2,6二-氨基吡啶修饰Fe3O4纳米粒子对Cu^2＋和Zn^2＋的吸附性能

制备了表面修饰2,6-二氨基吡啶试剂的新型复合磁性Fe3O4纳米粒子,采用红外光谱对其进行了表征,并以火焰原子吸收光谱法（FAAS）测定其对水中Cu^2＋和Zn^2＋等重金属离子的静态吸附性能,考察了溶液pH值、平衡时间、吸附物初始浓度、洗脱条件等对复合材料吸附性能的影响。结果表明,复合材料在pH6—7时可对水中Cu^2＋和Zn^2＋产生有效吸附,5min内即可达到吸附平衡,等温吸附数据符合Langmuir单分子层吸附模型,T=298K,pH=7,V=50mL时对两种离子的饱和吸附量分别为45mg.g^-1和32mg.g^-1,重复使用6次其饱和吸附能力未见明显下降。     

ICP-OES研究活性炭无纺布对镉的吸附

重金属污染是一个相当严重的环境问题。镉具有很强的生物毒性和不可降解性,对生态环境和人体健康有极大威胁,被列为优先控制污染物。环境中镉的主要污染源是电镀、采矿和化学工业等部门的废水,如何简单高效去除水中的镉,有重要的社会意义和经济意义。目前,水中重金属的去除方法有化学沉淀、膜分离、离子交换、吸附、电解等,其中吸附法因简单高效而广泛应用。活性炭纤维是一种新型活性炭,孔径小且均匀,表面官能团发达,吸附性能好,逐步应用于水处理领域。以电感耦合等离子体光谱为检测手段,佐以比表面积分析,X射线衍射,元素分析和傅里叶变换红外光谱,研究比较了三种活性炭纤维(纤维炭网、活性炭无纺布、活性炭纤维毡)的结构特点及其对水中镉的吸附性能。三种活性炭纤维结构基本类似,具有较发达的孔隙结构。活性炭无纺布极性较强,表面有丰富的羟基、羧基、醛基等含氧官能团,对水中镉的吸附作用最大。因此,选择活性炭无纺布为吸附剂进行后续实验。研究了活性炭无纺布吸附镉的影响因素,如溶液pH,吸附时间等。溶液pH影响吸附剂表面电荷及水中镉的存在状态。水中镉的去除效率随溶液初始pH的增大而增大,在较低pH时,吸附剂与Cd2+间存在静电斥力,同时H+和Cd2+存在竞争吸附,pH>9时,镉的去除是吸附与沉淀协同作用的结果,选择pH为6～7。在吸附的初始阶段,活性炭无纺布对Cd2+的吸附量迅速增加,10 min时,吸附率达到72%。随着吸附位点逐渐被Cd2+所填充,吸附速率逐渐变慢,300 min时,吸附容量基本无变化,吸附趋于平衡。优化了镉的吸附条件后,进行等温吸附实验和动力学实验。结果表明,25 ℃时,吸附时间为300 min,pH 6.0条件下,当镉的平衡浓度在20.00 mg·L-1时,活性炭无纺布对镉的单位质量吸附量和单位比表面积吸附量分别是3.04 mg·g-1和0.035 mg·m-2。用Langmuir方程(R2=0.997, K_L =1.796 L·mg-1)和Freundich方程(R2=0.895, K_F=0.918 L·mg-1, n=2.12)拟合活性炭无纺布对镉的等温吸附数据,Langmuir方程计算的理论吸附量为3.07 mg·g-1,与实验值相当,并且线性系数更高,说明该体系的吸附符合Langmuir方程,主要为单分子层吸附。Langmuir分离因子介于0和1之间,表明活性炭无纺布对镉的吸附容易进行。用准一级动力学方程、准二级动力学方程、颗粒内扩散方程和Elovich方程四种动力学模型拟合吸附过程。在吸附的前5 min,镉在活性炭无纺布上的吸附符合颗粒内扩散方程(R2=0.985),吸附主要受颗粒内扩散控制。在吸附的5～300 min,颗粒内扩散方程拟合较差。整个吸附过程符合准二级动力学方程(R2=0.999,k₂=0.367 g·mg-1·min-1),Elovich方程(R2=0.981,a=0.271 mg·g-1, b=0.083 mg·g-1·(lg min)-1)和准一级动力学方程(R2=0.927,k₁=0.008 8 min-1)次之,颗粒内扩散方程(R2=0.785)最差。活性炭无纺布对镉的吸附过程是一种化学作用为主的吸附过程。对5.00 mg·L-1含镉水样,活性炭无纺布投放量为10 g·L-1时,吸附后水中镉的浓度小于0.10 mg·L-1,符合《污水综合排放标准》(GB 8978-1996)。活性炭无纺布可同时吸附镉,铜,铅,铬等重金属离子,选择性较差。但在电镀、采矿等实际废水中重金属种类复杂,适当提高吸附剂投放量,可同时去除多种重金属。利用活性炭无纺布吸附处理含镉水样,处理效果好、操作简单,可以作为去除水中镉的吸附剂,为含镉废水的处理提供了技术支持和理论基础。     

