Enzyme-based Colorimetric and Potentiometric Biosensor for Detecting Pb (II Ions in Milk

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Hardeep Kaur

2014-08-01

Full Text Available The aim of the present work was to study a simple colorimetric and potentiometric biosensor based on urease inhibition by Pb (II ions for its estimation in milk samples. Urease immobilized on nylon membrane by hydrosol gel method was used as the biocomponent to demonstrate the metal effect on the enzyme activity using phenol red as the pH indicator. A lower limit detection of 38.6µm was achieved in the milk and the enzyme membranes were stable for more than two months at 4ºC. In potentiometric approach, response of an ion selective electrode (ISE to changing ammonium ion concentration as a consequence of urease inhibition by Pb (II ions was explored to achieve a detection limit of 9.66 µm. Lead specificity was attained by means of masking agents 1,10 - phenanthroline and sodium potassium tartarate. Validation of the developed biosensors was carried out with spiked milk samples.

Solid Phase Extraction of Trace Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) Ions in Beverages on Functionalized Polymer Microspheres Prior to Flame Atomic Absorption Spectrometric Determinations.

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Berber, Hale; Alpdogan, Güzin

2017-01-01

In this study, poly(glycidyl methacrylate-methyl methacrylate-divinylbenzene) was synthesized in the form of microspheres, and then functionalized by 2-aminobenzothiazole ligand. The sorption properties of these functionalized microspheres were investigated for separation, preconcentration and determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions using flame atomic absorption spectrometry. The optimum pH values for quantitative sorption were 2 - 4, 5 - 8, 6 - 8, 4 - 6, 2 - 6 and 2 - 3 for Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II), respectively, and also the highest sorption capacity of the functionalized microspheres was found to be for Cu(II) with the value of 1.87 mmol g -1 . The detection limits (3σ; N = 6) obtained for the studied metals in the optimal conditions were observed in the range of 0.26 - 2.20 μg L -1 . The proposed method was successfully applied to different beverage samples for the determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions, with the relative standard deviation of <3.7%.

Magnetic ion-imprinted and –SH functionalized polymer for selective removal of Pb(II) from aqueous samples

Energy Technology Data Exchange (ETDEWEB)

Guo, Bin; Deng, Fang [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Zhao, Yu [Technology Center of China Tobacco Hunan Industrial Corporation, Changsha 410007 (China); Luo, Xubiao, E-mail: luoxubiao@126.com [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Luo, Shenglian, E-mail: sllou@hnu.edu.cn [Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063 (China); Au, Chaktong [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)

2014-02-15

A magnetic ion-imprinted polymer (Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP) functionalized with –SH groups for the selective removal of Pb(II) ions from aqueous samples was synthesized by surface imprinting technique combined with a sol–gel process using 3-mercaptopropyl trimethoxysilane as monomer, tetraethyl orthosilicate as cross-linking agent, and Pb(II) ion as template. The Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP was characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectrometry. Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP showed higher capacity and selectivity than that of Fe{sub 3}O{sub 4}@SiO{sub 2}-NIP. The effects of initial concentration of Pb(II) and pH of medium on adsorption capacity of Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP were studied. The experimental data fits well with the Langmuir adsorption isotherm. The maximum Pb(II)-sorption capacity calculated from Langmuir isotherm is 32.58 mg/g and 16.50 mg/g for Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP and Fe{sub 3}O{sub 4}@SiO{sub 2}-NIP, respectively. Kinetics studies show that the adsorption process obeys a pseudo-second-order kinetic model with high correlation coefficient (R{sup 2} = 0.9982). The separation factor of Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP for Pb(II)/Cu(II), Pb(II)/Zn(II), and Pb(II)/Co(II) are 50.54, 52.14, and 37.39, respectively. The adsorption thermodynamic parameters ΔG, ΔH and ΔS were −4.98 kJ/mol, 3.27 kJ/mol and 28.84 J/mol/K, respectively. In addition, the spent Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP can be refreshed by simple washing with aqueous HCl solution, and there is no significant decrease in adsorption capacity after a test of up to five cycles, demonstrating that the Fe{sub 3}O{sub 4}@SiO{sub 2}-IIP is stable and reusable.

Penicillamine-modified sensor for the voltammetric determination of Cd(II) and Pb(II) ions in natural samples.

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Pérez-Ràfols, Clara; Serrano, Núria; Díaz-Cruz, José Manuel; Ariño, Cristina; Esteban, Miquel

2015-11-01

A new penicillamine-GCE was developed based on the immobilization of d-penicillamine on aryl diazonium salt monolayers anchored to the glassy carbon electrode (GCE) surface and it was applied for the first time to the simultaneous determination of Cd(II) and Pb(II) ions by stripping voltammetric techniques. The detection and quantification limits at levels of µg L(-1) suggest that the penicillamine-GCE could be fully suitable for the determination of the considered ions in natural samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Macrocyclic receptor showing extremely high Sr(II)/Ca(II) and Pb(II)/Ca(II) selectivities with potential application in chelation treatment of metal intoxication.

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Ferreirós-Martínez, Raquel; Esteban-Gómez, David; Tóth, Éva; de Blas, Andrés; Platas-Iglesias, Carlos; Rodríguez-Blas, Teresa

2011-04-18

Herein we report a detailed investigation of the complexation properties of the macrocyclic decadentate receptor N,N'-Bis[(6-carboxy-2-pyridil)methyl]-4,13-diaza-18-crown-6 (H(2)bp18c6) toward different divalent metal ions [Zn(II), Cd(II), Pb(II), Sr(II), and Ca(II)] in aqueous solution. We have found that this ligand is especially suited for the complexation of large metal ions such as Sr(II) and Pb(II), which results in very high Pb(II)/Ca(II) and Pb(II)/Zn(II) selectivities (in fact, higher than those found for ligands widely used for the treatment of lead poisoning such as ethylenediaminetetraacetic acid (edta)), as well as in the highest Sr(II)/Ca(II) selectivity reported so far. These results have been rationalized on the basis of the structure of the complexes. X-ray crystal diffraction, (1)H and (13)C NMR spectroscopy, as well as theoretical calculations at the density functional theory (B3LYP) level have been performed. Our results indicate that for large metal ions such as Pb(II) and Sr(II) the most stable conformation is Δ(δλδ)(δλδ), while for Ca(II) our calculations predict the Δ(λδλ)(λδλ) form being the most stable one. The selectivity that bp18c6(2-) shows for Sr(II) over Ca(II) can be attributed to a better fit between the large Sr(II) ions and the relatively large crown fragment of the ligand. The X-ray crystal structure of the Pb(II) complex shows that the Δ(δλδ)(δλδ) conformation observed in solution is also maintained in the solid state. The Pb(II) ion is endocyclically coordinated, being directly bound to the 10 donor atoms of the ligand. The bond distances to the donor atoms of the pendant arms (2.55-2.60 Å) are substantially shorter than those between the metal ion and the donor atoms of the crown moiety (2.92-3.04 Å). This is a typical situation observed for the so-called hemidirected compounds, in which the Pb(II) lone pair is stereochemically active. The X-ray structures of the Zn(II) and Cd(II) complexes show that

Removal of Pb(II ions and malachite green dye from wastewater by activated carbon produced from lemon peel

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Sayed Zia Mohammadi

2014-06-01

Full Text Available In the present study, a high-surface area activated carbon was prepared by chemical activation of lemon peel with H3PO4 as the active agent. Then, the adsorption behavior of Malachite green dye and Pb(II ions on the produced activated carbon was studied. Batch process was employed for sorption kinetics and equilibrium studies. Experimental data were �tted to various isotherm models. According to the Langmuir model, the maximum adsorption capacities of Malachite green dye and Pb(II ions were found to be 66.67 and 90.91 mg g-1, respectively, at room temperature. Kinetic studies showed the adsorption process followed a pseudo second-order rate model. The sorption kinetics were controlled by intra-particle diffusion. The results indicated that the produced activated carbon can be economically and effectively used as an adsorbent for the removal of Malachite green dye and Pb(II ions from wastewaters.

Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS)

Energy Technology Data Exchange (ETDEWEB)

Duran, Celal [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Gundogdu, Ali [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Giresun Faculty of Art and Science, Karadeniz Technical University, 28049 Giresun (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Art and Science, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Art and Science, Pamukkale University, 20020 Denizli (Turkey); Sentuerk, Hasan Basri [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Tuefekci, Mehmet [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey)

2007-07-19

A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L{sup -1} HNO{sub 3} in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 {mu}g L{sup -1}. The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.

Eriochrome Blue Black modified activated carbon as solid phase extractor for removal of Pb(II ions from water samples

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Hassan M. Albishri

2017-05-01

Full Text Available In the current study, a sensitive and simple method for the removal of lead Pb(II, from water samples prior to its determination by inductively coupled plasma optical emission spectrometry (ICP-OES, was investigated. The method utilized activated carbon (AC physically modified with Eriochrome Blue Black (EBB as a solid-phase extractant. Surface properties of the AC-EBB phase were characterized by FT-IR and SEM. The separation parameters for effective adsorption of lead Pb(II, including effects of pH, initial concentration of Pb(II, coexisting ions and shaking time using batch method were studied. The optimum pH value for the separation of Pb(II on the new sorbent was 7.0, and the maximum static adsorption capacity of Pb(II onto the AC-EBB was 127.896 mg/g at this pH and after 1 h contact time. The Pb(II adsorption data were modeled using Langmuir adsorption isotherms. Results demonstrated that the adsorption of Pb(II onto activated carbon followed pseudo second-order kinetic model.

Cd(II and Pb(II complexes of the polyether ionophorous antibiotic salinomycin

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Tanabe Makoto

2011-09-01

Full Text Available Abstract Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II ions in in vivo experiments, despite so far no Pb(II-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II and lead(II. Results New metal(II complexes of the polyether ionophorous antibiotic salinomycin with Cd(II and Pb(II ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa undergoes a reaction with heavy metal(II ions to form [Cd(Sal2(H2O2] (1 and [Pb(Sal(NO3] (2, respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

Science.gov (United States)

2011-01-01

Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II). Results New metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)2(H2O)2] (1) and [Pb(Sal)(NO3)] (2), respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming

Biosorption of Cd(II) and Pb(II) ions by aqueous solutions of novel alkalophillic Streptomyces VITSVK5 spp. biomass

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Saurav, Kumar; Kannabiran, Krishnan

2011-03-01

Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Biosorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution. The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species. The biosorption property of Streptomyces VITSVK5 spp. was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb). Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1, cadmium 3.1±0.3μg L-1, zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1, whereas mercury was well below the detection limit. The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated. The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively. The biosorbent dosage was optimized as 3 g L-1 for both the trace metals. Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (-COOH), hydroxyl (-CHOH) and amine (-NH2) groups of biomass with the metal ions. This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp. The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.

PVC Based Membrane of Ti(IV Iodovanadate for Pb(II Determination

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Mu. Naushad

2008-08-01

Full Text Available Ti(IV iodovanadate has been synthesized by mixing a mixture of aqueous solutions of 0.1 M sodium vanadate and 0.1 M potassium iodate with 0.1 M solution of Ti(IV chloride at pH 1.0. Distribution coefficients (Kd of various metal ions were determined on the column of Ti(IV iodovanadate which showed the selectivity of Pb(II ions by this cation exchange material. So Ti(IV iodovanadate has been used as an electoactive material for the construction of Pb(II selective electrode. The main purpose of this study is to develop an inexpensive, simple and reliable ion-selective electrode for Pb(II determination. The sensor exhibit Nernstian response for Pb(II ions over a wide concentration range of 1 x 10-7 M to 1 x 10-1 M with a slope of 30±0.4 mV per decade of activity. The electrode is suitable for use in aqueous solution in a pH range of 2-7.2 with a response time of 10 second. The membrane electrode can be used at least for 4 months without any divergence in potential. The selectivity coefficients were determined by the mixed solution method and revealed that the electrode was selective for Pb(II ions in the presence of interfering cations. The sensor could be used as an indicator electrode in the potentiometric titration of Pb(II ions with EDTA. The practical applicability of the proposed sensor has been reported for Pb(II determination in a standard rock sample and water sample. The results are found to be in good agreement with those obtained by using conventional methods.

Combination of sawdust from teak wood and rice husk activated carbon as adsorbent of Pb(II) ion and its analysis using solid-phase spectrophotometry (sps)

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Saputro, S.; Mahardiani, L.; Wulandari, D. A.

2018-03-01

This research aimed to know the usage of sawdust of teak wood and rice husk waste as Pb (II) ion adsorbents in simulated liquid waste, the combined optimum mass required adsorbent to adsorb Pb(II) ion, the sensitivity of the solid-phase spectrophotometry (sps) method in determining the decrease of Pb (II) metal ion levels in the μg/L level. This research was conducted by experimental method in laboratory. Adsorbents used in this study were charcoal of sawdust sawdust activated using 15% ZnCl2 solution and activated rice husk using 2 N NaOH solution. The adsorption processes of sawdust and rice husk with Pb(II) solution was done by variation of mass combination with a ratio of 1: 0; 0: 1; 1: 1; 1: 2; and 2: 1. Analysis of Pb(II) ion concentration using SPS and characterization of sawdust and rice husk adsorbent ads using FTIR. The results showed that activated charcoal from sawdust of teak wood and rice husks can be used as Pb (II) metal ion adsorbents with adsorption capacity of 0.86 μg/L, charcoal from sawdust of teak wood and rice husk adsorbent with a combination of optimum mass contact of sawdust and rice husk is 2:1 as much as 3 grams can adsorb 42.80 μg/L. Solid-phase spectophotometry is a sensitive method for analysis of concentration decreasing levels of Pb(II) ion, after it was absorbed by sawdust of teak wood and rice husk with high sensitivity and has the limit of detection (LOD) of 0.06 μg/L.

