A WATER-COMPATIBLE PHENOLIC HYDROXYL MODIFIED POLYSTYRENE AS AN ADSORBENT FOR ADSORBING PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTIONS

A water-compatible phenolic hydroxyl modified polystyrene adsorbent (AM-1) foradsorbing and removing phenolic compounds from aqueous solutions was prepared by covalent bonding of phenolic hydroxyl groups to the surface of porous polystyrene-divinylbenzene beads, this resin can be used directly without wetting process. A comparison of the sorption properties of the new resin and Amberlite XAD-4 toward four phenolic compounds, phenol, p-cresol, p-chlorophenol,and p-nitrophenol was made. The capacities of equilibrium adsorption of AM-l for all four phenolic compounds increased around 20% over that of Amberlite XAD-4, which may be contributed to phenol hydroxyl group on the surface and the unusual pore distributior. At their dilute solution, the equilibrium adsorption capacities of AM-1 for phenol increased about 62% over that of Amberlite X4D-4, while equilibrium adsorption capacities of the other three phenolic compounds increased 4-35%, suggesting an advantage of AM-I over Amberlite XAD-4 in the collection of phenol.Freundlich isotherm equations and isosteric adsorption enthalpies for the four phenolic compounds indicate a physical adsorption process on the Amberlite XAD-4 and AM-I resins. Column studies for phenol show that AM-1 resin has excellent adsorption and desorption performance.     

一种亲水的酚羟基修饰聚苯乙烯树脂对酚类化合物的吸附热力学

在283-323K和研究的浓度范围内,苯酚、对甲苯酚、对氯苯酚和对硝基苯酚在亲水性的酚羟基修饰聚苯乙烯树脂（AM-1）与大孔吸附树脂（Amberlite XAD-4)上平衡吸附数据符合Freundlich吸附等温方程。酚类化合物在AM-1上的吸附容量比在Amberlite XAD-4上的吸附容量增加20%以上,这主要得益于AM-1表面的酚羟基入树脂的微孔结构。在较稀的溶液中AM-1对苯酚的吸附量比AmberliteXAD-4对苯酚的吸附量增加60%,表明AM-1对苯酚有特殊的选择性。Freundlich吸附等温线、相对吸附容量以及等量吸附焓表明,四种酚在两种树脂上的吸附是物理吸附过程。对酚类化合物被两种树脂吸附的吸附焓、自由能、吸附熵也作了测试,并对吸附行为作了合理的解释。     

A WATER—COMPATIBLE PHENOLIC HYDROXYL ODIFIED POLYSTYRENE AS AN ADSORBENT FOR ADSORBING PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTIONS

A water-compatible phenolic hydroxyl modified polystyrene adsorbent (AM-1) for adsorbing and removing phenolic compounds from aqueous solutions was prepared by covalent bonding of phenolic hydroxyl groups to the surface of porous polystyrene-divinylbenzene beads,this resin can be used directly without wetting process.A comparison of the sorption properites of the new resin and Amberlite XAD-4 toward four phenolic compounds,phenol,p-cresol,p-chlorophenol,and p-nitrophenol was made.The capacities of equilibrium adsorption of AM-1 for all four phenolic compounds increased around 20% over that of Amberlite XAD-4,which may be contributed to pheonl hydroxyl group on the surface and the unusual poe distribution.At their dilute solution,the equilibrium adsorption capacities of AM-1 for phenol increased aout 62% over that of Amberlite XAD-4,while equilibrium adsorption capacities of the other three phenolic compounds increased 4-35%,suggesting an advantage of AM-1 over Amberlite XAD-4 in the collection of phenol.Freundlich isotherm equations and isosteric adsorption enthalpies for the four phenolic compunds indicate a physical adsorption process on the Amberlite XAD-4 and AM-1 resins,Column studies for phenol show that AM-1 resin has excellent adsorption and desorption performance.     

ADSORPTION OF 2,4-DICHLOROBENZOXYACETIC ACID ONTO HYPERCROSSLINKED RESIN MODIFIED BY PHENOLIC HYDROXYL GROUP (AM-1)

 An experimental comparison of the adsorption properties of hypercrosslinked resin AM-1 modified by phenolic hydroxyl group with Amberlite XAD-4 toward 2,4-dichlorobenzoxyacetic acid was performed. This paper focuses on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Two isotherm models were used to explain the results. It is seen that the Langmuir equation can give a perfect fit. The adsorption capacities from the different ranges of temperature, the adsorption enthalpy change value and the comparison of desorption conditions lead to the same conclusion that the adsorption of 2,4-dichlorobenzoxyacetic acid from water onto AM-1 is a type of physical and chemical transition.     

