羧酸型离子交换纤维对卡那霉素的吸附

测定了羧酸型离子交换纤维吸附卡那霉素的动力学曲线和吸附等温线,并研究了温度、pH值、盐浓度对吸附卡那霉素的影响. 研究结果表明,羧酸型离子交换纤维吸附卡那霉素在10 min达到平衡,其吸附平衡行为可用Langmuir方程描述;在pH 7时,羧酸型离子交换纤维吸附卡那霉素的静态交换容量为最大,可达5.6′104 U/g;羧酸型离子交换纤维吸附卡那霉素随温度变化很小;NaCl的存在使羧酸型离子交换纤维对卡那霉素的交换容量减小;对发酵液中卡那霉素的动态交换容量为5.16′104 U/g,洗脱率为88.1%.     

大庆油页岩及其半焦孔结构研究

采用比表面积吸附仪测定大庆油页岩及其半焦的低温氮吸附等温线,结果表明油页岩及不同干馏终温下的半焦均属于II型吸附等温线,说明其具有较连续的完整的孔系统,孔径范围小至分子级孔,大至无上限孔（相对而言）。各干馏终温半焦的比表面积及孔径分布具有相似的特点,分布曲线起始部分有较大程度的上翘,在孔直径40～50h内出现一个小的峰值。试验条件下,随着干馏终温的增加,试样的比表面积和孔容积均有增大趋势。     

甲烷、乙烷、丙烷和丁烷在中孔活性炭上的吸附平衡

以活性炭AC1为吸附剂,在体积法实验装置上分别测定了其对甲烷、乙烷、丙烷和丁烷4种气体的吸附等温线,吸附温度分别为283、293、303和313 K。利用77 K吸附氮气数据表征AC1,得到其比表面积为956 m²·g^-1,孔体积为1.36 mL·g^-1,孔径分布在1~5 nm,中孔的比例达到了61%。AC1对4种气体的吸附等温线均为I型等温线,分别采用Langmuir方程和Langmuir-Freundlich方程(简称L-F方程)对吸附平衡数据进行拟合,结果表明,L-F方程具有更好的拟合效果,为后序的多组分吸附平衡研究提供了基础数据。AC1对乙烷/丙烷的吸附平衡选择性系数在1.7~2.5,吸附选择性随吸附压力的增大而减小,吸附温度对吸附选择性无明显影响。     

阴离子交换纤维对草酸根离子吸附性能的研究

以含偕胺肟基团的螯合纤维为原料,分别经Hg（NO3）2、Pb（NO3）2等溶液化学处理,制得五种不同类型的阴离子交换纤维。研究了时间、温度、pH值和离子浓度等因素对阴离子交换纤维吸附草酸根离子性能的影响。实验结果表明,汞阴离子交换纤维、铅阴离子交换纤维和铜阴离子交换纤维可以吸附草酸根离子,且汞阴离子交换纤维吸附性能最好。汞阴离子交换纤维在反应时间为90min、温度为40℃、pH值为9、草酸根离子浓度为0．05mol/L时,最高吸附量可达1．65mmol/g.     

季铵型阴离子交换纤维的制备及其吸附性能研究

将棉纤维进行碱化、老化处理,所得的碱纤维与交联剂4,4 ′-二苯基甲烷二异氰酸酯反应制得中间产物,再与3-氯-2-羟丙基三甲基氯化铵接枝反应得到季铵型阴离子交换纤维;利用红外光谱分析对产品的结构进行表征,测定其交换容量,并作出其对水溶液中Na2SO4的吸附等温线,用Freundlich吸附等温方程对吸附等温线进行拟合和...     

XDA-8大孔树脂对高浓度咖啡因的吸附热力学研究

测定了不同温度下极性大孔吸附树脂XDA-8对高浓度咖啡因的吸附等温线,并采用Langmuir吸附等温方程进行了拟合,在此基础上对吸附行为进行了热力学研究.结果表明,Langmuir吸附等温方程对吸附过程拟合程度很高,XDA-8大孔树脂对咖啡因的吸附为单分子层吸附;XDA-8大孔树脂吸附咖啡因是一个放热过程,升高温度使其...     

弱酸性阴离子交换纤维吸附钼（Ⅵ）的性能研究

研究了弱酸性阴离子交换纤维对钼（Ⅵ）的吸附性能,考察了酸度、温度和时间等因素对吸附性能的影响。实验结果表明在pH为3时吸附性能最好,离子交换纤维对钼（Ⅵ）的吸附以液膜扩散为主,交换速度很快,30 min即可达到吸附饱和,吸附速率常数为0.231 s-1,离子交换过程服从Freundlish等温式,温度和流速影响动态吸附性能,使得穿透曲线和穿透时间发生改变,具有吸附速度快、吸附量大的优点,且解吸性能良好,可以进行再生使用。     