Adsorption of Pb(II) ions from aqueous solution by native and activated bentonite: Kinetic, equilibrium and thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Kul, Ali Riza [Yuzuncu Yil University, Faculty of Art and Science, Department of Chemistry, 65080 Van (Turkey); Koyuncu, Huelya, E-mail: hkoyuncu@yyu.edu.tr [Forensic Medicine Foundation, Felek Street No. 45, 06300 Kecioren, Ankara (Turkey)

2010-07-15

In this study, the adsorption kinetics, equilibrium and thermodynamics of Pb(II) ions on native (NB) and acid activated (AAB) bentonites were examined. The specific surface areas, pore size and pore-size distributions of the samples were fully characterized. The adsorption efficiency of Pb(II) onto the NB and AAB was increased with increasing temperature. The kinetics of adsorption of Pb(II) ions was discussed using three kinetic models, the pseudo-first-order, the pseudo-second-order and the intra-particle diffusion model. The experimental data fitted very well the pseudo-second-order kinetic model. The initial sorption rate and the activation energy were also calculated. The activation energy of the sorption was calculated as 16.51 and 13.66 kJ mol{sup -1} for NB and AAB, respectively. Experimental results were also analysed by the Langmuir, Freundlich and Dubinin-Redushkevich (D-R) isotherm equations at different temperatures. R{sub L} separation factor for Langmuir and the n value for Freundlich isotherm show that Pb(II) ions are favorably adsorbed by NB and AAB. Thermodynamic quantities such as Gibbs free energy ({Delta}G), the enthalpy ({Delta}H) and the entropy change of sorption ({Delta}S) were determined as about -5.06, 10.29 and 0.017 kJ mol{sup -1} K{sup -1}, respectively for AAB. It was shown that the sorption processes were an endothermic reactions, controlled by physical mechanisms and spontaneously.

Removal of Pb(II) ions from aqueous solution by a waste mud from copper mine industry: equilibrium, kinetic and thermodynamic study.

Science.gov (United States)

Ozdes, Duygu; Gundogdu, Ali; Kemer, Baris; Duran, Celal; Senturk, Hasan Basri; Soylak, Mustafa

2009-07-30

The objective of this study was to assess the adsorption potential of a waste mud (WM) for the removal of lead (Pb(II)) ions from aqueous solutions. The WM was activated with NaOH in order to increase its adsorption capacity. Adsorption studies were conducted in a batch system as a function of solution pH, contact time, initial Pb(II) concentration, activated-waste mud (a-WM) concentration, temperature, etc. Optimum pH was specified as 4.0. The adsorption kinetic studies indicated that the overall adsorption process was best described by pseudo-second-order kinetics. The equilibrium adsorption capacity of a-WM was obtained by using Langmuir and Freundlich isotherm models and both models fitted well. Adsorption capacity for Pb(II) was found to be 24.4 mg g(-1) for 10 g L(-1) of a-WM concentration. Thermodynamic parameters including the Gibbs free energy (Delta G degrees), enthalpy (Delta H degrees), and entropy (DeltaS degrees) indicated that the adsorption of Pb(II) ions on the a-WM was feasible, spontaneous and endothermic, at temperature range of 0-40 degrees C. Desorption studies were carried out successfully with diluted HCl solutions. The results indicate that a-WM can be used as an effective and no-cost adsorbent for the treatment of industrial wastewaters contaminated with Pb(II) ions.

Removal of Pb(II) ions from aqueous solution by a waste mud from copper mine industry: Equilibrium, kinetic and thermodynamic study

International Nuclear Information System (INIS)

Ozdes, Duygu; Gundogdu, Ali; Kemer, Baris; Duran, Celal; Senturk, Hasan Basri; Soylak, Mustafa

2009-01-01

The objective of this study was to assess the adsorption potential of a waste mud (WM) for the removal of lead (Pb(II)) ions from aqueous solutions. The WM was activated with NaOH in order to increase its adsorption capacity. Adsorption studies were conducted in a batch system as a function of solution pH, contact time, initial Pb(II) concentration, activated-waste mud (a-WM) concentration, temperature, etc. Optimum pH was specified as 4.0. The adsorption kinetic studies indicated that the overall adsorption process was best described by pseudo-second-order kinetics. The equilibrium adsorption capacity of a-WM was obtained by using Langmuir and Freundlich isotherm models and both models fitted well. Adsorption capacity for Pb(II) was found to be 24.4 mg g -1 for 10 g L -1 of a-WM concentration. Thermodynamic parameters including the Gibbs free energy (ΔG o ), enthalpy (ΔH o ), and entropy (ΔS o ) indicated that the adsorption of Pb(II) ions on the a-WM was feasible, spontaneous and endothermic, at temperature range of 0-40 o C. Desorption studies were carried out successfully with diluted HCl solutions. The results indicate that a-WM can be used as an effective and no-cost adsorbent for the treatment of industrial wastewaters contaminated with Pb(II) ions.

Removal of Pb(II) ions from aqueous solution by a waste mud from copper mine industry: Equilibrium, kinetic and thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Ozdes, Duygu; Gundogdu, Ali; Kemer, Baris; Duran, Celal; Senturk, Hasan Basri [Department of Chemistry, Karadeniz Technical University, Faculty of Arts and Sciences, 61080 Trabzon (Turkey); Soylak, Mustafa, E-mail: soylak@erciyes.edu.tr [Department of Chemistry, Erciyes University, Faculty of Arts and Sciences, 38039 Kayseri (Turkey)

2009-07-30

The objective of this study was to assess the adsorption potential of a waste mud (WM) for the removal of lead (Pb(II)) ions from aqueous solutions. The WM was activated with NaOH in order to increase its adsorption capacity. Adsorption studies were conducted in a batch system as a function of solution pH, contact time, initial Pb(II) concentration, activated-waste mud (a-WM) concentration, temperature, etc. Optimum pH was specified as 4.0. The adsorption kinetic studies indicated that the overall adsorption process was best described by pseudo-second-order kinetics. The equilibrium adsorption capacity of a-WM was obtained by using Langmuir and Freundlich isotherm models and both models fitted well. Adsorption capacity for Pb(II) was found to be 24.4 mg g{sup -1} for 10 g L{sup -1} of a-WM concentration. Thermodynamic parameters including the Gibbs free energy ({Delta}G{sup o}), enthalpy ({Delta}H{sup o}), and entropy ({Delta}S{sup o}) indicated that the adsorption of Pb(II) ions on the a-WM was feasible, spontaneous and endothermic, at temperature range of 0-40 {sup o}C. Desorption studies were carried out successfully with diluted HCl solutions. The results indicate that a-WM can be used as an effective and no-cost adsorbent for the treatment of industrial wastewaters contaminated with Pb(II) ions.

Selective Hg(II) adsorption from aqueous solutions of Hg(II) and Pb(II) by hydrolyzed acrylamide-grafted PET films.

Science.gov (United States)

Rahman, Nazia; Sato, Nobuhiro; Sugiyama, Masaaki; Hidaka, Yoshiki; Okabe, Hirotaka; Hara, Kazuhiro

2014-01-01

Selective Hg(II) adsorption from aqueous solutions of Hg(II) and Pb(II) using hydrolyzed acrylamide (AAm)-grafted polyethylene terephthalate (PET) films was examined to explore the potential reuse of waste PET materials. Selective recovery of Hg(II) from a mixture of soft acids with similar structure, such as Hg(II) and Pb(II), is important to allow the reuse of recovered Hg(II). An adsorbent for selective Hg(II) adsorption was prepared by γ-ray-induced grafting of AAm onto PET films followed by partial hydrolysis through KOH treatment. The adsorption capacity of the AAm-grafted PET films for Hg(II) ions increased from 15 to 70 mg/g after partial hydrolysis because of the reduction of hydrogen bonding between -CONH2 groups and the corresponding improved access of metal ions to the amide groups. The prepared adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The absorbent film showed high selectivity for the adsorption of Hg(II) over Pb(II) throughout the entire initial metal concentration range (100-500 mg/L) and pH range (2.2-5.6) studied. The high selectivity is attributed to the ability of Hg(II) ions to form covalent bonds with the amide groups. The calculated selectivity coefficient for the adsorbent binding Hg(II) over Pb(II) was 19.2 at pH 4.5 with an initial metal concentration of 100 mg/L. Selective Hg(II) adsorption equilibrium data followed the Langmuir model and kinetic data were well fitted by a pseudo-second-order equation. The adsorbed Hg(II) and Pb(II) ions were effectively desorbed from the adsorbent film by acid treatment, and the regenerated film showed no marked loss of adsorption capacity upon reuse for selective Hg(II) adsorption.

Solar photocatalytic removal of Cu(II), Ni(II), Zn(II) and Pb(II): Speciation modeling of metal-citric acid complexes

International Nuclear Information System (INIS)

Kabra, Kavita; Chaudhary, Rubina; Sawhney, R.L.

2008-01-01

The present study is targeted on solar photocatalytic removal of metal ions from wastewater. Photoreductive deposition and dark adsorption of metal ions Cu(II), Ni(II), Pb(II) and Zn(II), using solar energy irradiated TiO 2 , has been investigated. Citric acid has been used as a hole scavenger. Modeling of metal species has been performed and speciation is used as a tool for discussing the photodeposition trends. Ninety-seven percent reductive deposition was obtained for copper. The deposition values of other metals were significantly low [nickel (36.4%), zinc (22.2%) and lead (41.4%)], indicating that the photocatalytic treatment process, using solar energy, was more suitable for wastewater containing Cu(II) ions. In absence of citric acid, the decreasing order deposition was Cu(II) > Ni(II) > Pb(II) > Zn(II), which proves the theoretical thermodynamic predictions about the metals

Selective visual detection of Pb(II) ion via gold nanoparticles coated with a dithiocarbamate-modified 4′-aminobenzo-18-crown-6

International Nuclear Information System (INIS)

Mehta, Vaibhavkumar N.; Kailasa, Suresh Kumar; Solanki, Jignasa N.

2014-01-01

We have developed a crown ether based selective colorimetric sensing scheme for the determination of Pb(II) ion by using gold nanoparticles modified with dithiocarbamate derivative of 4′-aminobenzo-18-crown-6 that acts as a colorimetric probe. Monodisperse Au-NPs were prepared by reacting 4′-aminobenzo-18-crown-6 with carbon disulfide to generate the dithiocarbamate ligand which was then added to the Au-NPs to form a supramolecular assembly on their surface. The Au-NPs modified in this way undergo aggregation in the presence of Pb(II) ions, and this causes the color to change from red to blue. The Pb(II)-induced aggregation can be monitored by using UV-visible spectrometry and even with the bare eye. The absorbance ratio (A 650nm /A 520nm ) is linearly related to the concentration of Pb(II) in the 0.1 to 75 μM range (with a correlation coefficient of 0.9957), and the detection limit is 50 nM which is lower than the allowable level (75 nM) as defined by the US EPA. The method was successfully applied to the determination of Pb(II) in spiked water samples. (author)

Synthesis of poly(aminopropyl/methyl)silsesquioxane particles as effective Cu(II) and Pb(II) adsorbents.

Science.gov (United States)

Lu, Xin; Yin, Qiangfeng; Xin, Zhong; Li, Yang; Han, Ting

2011-11-30

Poly(aminopropyl/methyl)silsesquioxane (PAMSQ) particles have been synthesized by a one-step hydrolytic co-condensation process using 3-aminopropyltriethoxysilane (APTES) and methyltrimethoxysilane (MTMS) as precursors in the presence of base catalyst in aqueous medium. The amino functionalities of the particles could be controlled by adjusting the organosilanes feed ratio. The compositions of the amino-functionalized polysilsesquioxanes were confirmed by FT-IR spectroscopy, solid-state (29)Si NMR spectroscopy, and elemental analysis. The strong adsorbability of Cu(II) and Pb(II) ions onto PAMSQ particles was systematically examined. The effect of adsorption time, initial metal ions concentration and pH of solutions was studied to optimize the metal ions adsorbability of PAMSQ particles. The kinetic studies indicated that the adsorption process well fits the pseudo-second-order kinetics. Adsorption phenomena appeared to follow Langmuir isotherm. The PAMSQ particles demonstrate the highest Cu(II) and Pb(II) adsorption capacity of 2.29 mmol/g and 1.31 mmol/g at an initial metal ions concentration of 20mM, respectively. The PAMSQ particles demonstrate a promising application in the removal of Cu(II) and Pb(II) ions from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

KINETIC AND EQUILIBRIUM STUDY FOR THE SORPTION OF Pb(II ...

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passive process for adsorption of the metal ions by metabolically inactive biomass. ..... split in the concentration gradient between solute concentration in the .... binding capacity of Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Sn(II) ions increased with ...

A Comparative Study on the Sorption Characteristics of Pb(II and Hg(II onto Activated Carbon

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N. Muthulakshmi Andal

2010-01-01

Full Text Available Biosorption equilibrium and kinetics of Pb(II and Hg(II on coconut shell carbon (CSC were investigated by batch equilibration method. The effects of pH, adsorbent dosage, contact time, temperature and initial concentration of Pb(II and Hg(II on the activated carbon of coconut shell wastes were studied. Maximum adsorption of Pb(II occurred at pH 4.5 and Hg(II at pH 6. The sorptive mechanism followed the pseudo second order kinetics. The equilibrium data were analysed by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The equilibration data fitted well with both Langmuir and Freundlich isotherm model. The Langmuir adsorption capacity for Pb(II was greater than Hg(II. The mean free energy of adsorption calculated from Dubinin-Radushkevich (D-R isotherm model indicated that the adsorption of metal ions was found to be by chemical ion exchange. Thermodynamic parameter showed that the sorption process of Pb(II onto SDC was feasible, spontaneous and endothermic under studied conditions. A comparison was evaluated for the two metals.

A Novel Pb-Resistant Bacillus subtilis Bacterium Isolate for Co-Biosorption of Hazardous Sb(III and Pb(II: Thermodynamics and Application Strategy

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Yue Cai

2018-04-01

Full Text Available The present work is the first to study co-biosorption of Pb(II and Sb(III by a novel bacterium and its application strategy. The biosorption characteristics of Pb(II and Sb(III ions from aqueous solution using B. subtilis were investigated. Optimum pH, biomass dosage, contact time and temperature were determined to be 5.00, 6.00 mg/L, 45 min and 35 °C, respectively. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R models were applied to describe the biosorption isotherm of the metal ions by B. subtilis. Results showed that Langmuir model fitted the equilibrium data of Pb(II better than others, while biosorption of Sb(III obeyed the Freundlich model well. The biosorption capacity of B. subtilis biomass for Pb(II and Sb(III ions was found to be 17.34 ± 0.14 and 2.32 ± 0.30 mg/g, respectively. Kinetic data showed the biosorption process of Pb(II and Sb(III ions both followed the pseudo-second-order kinetic model, with R2 ranging from 0.974 to 0.999 for Pb(II and from 0.967 to 0.979 for Sb(III. The calculated thermodynamic parameters, negative ∆G and positive ∆H and ∆S values, indicated the biosorption of Pb(II and Sb(III ions onto B. subtilis biomass in water was feasible, endothermic, and spontaneous. Bacterial bioleaching experiment revealed B. subtilis can increase the mobility of Pb(II and Sb(III in polluted soil when pH was close to 6 at low temperature. Consequently, B. subtilis, as a cheap and original bacterial material, could be a promising biomass to remove Pb or isolate Sb from industrial wastewater and to assist phytoremediation of Pb and Sb from weak acid or near neutral pH polluted soils at low temperature.