碳纳米管吸附去除工业废水中亚甲基蓝的研究

研究了碳纳米管作为一种新型吸附剂去除水中亚甲基蓝。考察了溶液pH值、振荡时间、温度等对亚甲基蓝吸附的影响。溶液pH对亚甲基蓝吸附影响较大,动力学数据显示吸附在8h达到平衡。通过对吸附数据拟合,发现在温度为298—338K和浓度为2.5—12.5mg/L的范围内,碳纳米管对亚甲基蓝的吸附等温线均符合弗仑德里希（Feundlich）兰缪儿（Langmuir）吸附等温式。     

探针体耐尔蓝(NB)与DNA结合反应研究

应用微相吸附-光谱修正（MPASC）新技术研究DNA与耐尔蓝（NB）探针分子间的相互作用,分析生物大分子内静电场的形成与Langmuri吸附的关联性,测定了结合产物结合比、平衡常数等。通过在pH=10.38介质中对DNA-NB反应的光谱分析,结果表明产物结合比NB：DNA-P=3：1、平衡常数K=3.33×10^5,摩尔吸收系数ε^660nm=4.81×10^3L/mol cm。样品分析表明DNA回收率95.6%-108%,相对标准偏差RSD=2.8%。     

磷酸酯化改性梨渣吸附污染水体中锌离子的研究

以砀山梨渣为原料,经磷酸酯化改性,制备一种酯化梨渣阳离子吸附剂,用批次实验法研究了其在不同实验条件下（pH值、吸附剂量、吸附质浓度和吸附时间）对金属锌离子的吸附性能。结果表明,溶液pH=3.5时,锌离子吸附达到最大值;酯化梨渣≥5g.L-1能除去锌离子为100mg.L-1溶液中的96%锌离子。改性梨渣对锌离子的吸附符合Langmuir吸附等温线模型,最大吸附能力为28.986mg.g-1。锌离子达到吸附平衡的时间为30min;准一级反应动力学方程y=-0.0615x＋2.4437（r2=0.9921）描述锌离子在改性梨渣上的吸附过程。     

粉末活性炭吸附对氨基苯酚模拟废水的效果

在静态条件下,研究了活性炭吸附对氨基苯酚模拟废水的效果,确定了处理废水的pH值、活性炭用量、振荡时间、温度、废水中对氨基苯酚浓度、振荡速率以及电解质对吸附效果的影响.实验表明L活性炭在pH值为6.4,用量4.5g,温度35C,振荡2.5h的条件下,对100mL质量浓度为50mg/L的对氨基苯酚模拟废水处理效果最佳.     

粉末活性炭对模拟对苯二酚废水吸附研究

在静态条件下,研究了不同条件下活性炭对对苯二酚废水的吸附效果,确定了处理废水的pH值、活性炭用量、振荡时间、温度、废水中对苯二酚浓度、振荡速率以及电解质对吸附效果的影响。实验表明：活性炭在pH值为6.5,用量3.5g,温度35℃,振荡3.5h的条件下,对100mL质量浓度为100mg/L的对苯二酚模拟废水处理效果最佳。     

粉末活性炭对模拟间苯二酚废水的吸附

在静态条件下,研究了粉末活性炭对间苯二酚废水的吸附效果,通过实验优化了吸附条件,并在最佳处理效果下探究其吸附模式。结果表明,当水样pH值为4,温度30℃,活性炭用量0.3g,振荡时间10m in,振荡速率为120r/m in时,对废水的处理效果最佳。拟合得到活性炭吸附间苯二酚的模式符合F reund lich吸附模式。     

