高铝粉煤灰碱法提铝过程镓的吸附研究

我国内蒙古中西部以及山西北部地区的高铝粉煤灰中氧化铝含量高达50%以上,伴生的镓含量可达60 mg/kg,是重要的含铝、镓二次资源。为进一步提升高铝粉煤灰资源化利用附加值,实现粉煤灰提铝过程低浓度含镓溶液的高效提取,本文基于高铝粉煤灰预脱硅拜耳-亚熔盐联合法提铝工艺中的含镓碱液体系,研究了含镓模型溶液中镓离子的静态吸附规律,系统考察了不同吸附时间、吸附温度、镓初始浓度以及碱浓度对螯合树脂吸附镓离子的影响,完成了吸附动力学与吸附等温线的考察,并采用吸附柱进行了低浓度含镓碱液动态吸附及淋洗试验验证。静态吸附试验结果表明:采用LSC-600型螯合吸附树脂可实现低浓度含镓碱液中镓离子的高效吸附,树脂的平衡吸附容量随静态吸附时间增大而增大,吸附24 h后树脂吸附容量达到平衡;镓离子初始浓度低于400 mg/L,树脂的平衡吸附容量受吸附温度影响较小,在镓离子浓度高于400 mg/L体系中,树脂的平衡吸附容量随吸附温度升高而降低,其中吸附温度为50℃时树脂对镓离子的平衡吸附容量最大;随含镓碱液碱浓度增加,螯合树脂对镓离子的吸附容量先增大后减小,螯合树脂对镓离子的平衡吸附容量随镓离子初始浓度增大而增大,镓离子初始浓度高于1 200 mg/L时树脂吸附容量达到饱和,吸附温度为50℃,镓离子初始浓度为1 200 mg/L,碱浓度为5 mol/L时树脂的最大吸附容量为36 mg/g。动力学拟合结果表明:碱体系树脂对镓离子的吸附动力学过程符合准二级动力学方程,属于化学吸附过程;吸附等温线拟合结果表明,LSC-600型螯合树脂对镓离子的吸附满足Langmuir等温方程,说明镓离子的螯合吸附过程为单层吸附。树脂的动态吸附和淋洗结果表明,液体流速越大,树脂达到吸附平衡时的穿透床层数越小,树脂对镓离子的吸附容量和吸附率均较低,镓离子初始浓度50 mg/L,吸附温度为50℃,吸附流速为2. 5 BV/h时,树脂对低浓度含镓碱液吸附效果最优,最大吸附容量为3. 13 mg/g,淋洗过程淋洗液镓离子浓度随着床层数增加先增大后降低,淋洗流出液达到0. 7 BV时镓浓度最高为1 936mg/L,高浓度段(0. 3～1. 5 BV)溶液中镓离子浓度为1 248 mg/L,富集倍数达25倍。     

LX-92树脂对硫酸体系低浓度镓离子的动态吸附

研究了粉煤灰模拟硫酸浸出液中的镓在聚苯乙烯树脂(LX-92)上吸附分离的可能性,采用固定床吸附装置考察了树脂动态吸附?脱附镓的行为,利用Thomas, Yoon-Nelson和Adam-Bohart经验模型对动态吸附过程进行了分析和预测。结果表明,降低流速(F)、增加床层高度(Z)、减小镓(Ш)初始浓度(C0)有助于提高固定床吸附效率和平衡吸附容量;在C0为260 mg/L, Fad为5.0 mL/min、吸附温度为55℃的条件下,树脂的最大动态平衡吸附容量为56.65 mg/g;用3.0 mol/L H2SO4在1.0 mL/min流速的最佳洗脱条件下,洗脱率达到94.40%;树脂在硫酸体系中对低浓度镓离子的吸附?脱附具有良好的循环使用性,经过吸附?脱附镓离子可富集10倍以上;树脂吸附镓的动态行为满足Yoon-Nelson动态吸附模型,建立了动态吸附速率常数KYN和半穿透时间τ值常数与初始离子浓度、流速、床层高度的对应方程,为低浓度镓离子的吸附法提取工程化提供了理论基础。     

