磁性埃洛石复合材料的制备及其对亚甲基蓝吸附性能研究

利用简单的化学共沉淀法成功合成了磁性埃洛石复合材料,并用静态批示法对其吸附亚甲基蓝的行为进行研究。采用红外光谱仪( FT-IR)、透射电子显微镜( TEM)、X射线衍射仪( XRD)和振动样品磁强计( VSM)对磁性埃洛石进行表征,考察了埃洛石/FeCl3·6H2 O质量比、吸附剂投入量、亚甲基蓝初始浓度、溶液初始pH值和吸附时间等因素对亚甲基蓝在磁性埃洛石上吸附的影响,并进行了吸附动力学研究。结果表明：Fe3 O4纳米粒子成功地复合到埃洛石的表面;溶液初始pH值对磁性埃洛石吸附亚甲基蓝的影响较大;磁性埃洛石复合材料对亚甲基蓝的吸附行为符合准二级动力学模型。     

羟基磷灰石/石墨烯复合物对水中亚甲基蓝的吸附

以石墨烯为载体,通过一步水热法合成羟基磷灰石/石墨烯(HA/RGO)复合物。采用扫描电子显微镜对复合物形貌进行表征,探讨了溶液的pH、初始浓度及反应时间对HA/RGO复合物吸附亚甲基蓝(MB)的影响。结果表明,HA/RGO-1复合物对MB的吸附效果最好,HA/RGO-1复合物吸附量随着溶液的初始浓度和pH的上升而增大,HA/RGO-1复合物的吸附行为符合Langmuir吸附等温线,理论最大吸附量可达666.7 mg/g,反应过程在前80 min反应速率很快,约在480 min内达到吸附平衡,吸附动力学符合准二级动力学模型。     

壳聚糖纳米纤丝的制备及其对亚甲基蓝吸附行为的研究

采用湿磨机打磨和高压均质的物理方法,制备平均直径80 nm的壳聚糖纳米纤丝(CSNF),对亚甲基蓝进行吸附,探究了pH值、亚甲基蓝浓度、温度和吸附时间对吸附性能的影响。结果表明,最佳吸附条件为:亚甲基蓝溶液初始浓度100 mg/L,pH=6,吸附剂量1.0 g/L,35℃吸附120 min。在此条件下,吸附量28.14 mg/g。CSNF对亚甲基蓝的吸附行为符合准二级动力学方程和Freundlich模型,为非均相化学吸附。     

壳聚糖纳米纤丝的制备及其对亚甲基蓝吸附行为的研究

采用湿磨机打磨和高压均质的物理方法,制备平均直径80 nm的壳聚糖纳米纤丝(CSNF),对亚甲基蓝进行吸附,探究了pH值、亚甲基蓝浓度、温度和吸附时间对吸附性能的影响。结果表明,最佳吸附条件为:亚甲基蓝溶液初始浓度100 mg/L,pH=6,吸附剂量1.0 g/L,35℃吸附120 min。在此条件下,吸附量28.14 mg/g。CSNF对亚甲基蓝的吸附行为符合准二级动力学方程和Freundlich模型,为非均相化学吸附。     

Zn2SiO4/硅藻土复合材料制备及吸附亚甲基蓝性能的研究

以硅藻土为基体,Zn2SiO4为吸附改性剂,采用溶剂热法制备了Zn2SiO4/硅藻土复合材料.通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、氮气吸附/脱附仪(BET)对样品的物相组成、形貌和表面特性进行表征,测试复合材料对亚甲基蓝的吸附性能,并进行吸附动力学分析.结果表明:复合材料制备最佳条件为m(硅藻土):V(甲醇溶液)=1:1.6,Zn(NO3)2负载量为11.24％.该条件下,复合材料的比表面积比未负载的硅藻土提高了4倍,对亚甲基蓝溶液有较好的吸附性能,吸附量为44.74mg/g.动力学分析表明,复合材料对亚甲基蓝的吸附过程符合准二级动力学模型.     

氧化石墨烯/硅藻土复合材料的制备及去除废水中亚甲基蓝的应用

将天然硅藻土与Hummers法制得的氧化石墨烯进行复合,得到氧化石墨烯/硅藻土复合材料,并研究了该复合材料对亚甲基蓝染料的吸附过程。复合材料与亚甲基蓝染料处理时间为30min,初始溶液pH=8时,亚甲基蓝的脱色率和吸附量可达最大;吸附剂质量浓度为2mg/mL时,脱色率可达95%以上。氧化石墨烯/硅藻土吸附亚甲基蓝的过程可以用二级动力学模型很好地拟合,说明吸附速率对初始浓度较为敏感,主要为化学吸附。吸附等温线符合Freundlich等温线模型,已测得亚甲基蓝在氧化石墨烯(GO)/硅藻土上的最大吸附量为125mg/g。     

