Removal of Cu(II), Fe(III), and Cr(III) from Aqueous Solution by Aniline Grafted Silica Gel

Abstract

The aniline moiety was covalently grafted onto silica gel surface. The modified silica gel with aniline groups (SiAn) was used for removal of Cu(II), Fe(III), and Cr(III) ions from aqueous solution and industrial effluents using a batch adsorption procedure. The maximum adsorption of the transition metal ions took place at pH 4.5. The adsorption kinetics for all the adsorbates fitted better the pseudo second‐order kinetic model, obtaining the following adsorption rate constants (k₂): 1.233 · 10^?2, 1.902 · 10^?2, and 8.320 · 10^?3 g · mg^?1 min^?1 for Cr(III), Cu(II), and Fe(III), respectively. The adsorption of these transition metal ions were fitted to Langmuir, Freundlich, Sips, and Redlich‐Peterson isotherm models; however, the best isotherm model fitting which presented a lower difference of the q (amount adsorbed per gram of adsorbent) calculated by the model from the experimentally measured, was achieved by using the Sips model for all adsorbates chosen. The SiAn adsorbent was also employed for the removal of the transition metal ions Cr(III) (95%), Cu(II) (95%), and Fe(III) (94%) from industrial effluents, using the batch adsorption procedure.     

Application of Aqai Stalks as Biosorbents for the Removal of the Dye Procion Blue MX-R from Aqueous Solution

The aqai palm stalk (Euterpe oleracea) is a food residue used in its natural form (AS) and also protonated (AAS) as biosorbents for the removal of the textile dye Procion Blue MX-R from aqueous solutions. This biosorbent was characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption curves. The effects of pH, biosorbent dosages, and shaking time on the biosorption capacities were studied. In the acidic pH region (pH 2.0) the biosorption of the dye was favorable. The minimum contact time to obtain the equilibrium was 8 hours for AS and AAS biosorbents. The general order kinetic model provided the best fit to the experimental data compared with the pseudo-first order and pseudo-second order kinetic adsorption models. The equilibrium data were fitted to the Langmuir, Freundlich, and Sips isotherm models. For both dyes the equilibrium data were best fitted to the Sips isotherm model. The enthalpy and entropy of adsorption of PB were obtained from adsorption equilibrium experiments ranging from 298 to 323 K. Simulated dyehouse effluent was used to check the applicability of the proposed adsorbents for effluent treatment.     

MODIFIED PLANTAIN PEEL AS CELLULOSE-BASED LOW-COST ADSORBENT FOR THE REMOVAL OF 2,6-DICHLOROPHENOL FROM AQUEOUS SOLUTION: ADSORPTION ISOTHERMS,KINETIC MODELING,AND THERMODYNAMIC STUDIES

In this study, the feasibility of using modified plantain peel to remove 2,6-dichlorophenol from iaqueous solutions was investigated under batch mode. The effects of physical factors such as initial 2,6-dichlorophenol concentration, contact time, biosorbent particle size, biosorbent dosage and temperature on the removal process were evaluated. The results showed that biosorption of 2,6-dichlorophenol was dependent on these factors. The equilibrium biosorption data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) adsorption isotherm models. The four tested isotherm models provided good fits to the experimental data obtained at 30°C; however, the Freundlich isotherm model provided the best correlation (R² = 0.9874) of the experimental data. The maximum monolayer biosorption capacity (Q _max ) was found to be 14.25 mg/g. The biosorption kinetics data of 2,6-dichlorophenol were analyzed by pseudo-first-order, pseudo-second-order, Elovich, intraparticle diffusion, and liquid film diffusion models. The five kinetic models fitted well to the biosorption kinetic data; however, the pseudo-second-order kinetic model gave the best fit when the biosorption mechanism was controlled by film diffusion. Thermodynamic quantities such as standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), standard entropy change of biosorption (ΔS°), and activation energy (E_a) were evaluated, and it was found that the biosorption process was spontaneous, feasible, endothermic in nature and of dual nature, physisorption and chemisorption; however, the physisorption process was dominant. Therefore, modified plantain peel has potential for application as an effective bioadsorbent for removal of 2,6-dichlorophenol from aqueous solution.     

