol⁻¹ K⁻¹ and 49.195 kJ mol⁻¹, respectively. The ΔG^o values varied in range with the mean values showing a gradual increase from −0.256 to −0.780 to −2.764 and −7.914 kJ mol⁻¹ for 293, 313, 323 and 333 K, respectively, in accordance with the positive adsorption entropy value of the adsorption process.     

Investigation of Cationic Dye Adsorption from Water onto Acetic Acid Lignin

An adsorbent was prepared from acetic acid lignin (AAL) to investigate the adsorption mechanism of methylene blue (MB) from water. AAL was first deacetylated in NaOH aqueous solution and then fractionated by methanol to prepare adsorbents with various acidic hydroxy groups. The adsorption capacities of MB increased with the increase in initial pH and with the decrease in adsorbent dosage. The results of adsorption kinetics indicated the dye uptake process is a chemisorption. The adsorption capacity of lignin for MB adsorption increased from 18.2 to 63.3 mg g^?1 as AAL was deacetylated and fractionated.     

Removal of methylene blue from aqueous solutions by poly(2-acrylamido-2-methylpropane sulfonic acid-co-itaconic acid) hydrogels

In this study, removal of methylene blue (MB) from aqueous solution by poly(AMPS-co-IA) hydrogels was examined by batch equilibration technique. The effects of monomer ratio, concentration of initiator and crosslinker, pH, adsorption time, initial dye concentration and adsorption temperature on the removal of MB were studied. The results show that the removal of MB was highly effected by preparation conditions of hydrogel. The maximum removal was observed at 10/90 IA/AMPS monomer ratio, 1.0% KPS, and 10.0% MBAAm concentrations. Removal of MB was strongly affected by pH. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of MB on hydrogel followed pseudo-second-order kinetics. It was found that the adsorption isotherm of the MB fit Langmuir-type isotherms. From the Langmuir equation, the adsorption capacity was found as 1,000 mg/g for MB dye. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. Ten adsorption—desorption cycles demonstrated that the hydrogels were suitable for repeated use without considerable change in adsorption capacity. The results revealed that this hydrogels have potential to be used as an adsorbent for the removal of MB from aqueous solution.     

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.     

以纸巾为模板制备活性炭纤维

以纸巾为前驱体通过NaOH化学活化制备活性炭纤维,扫描电镜观测其微观结构为多孔纤维状。通过活性炭纤维对亚甲基蓝的吸附实验研究活性炭纤维吸附动力学,Pseudo-second-order方程比Pseudo-first-order方程更适于吸附数据模型,相关系数高达0.998,所制备活性炭纤维对亚甲基蓝最大平衡吸附量为200mg/g。     

聚丙烯酸/聚丙烯酰胺/凹凸棒复合材料对亚甲基蓝的吸附性能

将聚(丙烯酸-co-丙烯酰胺)/凹凸棒复合吸附剂用于亚甲蓝的吸附,研究了时间、浓度、酸度、表面活性剂和离子强度等因素对吸附性能的影响。复合吸附剂对亚甲蓝的吸附是吸热过程,60℃时吸附量达到1 273.3 mg.g-1,吸附过程符合Langmuir单分子层吸附等温模式,并计算了热力学常数ΔG、ΔH和ΔS。在实验考察范围内吸附过程均符合准二级动力学特征。该复合吸附剂具有高吸附容量和较快的吸附速率,是良好的亚甲蓝吸附剂。     

桑枝SCMP浆阴离子基团的吸附过程及吸附机理

通过研究桑枝SCMP浆中阴离子基团（AGs）对亚甲基蓝（MB）的吸附性能实验，运用Langmuir等温方程和Freundlich等温方程对桑枝SCMP浆H₂O₂漂白中AGs对亚甲基蓝（MB）的吸附结果进行拟合，表明桑枝SCMP浆对MB的吸附过程更符合Langmuir吸附模型，得出该吸附过程是单分子层吸附与非匀质吸附共存的优惠型吸附；并采用X射线光电子能谱（XPS）分析纸浆中阴离子基团和纸浆表面元素及种类的变化情况。H₂O₂漂白会形成新的SAGs，提高纸浆纤维表面的磺化程度，同时纸浆纤维中木素含量降低，纤维素和半纤维素含量增加。     

山核桃壳活性炭制备及其吸附苯胺特性

采用磷酸法制备山核桃壳活性炭,并以磷酸浓度、活化温度和活化时间为因素,亚甲基蓝脱色力、碘吸附值及得率为指标,进行正交设计优化,从热力学角度研究了山核桃壳活性炭对苯胺的吸附行为. 结果表明,磷酸法制备山核桃壳活性炭的优化工艺条件为：磷酸50%(w),活化温度300℃,活化时间45 min. 在此条件下,活性炭得率为53.21%,碘吸附值为804.36 mg/g,亚甲基蓝脱色力为102 mL/g. 在所研究的条件范围内,活性炭对苯胺的吸附能力随温度升高而增大,酸性条件有利于吸附. 吸附是自发吸热的物理吸附过程,遵循Freundlich吸附等温线.     

