Ion Sorption Processes Research Articles

INVESTIGATION OF THE EFFICIENCY OF RHENIUM ION SORPTION USING ION-EXCHANGE RESINS POLYACRYLIC ACID: POLY-4-VINYLPYRIDINE IN VARIOUS RATIOS

This study is devoted to the study of the efficiency of sorption of rhenium ions using ion-exchange resins containing polyacrylic acid (PAK) and poly-4-vinylpyridine (P4VP) in various composition ratios. Goals and objectives. To investigate synthesized resins with different ratios of PAK:P4VP and to study their sorption capacity, kinetics and selectivity with respect to rhenium ions. Methods. Thanks to a comprehensive experimental analysis, including periodic sorption experiments and characterization methods such as spectrophotometry and atomic emission spectroscopy, the effect of resin composition on sorption efficiency was clarified during the study. Results and discussion. Optimal ratios have been determined to ensure maximum efficiency of rhenium ion removal. In addition, the study examines the main mechanisms governing sorption properties, with an emphasis on the relationship between resin composition, surface chemical composition and ion interaction. Conclusion. The results obtained contribute not only to the development of special ion-exchange materials for the effective extraction and purification of rhenium, but also contribute to a deeper understanding of ion sorption processes. This research has important implications for rhenium-dependent industries, offering strategies for solving problems related to its extraction, purification and use.

Biocatalyst Based on Magnetic Nanoparticles with Cu(II), Mn(II), Zn(II) and Immobilised Catalase

AbstractThis article described a process for the preparation of a Fe3O4 nanocatalyst modified with Mn(II), Cu(II) and Zn(II) ions immobilised with catalase. The effectiveness of the description of the ion sorption process was compared with four equilibrium models: Langmuir, Freundlich, Redlich–Peterson and Sips. The proposed models allow the description of both single- and multi-component sorption. The results were also verified by DFT analysis. The Langmuir model describing single-component sorption and the extended Langmuir model for multi-component systems with the best fit represented the sorption of metal ions on Fe3O4. The maximum sorption capacity values in the pseudo-second-order kinetic model were 10.76, 12.87 and 10.52 mg/g for Cu(II), Zn(II) and Mn(II) in the single-component systems and 11.79, 8.54 and 2.03 mg/g for Cu(II), Zn(II) and Mn(II) in the multi-component system, respectively. The kinetics parameters were described most accurately by a pseudo-second-order model, which suggested, along with the Extended Langmuir model, the chemical nature of the sorption. After preparation of the Fe3O4/Mn–Zn–Cu material, catalase was immobilised on the surface of the material. The final material was able to decompose hydrogen peroxide with an activity of 7130 units/g of material. Modification of the material with Mn(II), Cu(II) and Zn(II) resulted in an increase in H2O2 removal efficiency exceeding 99.9%.

Comparison of Non-Linear and Linear Ho Models Applied for Copper Ions Sorption on Geopolymer

The Ho pseudo-second-order model is the best fitting model in describing the sorption of copper ions on synthesized geopolymer for the selected experimental conditions (particle size 0.071–0.090 mm at agitation speed of 240 rpm). For that reason, a comparison of one non-linear and five linear forms of the Ho pseudo-second-order model was made in the present study in order to obtain the optimum sorption kinetic parameters using the experimental kinetic data obtained for the copper ions sorption process on the synthesized geopolymer. Taking all the results into consideration, the non-linear Ho model proved to be more consistent in describing the copper ions sorption on geopolymer for various initial concentrations of sorbent, as well as for various temperatures.

Studies on the Mechanism of Cu(II) Ion Sorption on Purolite S 940 and Purolite S 950.

The aim of the presented research was to investigate the mechanism of sorption of Cu(II) ions on the commercially available Purolite S 940 and Purolite S 950 chelating ion exchangers with the aminophosphonic functional groups. In order to understand better the sorption mechanism, the beads were cut with an ultramicrotome before and after the Cu(II) ion sorption process. The cut beads were examined by scanning electron microscopy (SEM) with an EDX detector. The performed linear profiles of the elemental composition allowed us to examine the depth with which the sorbed metal penetrates into. For further investigations concerning the mechanism of the sorption process, the Fourier transform infrared spectroscopy (FTIR) analysis using the attenuated total reflectance (ATR) technique and the X-ray photoelectron spectroscopy (XPS) methods have been used. The comparison of FTIR and XPS spectra before and after the sorption of Cu(II) ions showed that free electron pairs from nitrogen and oxygen in the aminophosphonic functional groups participate in the process of copper ion sorption. In addition, the microscopic studies suggested that the process of ion exchange between Na(I) ions and sorbed Cu(II) ions takes place on the Purolite S 940 and Purolite S 950. This study concerning the in-depth understanding the of Cu(II) sorption mechanism, using modern analytical tools and research methods could be very useful for its further modifications leading to the improvement of the process efficiency.

