磁性膨润土对甲基橙的吸附特性研究

采用共沉淀法制备出磁性膨润土（M-Bent），并通过比表面积及孔径分析、SEM、FTIR、XRD和VSM等对其进行了结构和形貌分析。以废水中甲基橙（MO）为目标污染物，考察了膨润土（Bent）和M-Bent对MO的吸附特性。结果表明：Bent和M-Bent对MO的吸附量与溶液pH呈负相关；M-Bent对MO的吸附在2 h内达到平衡，吸附动力学过程能很好地由准二级动力学模型描述；Langmuir等温吸附模型能较好地描述MO在Bent和M-Bent上的吸附行为，最大吸附量分别为25.62、27.36 mg/g。热力学结果表明，Bent和M-Bent对MO的吸附过程为熵增加的自发放热过程。再生实验结果表明，吸附-解吸过程重复5次后，吸附容量仍维持在80.98%以上。研究显示，磁性膨润土可作为去除水体中MO的良好材料。     

金刚烷胺/氧化石墨烯复合材料的制备及其吸附性能

以氧化石墨烯和金刚烷为原料，通过水相合成法制备了金刚烷胺功能化氧化石墨烯复合材料A/GO，以FT-IR、XRD和XPS对A/GO进行了结构表征，并考察了A/GO对有机染料的吸附性能。结果表明，与氧化石墨烯相比，A/GO对甲基蓝（AB93）表现出高效吸附性，其吸附动力学和吸附等温模型分别符合拟二级动力学和Langmuir模型，理论最大吸附容量（qm）为1250.0 mg/g。热力学分析表明，A/GO吸附AB93是自发的放热过程。A/GO吸附AB93对盐（NaCl和KCl）表现出良好的耐盐性，而CaCl2能有效地促进A/GO吸附AB93。对于刚果红和AB93等的混合染料体系，A/GO能选择性吸附AB93。     

四乙烯五胺接枝膨润土对酸性大红GR的吸附性能

在膨润土（Bent）表面接枝四乙烯五胺（TEPA）制备四乙烯五胺改性膨润土（TEPA/Bent）,利用FTIR（红外光谱仪）、XRD（X射线衍射仪）、EA（元素分析）、SEM（扫描电镜）和EDS（能谱仪）对其进行表征分析,并考察对水体中阴离子染料酸性大红GR的吸附性能。结果表明：TEPA成功接枝于膨润土表面,提高了膨润土对酸性大红GR的吸附量;pH对TEPA/Bent表面电位和吸附量影响较大;随着初始pH的增大,TEPA/Bent的zeta电位由正变为负,对酸性大红GR吸附量减少;在pH=3,染料初始质量浓度为100mg/L条件下,TEPA/Bent对酸性大红GR的吸附量可达44.63mg/g;TEPA/Bent对酸性大红GR的吸附动力学符合准二级动力学模型;吸附等温线符合Langmuir吸附等温模型,为单分子层吸附;吸附热力学表明该吸附为自发吸热过程。吸附剂经过5次再生后,吸附量仍保持为初始80%以上。研究表明,TEPA/Bent是从水溶液中去除阴离子染料的潜在有效吸附剂。     

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。     

SiO2/还原氧化石墨烯复合材料的简易制备及对罗丹明B的吸附

以正硅酸乙酯（TEOS）为硅源,氧化石墨烯（GO）为载体,在不添加任何还原剂的情况下,通过水热法简易制备SiO₂/还原氧化石墨烯（SiO₂/RGO）复合材料。采用TEM、FTIR、XRD、TG-DSC、N₂-吸附对复合材料的微观结构进行表征,分析表明：负载量为76.60%（质量分数）的SiO₂纳米颗粒均匀分散在RGO表面上,且部分以Si-O-C键进行配位;具有多级孔结构的SiO₂/RGO复合材料孔径主要分布在1~7nm,比表面积高达676m²/g。以罗丹明B为目标污染物,考察了pH、投入量、温度和接触时间等因素对复合材料吸附性能的影响,结果表明：在pH为2、35℃时,复合材料具有最佳的吸附效果,吸附量为127.8mg/g。动力学分析表明吸附过程符合准二级动力学模型,热力学参数揭示吸附过程为自发吸热过程。     

