固载离子液体材料的制备及其对水环境中汞离子的去除

采用浸渍法将咪唑基离子液体固载于磁性纳米颗粒表面,制备得到固载离子液体复合材料Fe_(3)O_(4)@SiO_(2)@IL。采用Fe_(3)O_(4)@SiO_(2)@IL去除水环境中的Hg^(2+),研究了pH值、吸附时间、吸附剂用量及Hg^(2+)初始浓度对Hg^(2+)去除率的影响。结果表明,Fe_(3)O_(4)@SiO_(2)@IL适用pH值范围宽,pH=7.2~9.5时,Hg^(2+)去除率达99.1%以上。Fe_(3)O_(4)@SiO_(2)@IL对Hg^(2+)的吸附速度快,只需90 min即可达到吸附平衡。对于25 mL浓度2μg/mL的Hg^(2+)溶液,加入20 mg吸附剂即可基本去除其中Hg^(2+),Fe_(3)O_(4)@SiO_(2)@IL的吸附等温线研究结果表明,吸附剂对Hg^(2+)的饱和吸附量为548.37 mg/g。

Estimation of Separation of Electrolytes and Organic Compounds by Nanofiltration Membranes Using an Irreversible Thermodynamic Modei

Nanofiltration separation has become a popular technique for removing large organic molecules and inorganic substances from water. It is achieved by a combination of three mechanisms: electrostatic repulsion,sieving and diffusion. In the present work, a model based on irreversible thermodynamics is extended and used to estimate rejection of inorganic salts and organic substances. Binary systems are modeled, where the feed contains an ion that is much less permeable to the membrane as compared with the other ion. The two model parameters are estimated by fitting the model to the experimental data. Variation of these parameters with the composition of the feed is described by an empirical correlation. This work attempts to describe transport through the nanofiltration membranes bv a simple model.

活性炭电极电容法脱盐工艺和性能的研究

电容法脱盐技术是以直流电为驱动力,利用电化学双电层充电原理脱盐的方法。本文利用恒压充放电方法,对装置的运行工艺,如施加电压、原水浓度和流速等因素对活性炭电极电吸附容量的影响进行了探讨;同时,对比研究了碱金属和碱土金属氯化物在活性炭电极表面的等电势吸附等温线的差异。结果表明,随施加电压提高,可以提高单位质量活性炭对离子的吸附容量,且0.6～1.5V范围内,吸附容量与施加电压呈线性增加关系。碱金属和碱土金属离子在活性炭电极表面的平衡吸附容量主要受其水化离子半径影响,即水化离子半径小,所带电荷少的阳离子吸附性能更好,依次为K+>Na+>Li+>Ca2+>Mg2+。

新生态二氧化锰的性质及pH值影响除砷效果的研究

Fresh MnO2 was prepared by oxide reduction using KMnO4 and MnSO4. The structure and property of the products were characterized by TEM, SEM, XRD and BET, and the effect of pH value was studied on the removal of both As and As. The results show that δ-MnO2 is spherical, its specific surface is 325 m2·g-1 with lots of hydroxyl on the surface. Adsorption of fresh MnO2 of As(III)was a corporate action of both oxide reaction and electrostatic adsorption, but the adsorption of As was due to electrostatic and anion exchange adsorption.

活性污泥对回用净水中钙离子的去除研究

在静态条件下,进行了活性污泥对净水中钙离子的去除实验研究和机理探讨。在去除实验中,考察了活性污泥用量、搅拌强度、搅拌时间、初始钙离子浓度、溶液pH对钙离子的去除效果的影响。结果表明:用活性污泥去除钙离子可以获得较好的效果,去除量可达19mg/g,并且去除速度很快,5min即可完成;且去除机理可能有生物吸附、静电吸附和化学沉淀;适当的剪切力可以加速吸附反应的进程,证实了流体力化学效应的的存在。溶液pH不同,发生的沉淀反应不同,低pH条件下,钙离子与活性污泥中磷酸根生成Ca3(PO4)2沉淀,较高pH条件下,生成的沉淀为Ca5(OH)(PO4)3。