Lead Sorption by Chrysanthemum indicum: Equilibrium, Kinetic, and Desorption Studies

The research was aimed at checking the possibility of using the Chrysanthemum (Chrysanthemum indicum) as a sorbent for the removal of heavy metals. The chrysanthemum was divided into flower petals, stems, and leaves to check the affinity for the metals tested. In the work, equilibrium and kinetic modeling of the process was carried out by selecting nonlinear models with the best fit. The tested material was characterized by high sorption capacity in relation to lead ions, amounting to 87–89 mg/g. The equilibrium model that best describes the lead ion sorption process on Chrysanthemum indicum is the Langmuir model, while the kinetic model is the pseudo-second-order model. The performed tests of metal recovery from the surface of the tested material allowed for its recovery in the range of 43–55% with the use of acetic acid.

Pre-treatment of toxic element and cationic dye onto natural biomass: characterization and optimization

This researchdescribe wastewater pre-treatment that contaminated with Methylene Blue dye (MB) and Ni(II) ion by Athelia Bombacina fungus dead biomass (ABFDB). Researches finding on ABFDB characterization by SEM, XRD, CHNS and FT-IR analysis show that ABFDB can be used as efficient sorbent, because ABFDB cellular wall consist of Chitin, β-Glucan and Cellulose biopolymers, generally. Results show that removal of MB and Ni(II) ion by ABFDB sorbent is more than 86.41 and 66.2%, respectively. So, after parameters investigation of MB and Ni(II) ion sorption process by ABFDB, the response surface method was employed for optimization and study the interaction of operational parameters on the sorption of pollutants. This low-cost and natural environmental friendly biosorbent can be utilized for pretreatment process in the first step of wastewater treatment project.

Synthesis and characterization of mesoporous polymeric microspheres of methacrylic derivatives of aromatic thiols

The paper presents the synthesis and characterization of mesoporous microspheres of derivatives of three aromatic thiols: S-phenyl 2-methylprop-2-enethioate (PSM), S,S′-thiodi-4,1-phenylenebis(thiomethacrylate) (DMSPS), and bis[4(2-hydroxy-3-methacryloyloxypropoxy)phenyl]sulfide (BES.DM) with divinylbenzene (DVB). The microspheres were obtained by the emulsion-suspension polymerization procedure. The chemical and porous structure, morphology, and properties of the microspheres were analyzed by attenuated total reflection-Fourier transform infrared (ATR/FT-IR) spectroscopy, low-temperature nitrogen adsorption data, optical microscope MORPHOLOGI G3, differential scanning calorimetry (DSC), and wavelength dispersive X-ray fluorescence (WD-XRF). Moreover, studies on the Pb(II) ions sorption process were carried out on the above mentioned compounds. The sorption kinetics and mechanism were described by the pseudo-first order, pseudo-second order, and intraparticle diffusion models. The sorption equilibria were described by the Langmuir and Freundlich isotherms. The PSM-DVB, DMSPS-DVB, and BES.DM-DVB microspheres exhibit high thermal resistance and good adsorption properties of Pb(II) ions. The best adsorption properties for the examined microspheres were obtained at pH 5. The highest monolayer adsorption capacity determined by Langmuir isotherm was obtained for the DMSPS-DVB microspheres and was equal to 22.54 mg/g. The preliminary studies show that the synthesized microspheres can be used as heavy metal ion sorbents from aqueous solutions.

Spectrophotometric Analysis of the Kinetic of Pd(II) Chloride Complex Ions Sorption Process from Diluted Aqua Solutions Using Commercially Available Activated Carbon

AbstractIn this paper, results of adsorption kinetic studies of Pd(II) chloride complex ions on activated carbon Organosrob 10 CO are presented. Spectorphotometrical method was applied to investigate the process. Kinetic model was proposed, and fundamental thermodynamic parameters were determined. Proposed kinetic model describes well observed phenomenon in the studied range of concentration of Pd(II) chloride complex ions as well, as concentration of activated carbon.

