红霉素在大孔树脂上的吸附动力学研究

采用液膜及孔内扩散模型,模拟不同温度和不同红霉素(EM)初始浓度条件下,大孔吸附树脂HZ816及XAD16吸附红霉素的动态吸附曲线,并获得液膜传质及孔内扩散系数;考察了温度及溶质浓度对红霉素在两种树脂中吸附动力学的影响.结果表明,在实验范围内,红霉素在HZ816和XAD16两种树脂上的吸附平衡数据满足Langmuir吸附等温线方程,液膜及孔内扩散模型能较好地描述红霉素在两种树脂上的吸附动力学,同时,模型拟合得到的液膜传质系数随着温度的升高而增大,随着初始浓度的增大而增大,孔内扩散系数随着温度的升高而增大,随着初始浓度的增大而减小.     

聚酰基硫脲树脂对Cu~(2+)的吸附性能研究

采用对苯二甲酰基二异硫氰酸酯与苯二胺通过界面缩聚反应制备了含有硫脲基团的螯合树脂。通过静态吸附方法,考察了不同的pH值、时间、温度以及Cu2+的初始浓度条件下树脂对Cu2+的吸附性能,初步探讨了树脂对Cu2+的吸附热力学和动力学。结果表明,吸附过程符合Boyd液膜扩散方程,液膜扩散为吸附主要控制步骤;等温吸附可较好符合Langmuir吸附模型,吸附过程为单分子层吸附;吸附容量随温度的升高而增加,吸附为吸热过程。     

聚酰基硫脲树脂对Cu^2＋的吸附性能研究

采用对苯二甲酰基二异硫氰酸酯与苯二胺通过界面缩聚反应制备了含有硫脲基团的螯合树脂。通过静态吸附方法,考察了不同的pH值、时间、温度以及Cu^2＋的初始浓度条件下树脂对Cu^2＋的吸附性能,初步探讨了树脂对Cu^2＋的吸附热力学和动力学。结果表明,吸附过程符合Boyd液膜扩散方程,液膜扩散为吸附主要控制步骤;等温吸附可较好符合Langmuir吸附模型,吸附过程为单分子层吸附;吸附容量随温度的升高而增加,吸附为吸热过程。     

离子交换树脂吸附古龙酸的工艺

应用自行合成的阴离子树脂D02直接吸附发酵液中的2-酮基-L-古龙酸,并研究了其吸附的静态与动态过程.利用Langmuir和Freundlich吸附等温线方程对吸附等温线数据进行拟合,发现2种模型相关性都很好.测定了不同流速、温度、浓度以及pH条件下古龙酸在合成树脂柱中的穿透曲线,当上柱液pH为1.5、质量浓度为10 g/L、吸附温度为309 K、流速为0.35 mL/min时,每g湿树脂的动态附容量为133 mg.同时测定了不同洗脱剂、洗脱流速条件下的洗脱曲线.每g湿树脂的动态吸附容量达到了133 mg,当温度为283 K、洗脱剂为10%H2SO4-CH3OH、流速为0.2 mL/min时,洗脱收率可达65.3%.     

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.     

聚乙烯吡啶树脂吸附乳酸的研究

本文系统地研究了乳酸在聚乙烯毗啶(PVP)树脂上的吸附和解吸特性。测定了乳酸在PVP树脂上的吸附动力学曲线和吸附等温线,研究了温度、无机盐浓度及液相pH值等因素对乳酸在PVP树脂上的吸附特性的影响。用动态实验比较了不同有机溶剂的洗脱性能。选择甲醇作解吸剂,考察了乳酸进液浓度、流速、床层的初始状态等因素对乳酸在PVP树脂柱中的动态吸附及解吸特性的影响,并对动态吸附过程进行了数学模拟。     

米根霉磁性生物吸附剂的制备及其对刚果红的吸附

以产富马酸米根霉菌体粉末、FeSO4和FeCl3为原料,制备了米根霉磁性生物吸附剂,考察了吸附剂投加量、pH值、刚果红浓度、吸附时间及吸附动力学等对阴离子偶氮染料刚果红的吸附影响. 结果表明,刚果红去除率随吸附剂投加量增加而提高,增大溶液初始浓度能有效提高吸附量,当吸附剂为1.0 g/L, pH=7.0时,吸附效果最佳,刚果红浓度为20 mg/L去除率达98.68%以上. 米根霉磁性吸附剂对刚果红的吸附等温线符合Langmuir模型,吸附过程符合拟二级动力学方程,内扩散为主要控速步骤. 吸附剂有较强磁性,在外加磁场下能快速实现固液分离和回收,可简化刚果红偶氮染料吸附的后续处理.     