磷酸化木质素的合成及对铅离子的去除性能

针对碱木质素对水溶液中金属离子去除能力有限、难以直接作为重金属离子吸附剂的现状,对其进行磷酸化改性.采用红外光谱、颗粒电荷分析、扫描电镜、原子吸收光谱等方法研究改性木质素对Pb^(2+)的吸附性能及相关机理.结果表明:改性后的木质素表面粗糙多孔,比表面积由2.12 m^2/g增加至11.17 m^2/g,能快速吸附Pb^(2+)且性能明显优于原碱木质素,其主要是通过磷酸根、酚羟基、羧基等带负电荷官能团与Pb^(2+)的静电作用,以及分子中的H^+与Pb^(2+)的离子交换作用进行吸附;磷酸化木质素对Pb^(2+)的去除性能主要受投加量、Pb^(2+)初始质量浓度、pH值和温度的影响;随着木质素投加量和溶液pH值的增大,磷酸化木质素对Pb^(2+)的去除率升高,在30℃下对Pb^(2+)的去除率达92.36%.

管翅式换热器离子交换树脂涂层

采用浸渍法将离子交换树脂（IER）浸渍于饱和氯化锂或氯化镁溶液中，并依次经过滤、洗涤及干燥得改性离子交换树脂。经粉碎后的改性离子交换树脂粉与固体粉末涂料混合成喷涂料，对管翅式换热器铝箔表面进行静电喷涂、热固化得吸湿涂层。XRD分析表明，改性前后树脂结构没有发生根本性改变；SEM表明，吸湿涂层能够均匀紧密地分散在铝箔表面，涂层厚达120gm；EDS显示出吸湿涂层各成分组成及含量；TG曲线表明，吸湿涂层失重主要集中在30～150℃及400-600℃区域，前者与吸附剂脱附有关，后者与涂料及树脂粉热分解有关；静态和动态吸附曲线显示，吸湿涂层经改性后，其吸湿性能明显提高；吸湿涂层重复性测试显示，涂层具有较高吸附及脱附稳定性。

Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange adsorbent

A study of nonlinear competitive adsorption equilibria of proteins is of fundamental importance in understanding the behavior of preparative chromatographic separation.This work describes the nonlinear binary protein adsorption equilibria on ion exchangers by the statistical thermodynamic(ST)model.The single-component and binary protein adsorption isotherms of bovine hemoglobin(Hb)and bovine serum albumin(BSA)on SP Sepharose FF were determined by batch adsorption experiments in 0.05 mol/L sodium acetate buffer at three pH values(4.5,5.0 and 5.5)and three NaCl concentrations(0.05,0.10 and 0.15 mol/L)at pH 5.0.The ST model was found to depict the effects of pH and ionic strength on the single-component equilibria well,with model parameters depending on the pH and ionic strength.Moreover,the ST model gave acceptable fitting to the binary adsorption data with the fitted single-component model parameters,leading to the estimation of the binary ST model parameter.The effects of pH and ionic strength on the model parameters are reasonably interpreted by the electrostatic and thermodynamic theories.Results demonstrate the availability of the ST model for describing nonlinear competitive protein adsorption equilibria in the presence of two proteins.