活性炭纤维去除饮用水中痕量有机物的效果

采用了两种活性炭纤维（ACF）对水中TOC、UV254、CHCl3三种痕量有机物指标的去除进行了初步的研究并与颗粒活性炭（GAC）进行了对比。吸附速率线表明,ACFl对TOC、CHCl3的吸附速率较快,对UV254的吸附速率三种吸附剂相差不大;吸附等温线表明,ACFl对TOC、UV254、CHCl3的去除效果最好,在相同的平衡浓度下,ACFl的吸附容量最大;对CHCl3动态吸附穿透曲线进一步验证了静态实验的结论：ACFl去除水中CHCl3的效果最好,且当原水流经吸附柱的流速V=2．OL／h时,其饱和吸附量最大,为151．73μg／g。本实验的研究还表明,ACF及GAC对于TOC、UV254、CHCl3的吸附性能与其比表面积成正比。     

活性炭对汞离子的吸附动力学研究

以椰壳活性炭为原料,采用水蒸气法二次活化制备得到了微孔含量丰富的椰壳活性炭,其亚甲基蓝吸附值165 mg/g,碘吸附值1 090 mg/g。采用氮气吸附等温线对其比表面积和孔结构进行了表征。以氯化汞为污染目标物,考察了活性炭对于Hg2+的吸附性能。结果表明,活性炭对Hg2+的吸附量与其比表面积以及孔结构有关。吸附动力学实验表明活性炭吸附是一个快速吸附和缓慢吸附共存的双速过程,可以用Lagergren伪二级速率方程进行拟合;吸附等温线实验表明活性炭吸附Hg2+是一个放热的过程,属于单分子层吸附,符合Langmuir吸附等温式。     

离子交换纤维对偏二甲肼的吸附性能

以火箭推进剂主要成分偏二甲肼为研究对象,通过配制模拟水样,采用强酸阳离子交换纤维对其中的偏二甲肼进行吸附,研究了偏二甲肼在离子交换纤维上的等温吸附线、吸附动力学和动态吸附,并将其动态吸附效果与732强酸阳离子交换树脂进行了对比. 结果表明,强酸阳离子交换纤维对偏二甲肼的吸附以液膜扩散为主,符合Boyd液膜扩散方程. 在291 K和研究的浓度范围内,离子交换纤维对偏二甲肼的吸附符合Freundlich等温吸附方程. 动态吸附结果表明,离子交换纤维对偏二甲肼的交换吸附速率大于离子交换树脂. 离子交换纤维柱的利用率高,相同条件下的处理量是树脂的3.86倍.     

Study of the fluorine adsorption onto zirconium oxide deposited strong alkaline anion exchange fiber

A kind of adsorbent, strong alkaline anion exchange fiber loaded with zirconium strong alkaline anion exchange fiber (Zr@SAAEF) was prepared. Zr(IV) was uniformly distributed on SAAEF through chemical bonds and physical deposition. Zr@SAAEF has a decent effect on the removal of fluorine in water and scanning electron microscopy images and Fourier transform infrared spectroscopy spectrum showed that the Zr(IV) was successfully loaded on the fiber by chemical bonding. The average adsorption capacity of fluorine was 28.14 mg/g with pH ranging from 5.0 to 8.9, when fluorine solution (100 mg/L) was adsorbed by 0.1 g SAAEF, and the extent of removal exceed 96% when the adsorbent dose was 0.3 g. The adsorption isotherms were well fitted with Langmuir equation, and the maximum adsorption capacities calculated by Langmuir equation were close to the experiment results. The adsorption was an endothermic reaction. These results implied that fluorine adsorption onto Zr@SAAEF belonged to chemical adsorption using monolayer coverage on surface of the fiber. The adsorption kinetics of fluorine onto Zr@SAAEF could be described by pseudo‐second‐order rate mode. Zr@SAAEF showed a decent ability for fluorine removal from aqueous solution. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45855.     

阴离子交换树脂吸附辣椒碱的动力学研究

以辣椒树脂为原料,采用静态吸附法确定了201×7型阴离子交换树脂吸附辣椒碱的最优工艺和提取机理。通过可见分光光度法测定了辣椒碱的质量浓度,并绘制出了不同pH的吸附等温线,建立了离子交换吸附辣椒碱的动力学模型。实验结果表明:该树脂吸附辣椒碱的最优pH值为5.5,当pH5.0或pH6.0时,Langmuir方程能够更好地拟合该吸附过程;而当pH=5.0~6.0时,辣椒碱的吸附等温线更符合Freundlich方程。在pH=5.5、308.15K下,较高的辣椒树脂的质量浓度能显著提高离子交换速率,且初期(t30 min)800~1200r/min的搅拌速率有利于吸附过程。通过计算得出,树脂吸附辣椒碱模型的速率常数k0=2.11×10-3s-1、活化能Ea=12.6 k J/mol、反应级数为0.268,并利用Freundlich模型解析获得了最优pH值(5.5)下阴离子交换树脂吸附辣椒碱的动力学方程。     

