Equilibrium,Kinetic, and Thermodynamic Studies on the Biosorption of Selenium (IV) Ions onto Ganoderma Lucidum Biomass

The capacity of Ganoderma lucidum biomass for biosorption of selenium (IV) ions from aqueous solution was studied in a batch mode. In this study the effects of operating parameters such as solution pH, adsorbent dosage, initial metal concentration, contact time, and temperature were investigated. The adsorption capacity of G. lucidum was found to be 126.99 mg g^?1. The biosorption follows pseudo-first order kinetics and the isotherms fit well to both Langmuir and Freundlich isotherm models. Isotherms have been used to determine thermodynamic parameters of the process, that is, free energy, enthalpy, and entropy changes. Furthermore, the biosorbent was characterized by scanning electron microscopy and FT-IR analysis. FT-IR analysis of fungal biomass shows the presence of amino, carboxyl, hydroxyl, and carbonyl groups, which were responsible for the biosorption of selenium(IV) ions. The results indicated that the biomass of G. lucidum is an efficient biosorbent for the removal of selenium (IV) ions from aqueous solutions.     

Biosorption of As(III) and As(V) from Aqueous Solution by Lichen (Xanthoria parietina) Biomass

The biosorption of As(III) and As(V) from aqueous solution on lichen (Xanthoria parietina) biomass were investigated using different experimental parameters such as solution pH, biomass concentration, contact time, and temperature. The equilibrium data were evaluated by Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models. The biosorption capacity of X. parietina for As(III) and As(V) was found to be 63.8 mg/g and 60.3 mg/g. The mean sorption energy values calculated from D–R model indicated that the biosorption of As(III) and As(V) onto X. parietina biomass took place by chemical ion-exchange. The thermodynamic parameters showed that the biosorption of As(III) and As(V) ions onto X. parietina biomass was feasible, spontaneous, and exothermic in nature. Kinetic examination of the sorption data revealed that the biosorption processes of both As(III) and As(V) followed well the pseudo-second-order kinetics. The arsenic ions were desorbed from X. parietina using both 1 M HCl and 1 M HNO₃. The recovery yield of arsenic ions was found to be 80-90% and the biosorbent had good reusability after consecutive seven sorption-desorption cycles.     

Equilibrium,Kinetic, and Thermodynamic Analysis of Cd(II) Sorption from Aqueous Solutions using Polymeric Microcapsules containing an Acidic Organophosphonic Extractant

The equilibrium, kinetics, and thermodynamics of Cd(II) sorption from aqueous solutions onto polymeric microcapsules has been studied. Microcapsules were prepared by immobilizing an acidic organophosphonic extractant in a polymeric matrix prepared from styrene and ethylene glycol dimethacrylate following in situ free-radical suspension polymerization. Scanning electronic microscopy showed that the microcapsules were spherical and exhibited a rough surface with an average BET surface area of 12–20 m² g^?1 and an approximate pore size of 7.0 nm. The microcapsules were contacted with aqueous solutions containing Cd(II) approximately 100 mg L^?1 at an initial pH = 4.0 to study their sorptive behaviour over a temperature range of 293–323 K. The results of equilibrium experiments showed that the results filled the Langmuir isotherm model. The experimental kinetics followed a pseudo-second order model with an activation energy of 47.1±2.2 kJ mol^?1. Thermodynamics measurements showed that sorption is spontaneous and exothermic and that entropy had a negative value.     

Removal of Cr(VI) From Aqueous Solution by Turkish Vermiculite: Equilibrium,Thermodynamic and Kinetic Studies

Abstract

The adsorption of Cr(VI) from aqueous solution by Turkish vermiculite were investigated in terms of equilibrium, kinetics, and thermodynamics. Experimental parameters affecting the removal process such as pH of solution, adsorbent dosage, contact time, and temperature were studied. Equilibrium adsorption data were evaluated by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. Langmuir model fitted the equilibrium data better than the Freundlich model. The monolayer adsorption capacity of Turkish vermiculite for Cr(VI) was found to be 87.7 mg/g at pH 1.5, 10 g/L adsorbent dosage and 20°C. The mean free energy of adsorption (5.9 kJ/mol) obtained from the D–R isotherm indicated that the type of sorption was essentially physical. The calculated thermodynamic parameters (ΔG ^o , ΔH ^o and ΔS ^o ) showed that the removal of Cr(VI) ions from aqueous solution by the vermiculite was feasible, spontaneous and exothermic at 20–50°C. Equilibrium data were also tested using the adsorption kinetic models and the results showed that the adsorption processes of Cr(VI) onto Turkish vermiculite followed well pseudo-second order kinetics.     