CuO/腐植酸复合材料的制备及其吸附性能

采用水热法合成了CuO-腐植酸（HA）纳米复合材料,研究了其对亚甲基蓝的初始吸附性能及再生吸附性能。运用扫描电镜/能谱仪（SEM/EDS）、傅里叶变换红外光谱仪（FTIR）、X射线粉末衍射仪（XRD）、激光粒度分析仪和比表面积测定仪（BET）对其结构进行了表征。研究了pH、亚甲基蓝初始浓度和反应温度等因素对CuO/HA吸附亚甲基蓝的影响,采用多种模型研究了CuO/HA复合材料对亚甲基蓝的吸附动力学和热力学行为。结果表明：合成的CuO/HA平均粒径约为135.0nm,比表面积为188.15m²/g。CuO/HA对亚甲基蓝（MB）的吸附动力学行为符合拟一级动力学模型,在60min内达到吸附平衡,较好地符合Frendlich吸附模型。在室温下pH=7时,CuO/HA复合材料初始饱和吸附量达172.01mg/g;循环使用8次,可保持初始吸附能力的89.27%,表明有较好的吸附性能,可作为一种有效除去水体中亚甲基蓝污染物的高容量吸附材料。     

Ce-MCM-48分子筛的合成与吸附动力学研究

以硅溶胶为硅源、十六烷基三甲基溴化铵( CTAB)为模板剂,采用物质的量配比为Ce2O3:SiO2:CTAB:H2O:NaOH =0.015:1:0.45:60:0.48,静态水热合成了Ce-MCM-48分子筛,采用XRD、SEM (EDS)、TEM等方法对其进行了表征,并对其进行了吸附动力学研究.结果表明,本文成功合成了Ce-MCM-48介孔分子筛,其拟一级吸附动力学方程为lg(qe-q)=-0.4365-0.01026t,R2=0.9289,拟二级吸附动力学方程为t/qt =0.4027+0.27818t,R2=0.9999,相对拟一级反应模型,这个结果相关性更好,更能真实地反映分子筛吸附亚甲蓝溶液的反应机理.     

Removal of methylene blue from aqueous solution by sorption on lignocellulose-g-poly(acrylic acid)/montmorillonite three-dimensional cross-linked polymeric network hydrogels

Batch lignocellulose-g-poly(acrylic acid)/montmorillonite (LNC-g-PAA/MMT) hydrogel nanocomposites were applied as adsorbents. The nanocomposites were characterized by FTIR, XRD, SEM, and TEM. The results showed that montmorillonite (MMT) could react with the monomers and change the structure of polymeric network of the traditional superabsorbent materials, an exfoliated structure was formed in the nanocomposites. The effect of process parameters such as MMT content (wt%), contact time (t), initial concentration of dye solution (C ₀), adsorption temperature (T), and pH value (pH) of the dye solution for the removal of methylene blue (MB) from aqueous solution were also studied. The results showed that the adsorption capacity for MB increased with increasing contact time, initial dye concentration, and pH value, but decreased with increasing MMT content and temperature. The adsorption kinetics were better described by the pseudo-second-order equation, and their adsorption isotherms were better fitted for the langmuir equation. By introducing 20 wt% MMT into LNC-g-PAA polymeric network, the obtaining hydrogel composite showed the high adsorption capacity 1994.38 mg/g and economic advantage for MB. The desorption studies revealed that the composite provided the potential for regeneration and reuse after MB dye adsorption, which implied that the composite could be regarded as a potential adsorbent for cationic dye MB removal in a wastewater treatment process.     