中空聚丙烯基离子交换纤维的制备及表征

以CaCO_3为成孔剂,通过共混熔融纺丝和酸化制备中空聚丙烯纤维,以纤维为基体,通过引发剂接枝苯乙烯,再经氯甲基化和胺化反应制备强碱性阴离子交换纤维;采用红外光谱、电镜扫描、热重分析等分析手段对制备的离子交换纤维进行了表征,并对其交换容量、溶胀性及动力学吸附性能进行了测试。结果表明:制备的强碱性阴离子交换纤维具有较高的交换容量,约达到3.08 mmol/g,吸附性能良好,含水量大于56%,是一种性能优良的离子交换纤维。     

离子交换纤维吸附儿茶素的热力学

采用自制离子交换纤维对儿茶素的吸附特性进行了研究,在温度为286～328 K和研究的浓度范围内,离子交换纤维对儿茶素吸附平衡数据符合Langmuir和Freundlich吸附等温方程.Freundlich吸附等温线和等量吸附焓表明：离子交换纤维对儿茶素吸附是吸热过程.对儿茶素在离子交换纤维上的吸附焓、自由能、吸附熵的计算表明,该离子交换纤维对儿茶素的吸附没有化学键生成,并对吸附行为作了合理解释.     

Volatile fatty acid adsorption on anion exchange resins: kinetics and selective recovery of acetic acid

ABSTRACT

The removal of volatile fatty acids was examined through adsorption on anion exchange resins in batch systems. During the initial screening step, granular activated carbon and 11 anion exchange resins were tested and the resins Amberlite IRA-67 and Dowex optipore L-493 were chosen for further investigation. The adsorption kinetics and diffusion mechanism and adsorption isotherms of the two resins for VFA were evaluated. Based on the selective adsorption capacity of the resins, a sequential batch process was tested to achieve separation of acetic acid from the VFA mixture and selective recoveries > 85% acetic acid and ~ 75% propionic acid was achieved.     

Immobilization of imidazole in polymer electrolyte membranes for elevated temperature anhydrous applications

A novel functional absorbent, polyvinyltetrazole fiber (PVT), was made from polyacrylonitrile fiber through [3+2] azide-nitrile cycloaddition reaction of cross-linked polyacrylonitrile with sodium azide. The obtained PVT showed strong adsorption ability to the investigated heavy-metal ions, Cu(II), Cd(II), Ni(II), and Zn(II), with the maximum adsorption capacities of 323, 278, 200, and 175 mg g⁻¹, respectively. The adsorption process was described as an ion exchange mechanism. The adsorption isotherms were better fitted for Langmuir model, while adsorption kinetics was better described by the pseudo-second order equation. In addition, the tested heavy-metal ions could be desorbed efficiently from PVT at pH below 2.0, and the adsorption capacity of the regenerated PVT had no loss until seven cycles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

阴离子交换纤维对磷酸根离子吸附性能及机理研究

以含偕胺肟基团的螯合纤维为原料,经Fe(NO3)3溶液处理,制得阴离子交换纤维,以其为吸附材料,对磷酸根离子进行吸附规律研究;并采用红外光谱仪(IR)和扫描电子显微镜(SEM)对样品进行了表征。实验结果表明,阴离子交换纤维对磷酸根离子的吸附反应符合Freundlich及Langmuir等温吸附模型,饱和吸附量为8.299 mmol/g。采用初始浓度法确定该反应为一级反应;在不同温度下对初始浓度为0.04994 mol/L的磷酸根离子进行吸附,测定了各温度下的反应速率常数,由速率常数与温度的关系得出反应的活化能Ea=22.55 kJ/mol,速率常数k=40.65 e-Ea/RT。     

Quaternized biomass as an anion exchanger for the removal of nitrate and other anions from water

Dried Chinese Reed (Miscanthus sinensis), a fast growing plant, was used as a model biomass for the development of anion exchangers using a quaternization agent, N‐(3‐chloro‐2‐hydroxypropyl)trimethylammonium chloride (CHMAC), and a cross‐linking agent, epichlorohydrin. Anions studied include nitrate, phosphate, perchlorate and sulfate. Batch mode adsorption studies were conducted using aqueous solutions of anions. Detailed kinetics were studied for nitrate removal. Parameters studied included anion concentration, agitation time, adsorbent dose, and pH. Adsorption equilibrium occurred in 10 min for all the anions studied. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. The presence of phosphate, perchlorate, fluoride and sulfate lowered the adsorption significantly. The effects of pH on adsorption and desorption show that ion exchange is involved in the adsorption process. The adsorption capacity of the cross‐linked and quaternized Chinese Reed for nitrate, sulfate, phosphate and perchlorate was found to be 7.55, 13.25, 16.61 and 10.07 mg of anion per g of the anion exchanger, respectively. Copyright © 2004 Society of Chemical Industry