ADSORPTION OF 2,4-DICHLOROBENZOXYACETIC ACID ONTO HYPERCROSSLINKED RESIN MODIFIED BY PHENOLIC HYDROXYL GROUP (AM-1)

INTRODUCTIONAdsorption has been considered to be the best available technology for removing organics from water in the USSafe Drinking Water Act[1]. Due to many drawbacks of activated carbon[2-7], the most widely used adsorbent,hypercrosslinked polymeric adsorbents developed by Tsyurupa and Davankov[8] have been increasingly viewedas an alternative to activated carbon for selective removal of specific organic substances from contaminatedwater[9-12], and series of researches have been do…     

Adsorption behavior of phenolic compounds onto polymeric adsorbents modified with 2-carboxybenzoyl groups

<正>Two hypercrosslinked polymeric adsorbents(ZH-01 and Amberlite XAD-4 resin) were employed to remove three kinds of phenolic compounds including phenol,4-nitrophenol and 2,4-dinitrophenol from aqueous solutions.The study was focused on the static equilibrium adsorption behavior,the column dynamic adsorption and desorption profiles.The Freundlich model gave a perfect fitting to the isotherm data.The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite XAD-4 within the temperature range 288-318 K,which was attributed to the large micropore area and 2-carboxybenzoyl functional groups on the network of ZH-01 resin.The adsorption for phenol and 4- nitrophenol on ZH-01 was a physical adsorption process,while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption's transitions.The column test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds.Being used as the desorption reagent,sodium hydroxide solution showed an excellent performance.     

THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p-nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate.     

ADSORPTION OF BENZOIC ACID AND P-NITROBENZOIC ACID ON A NEW HYPERCROSSLINKED PHENOL GROUP PST ADSORBENT

1.INTRODUCTIONThepolymericadsorbentAmberliteXAD-4isconsideredoneofthemostsuitablepolymericadsorbentsforremovingphenoliccompoundsfromwaterstreams[1,2]becauseitischemicallystable,notsolubleinsolventsandmoreselectiveforaromaticringsduetoitshydrophobicproperties.However,methanol,acetoneoracetonitrile,hastobeusedtoenhancethesurfacecontactbetweenadsorbentandthesolute.DavankovandTsyurupadescribedanewseriesofadsorbents[3,4].Thistechniqueyieldedpolystyrenesorbentsofunusualhypercrosslinkedstructu…     

氨基修饰聚苯乙烯树脂对酚酸物质的吸附性能

通过对XAD 4聚苯乙烯树脂的氨基修饰制备了一种亲水性的NDA 10 0树脂 .研究了NDA 10 0树脂对苯酚和对羟基苯甲酸等酚酸类物质的吸附动力学和热力学行为 .结果表明 ,NDA 10 0树脂对苯酚和对羟基苯甲酸具有良好的吸附性能 ,在研究的浓度范围内 ,吸附平衡数据符合Langmuir和Freundlich等温吸附方程 ,吸附为放热的物理吸附过程 .吸附动力学符合Lagergren准二级速率方程 ,颗粒内扩散为吸附速率的主要控制步骤 .     

ADSORPTION OF BENZOIC ACID AND P-NITROBENZOIC ACID ON A NEW HYPERCROSSLINKED PHENOL GROUP PST ADSORBENT

A comparison of the adsorption of benzoic acid and p-nitrobenzoic acid on the new hypercrosslinked polymeric adsorbent AM-I, with that by macroporous Amberlite XAD-4, including the equilibrium adsorption isotherms, the dynamic adsorption behaviors through column and the adsorption thermodynamics were studied. Results show that Freundlich equation gives a fitting adsorption isotherm. The specific surface of AM-l is only 67% of that of Amberlite XAD-4, but the adsorption capacities on AM-1 are much higher about 125%～166% than that on Amberlite XAD-4,which is contributed to the micropore mechanism and polarity. The negative values of the adsorption enthalpy are indicative of an exothermic process. Enthalpy and free energy changes of adsorption both manifest a physic-sorption process. The negative values of the adsorption entropy indicate that the adsorption is well consistent with the restricted mobilities and the configurations of the adsorbed benzoic acid molecules on the surface of studied adsorbents with superficial heterogeneity. Both adsorbents were used in mini-column experiments for adsorbing benzoic acid expecting to elucidate the higher breakthrough adsorption capacity of the new hypercrosslinked polymeric adsorbent AM-1 as compared with that of Amberlite XAD-4.     