交联壳聚糖富集分离-分光光度法测定环境水样中的硒（Ⅳ）和硒（Ⅵ）

以二乙烯三胺为交联剂合成了一种新型交联壳聚糖（DCCTS）,研究了DCCTS对Se（Ⅳ）和Se（Ⅵ）的吸附行为,探讨了影响吸附的因素和吸附机理。结果表明,在pH 3.6时,DCCTS能富集分离Se（Ⅵ）,最大吸附率达94%,最佳吸附时间为30min,饱和吸附量为42.7mg/g,吸附符合Langmuir方程。在此基础上建立了DCCTS富集分离3,3′-二氨基联苯胺分光光度法测定环境水样中的硒（Ⅳ）和硒（Ⅵ）的方法,此法检出限（3σ）为0.011μg/L,相对标准偏差为5.5%,回收率为99%—105%。     

铁（Ⅲ）模板-硫脲交联壳聚糖的合成及其对Fe（Ⅲ）和Fe（Ⅱ）吸附性能比较

合成了铁（Ⅲ）模板-硫脲交联壳聚糖,研究了Fe（Ⅲ）和Fe（Ⅱ）在模板交联壳聚糖上的吸附行为.考察了pH值、接触时间等因素对吸附的影响,结果表明,适宜的pH值为5.0,吸附平衡时间为60min.研究了吸附热力学和吸附动力学,结果表明,吸附符合Langmuir模型和准二级动力学模型.     

The removal of MO molecules from aqueous solution by the combination of ultrasound/adsorption/photocatalysis

Methyl orange (MO) molecules had been removed from aqueous solution by nano-TiO(2)/exfoliated graphite composites with the combination of ultrasound/adsorption/photocatalysis. The experimental results had showed that nano-TiO(2)/exfoliated graphite composites provided with the adsorptive capability of exfoliated graphite and the photocatalysis capability of nano-TiO(2) synchronously. It had been proved that the removal ratios related to the adsorption and photocatalysis capability of the composites and were influenced by US and UV irradiation, the reaction times, the reaction temperatures, the initial pH values, the dosages and the initial MO solution concentrations. Moreover, it had been illuminated that the combination was very effective and useful on removing MO molecules from aqueous solution.     

磁性Pb(Ⅱ)表面印迹聚合物(Fe_3O_4/GO-IIP)的制备及谱学表征

吸附法处理含铅废水因其经济性备受关注。开发可回收的专一性Pb(Ⅱ)吸附材料是高效处理含铅废水和实现铅回收的关键。结合氧化石墨烯(GO)的强吸附性、Fe_3O_4的磁性和表面印迹技术,以氧化石墨烯负载四氧化三铁(Fe_3O_4/GO)为载体,硝酸铅为模板离子,甲基丙烯酸(MAA)及水杨醛肟(SALO)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂制备了磁性Pb(Ⅱ)表面印迹材料(Fe_3O_4/GO-IIP),并探讨其重复利用性和对Pb(Ⅱ)的专一性吸附性。结合XRD,SEM,FTIR等谱学方法,对Fe_3O_4/GO-IIP进行表征,并分析其对Pb(Ⅱ)的吸附机理。以Fe_3O_4/GO-IIP作为吸附剂选择性去除水溶液中的Pb(Ⅱ),结果表明,Fe_3O_4/GO-IIP对Pb(Ⅱ)具有很好的亲和性,反应在5min内,对初始浓度10mg·L-1的Pb(NO3)2的去除率达到70%,反应在20min左右达到吸附平衡。准二级吸附动力学和Langmuir吸附等温线能较好的表达其吸附过程。TEM和SEM图谱证明了Fe_3O_4均匀地分散在GO表面,粒径为10~20nm,Fe_3O_4/GO-IIP表面存在Pb(Ⅱ)印迹孔穴,增强其对Pb(Ⅱ)的选择吸附性;在竞争离子[Cd(Ⅱ),Zn(Ⅱ),Cu(Ⅱ)]存在条件下,Fe_3O_4/GO-IIP对目标污染物Pb(Ⅱ)的选择性系数比非印迹吸附材料(NIP)提高2~5倍;XRD和FTIR谱图分别从晶相结构和官能团证明了Fe_3O_4/GO-IIP的成功合成。对制备材料进行磁分离后洗脱再利用,结果表明Fe_3O_4/GO-IIP具有良好的重复利用性。该结果对于含铅废水处理和铅回收具有重要的意义。     

Covalent marriage of multi-walled carbon nanotubes (MWNTs) and β-cyclodextrin (β-CD) by silicon coupling reagents

In this study, β-cyclodextrin (β-CD) polymer was covalently bonded to multi-walled carbon nanotubes (MWNTs) with the aid of γ-glycidoxypropyltrimethoxysilane (GPTMS) for the fabrication of novel porous materials with special surface properties. The success of synthesis and physicochemical properties of β-CD polymer grafted MWNTs (MWNTs-g-CDP) were characterized by FT-IR, XPS, TGA, TEM and BET. The novel materials were further utilized to remove the typical contaminant of resorcinol in industrial wastewater. The results illustrated that MWNTs-g-CDP possessed much higher adsorption capability and demonstrated the shorter saturation adsorption time than that of pristine MWNTs. Therefore, MWNTs-g-CDP with the unique pore and surface characteristics may have great potentials in environmental applications.     