CPAM插层膨润土复合材料的制备及对磷吸附行为

分别采用十六烷基三甲基溴化铵(CTMAB)、阳离子聚丙烯酰胺(CPAM)两步湿法成功制备出CPAM插层钠基膨润土(Bent)复合材料(CTMAB/Bent和CPAM/Bent),利用XRD、FESEM、FTIR、BET以及TG-DTG-DSC对材料进行了表征,并进行模拟含磷废水的吸附研究。结果表明:CPAM已稳定插层在Bent的片层结构中,其层间距显著增大,红外光谱出现明显的羰基吸收峰,比表面积减小而表面疏水性增强。含磷废水处理结果表明,吸附性能大小的顺序为CPAM/Bent> CTMAB/Bent> Bent,随着反应温度升高、含磷废水初始浓度增加以及pH降低,CPAM/Bent对磷的去除率逐渐增大,当含磷废水初始质量浓度为3.5 mg/L、pH≈5、温度为35℃、投加量5 g/L,20 min去除率达75%。CPAM/Bent经过5次吸附和再生后,其吸附磷的能力显著下降。吸附等温线均符合Langmuir和Freundlich方程,吸附过程更好地满足准二级动力学方程。     

ZnS/AC复合材料的制备及其对铀酰离子的吸附性能

采用化学沉淀法制备了活性炭负载纳米硫化锌的复合材料ZnS/Ac，利用SEM、EDS、XRD、FTIR、BET等手段对该复合材料进行了表征分析。研究了ZnS/Ac对水溶液中铀酰离子的吸附性能，探讨了吸附时间、初始铀酰离子浓度、pH值、吸附剂投加量、温度等因素对吸附性能的影响，并对吸附过程进行了热力学和动力学模拟，探讨了吸附机理。结果表明：ZnS/Ac的比表面积为201.1961 m2/g，比活性炭的比表面积（165.0240 m2/g）明显增大，平均孔径为4.70 nm，孔容为0.038 cm3/g。在初始质量浓度为35 mg/L，pH=6，吸附时间为120 min，投加量为10 mg，处理温度为50 ℃的条件下，吸附剂对铀酰离子的吸附量为64.4736 mg/g。吸附过程符合准二级动力学方程和Langmuir 吸附等温线模型，热力学参数<0、>0、>0，表明该吸附是一个自发的吸热过程。     

乳液法制备石墨烯气凝胶及其吸附水中亚甲基蓝

利用乳液法制备多孔石墨烯气凝胶（emGA）,改变乳液油水比制备不同的emGA。扫描电子显微镜（SEM）、傅里叶红外光谱（FTIR）、氮气吸附脱附等表征显示,emGA具有多孔结构,经水热还原后含氧官能团大部分被除去,比表面积为103.3～243.1m²/g。以亚甲基蓝（MB）浓度和温度作为变量,考察emGA对水中MB的吸附效果。结果表明,emGA的比表面积越大,其对MB平衡吸附量越大;当初始浓度越大,温度越高,则吸附有利。吸附动力学数据表明emGA吸附MB符合准二级动力学模型和内扩散模型,吸附过程分为大孔扩散和微孔扩散。吸附等温线数据拟合结果符合Langmuir模型,表明emGA对MB的吸附属于单分子层吸附。Langmuir模型计算出emGA-2饱和吸附量为307.7mg/g,与实验值291.3mg/g较为接近。分析热力学参数发现,emGA吸附MB为自发吸热过程,且吸附过程属于物理吸附。     

偕胺肟化氧化石墨烯对铀(VI)吸附性能的研究

本文制备了偕胺肟/氧化石墨烯复合材料(AO/GO),利用SEM、FT-IR对AO/GO的形貌和结构进行表征,研究了溶液的p H值、吸附时间、溶液初始浓度、温度对功能化氧化石墨烯材料吸附铀(VI)的影响,采用吸附动力学、吸附等温线和吸附热力学进一步探讨吸附机理。研究表明:AO/GO对铀(VI)吸附的最佳p H值为5.0,3h达到吸附平衡,符合准二级动力学方程,吸附过程主要是受化学作用控制,吸附行为能被Langmuir吸附等温模型较好的描述,吸附是吸热和自发的,单层吸附量为285.71mg·g~(-1)。     