改性柿叶对亚甲基蓝的吸附性能

研究改性柿叶对亚甲基蓝的吸附性能,探讨了吸附剂用量、吸附时间、初始浓度、pH值、温度等因素对吸附性能的影响,结果显示:硝酸改性可明显提高柿叶对亚甲基蓝的吸附效果。室温下1L亚甲基蓝溶液(40mg/L),当吸附剂用量1g、吸附2.0h,溶液pH=5~11时吸附效果较好,吸附行为更符合Langmuir吸附等温式,饱和吸附量为100.4mg/g。     

常压下Fe3O4@C磁性复合材料的制备及其对亚甲基蓝的吸附

以共沉淀法合成的Fe₃O₄为载体,在常温常压下,利用浓硫酸蔗糖碳化法制备出Fe₃O₄@C磁性复合材料,通过傅里叶变换红外光谱仪（FTIR）、X射线粉末衍射仪（XRD）、扫描电镜（SEM）、透射电镜（TEM）和磁学测量系统（MPMS）手段对合成的磁性复合材料进行表征,并研究了Fe₃O₄@C对水中亚甲基蓝的吸附性能。考察了吸附剂用量、溶液pH、吸附温度、震荡时间等因素对吸附过程的影响。结果表明,Fe₃O₄@C表面分布有大量不规则的孔道,其饱和磁化强度为18.45emu/g;当亚甲基蓝初始浓度为100mg/L,吸附剂加入量1g/L,吸附时间150min,吸附温度25℃,pH=12时,得到吸附容量为96.74mg/g。Fe₃O₄@C对水中亚甲基蓝的吸附符合Langmuir模型,吸附过程动力学符合准二级动力学方程,吸附过程是吸热及熵增加的过程;Fe₃O₄@C经过稀硫酸溶液解吸之后可以重复利用。     

烟秆碳化材料对亚甲基蓝的吸附性能

为探索废弃烟秆改性后得到的烟秆碳化材料对亚甲基蓝的吸附性能,研究了pH、烟秆碳化材料投加量、反应时间和亚甲基蓝初始浓度对烟秆碳化材料吸附性能的影响,分析了吸附动力学和热力学以及烟秆碳化材料的形态特征.结果表明,烟秆碳化材料吸附亚甲基蓝的最佳条件为:pH 6,吸附剂投加量2 g/L.对于100～400 mg/L的亚甲基蓝溶液,吸附平衡时间为60～360 min.烟秆碳化材料对亚甲基蓝的吸附符合拟二级动力学模型和Langmuir模型,说明吸附过程是单层吸附,最大吸附量为636.9 mg/g.     

高岭土对染料废水中亚甲基蓝的吸附去除

利用天然硅酸盐矿物材料高岭土对染料废水亚甲基蓝进行吸附去除研究,采用平衡吸附法研究不同高岭土投加量、溶液初始pH条件下高岭土对亚甲基蓝吸附去除的影响,进一步考察了热力学和动力学吸附规律,确定最佳的试验条件。结果表明:高岭土最佳投加量选择0.8 g/L,对亚甲基蓝的吸附量随初始pH的升高而增加;热力学研究表明,Koble-Corrigan模型对吸附过程的拟合度最高,更适合高岭土对亚甲基蓝的吸附行为,吸附过程是一个自发吸热的过程;动力学研究表明,在60min时基本达到吸附平衡,吸附过程符合准二级动力学的吸附模型。     

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。     

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.     

Adsorption characteristics of methylene blue onto the N-succinyl-chitosan-<Emphasis Type="Italic">g</Emphasis>-polyacrylamide/attapulgite composite

N-succinyl-chitosan-g-polyacrylamide/attapulgite (NSC-g-PAM/APT) composite was applied as adsorbent for the removal of methylene blue (MB) from aqueous solution. The initial pH value of the dye solutions, the contact temperature, the contact time and the concentration of the dye solutions on adsorption capacity of the composite for MB dye were investigated. The adsorption kinetics and isotherms were also studied. It was shown that all the sorption processes were better fitted by pseudo-second-order equation and the Langmuir equation. The results indicated that the adsorption capacity of the composite was higher than those of chitosan (CTS) and attapulgite (APT). 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 used as quite effective adsorbent for the removal of MB from aqueous solution.     

聚丙烯酸/氧化石墨烯复合水凝胶制备及对亚甲基蓝吸附

以丙烯酸(AA)为原料,二丙烯酸酯(Pul DA)分散的氧化石墨烯(GO)纳米胶粒(GO-Pul DA)为增强剂,N,N'-亚甲基双丙烯酰胺(BIS)为交联剂,通过自由基共聚合制备了一系列结构均一的聚丙烯酸/氧化石墨烯复合水凝胶(PAA/GO-Pul DA)。考察了BIS质量浓度、GO质量浓度以及溶液pH值对复合水凝胶力学性能、吸水性和亚甲基蓝(MB)吸附量的影响。结果表明,当GO质量浓度从0.1 g/L增加至1.0 g/L时,复合水凝胶拉伸强度从5.0 k Pa增加至10.4 k Pa,断裂伸长率高于100%,当GO的质量浓度为0.3 g/L时,复合水凝胶的断裂伸长率最高为151%;复合水凝胶表现出pH敏感的高吸湿性,pH从3.0增加至6.8时,平衡溶胀比(SRe)变化可达386 g/g,pH=6.8时最大SRe高达490 g/g。当溶液pH值从3.0增加至11.0时,PAA/GO-Pul D对MB的平衡吸附量(qe)可增加1 400~1 500 mg/g,pH=11.0时最大的qe高达1 789 mg/g。复合水凝胶对MB的吸附行为符合准一级动力学模型。5次吸附-解吸附循环后,相对于首次吸附,PAA/GO-Pul D对MB的吸附能力仍保持高达60%,解吸附效率高于90%。     

