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Mohammad Kavand Tahereh Kaghazchi Neda Asasian 《Chemical Engineering Communications》2016,203(1):123-135
In this study, the competitive separation of lead, cadmium, and nickel ions from aqueous solutions using a commercial activated carbon (AC) has been investigated and optimized using response surface methodology (RSM). The optimal conditions to reach the highest adsorption capacity for these metals were found as follows: initial pH = 6.3, temperature = 56.8°C, and shaking speed = 308 rpm. Under these conditions, the sequence of adsorption capacity toward the metal ions was as follows: Pb (II): 9.44 mg g?1 > Cd (II): 9.37 mg g?1 > Ni (II): 4.52 mg g?1. The effect of shaking speed on the adsorption capacity of AC was higher than the effects of the initial pH and temperature, indicating the more important role of physisorption than chemisorption in the adsorption of these metal ions. This was confirmed by the results of thermodynamic studies. The equilibrium adsorption data were fitted to the Freundlich, Langmuir adsorption isotherm models and the Dubinin–Radushkevich model parameters were evaluated. All the models were tested and all were shown to represent the experimental data satisfactorily. The thermodynamic parameters such as ΔH, ΔS, and ΔG were computed from the experimental data. These values show that the adsorption is endothermic and spontaneous. The positive value of ΔS° indicates increasing of randomness at the solid/liquid interface during the adsorption of metal ions on AC. 相似文献
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《分离科学与技术》2012,47(1):112-123
The feasibility of using eggshells as a low-cost biosorbent for the removal of Direct Red 28 (DR 28) from aqueous solutions was studied in batch and dynamic flow modes of operation. The effect of biosorption process variables such as particle size, solution pH, initial dye concentration, contact time, temperature, feed flow rate, and bed height were investigated. Both the Langmuir and Freundlich isotherm models exhibited excellent fit to the equilibrium biosorption data. Optimum pH (6.0), particle size (<250 µm), initial dye concentration (50 mg g?1), temperature (313 K), and contact time (240 min) gave maximum monolayer biosorption capacity of 69.45 mg g?1 which was higher than those of many sorbent materials. Pseudo-second-order kinetic model depicted the biosorption kinetics accurately. Thermodynamic study confirmed the spontaneous and endothermic nature of the biosorption process. Breakthrough time increased with increase in the bed height but decreased with increase in flow rate. Overall, batch and continuous mode data suggest the applicability of eggshells as an environment friendly and efficient biosorbent for removal of DR 28 from aqueous media. 相似文献
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《分离科学与技术》2012,47(14):2283-2290
Removal of dyes from wastewaters causes a big concern from the environmental point of view due to their extreme toxicity towards aquatic life and humans. Commonly used traditional methods to treat these effluents are ineffective because dyes show resistance to many chemicals, oxidizing agents, and light. In this context, the biosorption process has attracted great attention in recent years since they utilize not only cheap plant materials but also a wide variety of microorganisms as biosorbing agents, displaying a high dye-binding capacity. In this study, biosorption potential of dried Penicillum restrictum (DPR) for Reactive Yellow 145 (RY 145) was studied with respect to pH, equilibrium time, and temperature to determine equilibrium and kinetic models. The most suitable pH and equilibrium time were determined as 1.0 ± 0.05 and 75 min respectively, at a biomass dosage of 0.4 mg L?1 and 20 ± 0.5°C. Data obtained from batch studies fitted well with the Dubinin-Radushkevich (D-R) followed by the Freundlich and Langmuir isotherm models. Maximum uptake capacities (qm) of DPR for the dyestuff (RY 145) were 109.7, 115.2, and 116.5 mg g?1 biomass at temperatures of 20, 30, and 40 ± 0.5°C, respectively. The overall biosorption process was best described by the pseudo-second-order kinetic model. Gibbs free energy changes were calculated as ?384.6, ?273.5, and ?245.9 J mol L?1 at 20, 30, and 40 ± 0.5°C, respectively. 相似文献
