Binary Adsorption in a Fixed-Bed Column Packed with an Ion-Exchange Resin

Abstract

A mathematical model was adopted to analyze a binary fixed-bed adsorption column packed with an ion-exchange resin. Two pairs of organic compounds, o-cresol-benzoic acid and p-chlorophenol-p-nitrophenol, were employed as the adsorbates. A modified Langmuir isotherm with interaction factors η _i was found suitable for representing the adsorption equilibrium. Scale-up of the binary adsorption column with respect to column length was effective based on the proposed mathematical model and corresponding methods for estimating the model parameters. The significance of excess concentration in the breakthrough curve was related to inlet concentration, column length, and the difference in adsorption affinity.     

活性炭填充床脱除水中苯酚及填充床的再生

实验研究了活性炭填充床脱除水中苯酚的吸附性能,探讨其饱和吸附填充床的再生方法,结果表明当平衡浓度范围为0－0．8kg/m^3时,活性炭对水中苯酚的吸附能力达230kg/kg（吸附剂）,吸附等温线符合Langmuir型,填充床的穿透曲线和穿透时间强烈依赖于实验条件,较高的进料浓度,较大的进料速度,以及较短的床层长度都将使填充床穿透较快;用热的NaOH稀溶液可再生被苯酚饱和的活性炭纤维填充床,再生效率达90％以上。     

Prediction of Mass Transfer Coefficients in a Packed Bed using Tamarind Nut Shell Activated Carbon to Remove Phenol

Phenol is a refractive pollutant that is generated from almost all the types of industries. Removal of phenol can be achieved economically by using a cost effective technique like adsorption on to activated carbon. The present paper reports on the preparation and characterization of activated carbon from tamarind nutshell, an agricultural waste byproduct, and its use in a packed bed for the removal of phenol. The breakthrough curves for column sorption of phenol from aqueous solutions to TNSAC have been measured at various flow rates and different particle sizes at 28 °C. The results obtained showed that the sorption of phenol is dependent on both the flow rate and the particle size of the adsorbent, and that the breakpoint time and phenol removal yield decrease with increasing flow rate and particle size. The overall mass transfer coefficient is calculated from the experimental data and compared with the values obtained from the correlation. Experimental values are in excellent agreement with the predicted values from the correlation.     

用锥形分层活性炭柱吸附去除对氯苯酚(英文)

The feasibility of adsorptive removal of single component organic compound(para-chlorophenol) by Calgon Filtrasorb 400(F400) carbon was investigated.The Redlich-Peterson equation was found to be the best fit model for describing the equilibrium relationship between the para-chlorophenol adsorption onto F400 carbon.Four adsorption columns with different column geometry and adsorbent particle stratification were used to examine the adsorption kinetics onto F400 carbons.The Bed Depth Service Time(BDST) model was applied and modified to analyse the performance of the columns and the effect of different operating variables.When combining the effects of adsorption efficiency and the associated pressure drop of each type of adsorption columns tested,the carbon stratified tapered column has been determined to be the most efficient engineering option for removing organics,in which the enhancement of the adsorbent bed in terms of longer breakthrough time and higher saturation percentage is the greatest amongst the four types of columns with reasonably small pressure drop across the fixed-bed column.     

Preparation and Characterization of Activated Carbon from Chestnut Shell and its Adsorption Characteristics for Lead

Activated carbons were prepared from chestnut shell by phosphoric acid activation and the prepared activated carbons were used to remove lead(II) from aqueous solutions. The effects of impregnation ratio (IR) and activation temperature on activated carbon production were investigated. The produced activated carbons were characterized by N₂ adsorption, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The highest surface area (1611 m²/g) and total pore volume (0.7819 cm³/g) were obtained at a carbonization temperature of 500°C with an impregnation ratio of 3/1. The resulting activated carbon was used for removal of lead(II) from aqueous solution. The effects of temperature, contact time, and adsorbent dosage were investigated. The adsorption isotherm studies were carried out and the obtained data were analyzed by the Langmuir, Freundlich, and Temkin equations. The rate of adsorption was found to conform to the pseudo-second-order kinetic model. The Langmuir isotherm equation showed better fit for all temperatures and the maximum adsorption capacities of lead(II) was obtained as 138.88 mg/g at 45°C.     

