超高交联吸附树脂吸附对硝基苯乙酮的热力学研究

比较两种超高交联聚苯乙烯吸附树脂NJ-8、AM-1与Amberlite XAD-4(以下简称XAD-4)对对硝基苯乙酮的静态吸附行为，根据吸附等温线研究了吸附热力学性质．在298～318K和研究的浓度范围内，NJ-8，AM-1、XAD-4对对硝基苯乙酮的吸附平衡数据符合Freundlich吸附等温方程．结果表明：吸附为放热过程，适当降低温度有利于吸附．计算了对硝基苯乙酮在NJ-8，AM-1、XAD-4树脂上的吸附焓变、自由能变，吸附熵变．对吸附行为作了合理的解释。     

胺化XAD-4螯合树脂的合成及其对Cu~(2+)的吸附

通过XAD-4树脂和氯代乙酰氯的Friedel-Crafts反应合成了氯乙酰化XAD-4树脂,再将氯乙酰化XAD-4树脂分别与二乙烯三胺、三乙烯四胺和四乙烯五胺反应制备了三种氨基螯合树脂,用电导率法研究了它们对Cu2+的吸附动力学。红外光谱和碱基全交换容量测定结果表明氯乙酰基被成功地引入到XAD-4树脂上以及二乙烯三胺、三乙烯四胺和四乙烯五胺被键合到氯乙酰化XAD-4树脂上。吸附动力学测试表明,螯合树脂对金属铜离子的吸附速率和吸附量与氨基含量密切相关,二级速率方程可用来描述螯合树脂对金属铜离子的吸附动力学。     

超高交联吸附树脂对苯甲酸的吸附研究

用新合成的NJ－8超高交联吸附树脂吸附苯甲酸，并与Amberlite XAD-4进行比较。从静态平衡吸附行为及其热力学性质讨论吸附机理。动态穿透吸附实验进一步验证了NJ－8提高交联吸附树脂对苯甲酸的吸附能力约为Amberlite XAD-4的1.6倍。     

2-氨基吡啶修饰的聚苯乙烯树脂对2,4-D的吸附性能

氯甲基聚苯乙烯和2-氨基吡啶发生亲核取代反应,合成2-氨基吡啶修饰的聚苯乙烯树脂(简记为JX-08),以XAD-4树脂为参照,研究JX-08树脂对水溶液中2,4-D的吸附性能。实验结果表明,JX-08树脂在较宽的pH值范围(pH值在2~11)对2,4-D的吸附量大,XAD-4树脂在pH值小于2时对2,4-D的吸附量大;JX-08树脂对2,4-D的吸附符合Freundlich方程模型,XAD-4树脂对2,4-D的吸附符合Langmuir方程模型;当2,4-D流出液浓度为上样浓度的1%时,JX-08树脂和XAD-4树脂对2,4-D的吸附量分别为148.2mg/mL和40.5mg/m L。JX-08树脂和XAD-4树脂吸附的2,4-D可分别用6.5BV 2mol/L NaOH和6.5BV C2H5OH解吸。吸附机理表明,XAD-4树脂吸附2,4-D以疏水作用为主要推动力,而JX-08树脂对2,4-D的吸附存在阴离子交换和疏水作用,且阴离子交换对JX-08树脂吸附2,4-D的贡献大于疏水作用对JX-08树脂吸附2,4-D的贡献。     

新型吸附树脂对苯乙酸的吸附热力学研究

研究了苯乙酸在新型超高交联树脂AH、NDa-150和大孔吸附树脂(Amberlite XAD-4)上的平衡吸附数据，测定了288K、303K和318K温度下的吸附等温线，结果表明吸附过程符合Langmuir吸附等温方程。苯乙酸在AH、NDa-150上的吸附容量分别比在Amberlite XAD-4上的吸附容量最高高出90％、113％，这主要归因于AH、NDa-150表面的极性基团及树脂的微孔结构．Langmuir吸附等温线、相对吸附容量以及等量吸附焓变表明，苯乙酸在AH树脂上的吸附是物理吸附和化学吸附共同作用的结果．对苯乙酸被3种树脂吸附的吸附焓变、自由能变、吸附熵变也作了计算，并对吸附行为作了合理的解释。     