Biosorption of Cd(II) From Aqueous Solution by Cocoa Pod Husk Biomass: Equilibrium,Kinetic, and Thermodynamic Studies

Cocoa pod husk biomass proved to be an effective biosorbent for the removal of Cd(II) from aqueous solution. The biosorbent was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, surface structural parameters, and proximate analysis. The effects of operational parameters were investigated. Equilibrium was reached after 120 min at 303 K and optimum biosorption capacity was obtained at pH 6. The biosorption kinetics was best predicted by the Avrami model. The results showed that the biosorption equilibrium was best described by the Freundlich isotherm model. From the thermodynamic parameters determined, the biosorption was spontaneous and endothermic.     

Equilibrium,Thermodynamic, and Kinetic Studies on Trichoderma viride Biomass as Biosorbent for the Removal of Cu(II) from Water

Equilibrium, thermodynamic, and kinetic studies on the biosorption of Cu(II) using biomass, Trichoderma viride were carried out. The biosorbent was characterized by Fourier transform infrared spectroscopy and Scanning Electron Microscopy. The Langmuir and Freundlich isotherm models were applied to describe the biosorption process. The influence of pH, the biomass dosage, the contact time, the initial metal ion concentration, and the temperature of the solution on the biosorption was studied. The maximum Cu(II) biosorption was attained at pH 5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The maximum biosorption capacity of T. viride biomass was found to be 19.6 mg/g for Cu(II). The kinetic studies indicated that the biosorption of Cu(II) followed the pseudo-second-order model. The calculated thermodynamic parameters, Gibbs-free energy (ΔG^o), enthalpy (ΔH^o), and entropy (ΔS^o) showed that the biosorption of Cu(II) onto T. viride biomass was spontaneous and endothermic. It can be concluded that the T. viride biomass has the potential as an effective and low-cost biosorbent for Cu(II) removal from aqueous solutions.     

谷壳对水中铜镉离子的生物吸附研究

研究了农业副产物谷壳对水中Cu2+、Cd2+的生物吸附过程及其影响因素,以间歇实验的方式考察了吸附时间、溶液初始pH值、谷壳用量、谷壳粒径、吸附温度、金属离子初始浓度等物化参数对吸附过程的影响,研究了其吸附热力学和动力学。结果表明谷壳对Cu2+、Cd2+的吸附均符合Langmuir和Freundlich等温吸附模式,都遵循拟二级动力学模型。利用谷壳做生物吸附剂去除废水中重金属离子,既是对农作物副产物的合理利用,也是重金属废水净化的一种有效方法,谷壳有望成为一种低成本有效、效果好的净化重金属废水的新型生物吸附剂。     

Biosorption of Reactive Yellow 145 Dye by Dried Penicillum restrictum: Isotherm,Kinetic, and Thermodynamic Studies

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.     

Hg(II) Removal from Aqueous Solution by Dead Fungal Biomass of Marine Aspergillus niger: Kinetic Studies

Abstract

Mercury removal from wastewater is a recognized pollution control challenge today. In the present investigation, the biosorption of Hg(II) onto the dead biomass of four different species of marine Aspergillus, prepared by alkaline treatment, was studied. Among the cultures studied, A. niger was found to be the most efficient for Hg(II) removal. The effects of initial Hg(II) concentration, contact time, pH, temperature, and biosorbent dosage on biosorption were also investigated. It was observed that biosorption equilibriums were established in about 2 h. Under the optimum conditions (pH: 3.0, Hg(II) concentration: 250 mg/L, biomass dose: 0.8 g/L, temperature: 40°C and contact time: 2 h), 40.53 mg Hg(II) was biosorbed per gram of dead biomass of A. niger. Kinetic studies based on fractional power, zero order, first order, pseudo first order, Elovich, second order, and second order rate expressions have also been carried out where the pseudo second order model exhibited best fit to experimental data. The intra‐particle diffusion study revealed that film diffusion is the rate‐limiting sorption process for Hg(II) on A. niger. The nature of the possible cell–metal ion interactions was evaluated by FTIR, SEM, and EDAX analysis. These examinations indicated the involvement of ‐OH and ‐NH₂ ⁺ groups in the biosorption process present on the surface of the dead fungal biomass. Here, Hg(II) ions were deposited on the surface of the biomass as a film like structure.     

