乙酰苯胺和水杨酸修饰的两种吸附树脂对对氯苯酚的吸附行为

分别用乙酰苯胺、水杨酸化学修饰氯甲基化低交联大孔苯乙烯-二乙烯苯聚合物,合成超高交联吸附树脂FZH03、FZH04。与Amberlite XAD-4对照,研究了这两种树脂在不同温度下对水溶液中对氯苯酚的静态吸附和动态吸附行为。结果表明,两种树脂的等温吸附数据可被Langmuir和Freundlich等温吸附方程很好地进行拟合,对对氯苯酚的吸附量明显高于XAD-4,是焓推动的吸附过程,对对氯苯酚吸附动力学均符合一级动力学方程,有两个独立的动力学过程,颗粒内扩散是该吸附过程的速控步骤。     

乙酰苯胺修饰的吸附树脂对对甲苯胺的吸附机理研究

合成了一种用乙酰苯胺修饰的新型超高交联吸附树脂ZH-05,并用Amberlite XAD-4作对照,比较了它们对水溶液中对甲苯胺的静态吸附和脱附行为。结果表明:经过乙酰苯胺修饰的吸附树脂ZH-05在一定温度下对对甲苯胺的吸附过程中存在化学吸附,ZH-05对对甲苯胺的吸附能力明显强于AmberliteXAD-4,两种树脂对甲苯胺的吸附均符合Freundlich方程。     

萘酚修饰超高交联吸附树脂的制备及吸附动力学

明胶为分散剂,液蜡为致孔剂,交联反应中溴乙烷代替有毒氯甲醚,以β-萘酚参与Friedel-Crafts后交联反应,成功制备了酚羟基修饰的超高交联吸附树脂LM-6。树脂物理性能研究表明,LM-6具有比苯酚修饰超高交联树脂更大的比表面积和酚羟基含量;扫描电镜(SEM)表明,β-萘酚修饰的超高交联吸附树脂具有纳米吸附高分子材料特征;动力学分析表明,树脂对β-萘酚吸附界面层厚于萘,树脂和β-萘酚分子间具有更大的吸附力;拟合曲线均不经过原点说明LM-6对β-萘酚和萘的吸附由颗粒内扩散和颗粒外膜扩散共同控制。     

巯基修饰的超高交联树脂对酚类化合物的吸附

对超高交联聚苯乙烯树脂进行巯基修饰,对比大孔吸附树脂(Amberlite XAD-4)对苯酚、对甲苯酚、对氯苯酚、对硝基苯酚在水溶液中进行吸附研究。经过巯基修饰的超高交联聚苯乙烯树脂(JN-8)具有亲水性高、对酚类化合物吸附容量大的优点,该树脂可望在高浓度含酚废水治理中得到应用。     

单宁酸修饰的吸附树脂对对甲苯胺和对氯苯胺的吸附行为

通过Friede-l Crafts后交联及化学修饰反应制备了单宁酸修饰的超高交联吸附树脂(FZH-11)。通过等温吸附-脱附、吸附动力学和小柱动态吸附脱附实验,研究了FZH-11树脂对对甲苯胺和对氯苯胺的吸附性能。结果表明,FZH-11树脂有较高比表面积和微孔面积,对苯胺类化合物有良好的吸附性能,对对甲苯胺和对氯苯胺的吸附过程存在着明显化学吸附作用。FZH-11树脂对苯胺类化合物的吸附可分为大孔和中孔区的吸附与微孔区的吸附两个独立的吸附动力学过程,均可用准一级动力学方程进行拟合。10%的HCl溶液对吸附苯胺类化合物饱和后的FZH-11树脂有良好的再生效果。     

醚键型超高交联吸附树脂对苯胺和苯酚的吸附性能

以苯乙醚和氯甲醚为原料,一步合成了含氧的亲水性超高交联吸附树脂OCHR-2。树脂的比表面积为352.45 m2/g,含氧量为11.91%。用树脂Amberlite XAD-4为对比对象,研究了两种树脂对水中苯酚及苯胺的吸附性能。结果表明,相同条件下,树脂OCHR-2对苯胺的吸附量可达XAD-4的2.25倍,对苯酚的吸附量最高为XAD-4的3倍。树脂对苯胺和苯酚的吸附符合Freundlich和Langmuir吸附等温线;树脂OCHR-2对苯胺的吸附为吸热过程,对苯酚的吸附为放热过程。树脂经过5次再生利用后,吸附量没有发生明显的变化,说明树脂具有很好的可再生能力;树脂OCHR-2有望在酚类和胺类废水资源化治理中得到实际应用。     