胺基修饰大孔树脂对腐殖酸的吸附研究

研究了腐殖酸在胺基修饰大孔树脂D-301上的吸附行为,并与胺基修饰超高交联树脂NDA-99和大孔非极性树脂XAD-4作对比,结果表明,带有弱碱性基团的大孔亲水性树脂D-301对腐殖酸的吸附效果优于XAD-4和NDA-99,这主要得益于D-301树脂大孔结构和表面胺基修饰.探讨了溶液pH值和重金属离子对D-301树脂吸附腐殖酸的影响,并对作用机理进行了初步探讨.     

硫辛酸在三种不同树脂上的吸附热力学和动力学研究

通过静态吸附实验,研究了大孔交联聚苯乙烯树脂(XAD-4)、氧修饰超高交联聚苯乙烯树脂(NDA-100)和胺基修饰超高交联聚苯乙烯树脂(ND-90)对乙醇．水溶液中硫辛酸的吸附热力学及动力学特性,结果表明：硫辛酸在XAD-4树脂上是单层吸附,符合Langmuir等温吸附方程,吸附过程符合准一级动力学吸附方程。硫辛酸在NDA-100和ND-90树脂上的吸附也符合Langmuir等温吸附方程,但并不只是单层吸附,同时兼有毛细管凝聚和微孔填充作用,吸附过程可分为大孔和中孔区的吸附以及微孔区的吸附两个阶段,两个阶段都符合准一级动力学吸附方程。     

烟草烘丝尾气收集液分级装置构建与评价

本文构建了一种基于FLASH色谱技术的烟草烘丝尾气收集液的分级装置。该装置采用阳离子交换柱、阴离子交换柱和大孔吸附树脂柱串联的方法分级烟草烘丝尾气收集液,优化分离条件,结合气相色谱/质谱(GC/MS)分析对烟草烘丝尾气收集液分级装置进行评价。结果显示,烟碱吸附于732型的阳离子交换树脂中,而717型阴离子交换树脂和AB-8型大孔吸附树脂富集了乙酰基吡咯、二氢猕猴桃内酯、β-二氢大马酮等烟草中的多种致香成分。     

几种吸附树脂对硝基化合物吸附性能的研究

研究NJ－8、AM－1、Amberlite XAD-4、JX－101 4种吸附树脂对对硝基苯乙酮和对硝基苯甲酸的静态吸附行为。结果表明：江苏南大戈德环保科技有限公司研制的NJ－8和AM－1两种吸附树脂对硝基化合物的吸附效果较好。并研究NJ－8型吸附树脂的动态吸附和脱附行为，结果显示：NJ－8型吸附树脂对对硝基苯甲酸的吸附容量为128mg/g干树脂，对对硝基苯乙酮的吸附容量为383mg/g干树脂。用8%NaOH:乙醇（体积比1：1）洗脱吸附酸的树脂，用甲醇或乙醇洗脱吸附酮的树脂，体积为5BV时，温度分别为333K和313K，脱附率均接近100％。     

乙酰苯胺修饰的吸附树脂对苯酚和对氯苯酚的吸附研究

通过Friedel-Crafts后交联及化学修饰反应,合成了乙酰苯胺基修饰的超高交联吸附树脂ZH-05,通过红外光谱(IR)和比表面及孔径分析(BET)对其结构进行表征.以Amberlite XAD-4树脂作为参照,通过等温吸附实验和吸附动力学实验探讨了ZH-05树脂对水溶液中苯酚和对氯苯酚的吸附性能和机理.结果表明,与XAD-4树脂相比,ZH-05树脂对苯酚和对氯苯酚均具有更佳的吸附性能.Langmuir和Freundlich方程均能较好拟合ZH-05树脂对苯酚和对氯苯酚的吸附等温线.ZH-05树脂对苯酚和对氯苯酚的吸附以焓推动的自发物理吸附过程为主,吸附过程放热;吸附符合准一级动力学吸附方程,颗粒内扩散是吸附过程的主要控制步骤.     