Electrospun Fibrous Membranes of Modified Polystyrene and its Copolymer With Butyl Acrylate and Their Respective Adsorption Capabilities for Cationic Blue and Copper Ions

Cationic dyes and metal ions in wastewater are considered as environmental pollutants. In order to treat these pollutants individually polystyrene (PS) and poly (styrene-co-butyl acrylate) (P(St-co-BA)) were first electrospun into fibrous membranes with a porous structure and then two simple modification methods were adopted to introduce -SO₃H and -COO^? groups into the PS fibrous membranes' and the P(St-co-BA) fibrous membranes' surfaces, respectively; finally the modified samples were used individually to adsorb either cationic blue dyes or copper ions, respectively. The results showed that the PS fibrous membranes were hydrophobic before modification but they became hydrophilic after modification due to the introduction of -SO₃H. Then the modified PS fibrous membranes had the capability to adsorb cationic blue dyes from water, and their adsorption efficiency, with an adsorption time of 300 min, reached 68.1%. For the P(St-co-BA) fibrous membranes, the -COO^? groups were introduced into their surfaces after hydrolysis in alkali lye; however, they showed very weak adsorption capability for copper ions due to the loss of the fiber-web structure. In addition, the thermal properties of the fibrous membranes before and after modification were analyzed, and the morphology was also observed by field emission scanning electron microscopy.     

Photocatalytic,sonocatalytic and sonophotocatalytic degradation of Rhodamine B using ZnO/CNTs composites photocatalysts

A series of ZnO nanoparticles decorated on multi-walled carbon nanotubes (ZnO/CNTs composites) was synthesized using a facile sol method. The intrinsic characteristics of as-prepared nanocomposites were studied using a variety of techniques including powder X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), transmission electron microscope (TEM), scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), Brunauer Emmett Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS). Optical properties studied using UV–Vis diffuse reflectance spectroscopy confirmed that the absorbance of ZnO increased in the visible-light region with the incorporation of CNTs. In this study, degradation of Rhodamine B (RhB) as a dye pollutant was investigated in the presence of pristine ZnO nanoparticles and ZnO/CNTs composites using photocatalysis and sonocatalysis systems separately and simultaneously. The adsorption was found to be an essential factor in the degradation of the dye. The linear transform of the Langmuir isotherm curve was further used to determine the characteristic parameters for ZnO and ZCC-5 samples which were: maximum absorbable dye quantity and adsorption equilibrium constant. The natural sunlight and low power ultrasound were used as an irradiation source. The experimental kinetic data followed the pseudo-first order model in photocatalytic, sonocatalytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than the sum of it at photocatalysis and sonocatalysis process. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of ZnO/CNTs photocatalyst. Chemical oxygen demand (COD) of textile wastewater was measured at regular intervals to evaluate the mineralization of wastewater.     

Magnetism of nanographene network influenced by the interaction with acid species

The magnetism of nanographite (stacked nanographene sheets)-based nanoporous carbon is investigated in relation to the interaction with acid guest species. The concentration of the localized spins of non-bonding π-electron state (edge state) localized in the nanographene edges decreases upon the sulfonation of nanographene edges through charge-transfer interaction with sulfonic groups. The sulfonation of nanographene edges enhances the hydrophilic nature of the edges, resulting in the easiness in the water adsorption into the nanopores. This enhances the mechanical compression effect of water molecules condensed in the nanopores on the nanographite domains, resulting in the decrease in the spin concentration. The change in the magnetism upon water uptake reveals ferrimagnetic nature of individual nanographene sheets. The adsorption of HCl having no oxidation ability shows a mechanical effect on the edge-state spins similar to water adsorption. The spin concentration is reduced in two-step manner by the charge-transfer interaction with guest concentrated HNO₃ that is strong oxidant. In the presence of H₂O molecules in diluted HNO₃ the cooperation of mechanical and charge-transfer interactions creates also a two-step change in the magnetism.     