Adsorption of Pb(II) ions present in aqueous solution on the oxy hydroxides: boehmite (γ-AIOOH), goethite (α-FeOOH) and manganite (γ-MnOOH); Adsorcion de iones Pb(II) presentes en solucion acuosa sobre los oxihidroxidos: boehmita (γ-AlOOH), goetita (α-FeOOH) y manganita (γ-MnOOH)

Energy Technology Data Exchange (ETDEWEB)

Arreola L, J. E.

2013-07-01

Boehmite, goethite and manganite were synthesized by different methods and characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric study , N{sub 2} physisorption measurements, scanning electron microscopy (Sem), semiquantitative elemental analysis (EDS), as well as additional studies were determined the surface active sites concentration and zero point of charge. Furthermore, we studied the Pb(II) ion adsorption capacity present in aqueous solution on these synthesized materials by batch-type experiments at room temperature, as a function of contact time between the phases liquid-solid system (adsorption kinetics), initial concentration of the adsorbate (adsorption isotherms), ph and temperature. The adsorption equilibrium time of adsorption processes in these studied systems was found at 60 minutes for boehmite and 30 minutes for goethite and manganite respectively after contacting the solid-liquid phase systems. The adsorption capacity of the lead ions on these adsorbent materials depended of lead concentration, ph and temperature of the systems. Were evaluated lead adsorption capacities in these materials to different contact times using an initial concentration of 20 mg/L of Pb(II) ions at ph = 4, the results of three systems were adjusted to second pseudo kinetic model order. With respect to the study of the adsorbate concentration effect, boehmite-Pb(II) and goethite-Pb(II) systems were adjusted to Langmuir isotherm model which proposes that the adsorption is carried out in a monolayer, moreover manganite-Pb(II) system was adjusted Temp kin isotherm model, which assumes that the adsorption heat of all the molecules in the layer decreases linearly with coverage due to adsorbent-adsorbate interactions and adsorption is characterized by a uniform distribution of the binding energies. Were studied the ph effect of Pb(II) ions solution on the adsorption capacity of such adsorbents, it was found that as the ph increases lead

Combinatorial screening of potentiometric Pb(II) sensors from polysulfoaminoanthraquinone solid ionophore.

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Huang, Mei-Rong; Ding, Yong-Bo; Li, Xin-Gui

2014-03-10

A potentiometric Pb(II)-selective sensor was fabricated by a combinatorial screening of electrically conducting polysulfoaminoanthraquinone (PSA) nanoparticles as a solid ionophore, ion exchangers (oleic acid (OA) and NaTPB), plasticizers in a polyvinyl chloride (PVC) matrix, membrane thickness, inner filling ion species, and concentration. The membrane sensor with the composition of PSA/PVC/DOP (dioctyl phthalate)/OA (1.0:33:61:5.0) exhibited the best performance, including a slope of 29.3 mV decade(-1) in the concentration range 10(-6.3)-10(-1.6) M, detection limit of 1.6 × 10(-7) M, response time of 16 s, lifetime of five months, and good response reversibility. The proposed sensor has demonstrated good selectivity for Pb(II) over other monovalent, divalent and trivalent interfering ions, and could be used in a pH range of 3.62-5.22. The Pb(II) sensor has been successfully applied for the determination of Pb(II) concentration in real-world samples and also as an indicator electrode for potentiometric titration of lead ions.

Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

International Nuclear Information System (INIS)

Shoaib, A.; Badar, T.; Aslam, N.

2011-01-01

Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

Solid phase extraction of Cd(II) and Pb(II) using a magnetic metal-organic framework, and their determination by FAAS

International Nuclear Information System (INIS)

Sohrabi, Mahmoud Reza; Matbouie, Zahra; Asgharinezhad, Ali Akbar; Dehghani, Ali

2013-01-01

We describe a novel magnetic metal-organic framework (MOF) for the preconcentration of Cd(II) and Pb(II) ions. The MOF was prepared from the Fe 3 O 4 -pyridine conjugate and the copper(II) complex of trimesic acid. The MOF was characterized by IR spectroscopy, elemental analysis, SEM and XRD. A Box-Behnken design through response surface methodology and experimental design was used to identify the optimal parameters for preconcentration. Extraction time, amount of magnetic MOF and pH value were found to be critical factors for uptake, while type, volume, concentration of eluent, and elution time are critical in the elution step. The ions were then determined by FAAS. The limits of detection are 0.2 and 1.1 μg L −1 for Cd(II), and Pb(II) ions, respectively, relative standard deviations are −1 of Cd(II) and Pb(II) ions), and the enrichment capacity of the MOF is at around 190 mg g −1 for both ions which is higher than the conventional Fe 3 O 4 -pyridine material. The magnetic MOF was successfully applied to the rapid extraction of trace quantities of Cd(II) and Pb(II) ions in fish, sediment, and water samples. (author)

Adsorption of Pb(II) ions from aqueous solutions by date bead carbon activated with ZnCl{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Danish, Mohammed; Hashim, Rokiah; Rafatullah, Mohd; Sulaiman, Othman [Division of Bioresource, Paper and Coatings Technology, School of Industrial Technology, Universiti Sains Malaysia, Penang (Malaysia); Ahmad, Anees [Division of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, Penang (Malaysia); Govind [Surface Physics and Nanostructures Group, National Physical Laboratory, New Delhi (India)

2011-04-15

This study reports on the adsorption characteristics of Pb(II) ions from aqueous solutions using ZnCl{sub 2}-activated date (Phoenix dactylifera) bead (ADB) carbon with respect to change in adsorbent dosage, initial pH, contact time, initial concentration, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo-second-order kinetic model. Thermodynamic parameters, enthalpy change ({Delta}H = 55.11 kJ/mol), entropy change ({Delta}S = - 0.193 kJ/mol/K), and Gibbs free energy change ({Delta}G ) were also calculated for the uptake of Pb(II) ions. These parameters show that adsorption on the surface of ADB was feasible, spontaneous in nature, and endothermic between temperatures of 298.2 and 318.2 K. The equilibrium data better fitted the Langmuir and Freundlich isotherm models than the D-R adsorption isotherm model for studying the adsorption behavior of Pb(II) onto the ADB carbon. It could be observed that the maximum adsorption capacity of ADB was 76.92 mg/g at 318.2 K and pH 6.5. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Adsorption of Pb(II) ions present in aqueous solution on the oxy hydroxides: boehmite (γ-AIOOH), goethite (α-FeOOH) and manganite (γ-MnOOH)

International Nuclear Information System (INIS)

Arreola L, J. E.

2013-01-01

Boehmite, goethite and manganite were synthesized by different methods and characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric study , N 2 physisorption measurements, scanning electron microscopy (Sem), semiquantitative elemental analysis (EDS), as well as additional studies were determined the surface active sites concentration and zero point of charge. Furthermore, we studied the Pb(II) ion adsorption capacity present in aqueous solution on these synthesized materials by batch-type experiments at room temperature, as a function of contact time between the phases liquid-solid system (adsorption kinetics), initial concentration of the adsorbate (adsorption isotherms), ph and temperature. The adsorption equilibrium time of adsorption processes in these studied systems was found at 60 minutes for boehmite and 30 minutes for goethite and manganite respectively after contacting the solid-liquid phase systems. The adsorption capacity of the lead ions on these adsorbent materials depended of lead concentration, ph and temperature of the systems. Were evaluated lead adsorption capacities in these materials to different contact times using an initial concentration of 20 mg/L of Pb(II) ions at ph = 4, the results of three systems were adjusted to second pseudo kinetic model order. With respect to the study of the adsorbate concentration effect, boehmite-Pb(II) and goethite-Pb(II) systems were adjusted to Langmuir isotherm model which proposes that the adsorption is carried out in a monolayer, moreover manganite-Pb(II) system was adjusted Temp kin isotherm model, which assumes that the adsorption heat of all the molecules in the layer decreases linearly with coverage due to adsorbent-adsorbate interactions and adsorption is characterized by a uniform distribution of the binding energies. Were studied the ph effect of Pb(II) ions solution on the adsorption capacity of such adsorbents, it was found that as the ph increases lead solution

Pecan nutshell as biosorbent to remove Cu(II), Mn(II) and Pb(II) from aqueous solutions.

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Vaghetti, Julio C P; Lima, Eder C; Royer, Betina; da Cunha, Bruna M; Cardoso, Natali F; Brasil, Jorge L; Dias, Silvio L P

2009-02-15

In the present study we reported for the first time the feasibility of pecan nutshell (PNS, Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946mmolg(-1) for Cu(II), Mn(II) and Pb(II), respectively.

Optimization, isotherm, kinetic and thermodynamic studies of Pb(II) ions adsorption onto N-maleated chitosan-immobilized TiO2 nanoparticles from aqueous media

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Shaker, Medhat A.; Yakout, Amr A.

2016-02-01

Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51 ± 3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, 1H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r2) and non-linear Chi-square (χ2) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters.

Equilibrium and kinetic studies of Pb(II, Cd(II and Zn(II sorption by Lagenaria vulgaris shell

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Mitić-Stojanović Dragana-Linda

2012-01-01

Full Text Available The sorption of lead, cadmium and zinc ions from aqueous solution by Lagenaria vulgaris shell biosorbent (LVB in batch system was investigated. The effect of relevant parameters such as contact time, biosorbent dosage and initial metal ions concentration was evaluated. The Pb(II, Cd(II and Zn(II sorption equilibrium (when 98% of initial metal ions were sorbed was attained within 15, 20 and 25 min, respectively. The pseudo first, pseudo-second order, Chrastil’s and intra-particle diffusion models were used to describe the kinetic data. The experimental data fitted the pseudo-second order kinetic model and intra-particle diffusion model. Removal efficiency of lead(II, cadmium(II and zinc(II ions rapidly increased with increasing biosorbent dose from 0.5 to 8.0 g dm-3. Optimal biosorbent dose was set to 4.0 g dm-3. An increase in the initial metal concentration increases the sorption capacity. The sorption data of investigated metal ions are fitted to Langmuir, Freundlich and Temkin isotherm models. Langmuir model best fitted the equilibrium data (r2 > 0.99. Maximal sorption capacities of LVB for Pb(II, Cd(II and Zn(II at 25.0±0.5°C were 0.130, 0.103 and 0.098 mM g-1, respectively. The desorption experiments showed that the LVB could be reused for six cycles with a minimum loss of the initial sorption capacity.

A study on adsorption of Pb(II), Cr(Ш) and Cu(II) from aqueous ...

African Journals Online (AJOL)

Peanut husk has been used in this work for removing Pb(II), Cr(Ш) and Cu(II) from aqueous solution. Batch adsorption studies were carried out under different pH, initial concentration of metal ions, interfering metal ions, time and temperature. Adsorption was poor in strongly acidic solution but was improved in alkaline ...

Nanomolar determination of Pb (II ions by selective templated electrode

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Mazloum-Ardakani Mohammad

2012-01-01

Full Text Available Polypyrrole modified electrode, prepared by electropolymerization of pyrrole in the presence of methyl red as a dopant, was templated with respect to Pb2+ ion and applied for potentiometric and voltammetric detection of this ion. The templating process improved the analytical response characteristics of the electrode, specially their selectivity, with respect to Pb2+ ion. The improvement depends on both the incorporated ligand (dopant and the templating process, with the latter being more vital. The potentiometric response of the electrode was linear within the Pb2+ concentration range of 2.0×10-6 to 5.0×10-2 M with a near-Nernstian slope of 28.6 mV decade-1 and a detection limit of 7.0 ×10-7 M. The electrode was also used for preconcentration differential pulse anodic stripping voltammetry (DPASV and results showed that peak currents for the incorporated lead species were dependent on the metal ion concentration in the range of 1.0×10-8 to 1.0×10-3 M. The detection limit of DPASV method was 3.5 ×10-9 M. The selectivity of the electrode with respect to some transition metal ions was investigated. The modified-templated electrode was used for the successful assay of lead in two standard reference material samples.

Optimization study for Pb(II) and COD sequestration by consortium of sulphate-reducing bacteria

Science.gov (United States)

Verma, Anamika; Bishnoi, Narsi R.; Gupta, Asha

2017-09-01

In this study, initial minimum inhibitory concentration (MIC) of Pb(II) ions was analysed to check optimum concentration of Pb(II) ions at which the growth of sulphate-reducing consortium (SRC) was found to be maximum. 80 ppm of Pb(II) ions was investigated as minimum inhibitory concentration for SRC. Influence of electron donors such as lactose, sucrose, glucose and sodium lactate was examined to investigate best carbon source for growth and activity of sulphate-reducing bacteria. Sodium lactate was found to be the prime carbon source for SRC. Later optimization of various parameters was executed using Box-Behnken design model of response surface methodology to explore the effectiveness of three independent operating variables, namely, pH (5.0-9.0), temperature (32-42 °C) and time (5.0-9.0 days), on dependent variables, i.e. protein content, precipitation of Pb(II) ions, and removal of COD by SRC biomass. Maximum removal of COD and Pb(II) was observed to be 91 and 98 %, respectively, at pH 7.0 and temperature 37 °C and incubation time 7 days. According to response surface analysis and analysis of variance, the experimental data were perfectly fitted to the quadratic model, and the interactive influence of pH, temperature and time on Pb(II) and COD removal was highly significant. A high regression coefficient between the variables and response ( r 2 = 0.9974) corroborate eminent evaluation of experimental data by second-order polynomial regression model. SEM and Fourier transform infrared analysis was performed to investigate morphology of PbS precipitates, sorption mechanism and involved functional groups in metal-free and metal-loaded biomass of SRC for Pb(II) binding.