Synthesis of activated carbon-nanomagnetite-pyrazolone(1-phenyl-3-methyl-5-pyrazolone) composite as adsorbent for Cd2+

Pyrazolone was impregnated onto activated carbon-nanomagnetite (AC-NM) composite and used as an adsorbent for cadmium (Cd(II)). AC-NM composite has been synthesized by hydrothermal method. The single phase of spinel magnetite and crystalinity of nanomagnetite (NM) and AC-NM composite were confirmed by X-ray diffraction (XRD). It has been found that the crystalinity of AC-NM composite was lower than NM. The synthesized activated carbon-nanomagnetite-pyrazolone (AC-NM-PZ) was characterized by Fourier Transform Infra-Red (FTIR). Moreover, the sorption capabilities for Cd(II) ions were evaluated by three adsorbent AC, AC-NM, and AC-NM-PZ. The pH range, adsorption time, and adsorbent dosage were optimized by Response Surface Method (RSM). Cd(II) ions sorption process was studied and evaluated by two adsorption isotherms and found to follow the Langmuir model. A value of 20.64 µmol/g was identified as the maximum sorption capacity of AC. AC-NM composite was found to increase the sorption capacity to be 36.73 µmol/g. The sorption capacity for AC-NM-PZ composite was 27.67 µmol/g, it was lower than KA-NM but higher than AC.

The application of experimental design methodology for the investigation of liquid radioactive waste treatment

The sorption properties of waste facade, brick, and asphalt sample towards Sr(II), Co(II), and Ni(II) ions from single and multicomponent solutions were investigated. The highest sorption capacity was found for Ni(II) ions, while the most effective sorbent was facade. Simplex Centroid Mixture Design was used in order to investigate the sorption processes of ions from solutions with different composition as well as the competition between the cations. Based on the statistical analysis results, the equations for data modeling were proposed. According to the observations, the investigated solid matrices can be effectively used for the liquid radioactive waste treatment. Furthermore, the applied methodology turned out to be an easy and operational way for the investigations of multicomponent sorption processes.

Equilibrium modeling of mono and binary sorption of Cu(II) and Zn(II) onto chitosan gel beads

Abstract The objective of the work are in-depth experimental studies of Cu(II) and Zn(II) ion removal on chitosan gel beads from both one- and two-component water solutions at the temperature of 303 K. The optimal process conditions such as: pH value, dose of sorbent and contact time were determined. Based on the optimal process conditions, equilibrium and kinetic studies were carried out. The maximum sorption capacities equaled: 191.25 mg/g and 142.88 mg/g for Cu(II) and Zn(II) ions respectively, when the sorbent dose was 10 g/L and the pH of a solution was 5.0 for both heavy metal ions. One-component sorption equilibrium data were successfully presented for six of the most useful three-parameter equilibrium models: Langmuir-Freundlich, Redlich-Peterson, Sips, Koble-Corrigan, Hill and Toth. Extended forms of Langmuir-Freundlich, Koble-Corrigan and Sips models were also well fitted to the two-component equilibrium data obtained for different ratios of concentrations of Cu(II) and Zn(II) ions (1:1, 1:2, 2:1). Experimental sorption data were described by two kinetic models of the pseudo-first and pseudo-second order. Furthermore, an attempt to explain the mechanisms of the divalent metal ion sorption process on chitosan gel beads was undertaken.

Sorption of Cd2+ ions onto zeolite synthesized from perlite waste

In this work, the studies on the formation of zeolites from expanded perlite waste and their use in the sorption process of Cd2+ ions will be reported. Such approach is innovative and has not been investigated elsewhere. The results of the synthesis of zeolites from aluminosilicate waste using hydrothermal method were presented. By-product from the process production of expanded perlite was used as the starting material. Theoretical and practical aspects of Cd2+ ions sorption process onto material synthesized in selected conditions (a material with good sorption capacity can be obtained by 24 h reaction of 1 g of perlite waste in 10 mL of 4.0 M NaOH solution with at 70 °C) will be presented. The atomic absorption spectroscopy has been used as the main method, from which the effective cation exchange capacity as well as the proportion of ion exchange to chemisorption in the sorption process have been determined. Structural analyses of the sample before and after sorption process have been also carried out by the mid-infrared spectra measurement, especially pseudolattice range of the spectra was analyzed in detail in which changes caused by ion exchange of non-tetrahedral ions have been observed.