角蛋白/聚乙烯醇复合膜对铜离子的吸附性能

为了提高羊毛的溶解率和角蛋白的提取率,采用三羧基乙基磷溶液法提取羊毛中的角蛋白。通过简单常用的制膜技术将角蛋白与聚乙烯醇(PVA)合成出一种对铜离子具有吸附性能的角蛋白/PVA复合膜,并探讨了角蛋白/PVA复合膜对重金属铜离子的吸附行为。结果表明:角蛋白/PVA复合膜对铜离子具有吸附性能,角蛋白/PVA复合膜与铜离子接触后发生静电络合反应,使得铜离子粘附在其表层;影响角蛋白/PVA复合膜对铜离子吸附性能的因素与其孔隙率无关,而与角蛋白含量密切相关,角蛋白含量越高其对铜离子的吸附性能越好。

超高效液相色谱-四极杆/静电场轨道阱高分辨率质谱法测定鸡肉中8种喹噁啉类药物及其代谢产物

目的建立超高效液相色谱串联四极杆/静电场轨道离子阱高分辨率质谱法同步测定鸡肉中8种喹噁啉类药物及其代谢物的分析方法。方法鸡肉样品分别经过1%甲酸乙腈提取5种喹噁啉类原药和1 mol/L盐酸溶液提取3种代谢物,超声、振荡处理及高速离心后,分别用多重基质吸附填料和Oasis HLB固相萃取柱净化并收集,氮气吹干,用0.1%甲酸-乙腈溶液定容后合并进行分析。采用Acquity UPLC BEH C18(2.1mm×100 mm,1.7μm)色谱柱进行分离,以0.1%甲酸水和0.1%甲酸甲醇作为流动相,进行梯度洗脱。质谱采用平行反应监测模式下进行定性与定量分析。结果8种化合物能够得到较好地分离,在线性范围内线性关系良好,相关系数均大于0.999。在1、10、100 ng/g加标水平下,8种化合物平均回收率为76.1%~112.8%,相对标准偏差小于15%。方法检出限和定量限分别为0.04~0.1μg/kg和0.12~0.3μg/kg。结论本方法样品处理过程简便、分析时间短,准确可靠、灵敏度高,可用于鸡肉产品中多种喹噁啉药物的监测。

三维花形层状双金属氢氧化物对甲基橙和亚甲基蓝的去除

采用软模板法制备有机三维花形层状双金属氢氧化物(O3D-LDH)。通过静态吸附实验考察不同投加量、反应时间、染料初始浓度条件下,O3D-LDH对甲基橙(MO)和亚甲基蓝(MB)的吸附性能,并结合XRD、SEM、FT-IR等测试表征手段探究其反应机制。结果表明,当吸附剂投加量分别为1.0和2.5 g·L-1时,O3D-LDH对MO和MB的去除效果最佳;反应时间均在360 min达到平衡;初始浓度为200 mg·L-1时,O3D-LDH对MO和MB的最大吸附量分别为174.20和57.46 mg·g-1。O3D-LDH对MO的去除机制主要为离子交换作用,对MB的去除机制主要为表面物理吸附。

金属有机骨架材料UiO-66的制备及其对溶液中NO_3^-的吸附

采用溶剂热法合成了金属有机骨架材料UiO-66。通过XRD、SEM、FTIR对其进行了表征。考察了UiO-66对溶液中NO_3^-的吸附性能。实验结果表明,加入冰乙酸作调节剂后,得到的UiO-66晶体形貌均匀,直径在100nm左右,结晶度更好。在初始溶液pH为5、反应温度为30℃的条件下,UiO-66吸附NO_3^-反应90 min后,吸附达到平衡,平衡吸附量为39.67 mg/g。UiO-66吸附NO_3^-的吸附行为符合Freundlich等温线和准二级动力学吸附模型。吸附作用主要是材料中金属位点Zr对NO_3^-的静电吸附。UiO-66材料具有良好的再生性能,可重复使用。