New Mn(II, Ni(II, Cd(II, Pb(II complexes with 2-methylbenzimidazole and other ligands. Synthesis, spectroscopic characterization, crystal structure, magnetic susceptibility and biological activity studies

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Shayma A. Shaker

2016-11-01

Full Text Available Synthesis and characterization of Mn(II, Ni(II, Cd(II and Pb(II mixed ligand complexes of 2-methylbenzimidazole with other ligands have been reported. The structure of the ligands and their complexes was investigated using elemental analysis, IR, UV–Vis, (1H, 13C NMR spectroscopy, molar conductivity and magnetic susceptibility measurements. In all the studies of complexes, the 2-methylbenzimidazole behaves as a neutral monodentate ligand which is coordinated with the metal ions through the N atom. While benzotriazole behaves as a neutral bidentate ligand which is coordinated with the Ni(II ion through the two N atoms. Moreover, the N-acetylglycine behaves as a bidentate ligand which is coordinated with the Mn(II, Ni(II and Pb(II ions through the N atom and the terminal carboxyl oxygen atom. The magnetic and spectral data indicate the tetrahedral geometry for Mn(II complex, irregular tetrahedral geometry for Pb(II complex and octahedral geometry for Ni(II complex. The X-ray single crystal diffraction method was used to confirm a centrosymmetric dinuclear Cd(II complex as each two metal ions are linked by a pair of thiocyanate N = S bridge. Two 2-methylbenzimidazole N-atom donors and one terminal thiocyanate N atom complete a highly distorted square pyramid geometry around the Cd atom. Besides, different cell types were used to determine the inhibitory effect of Mn(II, Ni(II, Cd(II and Pb(II complexes on cell growth using MTT assay. Cd(II complex showed cytotoxic effect on various types of cancer cell lines with different EC50 values.

Biosorption of Pb(II) ions by modified quebracho tannin resin

Energy Technology Data Exchange (ETDEWEB)

Yurtsever, Meral [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54187 Sakarya (Turkey)], E-mail: mevci@sakarya.edu.tr; Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54187 Sakarya (Turkey)

2009-04-15

In this study, the effect of temperature, pH and initial metal concentration on Pb(II) biosorption on modified quebracho tannin resin (QTR) was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to investigate QTR structure and morphology. Besides, the specific BET surface area and zeta-potential of the QTR were analysed. Thermodynamic functions, the change of free energy ({delta}G{sup o}), enthalpy ({delta}H{sup o}) and entropy ({delta}S{sup o}) of Pb adsorption on modified tannin resin were calculated as -5.43 kJ mol{sup -1} (at 296 {+-} 2 K), 31.84 kJ mol{sup -1} and 0.127 J mmol{sup -1} K{sup -1}, respectively, indicating the spontaneous, endothermic and the increased randomness nature of Pb{sup 2+} adsorption. The kinetic data was tested using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion model. The results suggested that the pseudo-second-order model (R{sup 2} > 0.999) was the best choice among all the kinetic models to describe the adsorption behavior of Pb(II) onto QTR. Langmuir, Freundlich and Tempkin adsorption models were used to represent the equilibrium data. The best interpretation for the experimental data was given by the Langmuir isotherm and the maximum adsorption capacity (86.207 mg g{sup -1}) of Pb(II) was obtained at pH 5 and 296 K.

Sorption of Pb(II and Cu(II by low-cost magnetic eggshells-Fe3O4 powder

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Ren Jianwei

2012-01-01

Full Text Available This study explored the feasibility of using magnetic eggshell-Fe3O4 powder as adsorbent for the removal of Pb(II and Cu(II ions from aqueous solution. The metal ionsadsorption media interaction was characterized using XRD and FTIR. The effects of contact time, initial concentrations, temperature, solution pH and reusability of the adsorption media were investigated. The metal ions adsorption was fast and the amount of metal ions adsorbed increased with an increase in temperature, suggesting an endothermic adsorption. The kinetic data showed that the adsorption process followed the pseudo-second-order kinetic model. The optimal adsorption pH value was around 5.5 at which condition the equilibrium capacity was 263.2 mg/g for Pb(II and 250.0 for Cu(II. The adsorption equilibrium data fitted very well to the Langmuir and Freundlich adsorption isotherm models. The thermodynamics of Pb(II and Cu(II adsorption onto the magnetic eggshell-Fe3O4 powder indicated that the adsorption was spontaneous. The reusability study has proven that magnetic eggshell-Fe3O4 powder can be employed as a low-cost and easy to separate adsorbent.

Cowpea pod (Vigna unguiculata) biomass as a low-cost biosorbent for removal of Pb(II) ions from aqueous solution.

Science.gov (United States)

Guyo, U; Moyo, M

2017-01-01

The use of cowpea pod (CPP) biomass for the removal of Pb(II) ions from aqueous solution was investigated. The effects of factors such as dosage concentration (0.2 to 1.6 g L -1 ), pH (2 to 8), contact time (5 to 120 min), metal ion concentrations (10 to 80 mg L -1 ) and temperature (20 to 50 °C) were examined through batch studies. The biosorption data conformed best to the Langmuir model at the three working temperatures (20, 30 and 40 °C) as revealed by the correlation coefficients (R 2 ) which were greater than 0.940. The maximum sorption capacity of the CPP for Pb(II) was 32.96 mg g -1 at 313 K. Furthermore, the kinetic data fitted well to the pseudo-second-order model as it had the lowest sum of square error (SSE) values and correlation coefficients close to unity (R 2  > 0.999). The thermodynamic parameters (ΔG°, ΔS° and ΔH°) showed that the biosorption process was spontaneous, feasible and endothermic. The results obtained in the present study indicated that cowpea pod biomass could be used for the effective removal of Pb(II) from aqueous solution.

Outer Sphere Adsorption of Pb(II)EDTA on Goethite

Energy Technology Data Exchange (ETDEWEB)

Bargar, John R

1999-07-16

FTIR and EXAFS spectroscopic measurements were performed on Pb(II)EDTA adsorbed on goethite as functions of pH (4-6), Pb(II)EDTA concentration (0.11 {micro}M - 72 {micro}M), and ionic strength (16 {micro}M - 0.5M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both amine groups bonded to Pb(II). No evidence was observed for inner-sphere Pb(II)-goethite bonding at Pb:EDTA = 1:1. Hence, the adsorbed complexes should have composition Pb(II)EDTA{sup 2{minus}}. Since substantial uptake of PbEDTA(II){sup 2{minus}} occurred in the samples, we infer that Pb(II)EDTA{sup 2{minus}} adsorbed as outer-sphere complexes and/or as complexes that lose part of their solvation shells and hydrogen bond directly to goethite surface sites. We propose the term ''hydration-sphere'' for the latter type of complexes because they should occupy space in the primary hydration spheres of goethite surface functional groups, and to distinguish this mode of sorption from common structural definitions of inner- and outer-sphere complexes. The similarity of Pb(II) uptake isotherms to those of other divalent metal ions complexed by EDTA suggests that they too adsorb by these mechanisms. The lack of evidence for inner-sphere EDTA-Fe(III) bonding suggests that previously proposed metal-ligand - promoted dissolution mechanisms should be modified, specifically to account for the presence of outer-sphere precursor species.

Tartrazine modified activated carbon for the removal of Pb(II), Cd(II) and Cr(III).

Science.gov (United States)

Monser, Lotfi; Adhoum, Nafaâ

2009-01-15

A two in one attempt for the removal of tartrazine and metal ions on activated carbon has been developed. The method was based on the modification of activated carbon with tartrazine then its application for the removal of Pb(II), Cd(II) and Cr(III) ions at different pH values. Tartrazine adsorption data were modelled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacities qm were 121.3, 67 and 56.7mgg(-1) at initial pH values of 1.0, 6.0 and 10, respectively. The adsorption of tartrazine onto activated carbon followed second-order kinetic model. The equilibrium time was found to be 240min at pH 1.0 and 120min at pH 10 for 500mgL(-1) tartrazine concentration. A maximum removal of 85% was obtained after 1h of contact time. The presence of tartrazine as modifier enhances attractive electrostatic interactions between metal ions and carbon surface. The adsorption capacity for Pb(II), Cd(II) and Cr(III) ions has been improved with respect to non-modified carbon reaching a maximum of 140%. The adsorption capacity was found to be a pH dependent for both modified and non-modified carbon with a greater adsorption at higher pH values except for Cr(III). The enhancement percent of Pb(II), Cd(II) and Cr(III) at different pH values was varied from 28% to 140% with respect to non-modified carbon. The amount of metal ions adsorbed using static regime was 11-40% higher than that with dynamic mode. The difference between adsorption capacities could be attributed to the applied flow rate.

Adsorption of Pb, Cd, Zn, Cu and Hg ions on Formaldehyde and ...

African Journals Online (AJOL)

Adsorption of Pb(II), Cd(II), Zn(II), Cu(II) and Hg(II) ions on formaldehyde and Pyridine modified bean husks were determined. The adsorption capacity of formaldehyde modified bean husks (mg/g) was: Pb2+, 5.01; Cd2+, 3.63; Zn2+, 2.18; Hg2+, 1.82; Cu2+, 1.58 and that of pyridine modified bean husk was: Hg2+, 6.92; Cd2+ ...

Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

Science.gov (United States)

Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping

2009-12-15

A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.

Uptake of Cd(II) and Pb(II) by microalgae in presence of colloidal organic matter from wastewater treatment plant effluents

International Nuclear Information System (INIS)

Worms, Isabelle A.M.; Traber, Jacqueline; Kistler, David; Sigg, Laura; Slaveykova, Vera I.

2010-01-01

The present study addresses the key issue of linking the chemical speciation to the uptake of priority pollutants Cd(II) and Pb(II) in the wastewater treatment plant effluents, with emphasis on the role of the colloidal organic matter (EfOM). Binding of Cd(II) and Pb(II) by EfOM was examined by an ion exchange technique and flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry in parallel to bioassays with green microalga Chlorella kesslerii in ultrafiltrate (<1 kDa) and colloidal isolates (1 kDa to 0.45 μm). The uptake of Cd by C. kesslerii was consistent with the speciation analysis and measured free metal ion concentrations, while Pb uptake was much greater than that expected from the speciation measurement. Better understanding of the differences in the effects of the EfOM on Cd(II) and Pb(II) uptake required to take into account the size dependence of metal binding by EfOM. - Colloids isolated from WWTP effluents decrease Cd uptake, but increase Pb uptake by microalga Chlorella kesslerii.

Uptake of Cd(II) and Pb(II) by microalgae in presence of colloidal organic matter from wastewater treatment plant effluents

Energy Technology Data Exchange (ETDEWEB)

Worms, Isabelle A.M. [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland); Traber, Jacqueline; Kistler, David; Sigg, Laura [Eawag, Swiss Federal Institute of Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf (Switzerland); Slaveykova, Vera I., E-mail: vera.slaveykova@epfl.c [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland)

2010-02-15

The present study addresses the key issue of linking the chemical speciation to the uptake of priority pollutants Cd(II) and Pb(II) in the wastewater treatment plant effluents, with emphasis on the role of the colloidal organic matter (EfOM). Binding of Cd(II) and Pb(II) by EfOM was examined by an ion exchange technique and flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry in parallel to bioassays with green microalga Chlorella kesslerii in ultrafiltrate (<1 kDa) and colloidal isolates (1 kDa to 0.45 mum). The uptake of Cd by C. kesslerii was consistent with the speciation analysis and measured free metal ion concentrations, while Pb uptake was much greater than that expected from the speciation measurement. Better understanding of the differences in the effects of the EfOM on Cd(II) and Pb(II) uptake required to take into account the size dependence of metal binding by EfOM. - Colloids isolated from WWTP effluents decrease Cd uptake, but increase Pb uptake by microalga Chlorella kesslerii.

Biosorption kinetics of Cd (II, Cr (III and Pb (II in aqueous solutions by olive stone

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M. Calero

2009-06-01

Full Text Available A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II, Cr (III and Pb (II from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is the one that best describes the biosorption of the three metal ions for all the range of experimental conditions investigated. For the three metal ions, the maximum biosoption capacity and the initial biosorption rate increase when the initial metal concentration rises. However, the kinetic constant decreases when the initial metal concentration increases. The temperature effect on biosorption capacity for Cd (II and Cr (III is less significant; however, for Pb (II the effect of temperature is more important, especially when temperature rises from 25 to 40ºC. The biosorption capacity at mmol/g of olive stone changes in the following order: Cr>Cd>Pb. Thus, for an initial concentration of 220 mg/ℓ, a maximum sorption capacity of 0.079 mmol/g for Cr (III, 0.065 mmol/g for Cd (II and 0.028 mmol/g for Pb (II has been obtained.

A metal-organic framework nanocomposite made from functionalized magnetite nanoparticles and HKUST-1 (MOF-199) for preconcentration of Cd(II), Pb(II), and Ni(II)

International Nuclear Information System (INIS)

Ghorbani-Kalhor, Ebrahim

2016-01-01

The author describes the preparation of a magnetic metal organic framework of type MOF-199 containing magnetite (Fe 3 O 4 ) nanoparticles carrying covalently immobilized 4-(thiazolylazo) resorcinol (Fe 3 O 4 -TAR). This material is shown to represent a viable sorbent for separation and preconcentration of Cd(II), Pb(II), and Ni(II) ions. Box-Behnken design was applied to optimize the parameters affecting preconcentration. Following elution with 0.6 mol L −1 EDTA, the ions were quantified by FAAS. The capacity of the sorbent ranged between 185 and 210 mg g −1 . The limits of detection are 0.15, 0.40, and 0.8 ng mL −1 for Cd(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations are <8.5 %. The method was successfully applied to the rapid extraction of trace amounts of these ions from sea food and agri food. (author)

Selective Adsorption of Pb(II from Aqueous Solution by Triethylenetetramine-Grafted Polyacrylamide/Vermiculite

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Shiqing Gu

2018-03-01

Full Text Available Amine groups play significant roles in polymeric composites for heavy metals removal. However, generating a composite with a large number of functional and stable amine groups based on clay is still a challenge. In this work, a new amine-functionalized adsorbent based on acid-activated vermiculite (a-Verm was prepared by organic modification of silane coupling agent as bridge, followed by in situ polymerization of acrylamide (AM and further grafting of triethylene tetramine (TETA. The obtained polymeric composite g-PAM/OVerm was characterized by scanning electron microscope (SEM, energy dispersive spectrometer (EDS, Fourier transform infrared (FTIR, thermal analysis (TG/DTG, X-ray photoelectron spectroscopy (XPS and Brunauer–Emmett–Teller (BET analyses, confirming that amine groups were successfully grafted onto the surface of Verm. The efficacy g-PAM/OVerm for removing Pb(II was tested. The adsorption equilibrium data on g-PAM/OVerm was in good accordance with the Langmuir adsorption isotherms, and the adsorption maximal value of Pb(II was 219.4 mg·g−1. The adsorption kinetic data fit the pseudo-second-order kinetic model well. Additionally, g-PAM/OVerm has better selectivity for Pb(II ion in comparison with Zn(II, Cd(II and Cu(II ions. The present work shows that g-PAM/OVerm holds great potential for removing Pb(II from wastewater, and provides a new and efficient method for the removal of heavy metal ions from industrial wastewater.

