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AB-8 resin was used as an adsorbent for the removal of trans-1,2-cyclohexandiol(CHD) from aqueous solutions.Batch experiments were carried out to investigate the effect of contact time and temperature on sorption efficiency.The adsorptive thermodynamic properties and kinetics of CHD from water onto AB-8 resin were studied.The Langmuir and Freundlich isotherm models were employed to discuss the adsorption behavior.Thermodynamic parameters such as G,H and S were calculated.The results indicate that the equilibrium data are perfectly represented by Langmuir isotherm model.Thermodynamic study reveals that it is an exothermic process in nature and mainly physical adsorption enhanced by chemisorption with a decrease of entropy process.The kinetics of CHD adsorption is well described by the pseudo second-order model.The adsorbed CHD can be eluted from AB-8 resin by 5% ethanol aqueous solution with 100% elution percentage. 相似文献
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The adsorption and mechanism of Re(VII) on resin D318 were studied using chemical methods and IR spectrometry. At pH 5.2, the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg&;#8226;g&;#61485;1, respectively. The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10&;#61485;4 s&;#61485;1. The desorption percentage was up to 99.7% when 2.0 mol&;#8226;L&;#61485;1 KSCN was used for dynamic desorption. 相似文献
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In this study,strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated.Among these resins,Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions.The effect of pH,contact time,mass of resin,temperature,and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process.The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models.The results indicated that the pseudo-second order kinetic model was more appropriate than the other one.Moreover,the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data. 相似文献
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The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle size, initial reactant molar ratio and temperature on the reaction rate have been examined. Experimental kinetic data were correlated by using the Pseudo-homogeneous, Langmuir-Hinshelwood and Eley-Rideal models. Nonideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to the group contribution method UNIFAC. Provided that the nonideality of the liquid is taken into account, the esterification kinetics of lactic acid with isobutanol and n-butanol catalyzed by the acid ion-exchange resin can be described using all three models with reasonable errors. 相似文献
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研究了D113弱酸性树脂在NaAc-HAc缓冲体系中对铟(III)的吸附性能及机理。对影响树脂吸附容量的不同因素,如溶液的pH、吸附时间和温度进行了研究。结果表明:D113弱酸性树脂对铟(III)的吸附在pH=5.00的NaAc-HAc缓冲体系中最佳,每克树脂在298 K下的静态饱和吸附容量为185 mg;在不同温度下,树脂吸附铟(III)的表观吸附速率常数分别为k288K=2.72×10.5 s.1,k298K=3.69×10.5 s.1,k308K=4.48×10.5 s.1,表观吸附活化能Ea=18.4 kJ.mol.1;测得热力学参数分别为.H=3.27 kJ.mol.1,.S=68.3 J.(mol.K).1,.G298K=.17.1 kJ.mol.1。与Freundlich等温曲线相比,吸附更加符合Langmuir等温曲线。用0.5 mol.L.1 HCl进行解吸时,解吸率为100%。此外,用红外光谱方法探讨了吸附机理,结果显示:D113树脂功能基COOH中的H与In(III)发生了离子交换;同时,C=O中的O与In(III)形成了配位键。 相似文献
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以四羟甲基硫酸鏻(THPS)为起始原料,合成了二官能团含磷苯并噁嗪单体二(3,4-二氢-1,3-苯并噁嗪-3-亚甲基)苄基氧化膦(BBOz),再采用无溶剂直接加热开环聚合法合成了含磷聚苯并噁嗪树脂(PBBOz),通过差示扫描量热法(DSC)、热重法(TG)和BET法对树脂PBBOz的性能进行了分析,并对其吸附机制进行了探究。结果表明,树脂PBBOz具有较好的热稳定性和阻燃性;树脂PBBOz对铁(Ⅲ)、铬(Ⅵ)均有一定的吸附能力,主要源于结构中的酚羟基和叔胺基,其吸附机理主要为化学吸附;树脂PBBOz经硝酸处理再生后可重复使用。 相似文献
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Muhammad Umar Yahia Abubakar Al-Hamed Abdulraheem Al-Zahrani Hisham Saeed Bamufleh 《中国化学工程学报》2013,21(10):1121-1128
Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether (ETBE), from etha-nol and tert-butyl alcohol (TBA) has been studied in catalytic distillation column (CDC) using ion exchange resin catalyst CT-145H. A packed CDC of 1.2 m height and 50 mm diameter with indigenously developed reactive sec-tion packing was used to generate experimental data. Effect of different key variables on product purity in distillate, was investigated to find the optimum operating conditions for ETBE synthesis. The optimum conditions for 0.2 kg·s-1 of ethanol feed were found:reboiler duty of 375 W, molar feed ratio of 1︰1.3 of reactants, and reflux ratio of 7. Concentration profiles for each component along each column section at optimum conditions were also drawn. Neither output nor input multiplicity was observed at experimental conditions. 相似文献
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The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption in a fixed-bed column packed with commercial active carbon is studied in laboratory.The adsorption column achieves high surfactin recovery(94%)by up-flow methanol elution at 25°C.The adsorption column is simulated with a complex one-dimensional plug flow dispersion model coupled with nonlinear adsorption equilibrium,based on the assumption that the adsorption of surfactin is monomolecular layer and no micelle is formed.The molecular diffusion coefficient of surfactin in water solution with electric neutrality is estimated to be 0.428×10 -5 cm 2 ·s -1 by molecular dynamics simulation.The model developed can describe the complex interplay of adsorption kinetics,fluid dynamics,and mass-transfer phenomena based on the assumption of no radial temperature and concentration gradients,and is of adequate precision.The work involved in this paper is valuable for the optimization of the production process of surfactin. 相似文献
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近年来,关于溶剂萃取法回收Cr(Ⅲ)的文献报道较多,而对其反萃行为的研究则较少。酸性磷氧类萃取剂负载Cr(Ⅲ)后易发生缩合反应,形成难以被反萃的稳定缩合物,萃取剂难以再生,即发生“陈化”现象。本文使用10% D2EHPA/10%正辛醇/磺化煤油为萃取剂,0.6 mol·L-1 H2SO4为反萃剂,以反萃为手段研究了陈化现象的机理。考察了Cr(Ⅲ)浓度和实验温度对陈化速率的影响,进而提出了缩合反应的机理和数学模型,并据此拟合了反应动力学参数,计算了反应活化能。结果显示,陈化反应速率随温度的升高而加快,反应级数为1.57,反应速率常数约(2.49×10-3)~(4.06×10-2),反应活化能(43.0 kJ·mol-1)较低,在常温下极易自发反应。采用拟合参数对陈化过程进行模拟,提出若以30 min内的陈化率控制在3%以下为目标,工业操作温度应控制在23 ℃以下。 相似文献
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采用液相沸腾回流法制备了氧化锌/氧化铝复合粉体,探讨了掺铝量、投加量、温度和吸附时间对所制材料吸附Cr(III)的影响。结果表明,掺铝量为0.5%(摩尔分数),投加量为40 mg,吸附温度为26℃,吸附时间为30 min时材料对Cr(III)的吸附效果最好,吸附量可达165.00μg/mg。 相似文献
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将Fe(Ⅲ)固载在胶原纤维上制备吸附材料,研究了该吸附材料对磷酸根的吸附性能。结果表明,当温度为303 K,溶液的初始浓度为62.0 mg P·L-1时,胶原纤维固载Fe(Ⅲ)(FeICF)对磷酸根的吸附容量为32.69 mg P·g-1。在pH为3.0~6.0范围内平衡吸附量较大,即当磷酸根在溶液中以H2PO-4的形式存在时有利于吸附。吸附等温线符合Langmuir方程,吸附容量随温度和Fe(Ⅲ)的固载量的增加而增加。FeICF对磷酸根的吸附动力学符合拟二级速度方程。溶液中存在的Cl-、NO-3、SO2-4及CO2-3对磷酸根的吸附没有影响,表明FeICF对磷酸根有较强的选择吸附能力。 相似文献
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将三价铁固化在胶原纤维上制备吸附材料,并对其吸附细菌的特性进行了研究.结果表明,铁(Ⅲ)是以化学键与胶原纤维结合,不会被水浸出;该吸附材料对细菌具有很强的吸附能力,当大肠杆菌和金黄色葡萄球菌菌体浓度分别为1.02×107 cfu8226;ml-1和9.80×106 cfu8226;ml-1时,30℃条件下吸附1 h后胶原纤维对它们的吸附容量分别达到2.04×109cfu8226;g-1和3.15×109 cfu8226;g-1,其吸附平衡符合Freundlich方程.菌龄对吸附平衡的影响较大,而温度及pH的影响不大.进一步研究表明,胶原纤维固化铁对细菌的吸附动力学可以用拟二级速率方程来描述,由该方程计算得到的平衡吸附量与实测值非常吻合,误差在2%以内;此外,其吸附速度非常快,吸附有可能是在材料的表面进行. 相似文献
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采用离子交换法对HY分子筛进行改性制备了Fe(Ⅲ)Y分子筛,采用X-射线衍射及N2吸附-脱附技术进行表征,并测试了其吸附性能。结果表明,离子交换法制备的Fe(Ⅲ)Y分子筛比表面积等结构参数较HY分子筛的略有降低,较好的保持了分子筛的晶体结构。在吸附时间2h,吸附温度70℃,剂油比为0.04时,Fe(Ⅲ)Y分子筛的吸附脱硫率可达到68.9%。分子筛再生性能测试表明,Fe(Ⅲ)Y分子筛重复使用4次后脱硫率下降了9.1%,说明催化剂稳定性及再生性能良好。 相似文献