离子交换树脂法提纯维生素C磷酰化反应液

采用D301大孔弱碱阴离子交换树脂分离提纯维生素C磷酰化反应液.测定了室温下D301树脂吸附维生素C磷酸酯钠的动力学曲线和吸附等温线,考察了溶液pH值、温度、盐酸洗脱液浓度等因素对吸附的影响.最后用D301树脂对磷酰化反应液进行梯度洗脱,并用HPLC进行分析.结果表明D301树脂吸附维生素C磷酸酯钠约60 min达到平衡,Freundlich方程可以较好地描述树脂对维生素C磷酸酯钠的吸附.在室温下将磷酰化反应液调节pH至1～2后上柱吸附,依次用0.05 mol/L、0.2 mol/L、2.0 mol/L的盐酸溶液洗脱,收集0.2 mol/L盐酸洗脱液,用HPLC分析,结果其维生素C磷酸酯含量大于97%.     

改性玉米秸秆复合高吸水树脂对亚甲基蓝的吸附性能研究

以植酸改性玉米秸秆与丙烯酰胺、乙烯基吡咯烷酮、衣康酸接枝共聚合成了植酸改性玉米秸秆复合高吸水树脂(PCS-SA),并将其用于亚甲基蓝(MB)水溶液的吸附,研究了MB初始质量浓度、pH值、温度对MB吸附性能的影响,并对MB吸附过程进行了热力学等温线和动力学拟合,采用SEM对PCS-SA的形貌进行了表征。结果表明,MB吸附容量和吸附速率随温度的升高而增加。随着MB初始质量浓度的增加,MB的吸附容量不断增大。当MB初始质量浓度为1 400 mg/L,pH为7.0时,MB吸附容量达1 317 mg/g。MB溶液吸附等温线符合Langmuir方程,吸附动力学符合准二级动力学方程。     

离子交换法去除有机胺吸收剂中SO_4~(2-)的平衡及动力学

研究了大孔阴离子交换树脂对有机胺吸收剂中SO_4~(2-)的吸附相平衡和动力学.结果表明,D296型树脂对SO_4~(2-)具有良好的吸附选择性,303 K下的吸附容量达120 mg/g;吸附平衡符合Langmuir等温方程;吸附过程符合拟二级动力学方程,由液膜扩散和颗粒内扩散共同控制.     

Lactic acid recovery from a model of Thermotoga neapolitana fermentation broth using ion exchange resins in batch and fixed-bed reactors

This study focused on the integration of lactic acid adsorption and desorption onto commercially available resins in batch reactors with consequent scale-up in fixed-bed reactors. Amberlite® IRA-900, IRA-400, IRA-96 and IRA-67 were used as adsorbents for lactic acid recovery from solutions that mimic the fermentation broth of Thermotoga neapolitana. The best resins were further tested in adsorption–desorption batch experiments, over 13 cycles, with IRA-67 showing an average removal efficiency of 97%. IRA-67 was tested in fixed-bed reactor experiments and an average desorption efficiency of 68% was achieved using three bed volumes of 0.5 M NaOH as the desorbing agent.     

Removal of Congo Red dye from aqueous solution using Amberlite IRA-400 in batch and fixed bed reactors

Removal of Congo Red (CR) azo dye by adsorption process using Amberlite IRA-400 resin was evaluated in both batch and fixed bed system. From the batch adsorption results, maximum loading efficiency (99.99%) of CR dye was obtained at the conditions pH 4.5, temp. 303?K, contact time 180?min., Amberlite IRA-400 dose 0.5?g. The isotherm study ascertained on favorability of adsorption process as the value of separation factor (K_L?=?0.88) and Freundlich constant (1/n?=?0.96?R²?=?0.99) than Freundlich model (R²?=?0.97). The kinetic data studied at three different CR dye concentration (50, 75, 100?mg) and results were fitted with both pseudo-first-order and second-order model equations. The values of R² obtained are of 0.95 and 0.99 for former and later one, respectively, ensuring on best fitting of pseudo-second-order kinetics and also suggesting about the chemisorptions type of adsorption. The bed depth service model was applied for competitive analysis of the CR dye adsorption in column variables indicating mass transfer from aqueous solution to Amberlite IRA-400 phase. Fourier transform infrared analysis of CR-loaded resin Amberlite IRA-400 showed a band shifted from 1057 to 1130?cm^?1 confirming CR adsorption with Amberlite IRA-400. Scanning electron microscope analysis of resin before and after adsorption was well evident from the phase patterns. Selective separation of CR dye from waste effluent of a textile industry bearing CR dye along with other trace heavy metal was achieved.     