The sorption of Cd(II) from aqueous solutions by fixed Lentinus edodes mushroom flesh particles

Lentinus edodes residue that is immobilized with polyvinyl alcohol–Na-alginate was studied as a sorbent for Cd(II) removal from solutions to discover a cost-effective and more practical sorption material for heavy metal ion removal from sewage. Results demonstrated that the sorption of Cd ions by immobilized L. edodes reached equilibrium within 7 h. The kinetics of Cd ion sorption were best described with a pseudo-second-order model with an equilibrium sorption capacity (qe) of 0.2008 mg/g. The optimal pH for Cd ion sorption ranged from 4 to 7. The sorption capacity for Cd ions gradually increased with increasing initial Cd concentration from 0 to 120 mg/L. When the Cd ion concentration was fixed at 10 mg/L and the interfering metal Cu or Pb ion concentration in the same solution was varied from 0 to 30 mg/L, the sorption rate of Cd ions decreased significantly, as determined with variance analysis. The Langmuir model was the most suitable for describing Cd ion sorption with a correlation coefficient (R2) of 0.9981 and a theoretical maximum sorption capacity (qm) of 6.4475 mg/g, which was similar to the experimentally observed qm of 6.046 mg/g. The Langmuir–Freundlich and Freundlich models were also suitable for describing the Cd ion sorption process. Scanning electron microscopy was used for observing the contractive change of the cell surface before and after absorbing Cd ions by immobilized L. edodes beads. Fourier transform infrared spectroscopy analysis demonstrated –OH, –CO, and –CO–NH in the cell wall of L. edodes plays an important role in Cd ion sorption.

Cd(II) and Pb(II) sorption by extracellular polymeric substances (EPS) extracted from anaerobic granular biofilms: Evidence of a pH sorption-edge

This work investigates the ability of EPS extracted by cationic exchange resin (CER) from 3 different anaerobic granular sludges to bind Pb or Cd as a function of pH. EPS display a better binding ability for Pb than Cd as it has been often shown in literature. The experimental sorption data show the presence of a pH sorption edge. The experimental data are well fitted by the Kurbatov model. Nevertheless, the molar ratio of proton exchanged with metal ions underlines that other mechanisms are also involved in metal ion sorption by EPS from anaerobic granular sludges. Moreover, the mineral fraction present in extracted EPS and trapped by the organic fraction or under particle form seems to be involved in the metal ions sorption process.

INVESTIGATIONS ON THE FEASIBILITY OF ROMANIAN PINE BARK WASTES CONVERSION INTO A VALUE-ADDED SORBENT FOR CU(II) AND ZN(II) IONS

The batch sorption capability of Romanian pine bark for the removal of Cu(II) and Zn(II) ions from diluted aqueous solutions was investigated as a function of initial pH, contact time, and temperature. The metal sorption sequence is Cu > Zn. The experimental data for Cu(II) and Zn(II) ions retention on the tested bark of Pinus sylvestris L. showed a better compliance with the pseudo–second order kinetic model. The values of the maximum capacity of sorption, determined on the basis of the Langmuir isotherm model, are 14.7 mg g-1 and 13.01mg g-1 (at 200C) for Cu(II) and Zn(II) ions, respectively. The computed thermodynamic parameters indicate the spontaneous and endothermic nature of Cu(II) and Zn(II) ions sorption process by pine bark. The obtained results suggest that Romanian pine bark is a promising material for the development of a low–cost sorption technology for the removal of Cu(II) and Zn(II) ions from aqueous streams.

Investigations on the feasibility of Romanian pine bark wastes conversion into a value-added sorbent for Cu(II) and Zn(II) ions

The batch sorption capability of Romanian pine bark for the removal of Cu(II) and Zn(II) ions from diluted aqueous solutions was investigated as a function of initial pH, contact time, and temperature. The metal sorption sequence is Cu > Zn. The experimental data for Cu(II) and Zn(II) ions retention on the tested bark of Pinus sylvestris L. showed a better compliance with the pseudo–second order kinetic model. The values of the maximum capacity of sorption, determined on the basis of the Langmuir isotherm model, are 14.7 mg g-1 and 13.01mg g-1 (at 200C) for Cu(II) and Zn(II) ions, respectively. The computed thermodynamic parameters indicate the spontaneous and endothermic nature of Cu(II) and Zn(II) ions sorption process by pine bark. The obtained results suggest that Romanian pine bark is a promising material for the development of a low–cost sorption technology for the removal of Cu(II) and Zn(II) ions from aqueous streams.

