首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 131 毫秒
1.
通过氯甲基化的苯乙烯-二乙烯苯共聚物的后交联及单宁酸的化学修饰反应制备了单宁酸修饰的超高交联吸附树脂(TAMR),通过红外光谱、元素分析、扫描电镜和比表面孔径分析对TAMR树脂的结构特征和表面参数及形貌进行表征.通过等温吸附实验和吸附动力学实验研究了苯酚、对硝基苯酚和对氯苯酚在TAMR树脂上的吸附性能和吸附机理.结果表明,TAMR树脂具有较高的比表面积(780.1 m2/g)和较丰富的微孔(482.3 m2/g),树脂表面修饰了较丰富的羟基.TAMR树脂对苯酚、对硝基苯酚和对氯苯酚均具有较好的吸附性能,288 K时吸附量分别可达1.43、2.07和2.48 mmol/g(c0为500 mg/L).3种酚类化合物在TAMR树脂上的吸附为典型的物理吸附,其吸附焓变和熵变均为负值.当酚类化合物以分子形态存在时,有利于其被TAMR树脂吸附.Langmuir和Freundlich方程均能较好地拟合酚类化合物在TAMR树脂上的吸附等温线.吸附动力学过程符合准一级动力学方程,颗粒内扩散过程是TAMR树脂吸附这3种酚的吸附速率的主要控制步骤.  相似文献   

2.
合成了用邻羧基苯甲酰基或苯甲酰基修饰的新型聚苯乙烯-二乙烯苯吸附树脂ZH-01, ZH-02和ZH-03, 利用瓶点法研究了它们和Amberlite XAD-4对288~318 K下水溶液中2,4,6-三氯苯酚的静态吸附和静态脱附特征以证实吸附质与吸附剂之间存在化学吸附, 并利用半经验分子轨道法(AM1)计算的几种吸附剂和2,4,6-三氯苯酚的前线轨道近似能级进行了解释. 结果表明: 经邻羧基苯甲酰基或苯甲酰基化学修饰后的树脂ZH-01, ZH-02和ZH-03对水溶液中2,4,6-三氯苯酚的吸附过程在合适温度时会使酚羟基和吸附剂表面的羰基发生作用, 对吸附剂进行适当的化学修饰后, 对2,4,6-三氯苯酚的穿透吸附容量均为Amberlite XAD-4树脂的150%, 饱和吸附容量是Amberlite XAD-4树脂的114%~128%.  相似文献   

3.
工业二乙烯苯悬浮聚合制备的大孔树脂,在二氯乙烷溶剂中以无水三氯化铁为催化剂进行悬挂双键后交联反应,得到的后交联树脂的比表面积和孔容都有显著增加.低温氮气吸附/脱附等温线得到的孔径分布曲线证明初始共聚物PDT-55(polydivinylbenzene,toluene as porogen)和PDH-55(polydivinylbenzene,heptane andtoluene as porogen)经后交联反应,所形成的新孔以微孔为主.树脂对水溶液中苯酚和维生素B12(VB12)的静态吸附研究发现树脂经后交联后,对苯酚的吸附量有显著提高,但对VB12的吸附量增加不大,原因是分子尺寸较大的VB12无法进入由悬挂双键后交联反应所形成的微孔.树脂PDT-55pc对苯酚的吸附量大于商品树脂XAD-4;后交联前后树脂PDT-55、PDT-55pc(post-crosslinking of PDT-55)、PDH-55、PDH-55pc(post-crosslinking ofPDH-55)对VB12的吸附量均大于树脂XAD-4.在本研究的实验条件下,Langmiur和Freundlich吸附等温线方程能很好地拟合树脂对水溶液中苯酚和VB12的吸附,相关系数在0.99以上.静态吸附动力学实验结果表明后交联前后树脂对苯酚的吸附较VB12更容易达到吸附平衡.吸附动力学数据的拟合结果显示,McKay二级吸附动力学模型符合树脂对苯酚的吸附,而对VB12的吸附更符合Lagergren一级吸附动力学模型.  相似文献   