Kinetic and Equilibrium Modeling of Pb(II) and Co(II) Sorption onto Rose Waste Biomass

Abstract

An attempt was made to assess the biosorption potential of rose waste biomass for the removal of Pb(II) and Co(II) ions from synthetic effluents. Biosorption of heavy metal ions (>90%) reached equilibrium in 30 min. Maximum removal of Pb(II) and Co(II) occurred at pH 5 and 6 respectively. The biosorbent dose for efficient uptake of Pb(II) and Co(II) was 0.5 g/L for both metals. The biosorbent size affected the Pb(II) and Co(II) biosorption rate and capacity. Rose waste biomass was found effective for Pb(II) and Co(II) removal from synthetic effluents in the concentration range 10–640 mg/L. Equilibrium sorption studies showed that the extent of Pb(II) and Co(II) uptake by the rose waste biomass was better described by the Langmuir isotherm in comparison to the Freundlich model. The uptake capacities of the two metal ions were 156 and 27.15 mg/g for Pb(II) and Co(II) respectively.     

Adsorption of Furfural from Aqueous Solution onto Activated Carbon: Kinetic,Equilibrium and Thermodynamic Study

Abstract

The present study aims to evaluate the influence of various experimental parameters viz. initial pH (pH ₀), adsorbent dose, contact time, initial concentration and temperature on the adsorptive removal of furfural from aqueous solution by commercial grade activated carbon (ACC). Optimum conditions for furfural removal were found to be pH ₀ ≈ 5.9, adsorbent dose ≈ 10 g/l of solution and equilibrium time ≈ 6.0 h. The adsorption followed pseudo‐second‐order kinetics. The effective diffusion coefficient of furfural was of the order of 10^?13 m²/s. Furfural adsorption onto ACC was found to be best represented by the Redlich‐Peterson isotherm. A decrease in the temperature of the operation favorably influenced the adsorption of furfural onto ACC. The positive values of the change in entropy (ΔS ⁰); and the negatived value of heat of adsorption (ΔH ⁰) and change in Gibbs free energy (ΔG ⁰) indicated feasible, exothermic, and spontaneous nature of furfural adsorption onto ACC.     

Biosorption of Direct Red 28 (Congo Red) from Aqueous Solutions by Eggshells: Batch and Column Studies

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.     

Equilibrium Studies in Adsorption of Hg(II) from Aqueous Solutions using Biocompatible Polymeric Polypyrrole-Chitosan Nanocomposite

This article deals with the adsorption of Hg(II) ions from aqueous solution on biocompatible polymeric polypyrrole-chitosan (PPy/CTN) nanocomposite. The Hg(II) uptake of PPy/CTN was quantitatively evaluated using sorption isotherms. In order to describe the isotherm mathematically, the experimental data of the removal equilibrium were correlated by either the Langmuir, Freundlich and Temkin equations. Results indicated that the Langmuir model gave a better fit to the experimental data than the other two equations. The adsorption capacity (q_max) of PPy/CTN for Hg(II) ions in terms of monolayer adsorption was 40 mg/g.     

Biosorptive Removal of Ni(II) from Aqueous Solution by Caesalpinia bonducella Seed Powder

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 (ΔG^o, ΔH^o, and ΔS^o) 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.     

Arsenic Removal from Aqueous Solution by Iron Oxide-Coated Biomass: Common Ion Effects and Thermodynamic Analysis

Abstract

A batch study showed that the presence of anions (sulfate, chloride, and nitrate) in solution did not affect the adsorption process of both As(V) and As(III) by iron oxide-coated A. niger biomass. It was found that the presence of Ca²⁺, Fe²⁺, and Mg²⁺ ions at a concentration of 200 mg/L in solution could increase the removal efficiency of As(V) by 86.5%, 95.4%, and 65.8%, respectively. Similarly, the presence of Ca²⁺, Fe²⁺, and Mg²⁺ ions at a concentration of 200 mg/L in solution could increase the removal efficiency of As(III) by 39.3%, 97%, and 8.4%, respectively. The batch adsorption-desorption study showed that the reactions between the arsenic species and the iron oxide-coated A. niger biomass were reversible. Desorption of As(V) and As(III) at neutral pH was approximately 15%. As(V) desorbed more than As(III) in acidic (pH 1.33) and alkaline (pH 12.56) solutions. At a pH of 1.33, 67% of the adsorbed As(V) desorbed, and the percentage of desorbed As(III) was only 47.1% in the same condition. At a solution pH of 12.56, 73.4% of the As(V), and 43.7% of As(III) desorbed. The thermodynamic study showed the spontaneous nature of the sorption of arsenic on IOCB. The high value of the heat of adsorption {ΔH ≈ ? 133 kJ/mol for As(V), and 88.9 k/mol for As(III)} indicated that the mechanism of arsenic sorption was chemisorption.     