KOH活化法制备椰壳活性炭研究

以椰壳炭化料为原料,采用KOH活化法制备活性炭,研究了KOH/炭化料的质量比、升温速率、活化温度和活化时间对活性性能的影响。实验结果表明,KOH/炭化料的质量比是该方法制备活性炭的最主要影响因素,较优的工艺参数为:KOH/炭化料的质量比为4∶1、升温速率为5℃/min、活化温度为800℃、活化时间为1 h。同时制备得到了比表面积达到2413 m2/g、微孔容积达到1.02 cm3/g,且以0.9 nm以下微孔为主的椰壳活性炭。     

填充床中椰壳活性炭负载季铵盐催化CO2连续环加成

将一种季铵盐固定在椰壳活性炭(CSAC)颗粒上,得到负载型季铵盐催化剂,于填充床反应器中无溶剂条件下连续催化CO2与环氧氯丙烷(ECH)环加成反应。采用低温氮气吸附、红外光谱(FTIR)、热重分析、X射线光电子能谱(XPS)测定了催化剂的结构、热性能。考察了压力、温度、反应时间对环加成反应性能的影响。结果表明,在ECH空速为14.1 h-1(WHSV),压力为1.4 MPa,温度为140℃时,ECH转化率为50.3%,氯丙烯碳酸酯(CPC)的选择性大于98%。     

Oxidation of SO2 in a Trickle Bed Reactor Packed with Activated Carbon at Low Liquid Flow Rates

In this study, the oxidation of SO₂ on activated carbon (AcC) by using distilled water and air was carried out in a laboratory scale trickle bed reactor (TBR). Distilled water and air containing 1.7 % (v/v) SO₂ were fed co‐currently downward through a fixed bed of AcC particles in a range of 1–7 cm³/s and 10–27 cm³/s respectively. H₂SO₃/H₂SO₄ solutions were the products obtained in the liquid phase. Steady‐state experiments were performed in a column of 0.15 m packing height and 0.047 m column diameter at 20 °C and atmospheric pressure. Experimental reaction rates of this study were compared with those of other studies on the basis of plug flow model of Mata‐Smith given in literature.     

微波辐射制备椰壳活性炭的研究

以海南椰子壳为原材料,氯化锌作活化剂,采用微波辐射加热制备了活性炭。研究了微波功率、辐射时间、浸泡时间和ZnCl2质量分数对活性炭吸附性能与产率的影响。通过正交实验优化制备条件,在微波功率800 W、辐射时间9 min、浸泡时间48 h、ZnCl2质量分数50%的条件下,所制得的椰壳活性炭样品碘吸附值为1258.34 mg/g,亚甲基蓝吸附值为200.00 mL/g,产率为32.46%,BET比表面积为1395.46 m2/g,总孔容0.7021 cm3/g,孔径集中分布在4～9 nm范围。     

Adsorptive Removal of Rhodamine B with Activated Carbon Obtained from Okra Wastes

This study aimed at preparing and optimizing an activated carbon (OAC) obtained from dry okra wastes by chemical activation with zinc chloride. Also, Rhodamine B removal performance from aqueous solution was analyzed by using this optimized activated carbon. The characterization of the resultant activated carbon, with a high surface area of 1044?m²/g, was carried out using thermogravimetric analysis, Brunauer–Emmett–Teller model, t-plot, N₂ adsorption/desorption isotherms, density functional theory, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and the point of zero charge. Furthermore, the effects of operating conditions (contact time, initial concentration, adsorbent dosage, temperature, and pH) on Rhodamine B adsorption onto OAC were investigated. Langmuir model was determined to be the best adsorption process, and the maximum adsorption capacity was calculated to be 321.50?mg/g at 25°C. Also, the intraparticle diffusion and boundary layer diffusion were involved in RhB adsorption onto OAC. Moreover, OAC adsorption curves of Rhodamine B followed pseudo second-order model. At 25°C, Gibbs free energy, enthalpy, and entropy obtained from thermodynamic studies were determined to be ?27.87?kJ/mol, 13.03?kJ/mol, and 0.15?kJ/mol K, respectively. These thermodynamic values revealed that Rhodamine B adsorption onto OAC was feasible, endothermic, physical, and spontaneous.     