Adsorption of three pharmaceuticals on two magnetic ion-exchange resins

The presence of pharmaceuticals in aquatic environments poses potential risks to the ecology and human health. This study investigated the removal of three widely detected and abundant pharmaceuticals, namely, ibuprofen（IBU）, diclofenac（DC）, and sulfadiazine（SDZ）, by two magnetic ion-exchange resins. The adsorption kinetics of the three adsorbates onto both resins was relatively fast and followed pseudo-second-order kinetics. Despite the different pore structures of the two resins, similar adsorption patterns of DC and SDZ were observed, implying the existence of an ion-exchange mechanism. IBU demonstrated a combination of interactions during the adsorption process. These interactions were dependent on the specific surface area and functional groups of the resin. The adsorption isotherm fittings verified the differences in the behavior of the three pharmaceuticals on the two magnetic ion-exchange resins. The presence of Cl-and SO2-4suppressed the adsorption amount, but with different inhibition levels for different adsorbates. This work facilitates the understanding of the adsorption behavior and mechanism of pharmaceuticals on magnetic ion-exchange resins.The results will expand the application of magnetic ion-exchange resins to the removal of pharmaceuticals in waters.

聚乙烯醇/聚乙烯亚胺纳米纤维对铬酸根离子的吸附性能

以聚乙烯醇(PVA)和聚乙烯亚胺(PEI)为原料,采用静电纺丝技术、戊二醛交联方法制备了PVA/PEI_(70 000)(重均分子量70 000)和PVA/PEI_(10 000)(重均分子量10 000)耐水性纳米纤维,通过傅里叶变换红外光谱和扫描电镜对其进行了表征,研究其力学性能和对铬酸根离子的吸附作用。结果表明,PVA/PEI_(70 000)纳米纤维具有较大的拉伸强度,对铬酸根离子的吸附效果明显好于PVA/PEI_(10 000)。溶液pH值的增加减弱了PVA/PEI纳米纤维对铬酸根离子的吸附效果,随着PVA/PEI纳米纤维用量的增加,对铬酸根离子的吸附率升高,但吸附量呈现逐渐降低的趋势。PVA/PEI纳米纤维的吸附机理遵循Langmuir等温吸附模型和准二级动力学方程,吸附过程具有自发性。重复使用性实验证明PVA/PEI纳米纤维材料具有良好的脱附再生性能。

四臂星型聚电解质刷在外加三价盐离子和电场下的塌缩

本文采用Langevin动力学模拟的方法,研究存在三价盐离子时,接枝在带相反电荷的极板上的部分带电的四个臂星型链呈现出的塌缩现象.结果表明,在电场作用下,接枝星型链的平均带电分数和盐浓度在带电单体和三价盐离子的竞争性吸附中起关键作用.对于接枝在带相反电荷的极板上的带电分数较高的星型链,刷子会塌缩到接枝极板上,并会产生极板表面电荷的过度补偿现象.当带电分数较低时,如果星型链所带电荷数与三价盐离子电荷数相同,即使在很低的盐浓度下,极板对三价盐离子的吸引能力也高于对星型链中的带电单体的吸引.结果表明,星型链在带电分数较低的情况下,三价盐离子的加入不会导致接枝电极表面电荷的过度补偿.此外,本文还研究了三价盐离子对电场作用下星型刷的拉伸的影响.

超分子结构纤维素基吸附剂对水体中钴离子的去除

以纤维素为原料,采用高碘酸钠氧化后接枝支化聚乙烯亚胺,制备超分子结构纤维素基吸附剂(Supramolecular amino-functionalized cellulose,SAC),并分析SAC去除Co^(2+)离子的能力,并通过FTIR、EDS、吸附动力学和吸附等温线模型探究其去除机理。结果表明:SAC能快速去除Co^(2+)离子,在10 min内达到吸附平衡;吸附容量随着pH值的增加而增加,吸附效率随着温度的增加而降低;SAC对Co^(2+)离子的吸附是一个自发的放热过程,符合伪二级吸附动力学和Langmuir等温吸附模型,SAC对Co^(2+)最大吸附容量为52.63 mg/g;SAC对Co^(2+)离子的高效去除效率是静电作用、配位络合及离子交换共同作用。为水体中Co^(2+)离子的去除提供了一种新方法。