Fixed‐Bed Adsorption Study for Fumaric Acid Removal from Aqueous Solutions by Amberlite IRA‐400 Resin

A fixed‐bed adsorption study was carried out by using a strong base anion‐exchange resin (Amberlite IRA‐400) for the removal of fumaric acid from aqueous solutions. The breakthrough curves were obtained as a function of flow rate, temperature, feed pH, and inlet fumaric acid concentration. The total adsorption capacity and the percent fumaric acid removal of the resin were calculated. The Yoon‐Nelson model was applied to the experimental data to predict the breakthrough curves and to determine the characteristic column parameters required for process design. The breakthrough curves fit the model predictions well.     

弱碱性树脂处理β-萘磺酸废水研究

研究了弱碱性树脂处理 β 萘磺酸废水。考察了废水中硫酸 ,β 萘磺酸在弱碱性树脂Indion 86 0上的吸附与洗脱性能 ,静态吸附平衡模型与实验数据吻合。结果表明 ,Indion 86 0树脂比其他树脂有更优的性能 ,可有效地分离出废水中的 β 萘磺酸 ,且易于洗脱再生 ,是一种具有工业应用前景的优良树脂     

Evaluation of polystyrene anion exchange resin for removal of reactive dyes from aqueous solutions

The Amberlite IRA-900 resin was tested to remove C.I. Reactive Black 5, C.I. Reactive Red 2 and C.I. Reactive Red 120 dyes from solutions. Batch adsorption studies concerning effects of the phase contact time, pH, temperature, the presence of salts and surfactants were run. A pseudo second-order kinetic model was used to evaluate the rate constants. The Langmuir equation provided good fit for the experimental data of the equilibrium adsorption. The studies of dyes uptake using the dynamic method were run. The treatment efficiency of Amberlite IRA-900 to model wastewaters was tested. Desorption experiments by the batch method were performed.     

Influence of synthesis method on the properties and catalytic performance of MCM-49 zeolites

Highly crystalline and pure MCM-49 was hydrothermally synthesized by dynamic and static methods, respectively. The properties of the samples were studied by N₂ adsorption, XRD, TEM and FT-IR techniques. The results indicated that MCM-49 synthesized by dynamic method showed much smaller crystal and lower concentration of acid sites. The Pd-supported catalyst on MCM-49 synthesized by static method showed higher acetone conversion in one-step synthesis of methyl isobutyl ketone from acetone, which was attributed to higher concentration of acid sites. While the higher selectivity to methyl isobutyl ketone for Pd-supported on MCM-49 synthesized by dynamic method might be related with the lower acidity and higher BET surface area.     

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.     

Vinyl resins with retention properties for heavy metal ions

Summary Resins with carboxylic pendant groups were synthesized. The resins were characterized by elemental analyses and FT-IR spectroscopy, and the ability to bind copper (II) and uranium (VI) by batch method at different pH was studied. Uranium(VI) is adsorbed at pH 3 and pH 4 above 88%. The maximum capacity of load for uranium(VI) is higher than IRA-400, a commercial resin. Elution assays for Cu(II) and U(VI) from the loaded resins with sulfuric acid and sodium carbonate were also carried out.     

ADSORPTION AND SEPARATION BEHAVIOR OF COBALT,NICKEL, AND COPPER IN NITRITE MEDIUM BY ANION EXCHANGER

ABSTRACT

To investigate the possibility of separation of metal ions in nitrite medium by anion exchange, adsorption and elution behavior of the three typical transition metals of Co(II), Ni(II) and Cu(II) in nitrite solution with a commercial anion exchanger, Amberlite IRA-900 and a novel silica-based anion exchanger, AR-01 with fine particle size has been studied. Furthermore, the separation behavior of these metal ions in nitrite solution was demonstrated by anion exchange chromatography. Co(II) and Cu(II) showed strong adsorption onto the anion exchangers in nitrite solution, while the adsorption of Ni(II) was very weak. The adsorption is considered to result from the formation of anionic nitro-complexes. Complete separation of Co(II) from Ni(II), and Cu(II) from Ni(II) was achieved in column experiments with a dilute nitric acid as eluent. Compared to IRA-900, AR-01 showed significantly faster adsorption and elution kinetics.     

Effect of pH on Fumaric Acid Adsorption onto IRA900 Ion Exchange Resin

The effects of pH on fumaric acid adsorption onto IRA900 ion exchange resin were studied. The optimum pH with the highest adsorption capacity depended on the fumarate concentration: the optimum pH was > 4.0 for fumarate concentrations < 5.0 g/L and < 3.0 for higher concentrations. Such different adsorption behaviors of IRA900 resins at different pHs were attributed to the different ion forms of fumarate present in solution at different pHs. Modeling results showed that the two-site-occupancy adsorption reaction between FA^2? and resin active sites contributed to the high adsorption capacity at pH 5, whereas the intraparticle diffusion resulting from the hydrophobic interaction between H₂FA and the hydrophobic resin backbone of IRA900 increased significantly and led to a higher adsorption capacity at pH 3.