山竹壳活性炭吸附亚甲基蓝性能研究

以山竹壳为原料,采用磷酸—硫酸活化法制备了比表面积为1730m~2·g~(-1)的活性炭。研究了山竹壳活性炭吸附亚甲基蓝的吸附性能,考察了亚甲基蓝溶液的pH、不同初始浓度、吸附时间、温度等条件对吸附效果的影响。应用准一级动力学方程、准二级动力学方程模拟了山竹壳活性炭吸附亚甲基蓝的动力学过程,结果表明准二级动力学方程适合描述整个吸附过程。用Langmuir和Freundlich模型模拟吸附等温线,Langmuir方程更适合描述此吸附过程,在298K下最大单层吸附量为526.31mg·g~(-1)。计算了吉布斯自由能(ΔG~0)、焓变(ΔH~0)、熵变(ΔS~0)等热力学参数,ΔG~0、ΔH~0、ΔS~0均小于0,说明此吸附过程是一个自发进行的、放热的、趋于有序的吸附过程。     

利用花生壳制备活性炭及其性能的测定

采用氯化锌法,以花生壳为原料制备高性能的活性炭,并对其实验影响条件进行分析研究.通过正交实验得出最优制备条件:花生壳与氯化锌溶液料液质量比为1∶2.5,氯化锌溶液质量分数60%,活化温度600 ℃,活化时间90 min.并对此条件下制备的活性炭的性能进行了测定,其表观密度0.4146 g/mL,水分含量9.3067%,铁含量0.002%,亚甲基蓝吸附值12.5 mL/(0.1 g),碘的吸附值1 269.08 mg/g.     

油茶果壳活性炭对苯酚的吸附动力学研究

以油茶果壳制备的活性炭为吸附剂,探讨了温度、苯酚初始浓度对油茶果壳活性炭吸附苯酚性能的影响,并用两种动力学模型进行了拟合。结果表明:油茶壳活性炭对苯酚的吸附是一个较为快速的过程,60 min就可接近吸附平衡。油茶壳活性炭对苯酚的吸附动力学过程可以用准一级与准二级模型进行很好的描述,相关系数达到0.96以上。     

油茶壳微孔活性炭的制备及表征

以油茶壳为原料,经炭化、KOH活化,制备微孔活性炭。考查了活化温度、活化时间和碱炭比对微孔活性炭碘吸附值和产率的影响,并采用正交试验优化了制备条件。研究结果表明：活化温度800℃、活化时间180 min、碱炭质量比3.5：1时,活性炭的碘吸附值达3 221 mg/g,产率51.2%。采用比表面积孔隙分析仪测定了氮气吸附/脱附等温线,计算得BET比表面积为1 755.72 m²/g,平均孔径为2.15 nm,总孔容为0.328 cm³/g,微孔孔容占总孔容的55.8%;SEM分析可见活性炭表面具有大量孔隙结构;FT-IR分析表明活化促进了—CH₃、—OH热解,活性炭中仍保存含氧官能团。     