Selective Competitive Biosorption of Au(III) and Cu(II) in Binary Systems by Magnetospirillum gryphiswaldense

The biosorption of Au(III) and Cu(II) ions in both single and binary systems by Magnetospirillum gryphiswaldense (MSR-1) was investigated. For comparison with the selective reinforced competitive biosorption process in a binary system, the experimental research first explored the biosorption of Au(III) and Cu(II) in a single system under various conditions. The biomass exhibited the highest single Au(III) and Cu(II) ion adsorption yields at room temperature (25°C), pH values of 2.5 and 5.0, respectively, and a biomass concentration of 10 g · L^?1 (3.83 g · L^?1, dry basis). The experimental data from the single component system for the two metallic ions fitted well to a Langmuir isotherm and a pseudo second-order kinetic models. In the Au(III)-Cu(II) binary system, the coexistence of Cu(II) cations promoted the adsorption of Au(III) within a certain range of ratios. A new sigmoidal Cu(II) biosorption isotherm was determined specifically to reveal the Cu(II) adsorption behavior in this case.     

Adsorptive Characteristics of Chromium(VI) Ions from Aqueous Phase by Iron(III) Coordinated Amino-Functionalized Poly(glycidyl methacrylate)-Grafted Cellulose: Equilibrium Kinetics and Thermodynamic Study

A novel sorbent, Iron(III)-coordinated amino-functionalized poly(glycidyl methacrylate)-grafted cellulose (Fe(III)-AM-PGMACell), was prepared through graft copolymerization of glycidyl methacrylate (GMA) onto cellulose (Cell) in the presence of N,N′-methylenebisacrylamide (MBA) as a cross linker using benzoyl peroxide initiator, followed by treatment with ethylenediamine and ferric chloride in the presence of HCl. The surface features of the adsorbent were characterized using FTIR, XRD, and SEM, N₂ adsorption, and potentiometric titration. The contact time to attain equilibrium and the pH value for maximum adsorption were found to be 90 min and 4.0, respectively. A two-step pseudo-first-order kinetic model agreed well with the dynamic behavior for the adsorption process. Equilibrium data were fitted with the Langmuir, Freundlich, and Sips isotherm equations with the latter giving the best fit to the experimental data with maximum adsorption capacity of 72.05 mg/g at 30°C. A simulated industry wastewater sample was treated by the Fe(III)-AM-PGMACell to demonstrate its efficiency in removing Cr(VI) from wastewater. The adsorbed Cr(VI) ions were desorbed effectively by 0.1 M NaCl solution and hence can be reused through many cycles of water treatment and regeneration without any loss in the adsorption capacity.     

Biosorption potential of the mediterranean plant (Posidonia oceanica) for the removal of Cu2+ ions from aqueous media : Equilibrium,kinetic, thermodynamic and mechanism analysis

The biosorption characteristics of copper(II) ions using Posidonia oceanica biomass were investigated. Experimental parameters affecting the biosorption process such as pH level, contact time, biosorbent dosage and temperature were studied. The equilibrium data were applied to the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir model fitted very well the equilibrium data, and the maximum uptake of Cu(II) by Posidonia oceanica was found to be 76.92 mg/g. The mean free energy E (10.78 kJ/mol) from the D-R isotherm indicated a chemical ion-exchange mechanism. Kinetic results showed that the pseudo-second-order kinetic model was well fitted to the experimental data. Thermodynamic parameters depicted the exothermic nature of biosorption and the process was feasible and spontaneous. The results of FTIR (Fourier-transform infrared spectroscopy) revealed that carboxyl, amine, and hydroxyl groups on the biomass surface were involved in the biosorption of Cu(II) ions.     

Adsorption behaviors of crystal violet from aqueous solution using Anatolian black pine (Pinus nigra Arnold.): kinetic and equilibrium studies

ABSTRACT

In this study, Anatolian black pine (ABP, Pinus nigra Arnold.) was evaluated as biosorbent for removal of crystal violet (CV) from aqueous solution. The influence of operational parameters including solution pH, initial CV concentration, biosorbent dosage, contact time, and temperature were studied in batch systems. The adsorption data followed well Langmuir isotherm with a maximum biosorption capacity of 12.36 mg/g. The equilibrium data were better fitted with pseudo-second-order kinetic model (R² ? 0.99). Moreover, the thermodynamic parameters indicated that the CV biosorption was feasible, spontaneous, and endothermic process. This study showed that ABP (Pinus nigra Arnold.) can be used to remove CV from aqueous solutions.     