化学师范专业活性炭吸附亚甲基蓝综合实验

为提高化学(师范)专业学生的综合实验能力,设计了"活性炭吸附亚甲基蓝"物理化学综合实验.以活性炭为吸附剂,亚甲基蓝( MB) 为吸附质,考察了吸附剂用量、吸附时间、 温度对活性炭去除亚甲基蓝的影响.探讨了水溶液中活性炭固体颗粒吸附阳离子有机染料亚甲基蓝的吸附热力学(吸附等温线类型)、吸附动力学方程和盐酸脱附条件.结果表明,活性炭对亚甲基蓝染料的热力学吸附行为符合 Langmuir 等温吸附方程,其动力学吸附行为符合准一级动力学方程.选择1:1浓盐酸未能有效的将吸附的亚甲基蓝脱附.     

不同黏土矿物种类和含量的泥粉对亚甲蓝值的影响

研究了石粉中含不同黏土矿物种类和含量的泥粉与亚甲蓝值的相互关系,探究不同黏土矿物吸附性能对亚甲蓝(MB)值的影响。结果表明:随着纯石粉含量的增加,MB值逐渐增大,但也远小于1.00,增幅较小、变化不大。纯泥粉和混合泥粉对MB值影响较大,呈现出线性关系;蒙脱土和以蒙脱土为主的混合泥粉对MB值影响最大,分别高达8.00、4.20;高岭土、伊利土的MB值最大为1.75、1.05,而以其为主要成分的2种混合泥粉MB值最大为2.10、1.95,影响相对较小;含有不同黏土矿物成分的混合泥粉较纯泥粉,能更好的减少对MB值的影响。与纯石粉相比,亚甲蓝对黏土矿物变化较为敏感,由大到小顺序为:蒙脱土、高岭土和伊利土,即蒙脱土的吸附能力最强。     

Removal of Cr(VI) from aqueous solution using magnetite/non-oxidative graphene composites: Synergetic effect of Cr(VI) on dyes removal

Non-oxidative graphene (nOG) synthesized from natural graphite powder was modified with magnetite (Fe₃O₄) for removal of Cr(VI) and dyes in aqueous solution. The adsorption behavior of Cr(VI) on Fe₃O₄/nOG (M-nOG) was systematically investigated, and the simultaneous adsorption of Cr(VI) and dyes such as methylene blue (MB) and rhodamine B (RhB) was evaluated. Adsorption kinetic and isotherm of Cr(VI) were fitted well with pseudo-second-order model and Sips model, respectively. For the binary system, Cr(VI) removal was not affected with increasing the dye concentration, whereas the adsorption capacity of both MB and RhB was enhanced with increasing the concentrations of Cr(VI).     

EFFECT OF TEMPERATURE ON THE ADSORPTION OF METHYLENE BLUE DYE ONTO SULFURIC ACID–TREATED ORANGE PEEL

The present study explains the preparation and application of sulfuric acid–treated orange peel (STOP) as a new low-cost adsorbent in the removal of methylene blue (MB) dye from its aqueous solution. The effects of temperature on the operating parameters such as solution pH, adsorbent dose, initial MB dye concentration, and contact time were investigated for the removal of MB dye using STOP. The maximum adsorption of MB dye onto STOP took place in the following experimental conditions: pH of 8.0, adsorbent dose of 0.4 g, contact time of 45 min, and temperature of 30°C. The adsorption equilibrium data were tested by applying both the Langmuir and Freundlich isotherm models. It is observed that the Freundlich isotherm model fitted better than the Langmuir isotherm model, indicating multilayer adsorption, at all studied temperatures. The adsorption kinetic results showed that the pseudo-second-order model was more suitable to explain the adsorption of MB dye onto STOP. The adsorption mechanism results showed that the adsorption process was controlled by both the internal and external diffusion of MB dye molecules. The values of free energy change (ΔG ^o) and enthalpy change (ΔH ^o) indicated the spontaneous, feasible, and exothermic nature of the adsorption process. The maximum monolayer adsorption capacity of STOP was also compared with other low-cost adsorbents, and it was found that STOP was a better adsorbent for MB dye removal.     

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     

柠檬皮渣对亚甲基蓝吸附性能研究

采用柠檬皮渣作为吸附剂对水溶液中亚甲基蓝进行吸附研究,考察了柠檬皮渣用量、溶液pH值、吸附时间、亚甲基蓝浓度、温度对吸附量的影响。结果表明:当柠檬皮渣用量为1 g/L,亚甲基蓝的初始质量浓度为100 mg/L,pH值为7,温度为30℃时,柠檬皮渣对亚甲基蓝吸附效果最好,吸附量为36.2 mg/g,吸附过程符合Langmuir等温吸附模型,吸附动力学遵从准二级动力学方程,热力学参数计算结果表明此吸附过程为自发的放热过程。