超高交联树脂对氯酚类化合物的吸附性能

通过静态吸附研究,比较了Am berlite XAD-4和ZH-01吸附树脂对水溶液中2-氯苯酚、2,4-二氯苯酚、2,4,6-三氯苯酚的吸附热力学特性。结果表明,在288 K~318 K和研究的浓度范围内,ZH-01、XAD-4对氯酚类化合物的吸附平衡数据符合F reund lich和L angm u ir吸附等温方程。2-氯苯酚在两树脂上的吸附为放热过程,是单分子层的物理吸附;而2,4-二氯苯酚和2,4,6-三氯苯酚在XAD-4吸附是单分子层物理吸附,在ZH-01的吸附属单分子层吸热过渡化学吸附,主要是毛细管凝聚和微孔填充作用造成的吸附。并计算了氯酚类化合物在两树脂上的吸附焓变、自由能变、吸附熵变,对吸附行为进行了合理的解释。     

光氯化-烷基化两步法制备超高交联树脂及对苯酚的吸附性能

通过对二甲苯侧链光氯化产物(CP)与苯(BE)的Friede-l Crafts烷基化聚合反应制备比表面积高达905m2/g的超高交联吸附树脂(CP-BE)材料,并用红外光谱(FT-IR)、元素分析(EA)及比表面积(BET)对其结构进行表征。以XDC-BE和市售Amberlite XAD-4为参照,在不同温度下,测试了三种吸附树脂对水溶液中苯酚的吸附性能,结果表明,CP-BE和XDC-BE树脂对苯酚的吸附量分别高达171 mg/g和143 mg/g,远高于国内外用于酚类吸附的Amberlite XAD-4树脂,有望在酚类废水资源化治理中得到实际应用。     

羽毛蛋白基高吸水性树脂吸附Cd2+的动力学和热力学研究

研究了羽毛蛋白-聚(丙烯酸-丙烯酰胺)高吸水性树脂吸附Cd2+的动力学和热力学特性。动力学研究表明,树脂在吸附Cd2+的同时,自身的吸水率先增大后减小,吸附过程符合准二级动力学模型。Langmuir等温吸附方程能较好地拟合不同温度下Cd2+在树脂上的吸附行为,吸附平衡常数随着温度的升高而增大。热力学研究表明,在本实验研究范围内,吸附焓变ΔH为正值,吸附自由能变ΔG为负值,吸附熵变ΔS为正值,因此,树脂对Cd2+的吸附是一个吸热的、熵增加的自发过程,升温有利于吸附的进行。     

复配壳聚糖树脂对Cu2+的等温吸附及吸附动力学研究

以活性炭和壳聚糖为复配原料合成复配壳聚糖树脂,对树脂的结构进行扫描电镜和红外表征,并研究了复配壳聚糖树脂对Cu2+的等温吸附动力学特性。结果表明复配改性后的壳聚糖具有多孔结构,比表面积增大;交联反应发生在壳聚糖分子中的氨基和羟基上;复配壳聚糖树脂对Cu2+的吸附符合Langmuir和Freundlich等温吸附模型;其吸附动力学过程符合Lagergren二级动力学方程,吸附过程容易进行。     

Sorption enhancement of 1-naphthol onto a hydrophilic hyper-cross-linked polymer resin

A hydrophilic hyper-cross-linked polymer resin NDA-150 was developed to remove 1-naphthol from the contaminated waters. The sorption performance of 1-naphthol on NDA-150 was explored and compared with that on the commercial hydrophobic resin XAD-4. The sorption rates of 1-naphthol onto both of the two resins obey the pseudo-second-order kinetics, and are limited by the successive steps of film diffusion and intraparticle diffusion. The greater sorption rate on XAD-4 than NDA-150 is probably due to the larger average pore diameter of XAD-4. All the adsorption isotherms can be represented by Langmuir equation. The larger capacity and stronger affinity of NDA-150 than XAD-4 probably result from the abundant microporous structure and polar groups of NDA-150. In aqueous phase hydrophobic XAD-4 adsorbs 1-naphthol driven principally by enthalpy change, while the adsorption onto hydrophilic NDA-150 driven mainly by entropy change. The breakthrough and the total sorption capacity of NDA-150 to 1-naphthol were obtained to be 1.10 and 1.58 mmol mL(-1) resin at 293 K, respectively. Nearly 100% regeneration efficiency for the resin was achieved by ethanol at 313 K.     

Ammonium and potassium removal for anaerobically digested wastewater using natural clinoptilolite followed by membrane pretreatment

On the basis of the wastewater characteristic of anaerobically digested wastewater, this work studied the individual and simultaneous adsorption of ammonium and potassium ions by the natural clinoptilolite. Langmuir, Freundlich, Langmuir-Freundlich, and Toth model were employed to fit the experimental isotherm data and the fitting performances of different models were compared. Both the individual and simultaneous adsorption kinetics of ammonium and potassium were studied at various pHs and temperatures. The individual adsorption of ammonium was very fast and potassium uptake was even faster than that of ammonium. The adsorption approached equilibrium within 1h in most cases. Five models, including pseudo-first-order, pseudo-second-order, Vermeulen's model, squared driving force model and Elovich equation were used to fit the individual and simultaneous adsorption kinetics of ammonium and potassium. The validities of the fittings for the ammonium and potassium adsorption kinetics were also evaluated.     