Sorption and decomposition of crude oil using exfoliated graphite/ZnO composites

Exfoliated graphite/ZnO composites (EG/ZnO) were prepared by impregnating expandable graphite with Zn(OH)₂, abruptly expanding at 700 °C for 40 s, and heating at 500 °C for 3 h. The composites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), nitrogen adsorption and mercury porosimetry. The sorption capacity of the composites for spilled crude oil was measured and under UV irradiation the decomposition of the absorbed crude oil was investigated. The results showed that the composites provided with the adsorption and photocatalysis capacity for crude oil at the same time. The sorption capacity of the composites decreased gradually on increasing the ZnO content of the composites. Moreover, the decomposition ratio of the absorbed crude oil increased on increasing the ZnO content or decreasing the weight ratio of crude oil to composites.     

Fabrication of α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>/TiO<Subscript>2</Subscript> bi-functional composites with hierarchical and hollow structures and their application in water treatment

The α-Fe₂O₃/TiO₂ bi-functional composites with hierarchical and hollow structures are fabricated through a hydrothermal route. The adsorption performance and photocatalytic activity of the composites towards Pb²⁺ are investigated in this work. Different adsorption kinetics models and equilibrium models are used to explore the adsorption behavior of hierarchical α-Fe₂O₃/TiO₂ hollow spheres. Experimental data show that adsorption kinetics of the hierarchical α-Fe₂O₃/TiO₂ hollow spheres can be fitted well by the pseudo-second-order model, while the isothermal data can be perfectly described by the Langmuir adsorption model. The maximum adsorption capacity of the hierarchical α-Fe₂O₃/TiO₂ hollow spheres is 32.36 mg g^?1. Moreover, the hierarchical α-Fe₂O₃/TiO₂ hollow spheres possess photocatalytic oxidation character under simulated solar light irradiation. The results demonstrate that the hierarchical α-Fe₂O₃/TiO₂ hollow spheres, as effective and cheap materials, can be applied to the removal of heavy metal ions from wastewater.     

A first principle study on the magnetic properties of Cu2O surfaces

Spin-polarized density functional theory calculations were performed to investigate the magnetism of bulk and Cu₂O surfaces. It is found that bulk Cu₂O, Cu/O-terminated Cu₂O(111) and (110) surfaces have no magnetic moment, while, the O-terminated Cu₂O(100) and polar O-terminated Cu₂O(111) surfaces have magnetism. For low index surfaces with cation and anion vacancy, we only found that the Cu vacancy on the Cu₂O(110) Cu/O-terminated surface can induce magnetism. For atomic and molecular oxygen adsorption on the low index surfaces, we found that atomic and molecular oxygen adsorption on the Cu-terminated Cu₂O(110) surface is much stronger than on the Cu/O-terminated Cu₂O(111) and Cu-terminated Cu₂O(100) surfaces. More interesting, O and O₂ adsorption on the surface of Cu/O terminated Cu₂O(111) and O₂ adsorption on the Cu-terminated Cu₂O(110) surface can induce weak ferromagnetism. In addition, we analysis origin of Cu₂O surfaces with magnetism from density of state, the surface ferromagnetism possibly due to the increased 2p–3d hybridization of surface Cu and O atoms. This is radically different from other systems previously known to exhibit point defect ferromagnetism, warranting a closer look at the phenomenon.     

Sonochemical preparation of polyaniline@TiO2 and polyaniline@SiO2 for the removal of anionic and cationic dyes

Polyaniline (PANI) synthesized by simple CDs (carbon dots) initiated polymerization has formed a composite with TiO₂ and SiO₂, respectively via a sonochemical method. These PANI@TiO₂ and PANI@SiO₂ composites were proven as effective adsorbent materials to rapidly adsorb the anionic and cationic dyes from wastewater at neutral pH and ambient temperature. Selected popular cationic and anionic organic dyes consisted of methylene blue (MB), brilliant blue (BB), Evans blue (EB), crystal violet (CV), Congo red (CR), rhodamine B (RB), and rhodamine 6G (R6G). The adsorption equilibria were governed by Langmuir and Freundlich isotherms. The kinetic results revealed that the PANI@TiO₂ and PANI@SiO₂ composite materials synthesized via the sonochemical method are efficient adsorbents compared to other adsorbent materials for the removal of organic dyes from the water. The adsorbed dyes were effectively desorbed from the composites, rendering the reusability of PANI@TiO₂ and PANI@SiO₂. The estimated adsorption capacities of PANI@TiO₂ and PANI@SiO₂ composites were 89, 93, 80, 94 and 74, 71, 61, 61 mg/g for MB, CR, CV, and R6G, respectively.