Adsorption of Hg(II) Ions by 3-Mercaptopropyltriethoxysilane Modified Mesoporous Silica Based on Multiwalled Carbon Nanotubes: Equilibrium,Kinetic, and Thermodynamic Studies

In this study, 3-mercaptopropyltriethoxysilane (MPTS) modified mesoporous silica based on multiwalled carbon nanotubes (MWCNTs@mSiO₂-MPTS) was successfully prepared. The adsorption material was characterized and used for adsorbing Hg(II) ions from aqueous solution. The equilibrium data conformed better to the Langmuir isotherm with maximum adsorption capacity calculated 349.65 mg/g at 40ºC. The kinetics analysis revealed the adsorption process fitted well with the pseudo-second-order kinetic model. The thermodynamic parameters indicated the adsorption process was spontaneous and endothermic. All results obtained suggested that MWCNTs@mSiO₂-MPTS may be employed as an efficient material for the adsorption or preconcentration of Hg(II) ions from aqueous solution.     

Kinetics,Equilibrium, and Thermodynamic of Pb(II) Biosorption by Citric Acid Modified Lawny Grass Containing Cyanex272

Lawny grass loaded Cyanex272 prepared by solid-liquid grind was used to remove Pb(II) in the batch and column process. Carboxylic groups were introduced to the grass by citric acid modification and Cyanex272 was successfully immobilized on grass. The removal rate of Pb(II) on 272-1CG is close to 100%. Cyanex272 also played an important role in improving maximum adsorption capacities from 328 to 380 mg/g and shortening equilibrium time from 60 min to 40 min. Thermodynamic results indicate the adsorption of Pb(II) is spontaneous and endothermic. 0.1 mol/L HCl is used as eluent and desorption percentages reach 95.1%.     

Effect of Temperature on the Pb (II) Removal from Single Aqueous Solutions by a Locally Natural Mordenite: Equilibrium and Kinetic Modeling

Abstract

Zeolites have been shown to be effective adsorbents for the removal of heavy metals from aqueous solutions. In this study, mordenite (a natural zeolite) has been used for the removal of lead ions to evaluate its potential use as a low‐cost adsorbent. Batch experiments have been conducted to evaluate the equilibrium and process kinetics at different temperatures. The equilibrium experimental data for various temperatures studied conformed to the six adsorption isotherm equations: the Langmuir, Freundlich, Sips, Redlich‐Peterson (RP), Dubinin‐Radwhkevich (DR), and Flory‐Huggins (FH). Constants were determined for each of the isotherms. The apparent thermodynamic parameters were calculated and the obtained values supported the conclusion that the lead ions adsorption onto mordenite was a spontaneous, exothermic process of physical nature. The kinetic experimental data fitted the pseudo‐second‐order, parabolic diffusion and Elovich equations successfully. The process of lead ions adsorption onto the Na‐mordenite was diffusion‐controlled. The value of apparent activation energy also confirmed a physical mechanism for the adsorption of lead ions onto Na‐mordenite.     

Biosorption of Zinc from Aqueous Solutions by Rice Bran: Kinetics and Equilibrium Studies

Abstract

Rice bran, an agricultural by‐product, was used for the removal of zinc ions from aqueous solution. The work considered the determination of zinc‐biomass equilibrium data in batch system. These studies were carried out in order to determine some operational parameters of zinc sorption such as the time required for the Zinc‐biosorbent equilibrium, the effects of biomass particle size, pH, and temperature. The results showed that pH has an importance effect on zinc biosorption capacity. The biosorbent size also affects the zinc biosorption capacity. The sorption process follows pseudo‐second‐order kinetics. The intraparticle diffusion may be the rate‐controlling step involved in the adsorption zinc ions onto the rice bran up to 30 min. The equilibrium data could be best fitted by the Langmuir sorption isotherm equation over the entire concentration range (40–160 mg/dm³). Thermodynamic parameters, such as ΔG°, ΔH°, ΔS°, have been calculated. The thermodynamics of zinc ion/rice bran system indicate spontaneous and endothermic nature of the process.