Effect of competitive interference on the biosorption of lead(II) by Chlorella vulgaris

Batch experiments were carried out to asses the effect of Cu(II) and Zn(II) on the biosorption of lead(II) ions by non-living Chlorella vulgaris. The uptake of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the uptake increased with increasing pH from 3.0 to an optimum value of 5.0. The biosorption of Pb(II) was found to be adversely affected by the presence of Cu(II) ions, while Zn(II) ions seemed to have negligible effect on the process. The equilibrium data were fitted to four isotherm models: Langmuir, Freundlich, Sips and Dubinin–Radushkevich; the Sips isotherm gave the best fit for the data. Modeling of the controlling mechanisms indicated that both intrinsic kinetics and mass transfer played major roles in controlling the process. A new dimensionless parameter, Ψ, was defined to asses the relative contributions of the two mechanisms to the biosorption of lead(II). Mass transfer seemed to be the dominant mechanism at low initial lead(II) concentrations, while intrinsic kinetics dominates at high concentrations.     

Adsorption of Cr(III), Ni(II), Zn(II), Co(II) ions onto phenolated wood resin

In this study, phenolated wood resin was used an adsorbent for the removal of Cr(III), Ni(II), Zn(II), Co(II) ions by adsorption from aqueous solution. The adsorption of metal ions from solution was carried at different contact times, concentrations and pHs at room temperature (25°C). For individual metal ion, the amount of metal ions adsorbed per unit weight of phenolated wood resin at equilibrium time increased with increasing concentration and pH. Also, when the amounts of metal ions adsorbed are compared to each other, it was seen that this increase was order of Cr(III) > Ni(II) > Zn(II) > Co(II). This increase was order of Cr(III) > Ni(II) > Co(II) > Zn(II) for commercial phenol–formaldehyde resin. Kinetic studies showed that the adsorption process obeyed the intraparticle diffusion model. It was also determined that adsorption isotherm followed Langmuir and Freundlich models. Adsorption isotherm obtained for commercial phenol–formaldehyde resin was consistent with Freundlich model well. Adsorption capacities from Langmuir isotherm for commercial phenol–formaldehyde resin were higher than those of phenolated wood resin, in the case of individual metal ions. Original adsorption isotherm demonstrated the monolayer coverage of the surface of phenolated wood resin. Adsorption kinetic followed the intraparticle diffusion model. The positive values of ΔG° determined using the equilibrium constants showed that the adsorption was not of spontaneous nature. It was seen that values of distribution coefficient (K_D) decreasing with metal ion concentration in solution at equilibrium (C_e) indicated that the occupation of active surface sites of adsorbent increased with metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2838–2846, 2006     

Application of tobacco hairy roots for the removal of malachite green from aqueous solutions: Experimental design,kinetic, equilibrium,and thermodynamic studies

Tobacco hairy roots (THR) were used to evaluate its potential for the biosorption and removal of malachite green (MG) from aqueous solutions. A 3² full factorial design was applied to study the effects of pH and THR concentration on the biosorption capacity. Under the optimal conditions (pH of 7.0 and THR concentration of 1?g?L^?1), dye removal efficiency was around 92%. Experimental data obtained from kinetic studies demonstrated good concordance with the pseudo-second-order model. Equilibrium studies were developed and the data were evaluated by Langmuir, Freundlich, and Sips models, being the Sips model the most adequate (maximum biosorption capacity of 277.2?mg?g^?1). Thermodynamically, the biosorption of MG on THR proved to be endothermic, spontaneous, and favorable. Desorption was feasible under acidic conditions and the biosorbent could be reused three times. THR was tested in simulated effluent and the removal percentage was 87%, demonstrating that this material is a promising biosorbent which can be used to treat colored wastewaters.     