白兰花头香和净油的化学成份研究

我们利用一种憎水性树脂来收集白兰花自然散发的香气,然后利用GC,GC/MS/DS进行香气的化学成份分析,并以同样的方法分析了净油的化学成份,共鉴定出62个已知化学组份。     

微波条件下固体酸催化剂催化酯化生物油的研究

以乙醇和乙酸的酯化作为反应模型,考察固体酸催化剂阳离子交换树脂、SO₄²-/ZrO₂和分子筛在微波加热条件下的酯化活性。结果表明,三类固体酸催化剂的活性顺序为Amberlite树脂﹥SO₄²-/ZrO₂﹥HZSM-5,催化剂活性与酸度一致;酯化反应中水的含量对催化剂的活性有不同程度的影响,水含量较高时催化剂SO₄²-/ZrO₂酯化活性明显变差,而阳离子交换树脂仍具有较高的酯化活性。采用阳离子交换树脂对生物油进行微波催化酯化提质后,原生物油中含有的大量不同种类的羧酸被有效地转化成各种酯类,酯类化合物由原油中的4种增加到13种。与传统加热条件下生物油催化提质比较,生物油微波提质具有明显优势,提质后生物油组分得到优化。     

Aluminium determination in environmental samples by graphite furnace atomic absorption spectrometry after solid phase extraction on Amberlite XAD-1180/pyrocatechol violet chelating resin

A chelating resin, pyrocatechol violet (PV) immobilised on an Amberlite XAD-1180 support, was prepared and its use for the atomic absorption spectrometric determination of aluminium was investigated. The XAD-1180-PV resin was characterised by infrared spectrometry and thermal gravimetric analysis. The optimum pH value for quantitative sorption is 8-9, and desorption can be achieved by using 5.0-10.0 ml of 2 M HCl. The effects of diverse ions on the sorption and recovery of aluminium have been studied. The capacity of sorbent was 6.45±0.59 mg g⁻¹ Al XAD-1180-PV. Recoveries for aluminium from water samples were in the range 95-105%. The accuracy of procedure was confirmed by aluminium determination in certified reference materials. The method developed was applied with varying results to the analysis of natural water, haemodialysis fluids and microwave digested red wine samples from Tokat City.     

Studies on synthesis and application of XAD-4-salen chelate resin for separation and determination of trace elements by solid phase extraction

The use of chemically modified XAD-4-salen chelating resin had been studied for the separative concentration of metal ions from an aqueous solution. XAD-4-salen was synthesized by diazonium coupling reaction of salen[N,N′-bis(salicylidene)ethylenediamine] and Amberlite XAD-4 resin. The distribution coefficient at various pH values and adsorption capacities were obtained with respect to Cu(II), Pb(II) and Bi(III). Trace elements were pre-concentrated on the synthesized XAD-4-salen by batch method for atomic absorption spectrometric determination. Some conditions, such as the pH of aqueous solution, amount of XAD-4-salen, kinds and concentration of acids were optimized for the analytical application of XAD-4-salen. For the pre-concentration of metal ions, the pH of the aqueous solution was adjusted to approximately 5.5, and then it was stirred 30 min after the addition of 50 mg of pulverized XAD-4-salen. The adsorbed metal ions were desorbed by 10 mL of 1.0 M HNO₃. The desorption efficiency of Bi(III) was enhanced by the addition of 30 mg/L of Pd(II). The addition of Pd(II) as a matrix modifier could improve the reproducibility and sensitivity in the Atomic Absorption Spectroscopy (AAS) determination of volatile lead and bismuth. In the present study, this procedure has been applied for the determination of Cu(II), Pb(II) and Bi(III) in real samples of five kinds of river water, using a standard calibration curve method. Recoveries of 85–120% were obtained in the spiked samples in which given amount of analytes were added.     