Selective Adsorption of Pb(II) from Aqueous Solution by Triethylenetetramine-Grafted Polyacrylamide/Vermiculite

Science.gov (United States)

Gu, Shiqing; Wang, Lan; Mao, Xinyou; Yang, Liping; Wang, Chuanyi

2018-01-01

Amine groups play significant roles in polymeric composites for heavy metals removal. However, generating a composite with a large number of functional and stable amine groups based on clay is still a challenge. In this work, a new amine-functionalized adsorbent based on acid-activated vermiculite (a-Verm) was prepared by organic modification of silane coupling agent as bridge, followed by in situ polymerization of acrylamide (AM) and further grafting of triethylene tetramine (TETA). The obtained polymeric composite g-PAM/OVerm was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared (FTIR), thermal analysis (TG/DTG), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analyses, confirming that amine groups were successfully grafted onto the surface of Verm. The efficacy g-PAM/OVerm for removing Pb(II) was tested. The adsorption equilibrium data on g-PAM/OVerm was in good accordance with the Langmuir adsorption isotherms, and the adsorption maximal value of Pb(II) was 219.4 mg·g−1. The adsorption kinetic data fit the pseudo-second-order kinetic model well. Additionally, g-PAM/OVerm has better selectivity for Pb(II) ion in comparison with Zn(II), Cd(II) and Cu(II) ions. The present work shows that g-PAM/OVerm holds great potential for removing Pb(II) from wastewater, and provides a new and efficient method for the removal of heavy metal ions from industrial wastewater. PMID:29597288

Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

Science.gov (United States)

Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-12-01

Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

Karakterisasi Adsorben dari Kulit Manggis dan Kinerjanya pada Adsorpsi Logam Pb(II dan Cr(VI - (Adsorbent Characterization from Mangosteen Peel and Its Adsorption Performance on Pb(II and Cr(VI

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Ulfa Haura

2017-06-01

Full Text Available The usage of biomass waste-based adsorbent for the adsorption of hazardous metal in wastewater is not only reducing waste but also lowering adsorbent price. This research aims to study the characteristics of adsorbent from mangosteen peel (Garcinia Mangostana L. and activated charcoal from mangosteen peel, also to compare the adsorption performance on metal ion Pb(II and Cr(VI. Synthetic wastewater used from a solution of Pb(NO32 and K2Cr2O7 with variations in initial concentration of 20, 40, 80, 100 and 200 mg/L. Adsorption performed at pH 5, ratio of adsorbent and waste solution 1/200 (w/v, 60 rpm, 0.5 gs nano-sized adsorbent. Characterization using SEM, FTIR and SEM-EDS showed that both adsorbents characteristics met the requirements of SNI 06-3730-1995. The highest adsorption capacity of activated carbon to adsorb Pb(II and Cr(VI were 38.543 mg/g and 36.838 mg/g while biosorbent adsorb Pb(II and Cr(VI respectively 3.98 mg/g and 36.12 mg/g.Keywords: adsorption, biosorbent, Cr(VI, mangosteen peel, Pb(IIABSTRAKPenggunaan adsorben berbasis limbah biomassa untuk adsorpsi kandungan logam berbahaya dari limbah cair industri selain dapat mengurangi limbah juga dapat menekan harga jual adsorben. Penelitian ini bertujuan untuk mempelajari karakteristik adsorben yang terbuat dari limbah kulit manggis (Garcinia mangostana L. dan arang aktif dari limbah kulit manggis serta membandingkan kinerja kedua jenis adsorben tersebut pada proses adsorpsi ion logam Pb(II dan Cr(VI. Limbah sintetis yang digunakan berupa ion dari Pb(II dan Cr(VI dari larutan Pb(NO32 dan K2Cr2O7 dengan variasi konsentrasi awal 20, 40, 80, 100 dan 200 mg/L. Proses adsorpsi dilakukan pada pH 5, rasio perbandingan berat adsorben dan volume larutan limbah 1:200, kecepatan pengadukan 60 rpm, adsorben berukuran nano dengan berat adsorben 0,5 g. Masing-masing adsorben dikarakterisasi menggunakan SEM untuk mengetahui sturktur morfologi, FTIR untuk mengetahui gugus fungsi dan SEM-EDS untuk

A novel starch-based adsorbent for removing toxic Hg(II) and Pb(II) ions from aqueous solution.

Science.gov (United States)

Huang, Li; Xiao, Congming; Chen, Bingxia

2011-08-30

A novel effective starch-based adsorbent was prepared through two common reactions, which included the esterification of starch with excess maleic anhydride in the presence of pyridine and the cross-linking reaction of the obtained macromonomer with acrylic acid by using potassium persulphate as initiator. The percentage of carboxylic groups of the macromonomer ranged from 14% to 33.4%. The cross-linking degree of the adsorbent was tailored with the amount of acrylic acid which varied from 10wt% to 80wt%. Both Fourier transform infrared spectra and thermogravimetric analysis results verified the structure of the adsorbent. The maximum gel fraction and swelling ratio of the adsorbent were about 72% and 6.25, respectively, and they were able to be adjusted with the amount of monomers. The weight loss percentage of the adsorbent could reach 96.9% after immersing in the buffer solution that contained α-amylase for 14h. It was found that the adsorption capacities of the adsorbent for lead and mercury ions could be 123.2 and 131.2mg/g, respectively. In addition, the adsorbent was able to remove ca. 51-90% Pb(II) and Hg(II) ions that existed in the decoctions of four medicinal herbals. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of the performance of different modified graphene oxide nanosheets for the extraction of Pb(II) and Cd(II) from natural samples

International Nuclear Information System (INIS)

Sayar, Omid; Mehrani, Kheirollah; Mehrani, Azadeh; Hoseinzadeh, Fatemeh; Sadeghi, Omid

2014-01-01

Graphene nanosheets were modified with amino groups and the resulting material was used as a sorbent for the extraction of cadmium and lead ions. The nanosheets were characterized by IR spectroscopy, transmission electron microscopy, thermal gravimetric analysis and elemental analysis. The effects of sample pH, eluent parameters (type, concentration and volume of eluent), flow rates (of both sample and eluent), and of a variety of other ions on the efficiency of the extraction of Cd(II) and Pb(II) were optimized. Following solid phase extraction, the elements were determined by FAAS. The limits of detection are <0.9 μg L −1 for Pb(II) and <5 ng L −1 for Cd(II). The relative standard deviations are <2.2 %. The method was validated by analyzing several certified reference materials and was then used for Pb(II) and Cd(II) determination in natural waters and vegetables. (author)

Application of EDTA-functionalized bamboo activated carbon (BAC) for Pb(II) and Cu(II) removal from aqueous solutions

Science.gov (United States)

Lv, Dan; Liu, Yu; Zhou, Jiasheng; Yang, Kunlun; Lou, Zimo; Baig, Shams Ali; Xu, Xinhua

2018-01-01

In this study, a novel bamboo activated carbon (BAC) with ethylene diamine tetraacetic acid (EDTA) functionality was prepared by direct grafting in the presence of tetraethyl orthosilicate (TEOS) as a crosslinking agent. The BAC@SiO2-EDTA was characterized by SEM, TEM, TGA, FTIR, XPS and its adsorption property for removal of Pb(II) and Cu(II) under various experimental conditions was also investigated. The characterization results reflected that EDTA was successfully assembled on the surface of the BAC and average pore size increased from 4.10 to 4.83 nm as BAC grafted with EDTA. Adsorption data fitted very well in Langmuir isotherm model and pseudo-second-order kinetic model. As compared with the raw BAC, the maximum adsorption capacities of BAC@SiO2-EDTA for the Pb(II) and Cu(II) increased from 45.45 to 123.45 mg g-1 and from 6.85 to 42.19 mg g-1, since the existence of EDTA on modified BAC promoted the formation of chemical complex. The removal of heavy metal ions mainly depended on the complexation with EDTA and the electrostatic attractions with negatively charged surface of BAC@SiO2-EDTA. The adsorption of Pb(II)/Cu(II) on the BAC@SiO2-EDTA was pH dependent and pH 5-6 was considered an optimum. However, lower temperature favored the adsorption and the maximum adsorption was recorded at 20 °C. In addition, BAC@SiO2-EDTA had an excellent reusability with about 40% decline in the adsorption capacity for Pb(II) after fifth reuse. Insignificant influences of co-existing cations and natural organic matter (NOM) were found on the adsorption of Pb(II) and Cu(II). All the results demonstrate that BAC@SiO2-EDTA is a potential adsorbent for metal ions in wastewater.

Synthesis of amino functionalized magnetic graphenes composite material and its application to remove Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II) from contaminated water

International Nuclear Information System (INIS)

Guo, Xiaoyao; Du, Bin; Wei, Qin; Yang, Jian; Hu, Lihua; Yan, Liangguo; Xu, Weiying

2014-01-01

Highlights: • Graphenes magnetic composite nanoparticles (Fe 3 O 4 -GS) were used to adsorb metal ions. • The adsorption of metal ions onto Fe 3 O 4 -GS could be well interpreted by the Freundlich equation. • The adsorption of metal ions onto Fe 3 O 4 -GS fit pseudo-second order kinetic model. • Thermodynamic studies illustrated that the adsorption process was endothermic and spontaneous in nature. - Abstract: In the present study, a kind of graphenes magnetic material (Fe 3 O 4 -GS) was prepared by compositing graphene sheet with ferroferric oxide, and shown to be effictive for removing Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II) ions from aqueous solution. The synthesized sorbent was characterized by SEM, TEM, FTIR, XRD, XPS and BET, respectively. The pH ZPC value of the sorbent was estimated to be 3.5 by alkaline-titration methods. Fe 3 O 4 -GS can be simply recovered from water with magnetic separation at low magnetic field within one minute. The sorption capacities of the metals were 17.29, 27.95, 23.03, 27.83 and 22.07 mg g −1 for Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II), respectively. Kinetic data showed good correlation with pseudo-second-order equation and the Freundlich model was found to fit for the isotherm data of all the heavy metal ions. It was found that the metals sorption was accomplished mainly via chelation or ion exchange. The results of thermodynamic studies illustrate that the adsorption process was endothermic and spontaneous in nature

Enhanced removal of Cd(II) and Pb(II) by composites of mesoporous carbon stabilized alumina

Energy Technology Data Exchange (ETDEWEB)

Yang, Weichun [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China); Tang, Qiongzhi; Wei, Jingmiao; Ran, Yajun [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chai, Liyuan [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China); Wang, Haiying, E-mail: haiyw25@163.com [Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Lushan South Road 932, Changsha 410017 (China); Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Lushan South Road 932, Changsha 410017 (China)

2016-04-30

Graphical abstract: - Highlights: • Mesoporous carbon stabilized alumina was prepared by one-pot hard-templating method. • MC/Al{sub 2}O{sub 3} showed excellent performance for Cd(II) and Pb(II) adsorption. • Enhanced adsorption was due to the high surface area and special functional groups. - Abstract: A novel adsorbent of mesoporous carbon stabilized alumina (MC/Al{sub 2}O{sub 3}) was synthesized through one-pot hard-templating method. The adsorption potential of MC/Al{sub 2}O{sub 3} for Cd(II) and Pb(II) from aqueous solution was investigated compared with the mesoporous carbon. The results indicated the MC/Al{sub 2}O{sub 3} showed excellent performance for Cd(II) and Pb(II) removal, the adsorption capacity reached 49.98 mg g{sup −1} for Cd(II) with initial concentration of 50 mg L{sup −1} and reached 235.57 mg g{sup −1} for Pb(II) with initial concentration of 250 mg L{sup −1}, respectively. The kinetics data of Cd(II) adsorption demonstrated that the Cd(II) adsorption rate was fast, and the removal efficiencies with initial concentration of 10 and 50 mg L{sup −1} can reach up 99% within 5 and 20 min, respectively. The pseudo-second-order kinetic model could describe the kinetics of Cd(II) adsorption well, indicating the chemical reaction was the rate-controlling step. The mechanism for Cd(II) and Pb(II) adsorption by MC/Al{sub 2}O{sub 3} was investigated by X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR), and the results indicated that the excellent performance for Cd(II) and Pb(II) adsorption of MC/Al{sub 2}O{sub 3} was mainly attributed to its high surface area and the special functional groups of hydroxy-aluminum, hydroxyl, carboxylic through the formation of strong surface complexation or ion-exchange. It was concluded that MC/Al{sub 2}O{sub 3} can be recognized as an effective adsorbent for removal of Cd(II) and Pb(II) in aqueous solution.

Biosorption of Cd(II), Ni(II) and Pb(II) from aqueous solution by dried biomass of aspergillus niger: application of response surface methodology to the optimization of process parameters

Energy Technology Data Exchange (ETDEWEB)

Amini, Malihe; Younesi, Habibollah [Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor (Iran)

2009-10-15

In this study, the biosorption of Cd(II), Ni(II) and Pb(II) on Aspergillus niger in a batch system was investigated, and optimal condition determined by means of central composite design (CCD) under response surface methodology (RSM). Biomass inactivated by heat and pretreated by alkali solution was used in the determination of optimal conditions. The effect of initial solution pH, biomass dose and initial ion concentration on the removal efficiency of metal ions by A. niger was optimized using a design of experiment (DOE) method. Experimental results indicated that the optimal conditions for biosorption were 5.22 g/L, 89.93 mg/L and 6.01 for biomass dose, initial ion concentration and solution pH, respectively. Enhancement of metal biosorption capacity of the dried biomass by pretreatment with sodium hydroxide was observed. Maximal removal efficiencies for Cd(II), Ni(III) and Pb(II) ions of 98, 80 and 99% were achieved, respectively. The biosorption capacity of A. niger biomass obtained for Cd(II), Ni(II) and Pb(II) ions was 2.2, 1.6 and 4.7 mg/g, respectively. According to these observations the fungal biomass of A. niger is a suitable biosorbent for the removal of heavy metals from aqueous solutions. Multiple response optimization was applied to the experimental data to discover the optimal conditions for a set of responses, simultaneously, by using a desirability function. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Synthesis and characterization of polyacrylamide zirconium (IV iodate ion-exchanger: Its application for selective removal of lead (II from wastewater

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Nafisur Rahman

2017-05-01

Full Text Available Polyacrylamide zirconium (IV iodate was synthesized using the sol–gel technique. The synthesis conditions such as reactant concentrations and temperature were changed to optimize the ion exchange properties of the hybrid organic–inorganic ion exchange material. Zirconium oxychloride (0.1 M was added to 0.1 M potassium iodate in the presence of 0.4 M acrylamide and heated at 70 °C for 6 h to yield the polyacrylamide zirconium (IV iodate with maximum capacity. The ion exchange capacity was found to be 3.27 meq/g for Pb(II. The hybrid material has been characterized on the basis of chemical composition FTIR, XRD, TGA-DTA, SEM and EDX studies. Sorption studies showed that the hybrid cation exchanger has a high selectivity to Pb(II in comparison to other metal ions. Its selectivity was evaluated by performing some important binary separations like Hg(II–Pb(II, Cu(II–Pb(II, Ni(II–Pb(II, Fe(III–Pb(II and Cd(II–Pb(II. In addition, the selective separation of Pb(II was also achieved from a synthetic mixture containing a large number of metal ions with a recovery of ∼98.5%. The proposed method was successfully applied for the selective removal of Pb(II from wastewater samples.