Heavy metals binding properties of esterified lemon

Sorption of Cd 2+, Cr 3+, Cu 2+, Ni 2+, Pb 2+ and Zn 2+ onto a carboxyl groups-rich material prepared from lemon was investigated in batch systems. The results revealed that the sorption is highly pH dependent. Sorption kinetic data indicated that the equilibrium was achieved in the range of 30–240 min for different metal ions and sorption kinetics followed the pseudo-second-order model for all metals studied. Relative sorption rate of various metal cations was found to be in the general order of Ni 2+ > Cd 2+ > Cu 2+ > Pb 2+ > Zn 2+ > Cr 3+. The binding characteristics of the sorbent for heavy metal ions were analyzed under various conditions and isotherm data was accurately fitted to the Langmuir equation. The metal binding capacity order calculated from Langmuir isotherm was Pb 2+ > Cu 2+ > Ni 2+ > Cd 2+ > Zn 2+ > Cr 3+. The mean free energy of metal sorption process calculated from Dubinin–Radushkevich parameter and the Polanyi potential was found to be in the range of 8–11 kJ mol −1 for the metals studied showing that the main mechanism governing the sorption process seems to be ion exchange. The basic thermodynamic parameters of metals ion sorption process were calculated by using the Langmuir constants obtained from equilibration study. The Δ G° and Δ H° values for metals ion sorption on the lemon sorbent showed the process to be spontaneous and exothermic in nature. Relatively low Δ H° values revealed that physical adsorption significantly contributed to the mechanism.

Prediction of the copper (II) ions dynamic removal from a medium by using mathematical models with analytical solution

A copper (II) ions biosorption by Sargassum sp. biomass was studied in a fixed bed column at 30 °C and pH 3.5. The experimental curves were obtained for the following feed concentrations −2.08, 4.16, 6.42 and 12.72 mmol/L of the copper ions. The mathematical models developed by Thomas and Bohart–Adams were used for description of ions sorption process in the column. The models principle hypothesis is that the mass transfer controlling stage of the process is the adsorption kinetics between sorbate and adsorbent. The phenomena such as intraparticle diffusion, a mass transfer external resistance and axial dispersion effects were out of considerations. Some of the models parameters were experimentally determined ( ρ B, ɛ, u 0, C 0) and the others were evaluated on the bases of the experimental data ( k a1, k a2). The unique fitting parameter in all models was the adsorption kinetic constant. The identification procedure was based on the least square statistical method. Simulation results show that the models describe well a copper ions sorption process in a fixed bed column. The used models can be considered as useful tools for adsorption process design and optimization in fixed bed column by using algae biomass of Sargassum sp. as an adsorbent.

Theoretical first step towards an understanding of the uranyl ion sorption on the rutile TiO2(110) face: A DFT periodic and cluster study

First results of a periodic and cluster Density Functional Theory (DFT) study of the uranyl ion (UO2 2+) sorption onto the rutile TiO2(110) face, based on plane wave and localised basis sets, are presented. A five layers slab with its most internal layer frozen to bulk positions was found to be a good surface model. In a first step and as reference data for the sorption process, the [UO2(H2O)n]2+ systems, with n=4 to 6 were studied. Relative solvation energies confirmed that the uranyl ion adopt a pentacoordinated structure in aqueous solution. From localised approach, an overall 0.91 electron transfer from the first hydration shell to the uranyl ion was calculated. Then, a periodic study of the uranyl sorption on a simplified hydroxylated TiO2(110) surface model was investigated. The resulting optimised structural parameters, for the three possible adsorption sites, show that the sorbed uranyl ion first coordination shell (saturated by three water molecules) plays an important role to model the adsorption process. Both methodologies (plane waves and localised atomic orbitals) were also used with a cluster model and gave similar results in agreement with experimental data. This first step in the understanding of the uranyl ion sorption onto the simplified hydroxylated TiO2(110) surface shows that hydrogen bonds should be included in the model in order to perform a more accurate description of the uranyl ion sorption process. A study with this surface model is currently performed in order to calculate the relative stabilities between the different uranyl adsorption sites and to compare with the experimental data.

Sorption Studies of Nickel ions Onto Sawdust of Dalbergia Sissoo

AbstractSawdust of Dalbergia sissoo, a byproduct of sawmills, was found to be a promising adsorbent for the removal of nickel ions from aqueous solution. Sorption of nickel ions onto sawdust of Dalbergia sissoo was studied using the batch technique. Kinetics studies show that nickel ions sorption process obeys a first order rate law. The applicability of the Langmuir and Freundlich models for the data was tested. Both the models adequately describe the experimental data of the biosorption of nickel ions. The sorption capacities and energies were calculated. Langmuir parameters Xm and K1 were found to increase with rise in temperature; Freundlich constants 1/n and Kf have been evaluated for 293K, 303K, 313K and 323K. Thermodynamic parameter ΔH° = 4.80 kJ mol−;1 shows that sorption of nickel ions onto sawdust is an endothermic process.