4.
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。  相似文献   

5.
通过后交联反应和化学修饰反应制备了没食子酸修饰的超高交联吸附树脂(GAMR),以大孔吸附树脂XAD-4树脂为对照,研究了GAMR对水中2,4-二氯苯氧乙酸(2,4-D)的吸附性能.实验结果表明:GAMR具有较丰富的微孔,比表面积和微孔面积分别为1 232.3和899.5 m~2·g~(-1).GAMR对2,4-D的吸附动力学过程符合准一级动力学方程,吸附过程同时存在物理吸附和化学吸附.Freundlich等温方程能较好地拟合GAMR对2,4-D的吸附等温线.GAMR对2,4-D吸附过程的ΔG为负值,ΔH和ΔS均大于0,表明吸附是自发、吸热和熵增加的过程.与XAD-4相比,所制备的GAMR对2,4-D的吸附去除率显著提高.  相似文献   

6.
对超高交联聚苯乙烯树脂进行酚羟基修饰得到修饰后的超高交联聚苯乙烯树脂(JN-2),将该树脂与大孔吸附树脂(Amberlite XAD-4)和超高交联树脂(NDA-150)在水溶液中对苯酚进行吸附-脱附性能比较,经过酚羟基修饰的超高交联聚苯乙烯树脂(JN-2)对苯酚的吸附性能有所提高,同时脱附性能明显改善,该树脂可望在含酚废水治理中得到广泛应用.  相似文献   

7.
通过水杨羟肟酸(SHA)与氯甲基化交联聚苯乙烯微球之间的Friedel-Crafts烷基化反应,实现了SHA在交联聚苯乙烯微球(CPS)上的固载化,制得了SHA功能化微球SHA-CPS。采用红外光谱对其结构进行表征;通过吸附动力学实验和等温吸附实验研究了SHA-CPS微球对苯酚及对硝基苯酚的吸附行为,考察了介质的pH、温度对SHA-CPS微球吸附苯酚的影响,探讨了其吸附热力学与吸附机理。结果表明,SHA-CPS对苯酚及对硝基苯酚具有较强的吸附能力和较快的吸附速率,其吸附能力受温度和pH影响较大。SHA-CPS对苯酚及对硝基苯酚的吸附动力学过程符合准一级方程,其吸附行为符合Freundich吸附模型,属单分子层吸附。SHA-CPS吸附树脂具有良好的重复使用性能。  相似文献   

8.
合成了新的胺基修饰的超高交联AH系列吸附树脂.以弱碱树脂D301和超高交联吸附树脂ND100为参照,测定了AH系列吸附树脂吸附水中苯酚、对氯苯酚、对甲苯酚、对硝基苯酚的吸附性能。结果表明:修饰的超高交联吸附树脂对苯酚.对甲苯酚、对氟苯酚的吸附量比ND100和D301更大,而D301树脂对对硝基苯酚有最大的吸附量.提出了AH系列树脂对4种酚类化合物吸附行为的作用机理.  相似文献   

9.
合成了1,2,4-苯三酸酐修饰超高交联吸附树脂,通过静态吸附,研究了树脂上对氯酚类物质的吸附性能及吸附机理。结果表明,树脂对4种氯酚类物质均具有较好的吸附性能,对2,4-二氯苯酚的吸附是化学吸附占主导作用,对对氯苯酚、2,6-二氯苯酚和2,4,6-三氯苯酚的吸附都是物理吸附和化学吸附共同作用的过程,Freundlich吸附等温方程很好地拟合4种氯酚类物质在树脂上的吸附行为。  相似文献   

10.
合成间氨基水杨酸修饰的超高交联吸附树脂LZ-01,比较LZ-01树脂与NJ-8树脂对对甲基苯酚和对硝基苯酚的吸附能力,研究LZ-01树脂在不同温度(288K,313K,318K)下吸附水溶液中对甲基苯酚和对硝基苯酚的静态吸附热力学和动力学行为。结果表明,由于LZ-01树脂具有更大的比表面积、更多的微孔且含有氨基、羟基和羧基等基团,使其对对甲基苯酚和对硝基苯酚的吸附量明显高于NJ-8树脂。Freundlich方程对等温吸附数据能够很好地拟合,吸附焓变绝对值小于40kJ/mol,表明吸附是焓驱动的物理吸附过程。LZ-01树脂对对甲基苯酚和对硝基苯酚吸附动力学均符合准一级动力学方程,吸附速率随温度升高而增大,颗粒内扩散是该吸附过程的速控步骤。  相似文献   

