Preparation and characterization of magnetic polymethylmethacrylate microbeads carrying ethylene diamine for removal of Cu(II), Cd(II), Pb(II), and Hg(II) from aqueous solutions

Magnetic polymethylmethacrylate (mPMMA) microbeads carrying ethylene diamine (EDA) were prepared for the removal of heavy metal ions (i.e., copper, lead, cadmium, and mercury) from aqueous solutions containing different amount of these ions (5–700 mg/L) and at different pH values (2.0–8.0). Adsorption of heavy metal ions on the unmodified mPMMA microbeads was very low (3.6 μmol/g for Cu(II), 4.2 μmol/g for Pb(II), 4.6 μmol/g for Cd(II), and 2.9 μmol/g for Hg(II)). EDA‐incorporation significantly increased the heavy metal adsorption (201 μmol/g for Cu(II), 186 μmol/g for Pb(II), 162 μmol/g for Cd(II), and 150 μmol/g for Hg(II)). Competitive adsorption capacities (in the case of adsorption from mixture) were determined to be 79.8 μmol/g for Cu(II), 58.7 μmol/g for Pb(II), 52.4 μmol/g for Cd(II), and 45.3 μmol/g for Hg(II). The observed affinity order in adsorption was found to be Cu(II) > Pb(II) > Cd(II) > Hg(II) for both under noncompetitive and competitive conditions. The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at around pH 5.0. The optimal pH range for heavy‐metal removal was shown to be from 5.0 to 8.0. Desorption of heavy‐metal ions was achieved using 0.1 M HNO₃. The maximum elution value was as high as 98%. These microbeads are suitable for repeated use for more than five adsorption‐desorption cycles without considerable loss of adsorption capacity. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 81–89, 2000     

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.     

Tilapia scales: characterization and study of Cu(II) removal by ion exchange with Ca(II)

ABSTRACT

A biosorbent material based on tilapia scales for the removal of Cu(II) ions was investigated. Modifications in the biosorbent caused by retention of Cu(II) and by the pH effect were evaluated separately in order to comprehend how the removal process occurs. For that, a physico-chemical characterization of the scales was performed before and after the Cu(II) removal. The results obtained from the characterization and biosorption tests led to the conclusion that the Ca–Cu ions exchange was responsible for purifying the solution. Furthermore, the tilapia scales were efficient, removing 95% of Cu(II) with 1 g of adsorbent (surface area ≈ 3 m²).     

Kinetic and equilibrium studies of Pb(II) and Cd(II) removal from aqueous solution onto colemanite ore waste

The adsorption characteristics of Pb(II) and Cd(II) onto colemanite ore waste (CW) from aqueous solution were investigated as a function of pH, adsorbent dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the adsorption isotherms. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The adsorption capacity of CW was found to be 33.6 mg/g and 29.7 mg/g for Pb(II) and Cd(II) ions, respectively. Analyte ions were desorbed from CW using both 1 M HCl and 1 M HNO₃. The recovery for both metal ions was found to be higher than 95%. The mean adsorption energies evaluated using the D-R model indicated that the adsorption of Pb(II) and Cd(II) onto CW were taken place by chemisorption. The thermodynamic parameters (ΔG^o, ΔH^o and ΔS^o) showed that the adsorption of both metal ions was feasible, spontaneous and exothermic at 20-50 °C. Adsorption mechanisms were also investigated using the pseudo-first-order and pseudo-second-order kinetic models. The kinetic results showed that the adsorption of Pb(II) and Cd(II) onto CW followed well pseudo-second order kinetics.     

Synergistic Solvent Extraction and Transport of Zn(II) and Cu(II) across Polymer Inclusion Membranes with a Mixture of TOPO and Aliquat 336

Separation of zinc(II) and copper(II) ions from aqueous solutions by synergistic extraction and transport through polymer inclusion membranes (PIMs) has been investigated. A mixture of trioctylphosphine oxide (TOPO) and trioctymethylammonium chloride (Aliquat 336) was used as a selective extractant as well as an ion carrier in polymer membranes. The effects of hydrochloric acid concentration in the aqueous phase and extractants concentration in the organic phase on the separation process of zinc(II) and copper(II) ions have been studied. Zn(II) ions were successfully separated from Cu(II) ions in solvent extraction process using 0.025 M TOPO and 0.06 M Aliquat 336 in kerosene. Polymer inclusion membranes (PIMs) containing a mixture of TOPO and Aliquat 336 as the ion carrier have been prepared and the facilitated transport of Zn(II) and Cu(II) ions has been studied. The influence of membrane composition on the transport kinetic of Zn(II) and Cu(II) has been evaluated. Zn(II) ions were preferably transported from the aqueous solutions containing Cu(II) and above 87% of Zn(II) ions were effectively recovered from the 0.5 M HCl solution as the source phase through PIM into 0.5 M H₂SO₄ as the stripping phase.     