Adsorption equilibria and kinetics for phenol and cresol onto polymeric adsorbents: effects of adsorbents/adsorbates structure and interface

Phenol and cresol (o-, m-, and p-) were selected as the adsorbates with different dipole moment (cresol>phenol, methyl being electron-drawing group) and solubility (phenol>cresol, methyl being hydrophobic group). Macropore polymers (NDA-1800 and XAD-4), hypercrosslinked polymers (NDA-100), and chemically modified adsorbents (NDA-150 and NDA-99), were comparatively used to investigate the adsorption properties including equilibria, thermodynamics and kinetics. First, all of the results about equilibria show that the adsorption data fit well to the Freundlich model. The adsorption capacity of NDA-99 and NDA-150 especially for phenol is larger in a certain extent than other three types of polymers. The hydrophobic interaction from large specific surface was mainly occurred, while the polar groups containing oxygen and amine markedly enhance the adsorption process via hydrogen interaction. Furthermore, the adsorption amount for NDA-99 and XAD-4 decrease linearly with the solubility of solutes tested. Then, the negative values of enthalpy demonstrate the predominantly exothermic and physical solid-extraction processes. Finally, the relatively more rapid adsorption process could be found onto NDA-150 than NDA-99, with the reason of the double larger pore size of the former. In conclusion, solubility of solute, together with surface area, pore size and modified groups, extremely exerts influences to the adsorption performances.     

Na_2O-CaO-Al_2O_3-SiO_2-H_2O系水化物凝胶对Cs~+的吸附机理

在35℃恒温水化反应90d条件下,制备了Na2O-CaO-Al2O3-SiO2-H2O系水化物凝胶,探讨了水化物凝胶的化学组成对Cs+吸附性能的影响;讨论了水化物凝胶对Cs+的吸附热力学行为。结果表明,当化学组成为n(CaO+Na2O)/n(SiO2+Al2O3)=0.66,n(Al2O3)/n(SiO2)=0.3时,凝胶对Cs+的3d吸附量可达10.6936mg/g;温度越低,吸附量越大,凝胶对Cs+的吸附近似服从Freudlich、Langmuir和D-R吸附等温式,反应为放热反应,且以离子交换吸附为主;吉布斯自由能和吸附熵为均为负值,反应能自发进行。吸附动力学符合Lagergren假二级速率方程模型。     

吸附温度对MgAl金属氧化物微观结构和吸附Cr(VI)性能的影响

研究了MgAl水滑石(LDH)焙烧产物(LDO)对Cr(VI)的吸附性能。考察了吸附温度对LDO吸附性能的影响, 研究了吸附过程的热力学和动力学行为。结合XRD和FT-IR表征, 阐明其吸附机理。结果表明, CrO₄^2–已成功插入水滑石层间, 适当提高吸附温度有利于LDO恢复LDH晶相。在20~60℃范围内, 随吸附温度升高, LDO对Cr(VI)吸附量增大, 50~60℃时, Cr(VI)吸附量为91 mg/g。Cr(VI)的吸附平衡数据符合Langmuir模型方程, ΔG_o为负值说明吸附过程为自发过程, ΔS_o和ΔH_o为正值表明吸附为熵增的吸热过程。吸附动力学符合伪二级动力学模型, LDO 的吸附活化能为20.04 kJ/mol, 表现为扩散控制的活性化学吸附过程。     

Adsorption of phenolic compound by aged-refuse

The adsorption of phenol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol by aged-refuse has been studied. Adsorption isotherms have been determined for phenol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol and the data fits well to the Freundlich equation. The chlorinated phenols are absorbed more strongly than the phenol and the adsorption capacity has an oblivious relationship with the numbers and the position of chlorine subsistent. The experiment data suggests that both the partition function and the chemical adsorption involve in the adsorption process. Pseudo-first-order and pseudo-second-order model were applied to investigate the kinetics of the adsorption and the results show that it fit the pseudo-second-order model. More than one step involves in the adsorption process and the overall rate of the adsorption process appears to be controlled by the chemical reaction. The thermodynamic analysis indicates that the adsorption is spontaneous and endothermic.     

强碱阴离子交换纤维对活性染料的吸附性能研究

采用聚丙烯强碱阴离子交换纤维对活性艳黄等几种活性染料进行静态吸附、动态吸附和再生实验,并与同类型树脂相比较.结果表明,强碱阴离子交换纤维对活性艳黄的吸附曲线符合Langmuer等温方程,吸附反应以液膜扩散为主,反应速率随温度和pH值的升高而增加,并且远大于树脂的吸附反应速率.动态吸附表明,强碱阴离子交换纤维对活性艳蓝、活性艳黄和活性艳红的吸附处理量依次增大.利用硝酸乙醇混合溶液再生,再生效率85.7%,纤维能够反复多次使用,可以作为活性染料废水的脱色剂使用.