气溶胶辅助法合成球形氧化镁及其吸附性能研究

以氯化镁为镁源,尿素为沉淀剂,采用气溶胶辅助法制备了球形氧化镁。利用X射线衍射（XRD）、扫描电镜（SEM）、红外光谱（IR）和氮气吸附-脱附等技术手段对不同反应温度下制备的前驱体和氧化镁样品进行了表征。实验结果表明：制备的球形氧化镁比表面积为36 m ²/g,平均孔径为34 nm,总孔容为0.26 cm ³/g;其对刚果红的吸附符合伪二级动力学,且5 min内达到吸附平衡;吸附等温线符合Langmuir模型,饱和吸附量为764.91 mg/g。     

Removal of Zinc (II) Ions from Aqueous Solutions Using Surfactant Modified Bamboo Sawdust

The present study explores the ability of surfactant modified bamboo sawdust in removing zinc (II) ions from aqueous solutions. The modified bamboo sawdust is characterized by surface area analysis, Scanning Electron Microscope, and Fourier Transform Infrared and X-ray fluorescence analysis. Adsorption isotherm and kinetic models were used to study the adsorption characteristics of zinc (II) ions onto modified bamboo sawdust. The equilibrium adsorption isotherm data were fitted into the Langmuir and Freundlich adsorption isotherms. It was found that modified bamboo sawdust yielded maximum adsorption capacity of 111.12 mg/g at 50°C for zinc (II) ions. The kinetic data obtained at different initial concentrations were analyzed using first-order-reversible reaction, pseudo-first-order, and pseudo-second-order models. The results provide strong evidence to support the hypothesis of adsorption mechanism.     

硼碳氮多孔材料的制备及其吸附再生性能研究

硼碳氮(BCN)多孔材料因其具有高的比表面积、优异的化学稳定性而被认为是一种优异的吸附材料。本文以废弃椰壳、硼酸(H₃BO₃)和尿素(CO(NH₂)₂)为原料,采用冷冻干燥法制备多孔生胚,并在NH₃气氛下通过高温固相反应法在不同的反应温度下合成BCN多孔材料。结果表明,随着反应温度的升高,BCN多孔材料孔径逐渐变大,当反应温度为950 ℃时平均孔径为2.1 nm。将BCN多孔材料用于吸附水中孔雀石绿(MG)有机染料,其最大吸附量可达1 239.8 mg·g^-1,5次循环再生后吸附量平均值仍高达1 138.6 mg·g^-1,说明BCN多孔材料具有优异的循环吸附性能。采用Langmuir和Freundlich等温吸附模型、准一级和准二级吸附动力学模型研究了浓度、吸附时间和平衡吸附量之间的关系。结果表明,BCN多孔材料的吸附与准二级吸附动力学模型吻合,其对MG的吸附属于均匀表面单层分子的Langmuir等温吸附。BCN多孔材料展现出优异的吸附能力,是一种非常有应用前景的新型吸附剂。     

Removal of Astrazone Blue from aqueous solutions onto brown peat. Equilibrium and kinetics studies

The aim of this study is to characterize and assess the sorption potential of brown peat, in relation to colored pollutants from the textile industry wastewater. The objectives of this paper were: the physicochemical, morphological, and mineralogical characterization of brown peat, testing the adsorption capacity of natural and chemically treated peat samples for Astrazone Blue, evaluation of adsorption process from equilibrium isotherm and kinetic point of view. The characteristics of the peat samples were investigated using elemental analysis, scanning electron microscopy and X-ray diffractometry. Experimental data indicated that the brown peat tested confirm a high level of adsorption (removal efficiency >93.00%, adsorption capacity reaching up to 24.27 mg/g) of Astrazone Blue from aqueous solution. The Langmuir and Freundlich adsorption isotherm models were used to find the best equation able to describe the adsorption process. Experimental adsorption data were successfully described by the Langmuir equilibrium isotherm model. This fact is supported by the agreement between the q values obtained using the Langmuir equation (26.32 mg/g), and the ones obtained experimentally (24.27 mg/g). The kinetic studies showed that the pseudo-second-order model described Astrazone Blue sorption kinetics, as confirmed by the high values of R ² , which are over 0.99 for the whole investigated concentration range (200 to 800 mg/L). The use of brown peat adsorbent is more advantageous compared with other materials since it does not require a preliminary treatment, is low-cost and is an eco-friendly adsorbent. Hence, this peat appears to be a viable material for the decontamination of effluents containing dyes.     