Photoproduced fluorescent Au(I)@(Ag2/Ag3)-thiolate giant cluster: an intriguing sensing platform for DMSO and Pb(II).

Science.gov (United States)

Ganguly, Mainak; Mondal, Chanchal; Jana, Jayasmita; Pal, Anjali; Pal, Tarasankar

2014-01-14

Synergistic evolution of fluorescent Au(I)@(Ag2/Ag3)-thiolate core-shell particles has been made possible under the Sun in presence of the respective precursor coinage metal compounds and glutathione (GSH). The green chemically synthesized fluorescent clusters are giant (∼600 nm) in size and robust. Among all the common water miscible solvents, exclusively DMSO exhibits selective fluorescence quenching (Turn Off) because of the removal of GSH from the giant cluster. Again, only Pb(II) ion brings back the lost fluorescence (Turn On) leaving aside all other metal ions. This happens owing to the strong affinity of the sulfur donor of DMSO for Pb(II). Thus, employing the aqueous solution containing the giant cluster, we can detect DMSO contamination in water bodies at trace level. Besides, a selective sensing platform has emerged out for Pb(II) ion with a detection limit of 14 × 10(-8) M. Pb(II) induced fluorescence recovery is again vanished by I(-) implying a promising route to sense I(-) ion.

Synthesis and Characterization Pectin-Carboxymethyl Chitosan crosslinked PEGDE as biosorbent of Pb(II) ion

Science.gov (United States)

Hastuti, Budi; Siswanta, Dwi; Mudasir; Triyono

2018-01-01

Pectin and chitosan are biodegradable polymers, potentially applied as a heavy metal adsorbents. Unfortunately both biosorbents pectin and chitosan have a weakness in acidic media. For this purpose required modified pectin and chitosan. The modified adsorben is intended to obtain a stable adsorbent and resistance under acid. The research was done by experimental method in laboratory. The stages of this research are the synthesis of carboxymethyl chitosan (CMC), synthesis of Pec-CMC-PEGDE film adsorbent, stabily test under acid, the characterization of active group using FTIR, stability characterization of Pec-CMC-PEGDE powder adsorbent using XRD, termo stability using DTA-TGA. The results of the research have shown that: pectin and CMC can be cross-linked using PEGDE crosslinking agent, the film adsorbent was stable under HCl 1 M, the film adsorbent have active group comprise of carboxylate and amine groups. The result of characterization using XRD, shows that the adsorbent is semi-crystalline. Base on termo stability, the film adsorbent Pec-CMC-PEGDE stable up to 600°C. The film can be applied as an adsobent of Pb (II) ion remediation. The optimum pH of pec-CMC-PEGDE in adsorbed of Pb(II) was reached at pH 5 with 99.99% absorbent adsorbed and of and adsorption capacity was 46.11 mg/g.

THE ADSORPTION OF Pb(II AND Cr(III BY POLYPROPYLCALIX[4]ARENE POLYMER

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Suryadi Budi Utomo

2010-06-01

Full Text Available A research has been conducted to investigate the adsorption behavior of Pb(II and Cr(III onto polypropylcalix[4]arene polymer. The polypropylcalix[4]arene polymer was synthesized in the presence of H2SO4 catalyst and chloroform under N2 condition for 5 h using 25-allyloxy-26,27,28-trihydroxycalyx[4]arene as the precursor. The Polymer was obtained as yellow crystal with melting point of  288-290 °C and its relative molecular weight was 44.810 g.mol-1. The application of polypropylcalix[4]arene for trapping heavy metal cations and its adsorption model were examined by stirring the suspension of the calixarene in the sample solutions for various pH, time, and concentration of Pb(II and Cr(III solution. Effect of pH on batch experiments for the mentioned ions indicated that the optimum pH for metal binding were 5 for lead(II and chromium(III. The adsorption model of metal ions on polypropylcalix[4]arene followed both the pseudo second order adsorption of Ho's and Langmuir isotherm adsorption kinetics models with rate constant (k were 6.81 x 101 min-1 for Pb(II and 2.64 x 10-2 min-1 for Cr(III. The adsorption equilibrium constant, K, were 5.84 x 105 L.mol-1 for Pb(II and 4.66 x 105 L.mol-1 for Cr(III. The maximum adsorption capacity of polypropylcalix[4]arene to Pb(II and Cr(III were 16.31 and 18.14 mg.g-1 with adsorption energy of 32.90 and 32.34 kJ.mol-1, respectively.   Keywords: polypropylcalix[4]arene, adsorption, Pb(II, and Cr(III

A solid phase extraction procedure for the determination of Cd(II) and Pb(II) ions in food and water samples by flame atomic absorption spectrometry.

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Daşbaşı, Teslima; Saçmacı, Şerife; Ülgen, Ahmet; Kartal, Şenol

2015-05-01

A relatively rapid, accurate and precise solid phase extraction method is presented for the determination of cadmium(II) and lead(II) in various food and water samples. Quantitation is carried out by flame atomic absorption spectrometry (FAAS). The method is based on the retention of the trace metal ions on Dowex Marathon C, a strong acid cation exchange resin. Some important parameters affecting the analytical performance of the method such as pH, flow rate and volume of the sample solution; type, concentration, volume, flow rate of the eluent; and matrix effects on the retention of the metal ions were investigated. Common coexisting ions did not interfere on the separation and determination of the analytes. The detection limits (3 σb) for Cd(II) and Pb(II) were found as 0.13 and 0.18 μg L(-1), respectively, while the limit of quantification values (10 σb) were computed as 0.43 and 0.60 μg L(-1) for the same sequence of the analytes. The precision (as relative standard deviation was lower than 4% at 5 μg L(-1) Cd(II) and 10 μg L(-1) Pb(II) levels, and the preconcentration factor was found to be 250. The accuracy of the proposed procedure was verified by analysing the certified reference materials, SPS-WW2 Batch 108 wastewater level 2 and INCT-TL-1 tea leaves, with the satisfactory results. In addition, for the accuracy of the method the recovery studies (⩾ 95%) were carried out. The method was applied to the determination of the analytes in the various natural waters (lake water, tap water, waste water with boric acid, waste water with H2SO4) and food samples (pomegranate flower, organic pear, radish leaf, lamb meat, etc.), and good results were obtained. While the food samples almost do not contain cadmium, they have included lead at low levels of 0.13-1.12 μg g(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

A study: removal of Cu(II), Cd(II), and Pb(II) ions from real industrial water and contaminated water using activated sludge biomass

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Kusvuran, Erdal; Yildirim, Deniz [Arts and Sciences Faculty, Chemistry Department, Cukurova University, Balcali, Adana (Turkey); Samil, Ali [Arts and Sciences Faculty, Chemistry Department, Sutcu Imam University, Kahramanmaras (Turkey); Gulnaz, Osman [Arts and Sciences Faculty, Biology Department, Cukurova University, Balcali, Adana (Turkey)

2012-11-15

This study aims to remove of Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion-exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (q{sub max}) were calculated as 0.478, 0.358, and 0.280 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+}, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L{sup -1} metal concentration was determined as 0.200, 0.167, and 0.155 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g{sup -1} for Cu{sup 2+}, Cd{sup 2+}, and Pb{sup 2+} ions, respectively, when initial metal concentration was 0.50 mmol L{sup -1}. In the multi-metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. In the presence of 100 mmol L{sup -1} H{sup +} ion, the order of ion-exchange affinity with H{sup +} was found as Cu{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. The adsorption kinetics were also found to be well described by the pseudo-second-order and intraparticle diffusion models. Two different rate constants were obtained as k{sub i1} and k{sub i2} and k{sub i1} (first stage) was found to be higher than k{sub i2} (second stage). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Simultaneous determination of Cd(II) and Pb(II) by differential pulse anodic stripping voltammetry based on graphite nanofibers-Nafion composite modified bismuth film electrode.

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Li, Dongyue; Jia, Jianbo; Wang, Jianguo

2010-12-15

A bismuth-film modified graphite nanofibers-Nafion glassy carbon electrode (BiF/GNFs-NA/GCE) was constructed for the simultaneous determination of trace Cd(II) and Pb(II). The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as deposition potential, deposition time, and bismuth ion concentration were optimized for the purpose of determination of trace metal ions in 0.10 M acetate buffer solution (pH 4.5). Under optimal conditions, based on three times the standard deviation of the baseline, the limits of detection were 0.09 μg L(-1) for Cd(II) and 0.02 μg L(-1) for Pb(II) with a 10 min preconcentration. In addition, the BiF/GNFs-NA/GCE displayed good reproducibility and selectivity, making it suitable for the simultaneous determination of Cd(II) and Pb(II) in real sample such as river water and human blood samples. Copyright © 2010 Elsevier B.V. All rights reserved.

Simultaneous trace-levels determination of Hg(II) and Pb(II) ions in various samples using a modified carbon paste electrode based on multi-walled carbon nanotubes and a new synthesized Schiff base

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Afkhami, Abbas; Bagheri, Hasan; Khoshsafar, Hosein; Saber-Tehrani, Mohammad; Tabatabaee, Masoumeh; Shirzadmehr, Ali

2012-01-01

Highlights: ► A new chemically modified carbon paste electrode was constructed and used. ► A new Schiff base and multi-walled carbon nanotube was used as a modifier. ► The electrochemical properties of the modified electrode were studied. ► The electrode was used to the simultaneous determination of Pb 2+ and Hg 2+ . - Abstract: A modified carbon paste electrode based on multi-walled carbon nanotubes (MWCNTs) and 3-(4-methoxybenzylideneamino)-2-thioxothiazolodin-4-one as a new synthesized Schiff base was constructed for the simultaneous determination of trace amounts of Hg(II) and Pb(II) by square wave anodic stripping voltammetry. The modified electrode showed an excellent selectivity and stability for Hg(II) and Pb(II) determinations and for accelerated electron transfer between the electrode and the analytes. The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as pH, deposition potential and deposition time were optimized for the purpose of determination of traces of metal ions at pH 3.0. Under optimal conditions the limits of detection, based on three times the background noise, were 9.0 × 10 −4 and 6.0 × 10 −4 μmol L −1 for Hg(II) and Pb(II) with a 90 s preconcentration, respectively. In addition, the modified electrode displayed a good reproducibility and selectivity, making it suitable for the simultaneous determination of Hg(II) and Pb(II) in real samples such as sea water, waste water, tobacco, marine and human teeth samples.

Removal of Cu(II) and Pb(II) from Aqueous Solutions Using Nanoporous Materials

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Dutta, Debajani; Roy, Sushanta Kumar; Das, Bodhaditya; Talukdar, Anup K.

2018-05-01

The present work deals with the adsorption of Cu2+ and Pb2+ on zeolites (ZSM-5, mordenite) and mesoporous materials (MCM-48, MCM-41). The characterization of the synthesized samples was performed by means of XRD, SEM, and thermogravimetric analysis. The batch method was employed to study the influence of adsorbent nature, contact time, initial metal ion concentration, and adsorbent load. The adsorption on MCM-48 follows a pseudo-second-order kinetic model. This material was found to be more effective for the removal of lead in a batch process as compared to the other adsorbents and the removal efficiency of the materials for Pb(II) followed the order MCM-48 > mordenite > ZSM-5 > MCM-41 and that for Cu(II) followed the order ZSM-5 > mordenite > MCM-41 > MCM-48.

Remediation capacity of Cd and Pb ions by mycelia of Imleria badia, Laetiporus sulphureus, and Agaricus bisporus in vitro cultures.

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Kryczyk, Agata; Piotrowska, Joanna; Sito, Magdalena; Sulkowska-Ziaja, Katarzyna; Dobosz, Konrad; Opoka, Włodzimierz; Muszyńska, Bożena

2017-09-02

The goal of this study was to evaluate cadmium and lead accumulation ability of in vitro cultures biomass containing selected edible mushroom species derived from the environment (Laetiporus sulphureus, Imleria badia) and those of commercial origin (Agaricus bisporus). Atomic absorption spectrometry was used to evaluate the content of Cd(II) and Pb(II) on the medium supplemented with Cd(II) or Pb(II), each of them at the same concentration of 5·10 -5 M. The highest concentration of Cd(II) ions was determined in the biomass from L. sulphureus in vitro cultures, while the highest concentration of Pb(II) ions was found in the biomass from A. bisporus in vitro cultures. The greatest Cd(II) and Pb(II) accumulation ability in mycelium per dry weight was shown for L. sulphureus. Among the test species, biomass of A. bisporus showed the lowest ability for the bioaccumulation of Cd(II); however, comparable ability for the remediation of Pb(II) was provided by the biomasses from A. bisporus and I. badia in vitro cultures. The results confirm the possibility of using these mushroom species for remediation and indicate the relationship between bioaccumulation of heavy metals and the test species.