Removal of Cu(II) and Zn(II) Using Lignocellulosic Fiber Derived from Citrus reticulata (Kinnow) Waste Biomass

Abstract

The biosorption of Cu(II) and Zn(II) using dried untreated and pretreated Citrus reticulata waste biomass were evaluated. The Cu(II) and Zn(II) sorption were found to be dependent on the solution pH, the biosorbent dose, the biosorbent particle size, the shaking speed, the temperature, the initial metal ions (800 mg/L), and the contact time. Twenty-eight physical and chemical pretreatments of Citrus reticulata waste biomass were evaluated for the sorption of Cu(II) and Zn(II) from aqueous solutions. The results indicated that biomass pretreated with sulphuric acid and EDTA had maximum Cu(II) and Zn(II) uptake capacity of 87.14 mg/g and 86.4 mg/g respectively. Moreover, the Langmuir isotherm model fitted well than the Freundlich model with R ² > 0.95 for both metal ions. The sorption of Cu(II) and Zn(II) occurred rapidly in the first 120 min and the equilibrium was reached in 240 min. FTIR and SEM studies were also carried out to investigate functional groups present in the biomass and the surface morphological changes of biomass.     

Removal of Copper(II) and Zinc(II) from Aqueous Solutions Using a Lignocellulosic-Based Polymeric Adsorbent Containing Amidoxime Chelating Functional Groups

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 ΔG^o, ΔH^o, and ΔS^o 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.     

Synergistic Effect of Maghemite and Titania Nanoparticles in PVA-Alginate Encapsulated Beads for Photocatalytic Reduction of Pb(II)

In this paper, maghemite (γ-Fe₂O₃) and titanium oxide (TiO₂) nanoparticles were synthesized by hydrothermal and coprecipitation methods, respectively. These nanoparticles were combined together in various ratios (1:10, 1:20, 1:60, 1:80, and 1) and embedded in polyvinyl alcohol (PVA)-alginate beads. These beads were tested for photocatalytic behavior in eliminating toxic Pb(II) from the aqueous solution. The photocatalytic experiments were performed under sunlight irradiation and without sunlight. Several operating conditions such as initial Pb(II) concentration, pH, contact time, and TiO₂: γ-Fe₂O₃ ratios were investigated to evaluate their effect on the process. The recycling attributes of these beads were also investigated. The results revealed that 100% of the Pb(II) was eliminated in 100 min at pH 7 under sunlight when the ratio of TiO₂:γ-Fe₂O₃ was kept to 1. The PVA-alginate maghemite and titania beads showed better efficiency for Pb(II) removal than PVA-alginate titania beads and PVA-alginate maghemite beads. X-ray photoelectron spectroscopy (XPS) analysis also revealed that Pb(II) removal was via photocatalytic reduction due to the presence of Pb(0) in the high-resolution scan at 130–160 eV. Also, the PVA-alginate titania and maghemite beads can be readily isolated from the aqueous solution after the photocatalytic process and reused for at least 6 times without significant losses in their initial properties. The reduction of Pb(II) with PVA-alginate titania and maghemite beads fitted the Langmuir–Hinshelwood (L–H) kinetic model at a correlation coefficient (R²) of 0.9923.     

Studies on the biosorption of Pb(II) ions using Pseudomonas putida

ABSTRACT

The complete removal of Pb(II) was achieved by intact Pseudomonas putida cells. The biosorption isotherm exhibited Langmuirian behaviour and followed pseudo-second-order rate kinetics. The standard Gibbs free energy change (?G°) for the biosorption of Pb(II) ions was found to be ?26.4 kJ mol^?1, attesting to a chemisorption process. Thermolysis of P. putida cells improved the Pb(II) binding capacity by around 27%. All the four components tested, namely DNA, protein, polysaccharide and lipid, were found to contribute to the uptake of Pb(II) ions. The possible mechanisms of Pb(II) binding by P. putida have been delineated.     