热解活化法制备高吸附性能椰壳活性炭

以椰壳为原料,采用高温直接热解活化法制备高吸附性能活性炭。研究了活化温度、活化时间对活性炭吸附性能的影响。研究结果表明,活化温度为 900 ℃,热解活化时间为 8 h,升温速率为 10 ℃/min,制得碘吸附值为 1 628.54 mg/g,亚甲基蓝吸附值为 375 mg/g 的高吸附性能椰壳活性炭,得率为 9.41 %。氮气吸附实验结果表明,该活性炭比表面积 1 723 m²/g、总孔容积 0.87 cm³/g、微孔容积 0.68 cm³/g、中孔容积0.18 cm³/g、平均孔径 2.03 nm。热解活化制备的椰壳活性炭样品性能优于市售水蒸气法椰壳净水活性炭国家标准。     

微波辐照核桃壳氯化锌法制备活性炭的研究

以核桃壳为原料,采用微波辐照氯化锌法制备活性炭。探讨了活化条件对产品活性炭的亚甲基蓝脱色力、碘吸附值及得率的影响。最佳工艺条件为核桃壳原料10 g,微波功率580 W、活化时间7 min、氯化锌质量分数50%。在此条件下制得的活性炭的碘吸附值为977.81 mg/g,亚甲基蓝脱色力为160 mL/g,得率为51.06%。其活化时间是传统工艺的7/90,得率是传统工艺的1.5倍左右。     

磷酸中添加剂对核桃壳活性炭性能的影响

采用磷酸活化法制备核桃壳颗粒活性炭,研究了在磷酸浸渍液中加入不同种类和含量添加剂对活性炭性能的影响。以亚甲基蓝和碘吸附值表征活性炭的吸附性能,并对活性炭的孔结构参数、机械强度和微晶结构进行了测试分析。结果表明：在磷酸中分别添加柠檬酸、柠檬酸钠、硼酸和糖精浸渍处理核桃壳原料,所得活性炭的亚甲基蓝吸附值都得到提高,而碘吸附值降低,说明添加剂促使活性炭中的微孔扩大为中孔。其中,添加0.5%的柠檬酸钠得到最佳的亚甲基蓝和碘吸附值,分别达到236.5和744.1 mg/g。此外,磷酸中添加1%硼酸后得到的活性炭结构中含坚固的炭微晶,起到了增强孔结构的作用,机械强度为85.8%;而添加1%糖精得到的活性炭中的炭微晶几乎全部发生了石墨化转变,生成质软的石墨,使强度下降,机械强度仅为80.1%;添加0.5%柠檬酸钠的活性炭由于发达的孔隙结构且没有炭微晶的加固而强度较低(82.5%)。     

用活性炭处理焦化废水的研究

研究了活性炭处理焦化废水的规律,考察了活性炭的粒径、投加量和曝气量的影响。结果表明,活性炭对焦化废水具有显著的去除作用,而且恬性炭的粒径越小,曝气量越大,效果越好,达到平衡的时间越短。     

Continuous Removal of Lead from Aqueous Solutions by Ca(II) Imprinted Chitosan Microspheres Packed Column

The continuous removal of lead from aqueous solutions by Ca(II) imprinted chitosan (Ca(II)-CS) microspheres packed column is carefully investigated in this work. The modified dose-response model and the Thomas model are exploited to evaluate dynamic behaviors of breakthrough curves. The results show 0.257 min of space time is enough for a Ca(II) imprinted chitosan microspheres packed column to realize deep purification of water containing Pb(II). The Thomas rate constants are higher than 3 mL min-1 mg-1. The Modified dose-response model is feasible to predict the breakthrough curve. The reusability is confirmed during a multi-cycle adsorption-desorption process.     

负载TiO2杏仁壳活性炭对亚甲基蓝的光解研究

研究了负载TiO2杏仁壳活性炭对亚甲基蓝的光解催化效果。结果表明,在室温下、pH值5.0亚甲基蓝初始浓度10.0 mg/L 50.0 mL溶液,加入负载TiO2杏仁壳活性炭100.0 g/L和30%H2O220.0 mL/L,用24 W紫外灯光照射60 min,亚甲基蓝降解率96.75%。对于光解亚甲基蓝负载TiO2杏仁壳活性炭具有与商业纳米TiO2P25近似效果。