Sensitive stripping voltammetric determination of Cd(II) and Pb(II) by a Bi/multi-walled carbon nanotube-emeraldine base polyaniline-Nafion composite modified glassy carbon electrode

International Nuclear Information System (INIS)

Zhao, Guo; Yin, Yuan; Wang, Hui; Liu, Gang; Wang, Zhiqiang

2016-01-01

Highlights: • A MWCNT-EBP-NA composite film modified GCE was fabricated and characterized. • The GCE modified with the MWCNT-EBP-NA composite film exhibited excellent performance in the analysis of Cd(II) and Pb(II) by SWASV. • The Cd(II) and Pb(II) detection limits of the developed electrode were approximately 0.06 μg/L and 0.08 μg/L, respectively. • Bi/MWCNT-EBP-NA/GCE was successfully used to determine metal ions in soil samples. - Abstract: In this study, a multi-walled carbon nanotube (MWCNT)-emeraldine base polyaniline (EBP)-Nafion (NA) composite modified glassy carbon electrode (MWCNT-EBP-NA/GCE) was prepared and used for the sensitive detection of trace Pb(II) and Cd(II), with a detection limit of 0.06 μg/L for Cd(II) and 0.08 μg/L for Pb(II) (S/N = 3), by square wave anodic stripping voltammetry (SWASV). A bismuth film was prepared through the in situ plating of bismuth on the MWCNT-EBP-NA/GCE. The morphologies and electrochemical properties of the modified electrode were characterized by SWASV, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The parameters affecting the stripping current response were investigated and optimized. The formed MWCNTs in the composite film enlarged the specific surface area of the electrode and significantly promoted electron transferring, and the formed polyaniline (PANI) enhanced the ion-exchange capacity and prevented the macromolecules in real samples from absorbing onto the surface of the electrode. The presence of NA effectively increased the stability and adhesion of the composite film, enhanced the cation-exchange capacity and improved the ability to preconcentrate metal ions. Under the optimized conditions, a linear range of 1.0 to 50.0 μg/L was achieved for both metal ions, with a detection limit of 0.06 μg/L for Cd(II) and 0.08 μg/L for Pb(II) (S/N = 3), offering good repeatability. Finally, the Bi/MWCNT-EBP-NA/GCE was used for the

KARAKTERISASI PERTUKARAN ION TIMBAL (II DENGAN KALSIUM PADA PROSES BIOSORPSI ALGA HIJAU CLADOPHORA FRACTA

Directory of Open Access Journals (Sweden)

Ade Wirli Putra

2016-05-01

Full Text Available ABSTRAKKarakterisasi pertukaran ion Pb2+ dengan Ion Ca2+ dalam larutan menggunakan proses biosorbsi dengan biomassa alga hijau cladofora fracta  telah diteliti.  Penelitian ini bertujuan untuk mengetahui selektifitas pertukaran pertukaran ion Pb2+  dengan ion Ca2+ dan sebaliknya, Pengaruh pH eluen terhadap desorpsi  ion Pb2+  dan adsorpsi Ion Ca2+, Karakterisasi desorpsi  Ion Ca2+ dan  Ion Pb2+ dengan larutan HNO3 0,1 M dan H2O akan diamati pada penelitian ini. Hasil penelitian yang diperoleh memperlihatkan bahwa proses pertukaran ion Ca2+ dengan ion Pb2+ lebih mudah terjadi dibandingkan pertukaran ion Pb2+ dengan Ca2+. Desorpsi  ion Pb2+ relatif rendah saat pH eluen sama dengan pH optimum biosorpsi  ion  Pb2+ (pH 4,0. Pada pH 5,0 kemungkinan terjadi endapan  timbal (II hidroksida ( Pb(OH2 .  Penyerapan  ion Ca2+, yang terdapat  dalam eluen, lebih besar terjadi pada pH yang lebih tinggi (pH 5,0. Desorpsi ion Pb2+ dengan larutan HNO3 0,1M dan H2O memperlihatkan hasil yang berbeda (masing-masing  28,10% dan 15,56%, sedangkan desorpsi ion Ca2+ dengan  larutan HNO3 0,1M dan H2O tidak memperlihatkan berbeda yang signifikan (masing-masing 37,91% dan 34,75%, sehingga larutan HNO3 0,1M sebagai eluen pendesorpsi ion Pb2+ dari biosorben lebih efektif dibandingkan eluen H2O.  ABSTRACTCharacterization of  Pb 2+ ion exchange with Ca2 + ions using the process biosorbtion with green algae biomass Cladofora fracta been investigated. This study aims to determine the selectivity of the exchange ion exchange Pb 2+ ions with Ca2 + and vice versa, Effect of pH eluent to desorption of ions Pb 2+ and adsorption of ions Ca2 +, Characterization desorption of ions Ca2 + and Ion Pb 2+ with a solution of HNO3 0.1 M and H2O will be observed in this study. The results obtained showed that the Ca2 + ion exchange process with Pb 2+ ions more readily than Pb 2+ ion exchange with Ca2 +. Desorption of Pb 2+ ion is relatively low at the same eluent pH with a p

CHARACTERIZATION OF SORBENT PRODUCED THROUGH IMMOBILIZATION OF HUMIC ACID ON CHITOSAN USING GLUTARALDEHYDE AS CROSS-LINKING AGENT AND Pb(II ION AS ACTIVE SITE PROTECTOR

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Uripto Trisno Santoso

2010-12-01

Full Text Available Sorbent produced through immobilization of humic acid (HA on chitosan using glutaraldehyde as cross-linking agent and Pb(II ions as active site protector has been characterized. Active sorption site of HA was protected by reacting HA with Pb(II ion, and the protected-HA was then activated by glutaraldehyde, crosslinked onto chitosan, and deprotected by 0.1 M disodium ethylenediamine tetra-acetic acid (Na2EDTA. The protected-crosslinking method enhanced the content of immobilized-HA and its chemical stability. Based on the FTIR spectra, crosslinking of HA on chitosan probably occurred through a chemical reaction. The sorption capacity of sorbent still remains unchanged after the second regeneration, but some of HA start to be soluble. The latter shows that cross-linking reaction between HA and chitosan is through formation an unstable product. The effectiveness of sorbent regeneration can also be identified by the XRD pattern.

Removal of Pb (II Ions from Aqueous Solutions by Cladophora rivularis (Linnaeus Hoek

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Naser Jafari

2012-01-01

Full Text Available Biosorption of Pb(II using Cladophora rivularis was examined as a function of initial pH heavy metal concentration and temperature. The optimum pH value for the biosorption of lead was 4.0. The adsorption equilibriums were well described by Langmuir and Freundlich isotherm models and it was implied by the results that the C. rivularis biomass is suitable for the development of efficient biosorbent in order to remove Pb(II from wastewater and to recover it. The high values of correlation coefficient (2=0.984 demonstrate equilibrium data concerning algal biomass, which is well fitted in Freundlich isotherms model equations. The dimensionless parameter RL is found in the range of 0.0639 to 0.1925 (0<<1, which confirms the favorable biosorption process. Fourier transform infra-red (FTIR spectroscopy of C. rivularis was used to reveal the main function groups of biosorption, which were hydroxyl, amine groups, C–H stretching vibrations of –CH3 and –CH2, and complexation with functional groups. All these results suggest that C. rivularis can be used effectively for removal of Pb(II.

Removal of Pb (II) ions from aqueous solutions by Cladophora rivularis (Linnaeus) Hoek.

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Jafari, Naser; Senobari, Zoreh

2012-01-01

Biosorption of Pb(II) using Cladophora rivularis was examined as a function of initial pH heavy metal concentration and temperature. The optimum pH value for the biosorption of lead was 4.0. The adsorption equilibriums were well described by Langmuir and Freundlich isotherm models and it was implied by the results that the C. rivularis biomass is suitable for the development of efficient biosorbent in order to remove Pb(II) from wastewater and to recover it. The high values of correlation coefficient (R(2) = 0.984) demonstrate equilibrium data concerning algal biomass, which is well fitted in Freundlich isotherms model equations. The dimensionless parameter R(L) is found in the range of 0.0639 to 0.1925 (0 < R(L) < 1), which confirms the favorable biosorption process. Fourier transform infra-red (FTIR) spectroscopy of C. rivularis was used to reveal the main function groups of biosorption, which were hydroxyl, amine groups, C-H stretching vibrations of -CH3 and -CH2, and complexation with functional groups. All these results suggest that C. rivularis can be used effectively for removal of Pb(II).

Removal of Pb(II) from aqueous solution using modified and unmodified kaolinite clay

International Nuclear Information System (INIS)

Jiang Mingqin; Wang Qingping; Jin Xiaoying; Chen Zuliang

2009-01-01

Modified kaolinite clay with 25% (w/w) aluminium sulphate and unmodified kaolin were investigated as adsorbents to remove Pb(II) from aqueous solution. The results show that amount of Pb(II) adsorbed onto modified kaolin (20 mg/g) was more than 4.5-fold than that adsorbed onto unmodified kaolin (4.2 mg/g) under the optimized condition. In addition, the linear Langmuir and Freundlich models were used to describe equilibrium isotherm. It is observed that the data from both adsorbents fitted well to the Langmuir isotherm. The kinetic adsorption of modified and unmodified kaolinite clay fitted well to the pseudo-second-order model. Furthermore, both modified and unmodified kaolinite clay were characterized by X-ray diffraction, Fourier transform infrared (FT-IR) and scanning electron microscope (SEM). Finally, both modified and unmodified kaolinite clay were used to remove metal ions from real wastewater, and results show that higher amount of Pb(II) (the concentration reduced from 178 to 27.5 mg/L) and other metal ions were removed by modified kaolinite clay compared with using unmodified adsorbent (the concentration reduced from 178 to 168 mg/L).

Removal of Pb(II) from water by the activated carbon modified by nitric acid under microwave heating.

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Yao, Shuheng; Zhang, Jiajun; Shen, Dekui; Xiao, Rui; Gu, Sai; Zhao, Ming; Liang, Junyu

2016-02-01

The rice husk based activated carbon (RH-AC) was treated by nitric acid under microwave heating, in order to improve its capability for the removal of heavy metal ions from water. The optimal conditions for the modification of RH-AC (M-RH-AC) were determined by means of orthogonal array experimental design, giving those as the concentration of nitric acid of 8mol/L, modification time of 15min, modification temperature of 130°C and microwave power of 800W. The characteristics of the M-RH-AC and RH-AC were examined by BET, XRD, Raman spectrum, pH titration, zeta potential, Boehm titration and FTIR analysis. The M-RH-AC has lower pore surface area, smaller crystallite, lower pHIEP and more oxygen-containing functional groups than the RH-AC. Removal capacity of Pb(II) ions by the M-RH-AC and RH-AC from water solution was estimated concerning the influence of contact time, pH value, and initial concentration. The equilibrium time of Pb(II) removal was found to be around 90min after modification process. Two kinetic models are adopted to describe the possible Pb(II) adsorption mechanism, finding that the adsorption rate of Pb(II) ions by the M-RH-AC is larger than that of RH-AC. Copyright © 2015 Elsevier Inc. All rights reserved.

o-Vanillin functionalized mesoporous silica – coated magnetite nanoparticles for efficient removal of Pb(II) from water

Energy Technology Data Exchange (ETDEWEB)

Culita, Daniela C., E-mail: danaculita@yahoo.co.uk [“Ilie Murgulescu” Institute of Physical Chemistry, Splaiul Independentei 202, Bucharest (Romania); Simonescu, Claudia Maria; Patescu, Rodica-Elena [Politehnica University, Faculty of Applied Chemistry and Materials Science, Bucharest (Romania); Dragne, Mioara [S.C. KEMCRISTAL S.R.L., Muncii Str., No. 51, Fundulea, Călăraşi (Romania); Stanica, Nicolae [“Ilie Murgulescu” Institute of Physical Chemistry, Splaiul Independentei 202, Bucharest (Romania); Oprea, Ovidiu [Politehnica University, Faculty of Applied Chemistry and Materials Science, Bucharest (Romania)

2016-06-15

o-Vanillin functionalized mesoporous silica – coated magnetite (Fe{sub 3}O{sub 4}@MCM-41-N-oVan) was synthesized and fully characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N{sub 2} adsorption–desorption technique and magnetic measurements. The capacity of Fe{sub 3}O{sub 4}@MCM-41-N-oVan to adsorb Pb(II) from aqueous solutions was evaluated in comparison with raw mesoporous silica – coated magnetite (Fe{sub 3}O{sub 4}@MCM-41) and amino – modified mesoporous silica coated magnetite (Fe{sub 3}O{sub 4}@MCM-41-NH{sub 2}). The effect of adsorption process parameters such us pH, contact time, initial Pb(II) concentration was also investigated. The adsorption data were successfully fitted with the Langmuir model, exhibiting a maximum adsorption capacity of 155.71 mg/g at pH=4.4 and T=298 K. The results revealed that the adsorption rate was very high at the beginning of the adsorption process, 80–90% of the total amount of Pb(II) being removed within the first 60 min, depending on the initial concentration. The results of the present work suggest that Fe{sub 3}O{sub 4}@MCM-41-N-oVan is a suitable candidate for the separation of Pb(II) from contaminated water. - Graphical abstract: A novel magnetic adsorbent based on o-vanillin functionalized mesoporous silica – coated magnetite was synthesized and fully characterized and its adsorption capacity for Pb(II) ions in aqueous solutions was evaluated. The maximum adsorption capacity for Pb(II) ions was determined to be 155.71 mg g{sup −1}. The adsorption rate was very high at the beginning of the adsorption process, 90% of the total amount of Pb(II) being removed within the first 60 min. Display Omitted.

o-Vanillin functionalized mesoporous silica – coated magnetite nanoparticles for efficient removal of Pb(II) from water

International Nuclear Information System (INIS)

Culita, Daniela C.; Simonescu, Claudia Maria; Patescu, Rodica-Elena; Dragne, Mioara; Stanica, Nicolae; Oprea, Ovidiu

2016-01-01

o-Vanillin functionalized mesoporous silica – coated magnetite (Fe 3 O 4 @MCM-41-N-oVan) was synthesized and fully characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N 2 adsorption–desorption technique and magnetic measurements. The capacity of Fe 3 O 4 @MCM-41-N-oVan to adsorb Pb(II) from aqueous solutions was evaluated in comparison with raw mesoporous silica – coated magnetite (Fe 3 O 4 @MCM-41) and amino – modified mesoporous silica coated magnetite (Fe 3 O 4 @MCM-41-NH 2 ). The effect of adsorption process parameters such us pH, contact time, initial Pb(II) concentration was also investigated. The adsorption data were successfully fitted with the Langmuir model, exhibiting a maximum adsorption capacity of 155.71 mg/g at pH=4.4 and T=298 K. The results revealed that the adsorption rate was very high at the beginning of the adsorption process, 80–90% of the total amount of Pb(II) being removed within the first 60 min, depending on the initial concentration. The results of the present work suggest that Fe 3 O 4 @MCM-41-N-oVan is a suitable candidate for the separation of Pb(II) from contaminated water. - Graphical abstract: A novel magnetic adsorbent based on o-vanillin functionalized mesoporous silica – coated magnetite was synthesized and fully characterized and its adsorption capacity for Pb(II) ions in aqueous solutions was evaluated. The maximum adsorption capacity for Pb(II) ions was determined to be 155.71 mg g −1 . The adsorption rate was very high at the beginning of the adsorption process, 90% of the total amount of Pb(II) being removed within the first 60 min. Display Omitted

Preparation and Spectral Properties of Mixed-Ligand Complexes of VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II with Dimethylglyoxime and N-acetylglycine

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Shayma A. Shaker

2010-01-01

Full Text Available A number of mixed-ligand complexes of the general formula [M(D(G] where D=dimethylglyoximato monoanion, G=N-acetylglycinato and M=VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II were prepared. Each complex was characterized by elemental analysis, determination of metal, infrared spectra, electronic spectra, (1H and 13C NMR spectra, conductivity and magnetic moments. All these complexes were not soluble in some of the organic solvent but highly soluble in dimethylformamide. The conductivity data showed the non-electrolytic nature of the complexes. The electronic spectra exhibited absorption bands in the visible region caused by the d-d electronic transition such as VO(IV, Ni(II and Pd(II. The IR and (1H, 13C NMR spectra which have indicate that the dimethylglyoxime was coordinated with the metal ions through the N and O atoms of the oxime group and N-acetylglycine was coordinated with metal ions through the N atom and terminal carboxyl oxygen atom.