Highly Efficient and Selective Transport of Cu(II) with a Cooperative Carrier Composed of Tetraaza-14-Crown-4 and Oleic Acid through a Bulk Liquid Membrane

Tetraaza-14-crown-4 and oleic acid was successfully applied for transport of Cu(II) in chloroform bulk liquid membrane. The uphill moving of Cu(II) during the liquid membrane transport process has occurred. The main effective variable such as the type of the metal ion acceptor in the receiving phase and its concentration, tetraaza-14-crown-4 and oleic acid concentration in the organic phase on the efficiency of the ion-transport system were examined. By using L-cysteine as a metal ion acceptor in the receiving phase, the maximum amount of copper (II) transported across the liquid membrane was achieved to 96 ± 1.5% after 140 minutes. The selectivity of copper ion transport from the aqueous solutions containing Pb²⁺, Tl⁺, Ag⁺, Co²⁺, Ni²⁺, Mg²⁺, Zn²⁺, Hg²⁺, Cd²⁺ and Ca²⁺ ions were investigated. In the presence of CH₃COONH₄ and Na₄P₂O₇ as suitable masking agents in the source phase, the interfering effects of Pb⁺² and Cd²⁺ were diminished drastically.     

Immobilization of copper(II)-poly(N-vinylimidazole) complex on magnetic nanoparticles and its catalysis of oxidative polymerization of 2,6-dimethylphenol in water

Poly(N-vinylimidazole) (PVI) was grafted onto magnetic Fe₃O₄ nanoparticles through siloxane bonds to produce PVI-grafted Fe₃O₄ nanoparticles (shortened as Fe₃O₄-g-PVI). The amount of imidazolyl groups in Fe₃O₄-g-PVI was estimated to be 1.16 mmol/g by elemental analysis and thermal gravimetric analysis. The Fe₃O₄-g-PVI coordinated with Cu(II) to form the immobilized Cu(II)-PVI complex. The stoichiometric ratio between imidazolyl groups in Fe₃O₄-g-PVI and Cu(II) was found to be 4 and the complex formation constant (K) was calculated to be 5.6 × 10¹⁴ mol⁻⁴ L⁴. The immobilized Cu(II)-PVI complex was employed to catalyze the oxidative polymerization of 2,6-dimethylphenol (DMP) in water and showed excellent C O/C C selectivity to form PPO. After polymerization, the immobilized Cu(II)-PVI complex catalyst was collected by an external magnetic field and reused in the next run with additional immobilized catalyst and copper ions. After three runs of oxidative polymerization of DMP, the recovery rate of the immobilized Cu(II)-PVI catalyst was above 95% and the yield of PPO maintained as high as 79.2% with the addition of supplementary catalysts. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Removal of Pb(ii) ions from aqueous solution using a novel composite adsorbent of Fe3o4/PVA/spent coffee grounds

ABSTRACT

A novel magnetic composite prepared from Fe₃O₄, poly(vinyl alcohol) and alkaline pretreated spent coffee grounds (Fe₃O₄/PVA/APSCGs) was utilized for the first time as an adsorbent for adsorption of Pb(II) ions after carefully characterizing it by various techniques (XRD, FTIR, SEM, EDX). The obtained results indicated that the adsorption was spontaneous, endothermic, fitting well with both Langmuir and Freundlich models, and more suitable to be described by the second-order kinetic model. The maximum adsorption capacity of Fe₃O₄/PVA/APSCGs for Pb(II) at optimum conditions (pH of 5, contact time of 24 h, APSCGs:Fe₃O₄ weight ratio of 4:1) was found to be 0.275 mmol.g^?1. Recycling study showed a good reusability of the composite with removal efficiency maintained at 78.12% after five continuous adsorption-desorption cycles.     

Modelling Individual and Competitive Adsorption of Cadmium(II) and Zinc(II) Metal Ions from Aqueous Solution onto Bagasse Fly Ash

Abstract

The present study deals with the competitive adsorption of cadmium (Cd(II)) and zinc (Zn(II)) ions onto bagasse fly ash (BFA) from binary systems. BFA is a waste obtained from the bagasse‐fired boilers of sugar mills. The initial pH≈6.0 is found to be the optimum for the individual removal of Cd(II) and Zn(II) ions by BFA. The equilibrium adsorption data were obtained at different initial concentrations (C ₀ = 10–100 mg/l), 5 h contact time, 30°C temperature, BFA dosage of 10 mg/l at pH ₀ = 6. The Redlich–Peterson (R–P) and the Freundlich models represent the single ion equilibrium adsorption data better than the Langmuir model. The adsorption capacities in the binary‐metal mixtures are in the order Zn(II)>Cd(II) and is in agreement with the single‐component adsorption data. The equilibrium metal removal decreases with increasing concentrations of the other metal ion and the combined action of Cd(II) and Zn(II) ions on BFA is found to be antagonistic. Equilibrium isotherms for the binary adsorption of Cd(II) and Zn(II) ions on BFA have been analyzed by non‐modified Langmuir, modified Langmuir, extended‐Langmuir, Sheindorf–Rebuhn–Sheintuch (SRS), non‐modified R–P and modified R–P adsorption models. The isotherm model fitting has been done by minimizing the Marquardt's percent standard deviation (MPSD) error function using MS Excel. The SRS model satisfactory fits for most of the adsorption equilibrium data of Cd(II) and Zn(II) ions onto BFA.     