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The ZnO/ZnMn2O4 nanocomposite (ZnMn) was used as adsorbent for the removal of cationic dye Basic Yellow 28 (BY28) from aqueous solutions. The adsorbent was characterized by X-ray diffraction, scanning electron microscope, TEM, Fourier transform infrared ray, BET, particle size distribution and zeta potential measurements. The adsorption parameters, such as temperature, pH and initial dye concentration, were studied. Kinetic adsorption data were analyzed using the pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The Langmuir and Freundlich isotherm models were applied to fit the equilibrium data. The maximum adsorption capacity of BY28 was 48.8 mg g?1. Various thermodynamic parameters, such as ΔG°, ΔH° and ΔS°, were calculated. 相似文献
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《分离科学与技术》2012,47(10):1456-1462
The biosorption behavior of lanthanum and cerium ions from aqueous solution by leaf powder of Pinus brutia was separately studied in a batch system as a function of initial pH, contact time, initial metal ion concentration, temperature, and adsorbent amount. The uptake of lanthanum and cerium was increased when the initial pH of the solution was increased. Thermodynamic parameters such as standard enthalpy (ΔH°), entropy (ΔS°) and free energy (ΔG°) were calculated and the results indicated that biosorption was endothermic and spontaneous in nature. The biosorption of lanthanum and cerium on powdered leaf of Pinus brutia was investigated by the Freundlich, Langmuir, and D-R isotherms. The results show that lanthanum and cerium adsorption can be explained by the Langmuir isotherm model and monolayer capacity was found as 22.94 mg g?1 for lanthanum and 17.24 mg g?1 for cerium. Desorption of lanthanum and cerium was studied using 0.5 M HNO3 solution. The results suggested that powdered leaf of Pinus brutia may find promising applications for the recovery of lanthanum and cerium from aqueous effluents. 相似文献
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ABSTRACTA novel mesoporous magnetic nanosorbent developed from macadamia nut shell residues was applied as an adsorbent for the removal of dissolved organic carbon (DOC) associated with melanoidin and its fractions in a batch system. The most favored molecular fraction of the melanoidin for adsorption onto the nanosorbent was 1–5 kDa with adsorption capacity of 10.26 mg DOC g?1 achieving 68.4% removal efficiency. The sorption behaviors were all well fitted to a pseudo-second-order kinetic model and Langmuir isotherm. Optimum operating conditions needed for the maximum uptake of 14.7 mg DOC g?1 were found to be pH of 6.3, temperature of 41.7°C at the dosage of the magnetic nanosorbent of 877.7 ppm. 相似文献
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《分离科学与技术》2012,47(1):192-211
Abstract In this study, the biosorption of Basic Blue 9 (BB9) dye from aqueous solutions onto a biomass of Euphorbia rigida was examined by means of the initial biosorbate concentration, biosorbent amount, particle size, and pH. Biosorption of BB9 onto E. rigida increases with both the initial biosorbate concentration and biosorbent amount, whereas decreases with the increasing particle size. The experimental data indicated that the biosorption isotherms are well‐described by the Langmuir equilibrium isotherm equation at 20, 30, and 40°C. Maximum biosorption capacity was 3.28×10?4 mol g?1 at 40°C. The biosorption kinetics of BB9 obeys the pseudo‐second‐order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to estimate the nature of biosorption. These experimental results have indicated that E. rigida has the potential to act as a biosorbent for the removal of Basic Blue 9 from aqueous solutions. 相似文献
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《分离科学与技术》2012,47(4):472-485
Fluoride removal with varying different parameters at 303 ± 1.6 K and pH 6.5 ± 0.2 was investigated by hydrous iron(III)-chromium(III) bimetal oxide. The kinetic and equilibrium data fitted with the pseudo-second order and Langmuir isotherm equations very well (R2 = 0.99?1.00), respectively. The Langmuir capacity (θ) and free energy (EDR) of adsorption evaluated were 16.34 (±0.50) mg·g?1 and 15.81 kJ·mol?1, respectively. The estimated thermodynamic parameters viz. ΔH0, ΔG0, and ΔS0 indicated that the reaction was endothermic but spontaneous for entropy increase. The small-scale column filtration of high fluoride (C0 = 7.37 mg·L?1) water gave encouraging results. 相似文献
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《分离科学与技术》2012,47(13):1886-1897