离子交换法脱除磷酸中锰离子的动态吸附研究

近年来离子交换技术在湿法磷酸净化领域得到了广泛的发展与应用。采用Sinco-430型阳离子交换树脂脱除磷酸中的锰离子,考察了流量、磷酸溶液初始锰浓度、温度对吸附效果的影响。结果表明：增大进液流量、提高溶液初始锰浓度以及升高温度均有利于缩短树脂饱和时间,但进液流量的增大会降低树脂的吸附率,而温度的升高则会降低树脂的饱和吸附量。在进液流量为4.0 mL/min、溶液初始锰质量浓度为10.22 mg/mL、体系温度为35 ℃的条件下,树脂对锰离子的饱和吸附量为64.76 mg/g、吸附效率为63.55%。采用Thomas,Yoon-Nelson和Yan 3种吸附模型对动态吸附过程数据进行拟合,发现Yan模型的拟合效果最佳,而且由其计算得出的饱和吸附量与实验测定值的相对偏差在6.93%~10.91%。     

混合离子交换树脂除盐的性能研究

研究了强酸型离子交换树脂D072和强碱型离子交换树脂D201混合吸附杂离子的性能。D072和D201的质量比为1∶2,考察其30℃时的吸附特性,结果表明,混合树脂符合兰格缪尔吸附模型,等温吸附平衡方程为q=7.55c/(0.97+c) (R2=0.9971)。此外,考察了树脂固定床的操作性能。进料流速与初始进料浓度对树脂固定床的穿透曲线影响显著,当液相初始进料浓度为800 mg/L、进料速度为3 min/L时,穿透时间为83 min,该操作条件大幅提高了离子交换树脂的吸附效率。     

纳米腐植酸动态吸附废水中镉离子及其洗脱特性

<正>在静态法研究纳米腐植酸吸附模拟含镉废水基础上搭建考察模拟含镉废水中镉离子在吸附剂上动态吸附及洗脱特性的吸附柱实验装置,考察镉离子溶液浓度、吸附(脱附)温度、共存离子和进料流速对穿透吸附量和饱和吸附量的影响,运用Thomas模型研究了纳米腐植酸柱吸附过程动力学机理,测定了再生后纳米腐植酸的穿透吸附量和饱和吸附量。结果表明:初始镉离子浓度150 mg/L和流     

铝基吸附剂固定床分离卤水锂资源过程研究

铝基锂吸附剂是一种非常适用于低锂品位、高镁锂比盐湖卤水提锂的吸附剂,具有无溶损、稳定性高等优点,也是目前唯一一种已投入工业化生产的吸附剂。使用自制的球形铝基锂吸附剂GLDH填充固定床,系统研究了吸附温度、进料流速、初始锂离子浓度和床层高度对GLDH固定床分离卤水锂资源过程中吸附穿透曲线的影响。结果表明：升高温度、增加床层高度、降低初始锂离子浓度和进料流速会导致穿透时间延长、穿透吸附容量升高。采用BDST、Clark、Thomas、Y-N和M-D-R 5种经验模型对锂吸附穿透曲线进行拟合,确定M-D-R模型能够较准确地描述固定床锂吸附过程。     

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%.     

D301阴离子交换树脂吸附2-酮基-L-古龙酸母液中草酸的研究

研究了分离出2-酮基-L-古龙酸母液中的草酸时,D301阴离子交换树脂在静态和动态情况下吸附草酸的过程,并利用Freundlich吸附等温方程对吸附等温线数据进行拟合。结果表明:D301树脂对草酸的平衡吸附数据符合Freundlich吸附等温方程,在293、303、313K三种温度下相关系数均大于0.99;且在pH值为6、温度313K、流速30mL/min时吸附量达到最大。这些研究为从古龙酸母液中除去或者回收草酸找到了一种有效的方法,并且可降低母液的COD值,从而降低污染。     

树脂吸附环已酮中己醛的研究

本文考察了3种树脂对环己酮中所含己醛的吸附能力,并用动态实验研究了树脂床层高径比、流速、己醛初始浓度对树脂吸附能力的影响.结果表明1*树脂效果较好,适宜流速为2～3BV(BV为树脂床层体积),床层高径比对吸附效果影响不大,己醛初始浓度越低,吸附效果越好.     