Investigation of α‐iron oxide‐coated polymeric nanocomposites capacity for efficient heavy metal removal from aqueous solution

In the present study, PS@α‐Fe₂O₃ nanocomposites were prepared by chemical microemulsion polymerization approach and the ability of magnetic beads to remove Cu(II) ions from aqueous solutions in a batch media was investigated. Various physico‐chemical parameters such as pH, initial metal ion concentration, temperature, and equilibrium contact time were also studied. Adsorption mechanism of Cu²⁺ ions onto magnetic polymeric adsorbents has been investigated using Langmuir, Freundlich, Sips and Redlich–Petersen isotherms. The results demonstrated that the PS@α‐Fe₂O₃ nanocomposite is an effective adsorbent for Cu²⁺ ions removal. The Sips adsorption isotherm model (R² > 0.99) was more in consistence with the adsorption isotherm data of Cu(II) ions compared to other models and the maximum adsorbed amount of copper was 34.25 mg/g. The adsorption kinetics well fitted to a pseudo second‐order kinetic model. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) were calculated from the temperature dependent sorption isotherms, and the results suggested that copper adsorption was a spontaneous and exothermic process. POLYM. ENG. SCI., 55:2735–2742, 2015. © 2015 Society of Plastics Engineers     

Assessment of Cu (II) removal from an aqueous solution by raw Gundelia tournefortii as a new low-cost biosorbent: Experiments and modelling

Lignocellulosic materials can be used as biosorbent for refinement of the wastewaters when they are available in large quantities. Many studies were conducted to uptake Cu (II) ion from aqueous solutions. In this paper, the biosorption efficiency of Cu (II) ions from a synthetic aqueous solution was investigated using Gundelia tournefortii (GT), without any pre-treatment. Fourier transform infrared spectroscopy, scanning electron microscopy and determining the point of zero charge were employed to characterise the biosorbent. Batch experiments were performed to study the influence of pH, biosorbent dosage, contact time, temperature and initial Cu (II) concentration on Cu (II) removal. The biosorption isotherms were investigated using the Langmuir, Freundlich, Temkin and D-R isotherm models. The findings show that the biosorption isotherm was better fitted by the Langmuir equation and the maximum adsorption capacity of GT was found to be 38.7597 mg·g^-1. The kinetics data were analysed by pseudo-first order, pseudo-second order, and intra-particle diffusion equations. The results indicate that the pseudosecond-order model was found to explain the adsorption kinetics most effectively. The values of thermodynamic parameters including Gibbs free energy (△G°), enthalpy (△H°), and entropy (△S°) demonstrate that the biosorption process was exothermic and spontaneous. The multiple nonlinear regression (MnLR) and artificial neural network (ANN) analyses were applied for the prediction of biosorption capacity. A relationship between the predicted and observed data was obtained and the results show that the MnLR and ANN models provided successful predictions.     

Cadmium biosorption by a glyphosate-degrading bacterium,a novel biosorbent isolated from pesticide-contaminated agricultural soils

In this study, biosorption of cadmium (II) ions from aqueous solutions by a glyphosate degrading bacterium, Ochrobactrum sp. GDOS, was investigated in batch conditions. The isolate was able to utilize 3 mM GP as the sole phosphorous source, favorable to bacterium growth and survival. The effect of different basic parameters such as initial pH, contact time, initial concentrations of cadmium ion and temperature on cadmium uptake was evaluated. The adsorption process for Cd (II) is well fitted with Langmuir adsorption isotherm. Experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. Maximum metal uptake q_max was obtained as 83.33 mg g⁻¹. The sorption process of cadmium onto the Ochrobactrum sp. GDOS biomass followed second-order rate kinetic (R² = 0.9986). A high desorption efficiency was obtained in pH 2. Reusability of the biomass was examined under successive biosorption–desorption cycle repeated thrice. The characteristics of the possible interactions between biosorbent and metal ions were also evaluated by scanning electron microscope (SEM), Fourier transform infrared (FT-IR) and X-ray diffraction analysis.     

Dye adsorption and desorption properties of Mentha pulegium in single and binary systems

This article deals with the dye adsorption and desorption properties of Mentha pulegium (MP) from single and binary (mixture of dyes) systems. Direct Red 80 (DR80) and Acid Black 26 (AB26) were used as model dyes. The Fourier transform infrared (FTIR) was used to investigate the biosorbent characteristics. The effects of biosorbent dosage, contact time, dye concentration, salt, and pH on dye removal were studied. The biosorption isotherms, kinetics, and thermodynamic were studied. In addition, dye desorption was carried out to study adsorbent recovery. The results showed that the isotherm data of single and binary systems of dyes followed the Langmuir isotherm. The adsorption kinetic of the dyes was found to conform to a pseudosecond order kinetic model. Desorption tests showed maximum dye releasing of 97% for DR80 and 95% for AB26 in single system and 92% for DR80 and 94% for AB26 in binary system of dyes at pH 12. The thermodynamic data showed that the biosorption process is spontaneous, endothermic, and a physisorption reaction. It can be concluded that MP is an ecofriendly biosorbent to remove dyes from single and binary systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Efficient decolorization of dye-containing wastewater using mycelial pellets formed of marine-derived Aspergillus niger

In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g~(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.     