空气消毒净化新技术在医院工程中的应用

介绍了空气消毒净化新技术的工作原理,各新技术的优缺点,应用新技术的产品。

Adsorption of single and mixed haloacetonitriles on silica-based porous materials: Mechanisms and effects of porous structures

Adsorption mechanisms and the role of different porous and crystalline structures on the removal of five haloacetonitriles(HANs) over hexagonal mesoporous silica(HMS), titanium substituted mesoporous silica(Ti-HMS), rod-shaped SBA-15 and microporous zeolite Na Y were investigated. In addition, the effect of p H on adsorption mechanism and selective adsorption of five HANs individually and in an equimolar mixed solution were evaluated.The results indicated that the intraparticle diffusion rate constants of the mesoporous adsorbents were higher than that of the microporous Na Y. In single solute, the order of adsorption preference(highest to lowest) was mono-HANs > di-HANs > tri-HAN. However,in mixed solute, the large molecular weight of the tri-HAN and di-HANs are more easily adsorbed than the smaller molecular weight mono-HANs. Except for SBA-15, the order of adsorption capacities in mixed HANs solute was not different compared to that observed for the single HAN solute, which might be caused by the higher accessibility to the active sites due to larger pore size. The ion-dipole electrostatic interaction was likely to be the main adsorption mechanism, and was favored at high p H values due to the high negative surface charge density of the adsorbent. The molecular structure of the HANs and hydrophilic/hydrophobic nature affected the adsorption capacities and their selective adsorption from mixed solutes.

Removal of ammonium ion from water by Na-rich birnessite:Performance and mechanisms

Na-rich birnessite（NRB） was synthesized by a simple synthesis method and used as a high-efficiency adsorbent for the removal of ammonium ion（NH＋4） from aqueous solution.In order to demonstrate the adsorption performance of the synthesized material,the effects of contact time,pH,initial ammonium ion concentration,and temperature were investigated.Adsorption kinetics showed that the adsorption behavior followed the pseudo second-order kinetic model.The equilibrium adsorption data were fitted to Langmuir and Freundlich adsorption models and the model parameters were evaluated.The monolayer adsorption capacity of the adsorbent,as obtained from the Langmuir isotherm,was 22.61 mg NH＋4-N/g at283 K.Thermodynamic analyses showed that the adsorption was spontaneous and that it was also a physisorption process.Our data revealed that the higher NH＋4adsorption capacity could be primarily attributed to the water absorption process and electrostatic interaction.Particularly,the high surface hydroxyl-content of NRB enables strong interactions with ammonium ion.The results obtained in this study illustrate that the NRB is expected to be an effective and economically viable adsorbent for ammonium ion removal from aqueous system.

石墨烯/离子液体体系静电吸附机理及非平衡热力学模型

超级电容是基于固液界面静电吸附原理的先进储能技术.石墨烯和高浓度离子液体被认为是超级电容储能的理想材料和电解液工质,但是其静电吸附过程中能量载子间具有复杂交互作用、纳米尺度效应和非平衡热力学特征,显著区别于常规低浓度、低黏度和非受限体系,无法通过经典理论和模型进行解释.本文通过分子动力学模拟,结合恒定电势和热力学方法,系统研究了离子液体在石墨烯纳米通道内的静电吸附机理,包括热力学平衡态结构和非平衡传递过程;提出了可在分子动力学模拟中量化离子传递的判据,发现离子液体在纳米通道内传递与电势、受限效应、粒子间交互作用密切相关;基于时间微元原理,建立了描述纳米通道静电吸附过程的非平衡热力学模型,更为真实地描述了静电吸附充/放电过程;发现纳米受限状态下高密度异性离子和低密度同性离子间相界面的形成会阻碍同性离子的传输,进而造成高充/放电速率下储能容量下降,不同于传统观点所提出的异性离子吸附滞后的机理.研究结果揭示了高浓度离子液体在纳米通道内的特殊静电吸附机理,为构筑高性能超级电容提供了理论指导.