大孔螯合树脂对Pb2+的吸附行为及机理

通过静态和动态吸附实验,研究了Pb2+在D418树脂上的吸附行为,从热力学和动力学方面对吸附过程进行了分析,并通过红外光谱探讨了吸附机理. 结果表明,在所研究的条件范围内,Pb2+在D418树脂上的吸附是吸热过程,同时符合Freundlich和Langmuir等温吸附方程;液膜扩散为Pb2+在D418树脂上吸附速率的主要控制步骤,随着溶液初始浓度的增大,吸附速率逐渐减小;313 K温度下树脂的静态饱和吸附容量为375 mg/g,在298 K下用3 mol/L的硝酸作为解吸剂,解吸率可达97%;最佳的解吸剂用量为5倍床层体积. 该树脂吸附操作简单,易再生,不产生二次污染,有望用于含铅废水的治理及铅的富集.     

β-CAROTENE ADSORPTION ONTO MESOPOROUS CARBON-COATED MONOLITH COLUMN: DYNAMIC STUDIES

β-carotene adsorption dynamics from isopropyl alcohol (IPA) solution onto a mesoporous carbon-coated monolith (MCCM) column was studied. Kinetics and mass transfer parameters were modeled. Thomas and Adams-Bohart models were applied to the experimental data obtained from dynamic studies. The effects of bed depth, flow rate, and influent concentration on breakthrough curves and adsorption capacity were investigated. The results showed that β-carotene equilibrium uptake increased with decreasing flow rate and increasing influent concentration. The optimum adsorption capacity (1.37 mg/g) was achieved at 20 mg/L initial β-carotene concentration, 47.5 cm bed height, and 1.0 mL/min flow rate. The time to attain breakthrough point decreased, while a sharp breakthrough curve was observed with increase in flow rate and influent concentration and a decrease in bed height.     

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.     

大孔吸附树脂HZ816对红霉素的固定床吸附过程研究

在上柱质量浓度为2.31—6.56 mg/mL、流量为14.33—42.80 mL/h的范围内研究了固定床吸附柱中大孔吸附树脂HZ816对红霉素的动态吸附过程,考察了原料液质量浓度和进口流量等操作参数对穿透曲线的影响。并采用基于液膜及孔内扩散模型的动力学模型,同时考虑吸附树脂颗粒内外扩散阻力及轴向扩散的影响,研究了固定床上红霉素在大孔吸附树脂中的吸附动力学,并从穿透曲线回归得到液膜传质系数孔内扩散系数。结果表明,在实验范围内,该模型能较好地描述红霉素在HZ816树脂上的吸附过程,由模型拟合得到的液膜传质系数随着原料液质量浓度减小而增大,随着流量升高而增大;孔内扩散系数随着原料液质量浓度增大而减小,随着流量升高而减小。为采用大孔吸附树脂HZ816吸附技术分离纯化红霉素工艺提供了实验和理论基础。     

Adsorption of Carbamazepine in Fixed Bed Columns: Experimental and Modeling Studies

The adsorption of carbamazepine was evaluated on activated carbon in fixed bed columns. The effect of various parameters on breakthrough curves like carbamazepine initial concentrations (1.2, 1.6, and 2.5 mg/L), bed depths (0.4, 0.6, and 0.8 cm) and volumetric flow rates (1.0, 2.0, and 3.0 mL/min) was investigated. The breakthrough time increased with increase of bed depth, and decreased with increase of initial concentration and volumetric flow rate. In order to predict the theoretical breakthrough curves and to determine model parameters, BDST, Thomas, Yoon-Nelson and Clark models were applied to the experimental adsorption processes under the operational conditions described above. The Thomas and Yoon-Nelson models were in good agreement with the experimental data.     