Fast Removal of Sr(II) From Water by Graphene Oxide and Chitosan Modified Graphene Oxide

Graphene oxide is a unique material that can be used for adsorption of radioactive waste because it contains various function groups such as epoxide, carbonyl, carboxyl and hydroxyl in addition to its high specific surface area. The as-prepared GO and the modified one (GO-chitosan composite) have been prepared then characterized and used as adsorbent for radioactive metal ions [Strontium, Sr(II)]. The results showed that the prepared materials are efficient adsorbents for removal of Sr(II) from water. The effect of contact time, pH and temperature on adsorption have been studied. The results indicated that the maximum adsorption capacity was about 140 and 179.6 mg/g for GO and GO-chitosan composite respectively. It was found that pH?~?6 and temperature?~?40 °C are the best condition for removal of Sr(II) from water. Two isotherm models (Langmuir and Freundlich) and three kinetic models (Pseudo-first-order, pseudo-second-order, and intra-particle particle diffusion model) have been applied. Based on the calculated isotherm parameters (R²), it can be concluded that Langmuir model fits the adsorption equilibrium data better than Freundlich model, the results also indicated that the second order kinetic model is the best representative for adsorption of Sr(II) on GO, Chitosan and GO-Chitosan. Based on the regressions of intraparticle diffusion model, experimental data showed that the adsorption process involved intraparticle diffusion, which was not the only rate-controlling step.     

氧化石墨烯-TiO2复合材料对三种染料的吸附动力学及光催化性能

通过在氧化石墨烯分散溶液中水解钛酸丁酯成功制备氧化石墨烯-TiO₂复合材料（GO-TiO₂）,采用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、全自动比表面及孔径分析仪（BET）和紫外-可见漫反射光谱（UV-vis DRS）等对样品进行了表征。研究了GO10-TiO₂对亚甲基蓝（MB）、甲基橙（MO）和罗丹明B（RhB）3种染料的吸附动力学和光催化性能。结果表明：TiO₂颗粒均匀地附着在GO片层表面;GO10-TiO₂对3种染料的吸附过程为多层吸附,吸附动力学符合拟二级动力学模型;在25℃条件下GO10-TiO₂对废水中MB、MO和Rh B的吸附因共轭结构、极性等的差异而呈现选择性吸附,吸附容量分别为9.2mg/g、5.4mg/g和23.0mg/g。对3种染料废水的光催化降解效果与吸附性能相关联,吸附容量越大降解效率越高,光催化反应60min时,MB、MO和Rh B降解率分别为89%、75%和98%。     

Facile fabrication of graphene oxide-polyethylenimine composite and its application for the Cr(VI) removal

A binary composite consisting of graphene oxide (GO) and polyethylenimine (PEI) was fabricated by a facile physical mixing. Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and Zeta potential were used to characterize the prepared graphene oxide-polyethylenimine composite (GOPC). A series of experiments were carried out to investigate the effects of some important parameters, such as molecular weight of PEI, pH, time and temperature, on the adsorption efficiency of GOPC. Due to the high amine density of GOPC, its adsorption for Cr(VI) occurred more easily at lower pH mainly via electrostatic interaction. The adsorption process matched well with the Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum adsorption capacity from the Langmuir model was 370.37 mg/g at pH 2.0 and 45°C for GOPC. Thermodynamic parameters revealed spontaneous and endothermic nature of the Cr(VI) adsorption onto GOPC. The main adsorption mechanism of GOPC toward Cr(VI) was electrostatic interaction. The adsorption-desorption experiments suggested GOPC was easily recycled and its stable adsorption capacity endowed it great potential as an adsorbent of Cr(VI) from wastewater.     

Efficient decolorization of dye-containing wastewater using mycelial pellets formed of marine-derived Aspergillus niger

In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g~(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.     

农业废弃物香芋柄对含Mn2+废水的吸附

以废弃香芋柄作为新型生物吸附剂,通过静态吸附实验,研究了pH、温度、吸附时间、Mn2+初始浓度等因素对香芋柄吸附Mn2+的影响,分析了吸附过程的热力学、动力学和等温吸附规律. 结果表明,溶液初始pH=4,香芋柄用量6 g/L,30℃下吸附60 min,溶液中Mn2+吸附去除率达90.79%以上,吸附容量高达18.16 mg/g. 应用Langmuir和Freundlich模型描述香芋柄对Mn2+的吸附过程,结果显示Freundlich吸附等温线拟合效果更好. 吸附动力学实验数据符合准二级动力学模型. 计算得到热力学参数DG<0, DH>0, DS>0,表明该吸附过程是自发和吸热的过程.