Synthesis of AgBiS2/gC3N4 and its application in the photocatalytic reduction of Pb(II) in the matrix of methyl orange,crystal violet,and methylene blue dyes

The removal of lead ions in contaminated water by the reduction of Pb(II) ions to the useful metallic Pb is challenging, especially in water polluted by other contaminants such as dye molecules. Most investigations focussed on the removal of Pb(II) in a single system. In reality, contaminated water contains a mixture of organic pollutants and heavy metals. Herein, we synthesized graphitic carbon nitride functionalized with ternary silver bismuth sulphide (AgBiS₂/gC₃N₄) for the photocatalytic removal of Pb(II) from dye-containing water. The as-synthesized gC₃N₄, AgBiS₂, and AgBiS₂/gC₃N₄ composite were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). The composite was used for the photocatalytic reduction of Pb(II) in the matrix of methyl orange, crystal violet, and methylene blue. The effect of the presence of easily-oxidizable organics and persulphate on the photocatalytic reduction of Pb(II) was also investigated. The results revealed that the presence of easily-oxidizable organics has synergistic effects on the photocatalytic reduction of Pb(II), while persulphate displayed inhibitive effect on Pb(II) reduction. The removal of Pb(II) in the dyes matrix was influenced by the type of dyes that were present in the water. The rate of Pb(II) reduction was reduced in the presence of methylene blue and methyl orange, but crystal violet displayed synergistic effects. Finally, the rate of degradation of dyes in the presence of Pb(II) was investigated. The rate of photocatalytic reduction of Pb(II) decreased from 0.0045 min^?1 to 0.0036 min^?1 and 0.0016 min^?1 in the matrix of methyl orange and methylene blue respectively. On the contrary, there was an increase in the rate of photocatalytic reduction of Pb(II) from 0.0045 to 0.0096 min^?1 in the matrix of crystal violet.     

Removal of Copper (II) and Nickel (II) Ions from Aqueous Solutions by a Composite Chitosan Biosorbent

Abstract

A composite chitosan biosorbent (CCB) was prepared by coating chitosan on to ceramic alumina. The adsorption characteristics of the sorbent for copper and nickel ions were studied under batch equilibrium and dynamic flow conditions at pH 4.0. The equilibrium adsorption data were correlated with Langmuir, Freundlich, and Redlich‐Peterson models. The ultimate monolayer capacities, obtained from Langmuir isotherm, were 86.2 and 78.1 mg/g of chitosan for Cu(II) and Ni(II), respectively. In addition, dynamic column adsorption studies were conducted to obtain breakthrough curves. After the column was saturated with metal ions, it was regenerated with 0.1 M sodium hydroxide. The regenerated column was used for a second adsorption cycle.     

Simultaneous preconcentration of Cd(II), Cu(II) and Pb(II) on Nano-TiO2 modified with 2-mercaptobenzothiazole prior to flame atomic absorption spectrometric determination

Nano-TiO₂ modified with 2-mercaptobenzothiazole (MBT) was investigated as a new adsorbent for preconcentration of Cd(II), Cu(II) and Pb(II). The metal ions are adsorbed onto nano-TiO₂-MBT, eluted by nitric acid and determined by flame atomic absorption spectrometry. The parameters affecting the adsorption were investigated. Under optimized conditions, the calibration curves were linear in the range of 0.2–25.0, 0.2–20.0, and 3.0–70.0 ng mL⁻¹ for cadmium, copper and lead, respectively. The limits of detection for Cd(II), Cu(II) and Pb(II) were 0.12, 0.15 and 1.38 ng mL⁻¹, respectively. The method was applied to determination of Cd(II), Cu(II) and Pb(II) in water and ore samples.     