The biosorption potential of Padina sp. algae for the removal of strontium from aqueous solutions was studied. The effects of contact time, solution pH, initial metal concentration, and temperature on the strontium uptake by the algae were investigated. The pseudo-first-order, pseudo-second-order, and Weber and Morris kinetic models were applied to test the dynamic experimental data. The pseudo-second-order kinetic model provided the best correlation of the experimental data. The equilibrium experimental results were analyzed in terms of Langmuir, Freundlich, and Sips isotherms. Equilibrium data fitted very well to the Sips model. The maximum uptake estimated by using the Sips model was 330.38 mg/g at pH of 9.5 and temperature 45°C. Using thermodynamic equilibrium coefficients obtained at different temperatures, various thermodynamic parameters, such as ΔG°, ΔH°, and ΔS° were calculated. The thermodynamics of the strontium ion–Padina sp. algaebiosorption system indicate an endothermic process at 288–318 K. 相似文献
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《分离科学与技术》2012,47(16):2383-2393
In this study, the adsorption of Cu(II) and Zn(II) ions from aqueous solutions onto amidoximated polymerized banana stem (APBS) has been investigated. Infrared spectroscopy was used to confirm graft copolymer formation and amidoxime functionalization. The different variables affecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration, and temperature have been investigated. The optimum pH for maximum adsorption was 10.5 (99.99%) for Zn2+ and 6.0 (99.0%) for Cu2+ at an initial concentration of 10 mg L?1. Equilibrium was achieved approximately within 3 h. The experimental kinetic data were analyzed using pseudo-first-order and pseudo-second-order kinetic models and are well fitted with pseudo- second-order kinetics. The thermodynamic activation parameters such as ΔGo, ΔHo, and ΔSo were determined to predict the nature of adsorption. The temperature dependence indicates an exothermic process. The experimental isotherm data were well fitted to the Langmuir model with maximum adsorption capacities of 42.32 and 85.89 mg g?1 for Cu(II) and Zn(II), respectively, at 20°C. The adsorption efficiency was tested using industrial effluents. Repeated adsorption/regeneration cycles show the feasibility of the APBS for the removal of Cu(II) and Zn(II) ions from water and industrial effluents. 相似文献
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Yan Li Jian Zhang Chenglu Zhang Li Wang Bo Zhang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(12):1639-1647
BACKGROUND: The removal of methylene blue from aqueous solution was studied using softstem bulrush (Scirpus tabernaemontani Gmel.) as the biosorbent. The effects of various parameters including contact time, biosorbent dosage, ionic strength and solution pH on the biosorption were investigated. RESULTS: The sorption capacity increased with an increase in biosorbent dosage and a decrease in ionic strength. The equilibrium time was found to be 240 min for full equilibration. Pseudo‐first‐order, pseudo‐second‐order, Bangham equation and intraparticle diffusion models were applied to fit the kinetic data, and the results showed that the sorption process followed the pseudo‐second‐order model. Equilibrium data conformed to Langmuir and Redlich–Peterson isotherm models, with a maximum monolayer biosorption capacity of 53.8 mg g?1 for the Langmuir isotherm at 18 °C. The value of ΔG was estimated to be ? 29.24 kJ mol?1, indicating the spontaneous nature of the biosorption. The biosorption process was strongly pH‐dependent and favourable at alkaline pH. CONCLUSION: Softstem bulrush, which is readily available and inexpensive, could be employed as a promising biosorbent for the removal of dye. Copyright © 2008 Society of Chemical Industry 相似文献
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《分离科学与技术》2012,47(12):1966-1976
The present study explores the ability of a new adsorbent—conch shell powder (CSP) in removing Malachite Green from aqueous solutions. The effect of various process parameters, namely initial solution pH, temperature, initial dye concentration, adsorbent dose, and contact time was investigated. Adsorption equilibrium data were well described by the Langmuir isotherm with maximum adsorption capacity of 92.25 mg g?1 at 303 K. The kinetic data conformed to the pseudo-second-order kinetic model. A thermodynamic study showed the spontaneous nature and feasibility of the adsorption process. The results provide strong evidence to support the hypothesis of adsorption mechanism. 相似文献
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M. Ghaedi A. Amiri Pebdani B. Sadeghian R. Sahraei A. Daneshfar 《Chemical Engineering Communications》2013,200(8):1071-1088