Fitting of equilibrium and kinetic data for the removal of Novacron Orange P-2R by sugarcane bagasse

In this study, the potential of sugarcane bagasse, to remove Novacron Orange P-2R dye from aqueous solution by adsorption was investigated in batch mode. Different process parameters were optimized for biosorption process. Equilibrium biosorption isotherms, kinetics and thermodynamics were investigated in batch mode. The biosorption data were fitted well to the Langmuir isotherm. The kinetic data obtained at different concentration have been analyzed using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The best fitted kinetic model was found to be pseudo-second-order. The FTIR spectrum was recorded to find out the functional groups involved.     

重金属生物吸附的吸附模型

排污系统中的重金属通过生物的方法进行吸附除掉,是一种重金属回收和再利用的较为有效治理方法。本研究通过热平衡的机理分析,采用普通的物质吸附模型,通过大量的实验数据处理,得到了重金属吸附脱俯的数学模型。该模型具有较好计算与实验数据的吻合性。但是实验结果也表明,生物吸附模型不适用于计算在生物质中的重金属离子脱附量,即重金属生物吸附模型没有满足可逆性。这一点在使用该模型时需要给予考虑。因此吸附的机理分析还需要结合实践过程的热力学平衡数据来进行分析回归。     

Nickel removal characteristics of an immobilized macro fungus: equilibrium,kinetic and mechanism analysis of the biosorption

BACKGROUND: An immobilized new biosorbent was prepared from macro fungi Lactarius salmonicolor for the effective removal of nickel ions from aqueous media. Operating conditions were optimized as functions of initial pH, agitation time, sorbent amount and dynamic flow rate. Immobilization and biosorption mechanism were examined and the developed biosorbent was tested for the removal of nickel ions from real wastewater. RESULTS: Biosorption performance of the biomass continuously increased in the pH range 2.0–8.0. The coverage of the biosorbent surface by silica gel resulted in a significant increase in biosorption yield of nickel ions. The highest nickel loading capacity was obtained as 114.44 mg g^?1 using a relatively small amount of immobilized biosorbent. Biosorption equilibrium time was recorded as 5 min. Experimental data were analyzed by different isotherm and kinetic models. Infrared spectroscopy, scanning electron microscopy and X‐ray energy dispersive analysis confirmed the process. The sorbent exhibited relatively good recovery potential in dynamic flow mode studies. Biosorption capacity of immobilized biosorbent was noted as 14.90 mg g^?1 in real wastewater. CONCLUSION: Silica gel immobilized biomass of L. salmonicolor is to be a low cost and potential biosorbent with high biosorption capacity for the removal of contaminating nickel from aqueous media. © 2012 Society of Chemical Industry     

BIOSORPTION STUDIES ON NACL-MODIFIED CERATOPHYLLUM DEMERSUM: REMOVAL OF TOXIC CHROMIUM FROM AQUEOUS SOLUTION

The present research provides information on the Cr(VI) removal potential of NaCl-modified Ceratophyllum demersum, an aquatic plant biomass. The effects of various parameters including pH, biomass dosage, contact time, and initial concentration on Cr(VI) biosorption were investigated. The best conditions for Cr(VI) biosorption in the present study were: pH of 2, biosorbent dose of 8 g/L, and contact time of 60 min. Under these conditions, maximum adsorption capacity of modified C. demersum for Cr(VI) was 10.20 mg/g. The experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The biosorption process followed the Langmuir isotherm model with a high coefficient of determination (R² > 0.99). The biosorption process followed pseudo-second-order kinetics. Further, the biosorbent was characterized by Fourier transform-infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The results showed that biosorption of Cr(VI) on NaCl-modified C. demersum occurred through chemical sorption.