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％。     

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。     

超高交联吸附树脂对芳香有机物的吸附机理

通过3种吸附树脂AmberliteXAD-4、AM-1和JX101对芳香化合物苯胺、苯酚和苯甲酸在不同温度下的吸附特征,利用前线轨道理论进行了合理解释。结果表明,吸附剂表面进行适当的修饰,可以改变吸附剂的LUMO或HOMO,使吸附质分子与吸附剂表面的功能基产生化学作用,从而产生额外的化学吸附量,为优化设计吸附剂提供了理论指导。     

STUDIES ON THE ADSORPTION OF PHENOLIC COMPOUNDS ON A PS-BASED RESIN MODIFIED BY NITRO FUNCTIONAL GROUPS

A new adsorbent (JN-01) was prepared by modifying resin NDA-1800 with nitro functional groups.The adsorption capacities of resins XAD-4,NDA-1800 and JN-01 were investigated,and the results indicated that the modified resin JN-01 was much better in adsorbing phenol,p-nitrophenol and p-cresol.The adsorption capacities of the resin JN-01 were higher than those of the resins XAD-4 and NDA-1800 within a temperature range of 283-323 K,which might be attributed to the higher surface area and the partial polarit...     

Adsorption equilibrium and heat of phenol onto aminated polymeric resins from aqueous solution

Aminated polystyrene resins (NDA-101 and NDA-103) were synthesized, and their adsorption performances for phenol in aqueous solution were investigated and compared with the commercial polystyrene resin (Amberlite XAD-4) and weakly basic polystyrene resin (Amberlite IRA-96). All the associated adsorption isotherms are well described by Freundlich and Langmuir equations. The results indicated that all the four resins spontaneously adsorb phenol driven mainly by enthalpy change, and their adsorption capacities, free energy changes, enthalpy changes, and entropy changes for phenol followed the same order as: NDA-101 > NDA-103 > XAD-4 > IRA-96. Surface energy heterogeneity analysis by Do's model also suggested that the surfaces of XAD-4 and IRA-96 were more homogeneous, and the better adsorption capacity and affinity of the aminated resins (NDA-101 and NDA-103) are probably due to their multiple hydrogen bonding and π–π stacking interactions with phenol molecule.     

ADSORPTION OF PHENOL AND Pb^2＋ FROM AQUEOUS SOLUTIONS BY A NEW DI-FUNCTION ADSORBENT WITH SULFHYDRYL GROUPS

A new di-function adsorbent （JN-3） was prepared by sulfhydryl modified. Comparing with Amberlite XAD-4 and NDA-150, the equilibrium adsorption for phenol on the JN-3 from aqueous solutions was tested, perfect adsorption capacity was shown. Pb^2＋ can be also removed by JN-3 because of the chelate interaction between sulfhydryl groups and metal ions. This adsorbent could be used in removal of combine pollutants such as phenolic compounds and heavy metal ions from waste streams.     

超高交联树脂对苯胺的吸附机理研究

在静态条件下，研究了水溶液中超高交联树脂AM－1和NJ－8及大孔吸附树脂Amberlite XAD－4吸附苯胺的热力学特性，测定了不同温度下的吸附等温线。结果表明，在稀溶液中3种树脂吸附苯胺都符合Langmuir和Freundlich模型，其中AM－1和NJ－8对苯胺的吸附是一个吸热过程；由于AM－1和NJ－8的微孔结构和表面存在酸性基团的吸附中心，对苯胺的吸附是物理吸附和化学吸附共同作用的结果。     

超高交联树脂对苯胺和对硝基苯胺的吸附行为

吸附热力学;化学吸附;超高交联树脂对苯胺和对硝基苯胺的吸附行为     

吸附树脂的修饰官能团设计及其吸附机理研究

利用AM1半经验计算法计算出用不同官能团修饰的聚苯乙烯型吸附树脂的前线轨道能量值.设计筛选出合适的官能团,根据吸附质的分子尺寸,修饰合成出具有匹配孔径、较大比表面积的吸附树脂.在303K下,测定了它们对不同取代基的酚类化合物的吸附等温线.以Amberlite XAD-4作参照,比较了吸附剂的吸附效果,并阐明了吸附机理.     

ADSORPTION OF 2,4-DICHLOROPHENOL IN AQUEOUS SOLUTION ONTO ADSORPTION RESIN MODIFIED BY N-ACETYLANILINE

A hypercrosslinked adsorption resin （ZH-05） modified by N-acetylaniline in the post crosslinking process was prepared. The adsorption properties of ZH-05 toward 2,4-dichlorophenol in comparison with granular activated carbon （GAC） and Amberlite XAD-4 were observed. The present study mainly focuses on the static equilibrium adsorption behaviors, desorption profiles and the proof of chemisorption. The results show that the Langmuir equation can give a perfect fitting to experimental data, and high temperature was favorable for adsorption of 2,4-dichlorophenol on ZH-05. A related equation was used to correlate the amount of chemisorption and the suppositionai chemisorption equilibrium concentration of adsorbate in aqueous solution. The adsorption capacities from different ranges of temperature and the static desorption experiment both reveal the same conclusion, i.e., the adsorption of 2,4-dichlorophenol from water on ZH-05 is a coexistent process of physical adsorption and chemical transition as on GAC.