The objective of this study was to evaluate the adsorption potential of cadmium sulfide nanoparticle–loaded activated carbon (CdSN-AC) for removal of reactive orange 12 (RO-12) dyestuffs from aqueous solutions. The characterization of CdSN-AC was performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM) techniques. The effects of experimental parameters such as initial solution pH, contact time, initial RO-12 concentration, amount of CdSN-AC, and temperature on the adsorption process were evaluated in detail. The kinetic studies indicated that the adsorption process was best described by the pseudo-second-order kinetics model. The experimental data were analyzed by the Langmuir, Freundlich, and Tempkin isotherm models, and the monolayer adsorption capacity of CdSN-AC was found to be 150.0 mg g?1 by using the Langmuir isotherm model. The thermodynamic parameters indicated that the adsorption of RO-12 onto CdSN-AC was feasible, spontaneous, and endothermic in nature. 相似文献
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Mridusmita Goswami Lukumoni Borah Debajyoti Mahanta Prodeep Phukan 《Journal of Porous Materials》2014,21(6):1025-1034
A new porous carbon with high surface area of 1,313.41 m2 g?1 with pore volume 1.359 cm3 g?1 has been synthesized from matured tea leaves by chemical activation method using phosphoric acid. The carbon was found to be highly efficient for removal of Cr(VI) from aqueous solution. The effects of various parameters such as contact time, initial metal ion concentration, pH, temperature and amount of adsorbent on the extent of adsorption were studied. Langmuir, Freundlich and Temkin adsorption models were used to interpret the experimental data. The adsorption data were best fitted with Langmuir isotherm model. The adsorption capacity of Cr(VI) onto the activated carbon calculated from Langmuir isotherm was found to be 30.8 mg g?1 at pH 4.8 and temperature 303 K. The adsorption capacity increases from 25.36 to 32.04 mg g?1 with an increase in temperature from 303 to 323 K at initial Cr(VI) concentration of 60 mg L?1. The adsorption process followed a pseudo second order kinetic model. Thermodynamic parameters ΔH0 (28.6 KJ mol?1), ΔG0 at three different temperatures [(?0.145, ?1.09, ?2.04) KJ mol?1] and ΔS0 (94.87 J mol?1 K?1) were calculated. These values confirm the adsorption process to be endothermic and spontaneous in nature. 相似文献
16.
Poly(N-vinyl imidazole) hydrogel (p-VIm) and its partially quaternized analogue (p-VIm-Ar) were prepared and used for the removal of Orange II (OII). A fourier transform infrared spectrophotometer, scanning electron microscope with an energy dispersive X-ray spectrometer attached, thermogravimetric analyzer, zeta potential analyzer, and a drop shape analyzer were used for the characterization of the hydrogels. The influence of some experimental parameters, such as pH of the OII solution, contact time, and initial OII concentration on the adsorption process, was examined, and the obtained data were used to calculate the isotherm and kinetic parameters. Adsorption processes of OII onto adsorbents were coherent with the Langmuir isotherm and pseudo-second-order kinetic models. The quaternized analogue exhibited remarkable adsorption performance in the pH range of 2–12, while the effective adsorption with p-VIm occurred only at pH 2.0. The maximum adsorption capacity values of adsorbents were determined as 2331 (for p-VIm) and 1327 mg g?1 (for p-VIm-Ar) at pH 2.0 and 132 (for p-VIm) and 1357 mg g?1 (for p-VIm-Ar) at pH 6.0. 相似文献
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《分离科学与技术》2012,47(5):742-752
The efficacy of activated carbon prepared from Palm Kernel Shell (PKSAC) from agriculture biomass and coated with magnetic nanoparticle (Fe3O4) in the removal of Rhodamine B dye was investigated. Adsorption experiments were carried out at various initial pH, adsorbent dosage, initial dye concentration, particle size, and temperature. Kinetic analyses were conducted using pseudo first order, pseudo second order and intra particle diffusion models. However, the regression results showed that the adsorption kinetics was represented more accurately by the pseudo second order model. The pseudo second order kinetic constant obtained was 1.7 × 10?4 min?1 at 323 K when 200 mg L?1 dye concentration was used. The equilibrium data were well described by both Langmuir and Freundlich isotherm models. The Langmuir adsorption capacity was 625 mgg?1. The rate of adsorption improved with increasing temperature and the process was endothermic with ΔH value assessed at 80 kJmol?1. Results obtained reveal that activated carbon prepared from Palm Kernel Shell coated with magnetic nanoparticle from agriculture biomass can be an attractive option for dye removal from industrial effluent. 相似文献
18.