11.
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.  相似文献   

12.
研究了小檗碱在HPD-100树脂上的吸附热力学和动力学行为。考察了小檗碱在HPD-100树脂上的吸附等温曲线和吸附动力学曲线,确定了吸附过程的热力学及动力学参数。结果表明,HPD-100树脂对小檗碱的等温吸附可采用Langmuir方程描述、吸附为自发进行的放热型物理吸附过程;Dunwald–Wagnen内扩散方程能较好地拟合吸附动力学数据,吸附过程以颗粒内扩散为主要控制步骤,该吸附过程的表观活化能为29.11kJ/mol。本文为HPD-100树脂分离富集小檗碱类生物碱的实际应用提供基础数据及指导。  相似文献   

13.
Experimental investigations were conducted on the adsorption characteristics of 2,6-dichlorophenol by two hypercrosslinked resin, ZH-01 and XAD-4. The static adsorption was studied. Within temperature range of 288K~313K, the equilibrium adsorption date was fitted to freundlich adsorption isotherm models to evaluate the model parameters. The enthalpies, free energy,entropy were indicative of an exothermic, a spontaneous and disorder decreasing process. The magnitudes for 2,6-dichlorophenol on ZH-01 showed a chemisorption's transitions while on XAD-4shows a physical adsorption process. The results showed that the ZH-01 adsorbents were better than the Amberlite XAD-4 for removing the 2,6-dichlorophenol in aqueous solutions.  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
1. INTRUDUCTION As most phenolic compounds are extremely toxic at the concentrations discharged into accepting effluents, the removal or destruction of phenolic compounds from such streams has become a significant environmental task [1]. Increasing concern for public health and environmental quality has led to the establishment of limits on the acceptable environmental levels of specific pollutants [2]. Consequently there has been a growing interest in developing and implementing various …  相似文献   

17.
氨基修饰聚苯乙烯树脂对酚酸物质的吸附性能   总被引:7,自引:1,他引:6  
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 .  相似文献   

18.
STUDY ON THE ADSORPTION OF PHENOL BY CHITOSAN FROM AQUEOUS SOLUTION   总被引:1,自引:0,他引:1  
The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan were investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters (AH, AG, AS) were calculated according to the values of binding Langmuir constant, KL. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ΔH constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results.  相似文献   

19.
以对氨基苯磺酸、苯酚、甲醛为基本原料,设计并合成了内盐结构稳定、对 (NH4)2SO4有较大亲合力的新型两性吸附树脂-PSN树脂,研究了PSN树脂对 (NH4)2SO4的吸附性质,同时研究了PSN树脂对 (NH4)2SO4的吸附等温线的静态性能。实验结果表明,PSN树脂对 (NH4)2SO4的吸附是以分子吸附形式进行,常温下PSN树脂对与自身结构相似的 (NH4)2SO4饱和吸附量可达3.16mmol/g干树脂,吸附等温线符合Langmuir等温方程。  相似文献   

20.
The adsorption of isomaltotriose from aqueous solution on Ca2+ resin was investigated.The adsorption isotherm and the rate curve were determined. The pseudo-first-order model,pseudo-second-order model and the intraparticle diffusion model were used to predict the rate constants of adsorption. The activation energy of adsorption has been also evaluated using the pseudo-second-order rate constants. The results showed that the adsorption of isomaltotriose onto Ca2+ resin is an exothermically activated process. The adsorption isotherm can be described by Langmuir equation. The pseudo-second-order model can fit well to the adsorption rate curve of isomaltotriose onto Ca2+ resin. It suggests that the adsorption of isomoltotriose onto Ca2+ resin involve chemical adsorption.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号