Assessment on the removal of dimethyl phthalate from aqueous phase using a hydrophilic hyper-cross-linked polymer resin NDA-702

A hydrophilic hyper-cross-linked polymer resin (NDA-702) was synthesized, and the adsorption performance of dimethyl phthalate (DMP) on NDA-702 was compared with that on the commercial hydrophobic macroporous resin (Amberlite XAD-4) and granular activated carbon (AC-750). The kinetic adsorption of DMP onto NDA-702 and AC-750 is limited mainly by intraparticle diffusion and obeys the pseudo-second-order rate model, while the uptake on XAD-4 is limited mainly by film diffusion and follows the pseudo-first-order rate model. All the associated adsorption isotherms are well described by the Freundlich equation, and the larger uptake and stronger affinity of NDA-702 than AC-750 and XAD-4 probably result from the microporous structure, phenyl rings, and polar groups on NDA-702 polymer matrix. An interesting observation is that in the aqueous phase all the adsorbents spontaneously adsorb DMP driven mainly by enthalpy change, but the hydrophilic nature of NDA-702 and AC-750 surfaces results in less entropy change compared to hydrophobic XAD-4. Dynamic adsorption studies show that the high breakthrough and the total adsorption capacities of NDA-702 are 388 and 559 mg per gram dry resin at 313 K. Nearly 100% regeneration efficiency for the resin was achieved by methanol at 313 K.     

Use of amberlite XAD-7HP for the separation of Mn(II) and Mn(VII) in waters

A simple method is proposed for the determination and speciation of Mn(II) and Mn(VII) in waters utilizing a macroporous resin, Amberlite XAD-7HP. The batch method was employed and flame atomic absorption spectrometry was used in all determinations. Amberlite XAD-7HP resin was shown to retain Mn(VII) between pH 4 and 12. If the solution contains only one of the species, either Mn(II) or Mn(VII), the resin behaves selectively depending on the pH of the solution. The elution from the sorbent was realized using K₂C₂O₄ in HNO₃. The efficiency of the method was checked via spike recovery experiments. The proposed method was successfully applied to industrial wastewater samples and quantitative recoveries (≥96.0%) confirmed the accuracy of the method.     

Production of mutagenic artifacts by the action of residual chlorine on XAD-4 resin

XAD resins are commonly used to recover and concentrate organics from chlorinated water. It was found that the action of residual chlorine on XAD-4 resin produced mutagenic artifacts in a dose dependent manner. The production of mutagenic artifacts could be suppressed at least ten-fold by converting free chlorine to monochloramine. Kinetic studies of the reaction between free chlorine and XAD-4 resin showed a reaction rate dependence upon pH and chloride ion concentration that suggests participation of species besides hypochlorous acid.     

Separation and determination of traces of heavy metals complexed with humic substances in river waters by sorption on indium-treated amberlite xad-2 resin

A nonionic macroreticular styrene/divnylbenzene copolymer, Amberlite XAD-2 resin is pulverized to 1–10 μm and treated with indium ions to saturate traced of cation exchange sites for the quantitative separation of humic complexes from cations. A 100-ml filtered sample is passed through an indium-treated XAD-2 column (16 diameter, 5 mm tall) at pH 5 at a flow rate of 2 ml min^? to sorb heavy metals complexed with humic and fulvic acids. Inorganic cations and anions, EDTA complexes and colloidal hydrated iron(III) oxide are not retained on the column at all. The heavy metals sorbed on the column are then ultrasonically desorbed with 0.5 M nitric acid and determined by graphite-furnace atomic absorption spectrometry. The results fo two river water samples obtained are in good agreement with those obtained when the macroreticular weak-base anion-exchanger DEAE-Sephadex A-25 is used.     

Preconcentration and separation with Amberlite XAD-4 resin; determination of Cu, Fe, Pb, Ni, Cd and Bi at trace levels in waste water samples by flame atomic absorption spectrometry

A method for the preconcentration of Cu, Fe, Pb, Ni, Cd and Bi as their diethyldithiocarbamate chelates was proposed using a column filled with Amberlite XAD-4 resin. The retained analytes on the resin were recovered with a small volume of acetone. The metal ions in the effluent were determined by a flame atomic absorption spectrometer. Different factors including pH of sample solution, sample volume, amount of XAD-4 resin, amount of ligand, eluent volume and matrix effects for preconcentration were examined. The recoveries for the analytes under the optimum working conditions were higher than 95%. The relative standard deviations of the determinations were below 9%. The limits of detection (3 s, n=20) for analytes were found to be between 4 and 23 mug l(-1). The proposed method was applied to the analysis of some waste waters from the organized industrial region of Kayseri.