Tarek G. Ammari 《Chemical Engineering Communications》2016,203(6):831-839
The reuse of paper solid waste (PSW) as a low-cost sorbent for Cd removal from aqueous phase was investigated. Batch experiments were conducted to study the effects of pH (3.5, 5.5, 7.5), contact time (10–360 min), PSW dose (2.5–20 g L?1), and Cd concentration (5–50 mg L?1) at an ionic strength of 0.01 M NaNO3 on adsorption efficiency and capacity. Cd removal of ~96% occurred in 20 mg L?1 Cd solution at pH 5.5 containing 20 g L?1 PSW. Equilibrium was attained after 120 min and the equilibrium adsorption capacity of PSW increased with increasing Cd concentration from 5 to 50 mg L?1. The kinetic process of Cd adsorption obeyed the pseudo-second-order kinetic model. Langmuir and Freundlich models described equally well the experimental data and the maximum adsorption capacity was 4.89 mg g?1. PSW can be used for reducing Cd concentration in Cd-contaminated water systems. 相似文献
19.
《分离科学与技术》2012,47(14):2291-2297
The present work deals with the use of Caesalpinia bonducella seed powder (CBSP) as a biosorbent for Ni(II) removal from aqueous solution. The nature and morphology of the sorbent were determined using FTIR spectral, SEM, and EDX analysis. The biosorption characteristics of Ni(II) onto CBSP was investigated as a function of pH, biosorbent dosage, contact time, initial metal ion concentration, and temperature. Langmuir and Freundlich isotherms were used to fit the experimental data. The best interpretation for the equilibrium data was given by the Langmuir isotherm. The maximum biosorption capacity was found to be 188.7 mg/g for Ni(II) at pH 5.0 and at 323 K. The equilibrium biosorption data were well fitted with the pseudo-second-order kinetic equation. The values of thermodynamic parameters (ΔGo, ΔHo, and ΔSo) indicated that the biosorption of Ni(II) onto CBSP was feasible, spontaneous and exothermic in nature. The FTIR results revealed that hydroxyl, amine, carboxyl, and carbonyl functional groups are responsible for Ni(II) biosorption onto CBSP. 相似文献
20.
Daniela Cristina Culita Claudia Maria Simonescu Rodica Elena Patescu Silviu Preda Nicolae Stanica Cornel Munteanu Ovidiu Oprea 《Journal of Inorganic and Organometallic Polymers and Materials》2017,27(2):490-502
Three novel magnetic adsorbents were synthesized through the immobilization of di-, tri-, and tetraamine onto the surface of silica coated magnetite nanoparticles. The adsorbents were characterized by XRD patterns, FTIR spectroscopy, elemental and thermogravimetric analysis, magnetic measurements, SEM/TEM, EDX spectroscopy, and N2 adsorption/desorption isotherms. Their capacity to remove copper ions from aqueous solutions was investigated and discussed comparatively. The equilibrium data were analyzed using Langmuir and Freundlich isotherms. The kinetics was evaluated using the pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The best interpretation for the equilibrium data was given by the Langmuir isotherm for the tri- and tetraamine functionalized adsorbents, while for the diamine functionalized adsorbent the Freundlich model seemed to be better. The kinetic data were well fitted to the pseudo-second-order model. The overall rate of adsorption was significantly influenced by external mass transfer and intraparticle diffusion. It was observed that the adsorption capacity at room temperature decreased as the length of polyamine chain immobilized on the adsorbent surface increased, the maximum adsorption capacities being 52.3 mg g?1 for 1,3-diaminopropan functionalized adsorbent, 44.2 mg g?1 for diethylenetriamine functionalized adsorbent, and 39.2 mg g?1 for triethylenetetramine functionalized adsorbent. The sorption process proved to be highly dependent of pH. The results of the present work recommend these materials as potential candidates for copper removal from aqueous solutions. 相似文献