Biosorption of cadmium(II) and lead(II) from aqueous solutions using Pleurotus ostreatus immobilized on bentonite

The purpose of this work was to evaluate the potential of a white rot fungi (P. ostreatus) immobilized on bentonite, in a continuous flow removal of trace heavy metals. The procedure is based on the biosorption of Cd(II) and Pb(II) ions on a column of bentonite loaded with dried, dead fungi components prior to their determination by atomic absorption spectroscopy (AAS). Cd(II) and Pb(II) were determined with a relative error of less than 5%. Various parameters such as “pH, amount of adsorbent, eluent type and volume, flow rate of the solution and matrix interference effect” on the retention of the metal ions were investigated. This procedure was applied to Cd(II) and Pb(II) determination in aqueous solutions, including tap water system. The optimum experimental parameters were determined to be pH 5, concentration of 10 mg/L, contact time of 30 min and 0.2 g of adsorbent for a quantitative adsorption of the metals. The optimum flow rate was found to be 2.5 mL/min for all metal ions. Each column can be used up to 20 successive analyses without considerable change in recoveries of metal ions.

The proposed method is excellent as regards simplicity, sensitivity, selectivity, precision, accuracy and column stability.     

Retention of Pb(II) by a Low-Cost Magnetic Composite Prepared by Environmentally-Friendly Plasma Technique

A low-cost magnetic composite (gelatin/Fe₃O₄) is prepared by Fe₃O₄ nanoparticles treated with gelatin using an environmentally-friendly plasma technique, and is applied for the removal of toxic Pb(II) ions from aqueous solutions. Not only that it originates from cheap and abundant raw materials, the gelatin/Fe₃O₄ composite also has advantages in convenient magnetic separation from aqueous solution, which can hopefully reduce water treatment expenses. The batch experimenta results indicate that the maximum adsorption capacity (q_max) of Pb(II) on this gelatin/Fe₃O₄ composite is ～115 mg/g, higher than most of the other bare and modified magnetic materials, which is considered to be attributed to the strong interaction between Pb(II) and the abundant functional groups introduced by gelatin. When exposed to acidic solutions, the dissolution of the gelatin/Fe₃O₄ nanoparticles is minimal due to the protective character of the grafted gelatin layer on the Fe₃O₄ nanoparticles. The utilization of the plasma technique in the synthesis of magnetic composite agrees well with the tenet of green chemistry. It is promising that this gelatin/Fe₃O₄ composite would become an efficient and economic material for heavy metal ion removal in the practical environmental remediation.     

Facile preparation of a silica‐sphere–poly(catechol hexamethylenediamine) composite for the competitive removal of cadmium(II), lead(II), and copper(II) ions

A silica‐sphere–poly(catechol hexamethylenediamine) (PCHA–SiO₂) composite was prepared via the one‐step facile polymerization of catechol and hexamethylenediamine; this method uses a silica sphere as a hard template. The chemical structures and morphologies of this composite were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy. The adsorption experiments indicated that the PCHA–SiO₂ composite served as a very attractive adsorbent for Pb(II)‐, Cu(II)‐, and Cd(II)‐ion removal at lower concentrations and had very good selective adsorption abilities for Pb(II) and Cu(II) ions in a solution contaminated with these three ions at higher concentrations. These interesting results may have been due to the reversible H⁺ adsorption–desorption properties of the characteristic phenol amine structure of the PCHA–SiO₂ composite. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45839.     

Selective Transport of Cu(II) across a Polymer Inclusion Membrane with 1-Alkylimidazole from Nitrate Solutions

The selective transport of copper(II), zinc(II), cobalt(II), and nickel(II) ions from nitrate solutions across polymer inclusion membranes (PIMs), which consist of cellulose triacetate as polymeric support, o-nitrophenyl pentyl ether as plasticizer, and 1-alkylimidazole (alkyl from hexyl- to decyl) as ion carrier was reported. PIM was characterized by using atomic force microscopy (AFM) technique. The results show that Cu(II) can be separated very effectively from other transition metal cations as Zn(II), Co(II), and Ni(II) (at a concentration of 10^?3 mol/dm³ each). Alkyl substituents at position 1 of the imidazole ring have been found to affect the hydrophobic properties and initial flux of the transported metal ions. The efficiency of separation of metal ions by 1-alkylimidazole followed the sequence: Cu(II) > Zn(II) > Co(II) > Ni(II). The highest selectivity coefficient for Cu(II) was found with 1-hexylimidazole and its 1 mol/dm³ solution in PIM. Separation of the ions was more effective for the nitrates(V) than for chlorides.