Characteristics of coal fly ash and adsorption application

Several fly ash samples were collected and their physico-chemical properties were characterised using N₂ adsorption, XRD, SEM, and pH titration. These fly ash samples were applied as low-cost adsorbents for removal of methylene blue and humic acid from aqueous solution. It is found that the adsorption has a close relationship with surface area and pore volume. Higher surface area and pore volume of fly ash will result in higher adsorption of methylene blue (MB) and humic acid (HA). The adsorption of MB and HA on various fly ash samples can reach 7 and 10 mg/g, respectively. Solution pH will also influence humic acid adsorption on fly ash and higher pH will result in lower adsorption. Ionic strength will also influence HA adsorption.     

Adsorptive removal of methylene blue from aqueous solution on activated carbon prepared from Malawian baobab fruit shell wastes: Equilibrium,kinetics and thermodynamic studies

Baobab fruit shell (BFS), a renewable bio-waste from Malawian baobab tree was used as a precursor for the production of a low-cost activated carbon to remove methylene blue (MB) from aqueous solution. Parameters such as contact time, initial methylene blue concentration, adsorbent dose and temperature were studied. The adsorption process can be well described by both Langmuir isotherm and the pseudo-second-order kinetics. The maximum monolayer adsorption capacity of MB dye was ca. 334.45 mg/g. The negative value of the Gibb’s free energy and positive value of adsorption enthalpy showed the spontaneous nature and endothermic nature of the adsorption process, respectively.     

复合材料POSS/TX-10/Bent的制备及其吸附性能

以多面齐聚倍半硅氧烷(POSS)、TX-10型非离子表面活性剂为改性剂对膨润土(Bent)进行复合改性制备了复合材料(POSS/TX-10/Bent),并利用亚甲基蓝研究了其吸附性能。采用XRD、XPS、EA、FTIR、SEM对POSS/TX-10/Bent进行了组成与结构表征。结果表明,POSS和TX-10型非离子表面活性剂都成功插入到膨润土层间,使得复合材料层间距增大,疏水性增强。吸附实验表明,在30℃、pH为6.52(原始值)的条件下,复合材料投加量5 g/L、吸附180 min时效果最佳。在同等吸附条件下,复合改性膨润土对亚甲基蓝的吸附能力远大于未改性的膨润土。吸附过程更符合准二级动力学模型,平衡吸附数据与Langmuir等温吸附曲线吻合较好,吸附是一个自发的吸热过程,POSS/TX-10/Bent对亚甲基蓝的理论最大吸附量为253.81 mg/g。     

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.     

基于三维框架材料H3PW6Mo6O40/Zn(BDC)(4,4'-Bipy)0.5高效吸附亚甲基蓝

采用溶剂热法,用H3PW6Mo6O40对金属有机骨架Zn(BDC)(4,4'-Bipy)05进行改性,制备出金属有机骨架复合材料H3PW6Mo6O40/Zn(BDC)(4,4'-Bipy)0.5.利用IR、XRD、TG、SEM对其结构进行分析.同时,以亚甲基蓝溶液模拟染料废水进行吸附实验,考察了初始pH、温度对吸附容量的影响,探究了其吸附等温线和动力学特征.实验结果表明,H3PW6Mo6O40/Zn(BDC)(4,4'-Bipy)05对亚甲基蓝有很好的吸附性能,在20℃和pH 2的条件下,吸附量达588.24mg/g,且该吸附符合Langmuir等温吸附模型和拟二级动力学方程,吸附过程自发且放热.     

Preparation of Sodium carboxymethylcellulose/poly(methyl acrylate) IPN hydrogels and their application for adsorption

Sodium carboxymethylcellulose/poly(methyl acrylate) (NaCMC/PMA) interpenetrating polymer networks (IPNs) were prepared by fractional step in 40 wt % ethanol solution with N,N′‐methylenebisacrylamide as a crosslinker. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimeter were used to characterize the NaCMC/PMA IPN hydrogels and confirm the IPN structure as well. Simultaneously, adsorption of the obtained IPN hydrogels to methylene blue (MB) was also investigated. It was observed that the adsorption of MB onto the hydrogels was mainly dependent on the initial concentration of MB and the pH of the solution. Adsorption rate of MB was much higher in the first 9 h than that in the following period and saturated adsorption amount of MB was 2370 mg/g at the initial MB concentration of 100 mg/L. Moreover, the adsorption capacity of the IPN hydrogels at the neutral pH condition is much higher than those at acid or alkaline pH conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41101.