大孔吸附树脂纯化石榴皮多酚

从D3520、D4020、AB-8、D140、D141、D160、DM-301、DA-201、SAD-7和D101大孔吸附树脂中筛选出D141树脂,研究了其对石榴皮多酚的静态与动态吸附和解吸性能。结果表明,D141树脂对石榴皮多酚的饱和吸附量为19.86 mg/g(干树脂),吸附等温线符合Langmuir方程,饱和吸附时间为5 h,适宜解吸剂为体积分数70%的乙醇溶液;以质量浓度9 mg/mL的石榴皮提取液上柱,流速为1.8~2.0 BV/h时,树脂的多酚穿透吸附容量为39.42 mg/g(干树脂),2.5 BV体积分数70%的乙醇溶液可将吸附于柱上的石榴皮多酚完全洗脱。以该条件纯化石榴皮多酚提取物时,纯化样的收率为15.4 g/100 g(石榴皮),多酚质量分数从34%提高到76.34%。     

Hydrophobic–hydrophilic polydivinylbenzene/polyacryldiethylenetriamine interpenetrating polymer networks and its adsorption performance toward salicylic acid from aqueous solutions

Hydrophobic–hydrophilic interpenetrating polymer networks (IPNs) composed of polydivinylbenzene (PDVB) and polyacryldiethylenetriamine (PADETA) were prepared and its adsorption performance toward salicylic acid was studied from aqueous solutions. The structure of PDVB/PADETA IPNs was characterized by Fourier transform infrared spectroscopy, N₂ adsorption–desorption isotherms, weak basic exchange capacity, and swelling ratio, respectively. The results indicated that PDVB/PADETA IPNs possessed both hydrophobic and hydrophilic properties and they were much superior to the hydrophobic PDVB and the hydrophilic PADETA in adsorption of salicylic acid from aqueous solutions. The Freundlich model was more appropriate for fitting the equilibrium data than the Langmuir model and the isosteric enthalpy decreased with increment of the equilibrium uptakes. The breakthrough dynamic capacity of salicylic acid on PDVB/PADETA IPNs was 77.27 mg/mL wet resin at an initial concentration of 650.4 mg/L and a flow rate of 7.2 BV/h (bed volume, 1 BV = 10 mL) and the saturated dynamic capacity was calculated to be 93.28 mg/mL wet resin. One hundred and forty milliliter of 0.01 mol/L of sodium hydroxide (w/v) and 40% of ethanol (v/v) could regenerate the resin column completely. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2636–2643, 2014     

锰氧化物负载沸石固定床离子交换柱去除铀(VI)的研究

The adsorption of uranium (VI) on the manganese oxide coated zeolite (MOCZ) from aqueous solution was investigated in a fixed-bed column. The experiments were conducted to investigate the effects of bed height, flow rate, particle size, initial concentration of uranium (VI), initial pH, presence of salt and competitive ions. The U-uptake by MOCZ increased with initial uranium (VI) concentration and bed height, but decreased as the flow rate and particle size increased. In the presence of salt and competitive ions, the breakthrough time was shorter. The ad-sorption capacity reached a maximum at pH of 6.3. The Thomas model was applied to the experimental data to de-termine the characteristic parameters of the column for process design using linear regression. The breakthrough curves calculated from the model were in good agreement with the experimental data. The BDST model was used to study the influence of bed height on the adsorption of uranium (VI). Desorption of uranium (VI) in the MOCZ column was investigated. The column could be used for at least four adsorption-desorption cycles using 0.1 mol&#8226;L－1 NaHCO3 solution as the elution. After desorption and regeneration with deionized water, MOCZ could be reused to adsorb uranium (VI) at a comparable capacity. Compared to raw zeolite, MOCZ showed better capacity for uranium (VI) removal.