Synthesis and characterization of a surface-grafted Cd(II) ion-imprinted polymer for selective separation of Cd(II) ion from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Li, Min [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Feng, Changgen, E-mail: cgfeng@cast.org.cn [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Li, Mingyu; Zeng, Qingxuan; Gan, Qiang [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Yang, Haiyan [Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China)

2015-03-30

Highlights: • Cd(II) ion-imprinted polymer (Cd(II)-IIP) is prepared. • Cd(II)-IIP shows high stability, good selectivity and reusability. • Cd(II)-IIP can be used as a sorbent for selective removal of Cd(II) ion. - Abstract: A novel Cd(II) ion-imprinted polymer (Cd(II)-IIP) was prepared with surface imprinting technology by using cadmium chloride as a template and allyl thiourea (ATU) as a functional monomer for on-line solid-phase extraction of trace Cd(II) ion and selective separation Cd(II) ion in water samples. The Cd(II)-IIP exhibited good chemical performance and thermal stability. Kinetics studies showed that the equilibrium adsorption was achieved within 8.0 min and the adsorption process can be described by pseudo-second-order kinetic model. Compared to the Cd(II) non-imprinted polymer (Cd(II)-NIP), the Cd(II)-IIP had a higher adsorption capacity and selectivity for Cd(II) ion. The maximum adsorption capacities of the Cd(II)-IIP and Cd(II)-NIP for Cd(II) were 38.30 and 13.21 mg g{sup −1}, respectively. The relative selectivity coefficients of the adsorbent for Cd(II) in the presence of Cu{sup 2+}, Ni{sup 2+}, Co{sup 2+}, Pb{sup 2+} and Zn{sup 2+} were 2.86, 6.42, 11.50, 9.46 and 3.73, respectively. In addition, the Cd(II) ion adsorbed was easy to remove from sorbent and the Cd(II)-IIP exhibited good stability and reusability. The adsorption capacity had no obvious decrease after being used six times. The accuracy of this method was verified by the standard reference material, it was then applied for cadmium ion determination in different types of water samples.

Kinetic and equilibrium studies of Pb(II and Cd(II adsorption on African wild mango (Irvingia gabonensis shell

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F. A. Adekola

2016-08-01

Full Text Available The adsorption behavior of NaOH-activated African wild mango (Irvingia gabonensis shell with respect to Pb2+ and Cd2+ has been studied in order to consider its application to purify metal finishing waste water. The optimum conditions of adsorption were determined by investigating the initial metal ions concentration, contact time, adsorbent dose, pH value of aqueous solution and temperature. The extent of adsorption of metal ions was investigated by batch method using metal concentrations in solution ranging from 5-200 mg/L. The adsorption efficiencies were found to be pH dependent, with maximum metals uptake recorded at pH of 5. The equilibrium adsorption capacity for lead and cadmium ions were obtained from Freundlich, Langmuir, Temkin and DRK isotherms and the experimental data were found to fit best the Langmuir isotherm with values of 21.28 and 40.00 mg/g for Cd(II and Pb(II ions, respectively. The Pseudo-second order kinetics model had the best fitting for lead and cadmium adsorption kinetic data. The thermodynamic investigation showed that the adsorption processes of both metals are exothermic. An optimum concentration of 0.05 M HCl was found to be adequate for the regeneration of the spent adsorbent with recovery values of 78% and 71% for Pb2+ and Cd2+ respectively from the spent adsorbent. The results revealed that lead and cadmium are considerably adsorbed on the adsorbent and could be an economic method for the removal of these metals from aqueous solutions.

Removal of Cd(II) and Pb(II) from aqueous solution using dried water hyacinth as a biosorbent

Science.gov (United States)

Ibrahim, Hanan S.; Ammar, Nabila S.; Soylak, Mustafa; Ibrahim, Medhat

2012-10-01

Possible usages of dried water hyacinth as biosorbent for metal ions were investigated. A model describing the plant is presented on density functional theory DFT and verified experimentally with FTIR. The model shows that water hyacinth is a mixture of cellulose and lignin. Dried shoot and root were found as good sorbent for Cd(II) and Pb(II) at optimum dosage of 5.0 g/l and pH 5.0; equilibrium time was attained within 30-60 min. The removal using root and shoot were nearly equal and reached more than 75% for Cd and more than 90% for Pb. Finally the second-order kinetics was the applicable model. Hydrogen bonds of reactive functional groups like COOH play the key role in the removal process.

Pb II

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This investigation describes the use of non-living biomass of Aspergillus caespitosus for removal of ... Pb(II) production has exceeded 3.5 million tons per year. It has been used in the ... This biomass was selected after screening a wide range of microbes. .... prolonged, which proved better biopolymer in metal uptake (Gadd ...

Potential of polyaniline modified clay nanocomposite as a selective decontamination adsorbent for Pb(II) ions from contaminated waters; kinetics and thermodynamic study.

Science.gov (United States)

Piri, Somayeh; Zanjani, Zahra Alikhani; Piri, Farideh; Zamani, Abbasali; Yaftian, Mohamadreza; Davari, Mehdi

2016-01-01

Nowadays significant attention is to nanocomposite compounds in water cleaning. In this article the synthesis and characterization of conductive polyaniline/clay (PANI/clay) as a hybrid nanocomposite with extended chain conformation and its application for water purification are presented. Clay samples were obtained from the central plain of Abhar region, Abhar, Zanjan Province, Iran. Clay was dried and sieved before used as adsorbent. The conductive polyaniline was inflicted into the layers of clay to fabricate a hybrid material. The structural properties of the fabricated nanocomposite are studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The elimination process of Pb(II) and Cd(II) ions from synthetics aqueous phase on the surface of PANI/clay as adsorbent were evaluated in batch experiments. Flame atomic absorption instrument spectrophotometer was used for determination of the studied ions concentration. Consequence change of the pH and initial metal amount in aqueous solution, the procedure time and the used adsorbent dose as the effective parameters on the removal efficiency was investigated. Surface characterization was exhibited that the clay layers were flaked in the hybrid nanocomposite. The results show that what happen when a nanocomposite polyaniline chain is inserted between the clay layers. The adsorption of ions confirmed a pH dependency procedure and a maximum removal value was seen at pH 5.0. The adsorption isotherm and the kinetics of the adsorption processes were described by Temkin model and pseudo-second-order equation. Time of procedure, pH and initial ion amount have a severe effect on adsorption efficiency of PANI/clay. By using suggested synthesise method, nano-composite as the adsorbent simply will be prepared. The prepared PANI/clay showed excellent adsorption capability for decontamination of Pb ions from contaminated water. Both of suggested synthesise and

Adsorption Efficiency of Iron Modified Carbons for Removal of Pb(II Ions from Aqueous Solution

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Mohammad Hossein Salmani

2016-06-01

Full Text Available Abstract Introduction: The Lead causes severe damage to several systems of the body, especially to bony tissues. Until now, several low-cost biosorbents have been studied for removal of heavy metal ions from aqueous solutions. In the present study, carbonized pomegranate peels modified with Fe2+ and Fe3+ ions and then it was investigated for removal of Pb(II ions from aqueous solution. Materials and methods: the washed granola of pomegranate peel was separately socked with FeCl3 and FeCl2 solutions for 24 h. Then, the granules were carbonized at 400 ºC for 3 h in a programmable furnace in the atmosphere of nitrogen. The adsorption experiments were carried out for two types of iron-modified carbons by batch adsorption using one variable at a time procedures. Results: The optimum conditions were found as contact time 90 min, initial concentration 50 mg/l, and adsorbent dose, 1.00 g/100 ml solution. Maximum removal efficiency was calculated as 84% and 89% for Fe3+ and Fe2+ impregnated pomegranate peel carbons respectively. Conclusion: The iron treatment pomegranate peel carbons modified their surfaces for adsorption of heavy metals. The results showed that chemical modification of the low-cost adsorbents originating from agricultural waste has stood out for metal removal capabilities.

Influence of phosphate buffer and proteins on the potentiometric response of a polymeric membrane-based solid-contact Pb(II) ion-selective electrode

DEFF Research Database (Denmark)

Joon, Narender Kumar; He, Ning; Wagner, Michal

2017-01-01

In this work, the influence of phosphate buffer and proteins on the potentiometric response of a polymeric membrane-based solid-contact Pb2+-selective electrode (Pb2+-ISE) was studied. The effects of bovine serum albumin (BSA) adsorption at the surface of the ion-selective membrane combined...... ions studied (Cu2+, Cd2+). Conditioning of the Pb2+-ISE in 0.01 mol dm–3 PBS resulted in a super-Nernstian response which was related to fixation/extraction of Pb2+ in the ion-selective membrane via precipitation of Pb3(PO4)2 by PO43– anions present in PBS. By conditioning of the Pb2+-ISE in 0.01 mol...

Polypyrrole-polyaniline/Fe{sub 3}O{sub 4} magnetic nanocomposite for the removal of Pb(II) from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Afshar, Amirhossein; Sadjadi, Seyed Abolfazl Seyed; Mollahosseini, Afsaneh; Eskandarian, Mohammad Reza [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

2016-02-15

Lead ion which is engaged in aqueous solution has been successfully removed. A novel technique was utilized for the separation and absorption of Pb(II) ions from aqueous solution. Magnetic Fe{sub 3}O{sub 4} coated with newly investigated polypyrrole-polyaniline nanocomposite was used for the removal of extremely noxious Pb(II). Characteristic of the prepared magnetic nanocomposite was done using X-ray diffraction pattern, Field emission scanning electron microscopy (FE-SEM), Fourier transform-infrared spectroscopy (FT-IR) and energy dispersive x-ray spectroscopy (EDX). Up to 100% adsorption was found with 20mg/L Pb(II) aqueous solution in the range of pH=8-10. Adsorption results illustrated that Pb(II) removal efficiency by the nanocomposite increased with an enhance in pH. Adsorption kinetics was best expressed by the pseudo-second-order rate form. Isotherm data fitted well to the Freundlich isotherm model. Upon using HCl and HNO{sub 3}, 75% PPy-PAn/Fe{sub 3}O{sub 4} nanocomposite, desorption experiment showed that regenerated adsorbent can be reused successfully for two successive adsorption-desorption cycles without appreciable loss of its original capacity.

Pb(II) and Hg(II) binding to $\\textit{de novo}$ designed proteins studied by $^{204m}$Pb- and $^{199m}$Hg-Perturbed Angular Correlation of $\\gamma$-rays (PAC) spectroscopy : Clues to heavy metal toxicity

CERN Multimedia

2002-01-01

$\\textit{De novo}$ design of proteins combined with PAC spectroscopy offers a unique and powerful approach to the study of fundamental chemistry of heavy metal-protein interactions, and thus of the mechanisms underlying heavy metal toxicity. In this project we focus on Pb(II) and Hg(II) binding to designed three stranded coiled coil proteins with one or two binding sites, mimicking a variety of naturally occurring thiolate-rich metal ion binding sites in proteins. The $^{204m}$Pb- and $^{199m}$Hg-PAC experiments will complement data already recorded with EXAFS, NMR, UV-Vis and CD spectroscopies.

Preparation and Pb(II Adsorption Properties of Crosslinked Pectin-Carboxymethyl Chitosan Film

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Budi Hastuti

2015-11-01

Full Text Available A modified pectin has been synthesized by reacting/combining -OH group among pectin and chitosan with BADGE (Bisphenol A diglycidyl ether crosslinker agent. The structure and morphology of the new material were characterized by Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM and X-ray Diffraction (XRD analysis. Thermogravimetric studies showed an improvement in thermal characteristic. Adsorption experiments were performed in batch processes; sorption isotherms and kinetics were also studied. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherms and isotherm constants for the adsorption of Pb(II ion onto adsorbent pectin-carboxymethyl chitosan-BADGE (pec-CMC-BADGE. The dynamic study showed that the sorption process followed the second-order kinetic equation. Result indicated also that Pb(II ion uptake could be well described by the Langmuir and Freundlich adsorption model of pec-CMC-BADGE and CMC with DG° of 25.3 and 23.1 kJ mol-1,respectively, while that of pectin followed Freundlich isotherm with DG° of 16.6 kJ mol-1.

Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO Composites Used for Pb(II Removal

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Mingyi Fan

2016-08-01

Full Text Available Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, Raman spectroscopy, N2-sorption and X-ray photoelectron spectroscopy (XPS. Operating parameters for the removal process of Pb(II ions, such as temperature (20–40 °C, pH (3–5, initial concentration (400–600 mg/L and contact time (20–60 min, were optimized using a quadratic model. The coefficient of determination (R2 > 0.99 obtained for the mathematical model indicates a high correlation between the experimental and predicted values. The optimal temperature, pH, initial concentration and contact time for Pb(II ions removal in the present experiment were 21.30 °C, 5.00, 400.00 mg/L and 60.00 min, respectively. In addition, the Pb(II removal by nZVI/rGO composites was quantitatively evaluated by using adsorption isotherms, such as Langmuir and Freundlich isotherm models, of which Langmuir isotherm gave a better correlation, and the calculated maximum adsorption capacity was 910 mg/g. The removal process of Pb(II ions could be completed within 50 min, which was well described by the pseudo-second order kinetic model. Therefore, the nZVI/rGO composites are suitable as efficient materials for the advanced treatment of Pb(II-containing wastewater.

Preparation of PbO nanoparticles by microwave irradiation and their application to Pb(II)-selective electrode based on cellulose acetate

International Nuclear Information System (INIS)

Li Shengying; Yang Wu; Chen Miao; Gao Jinzhang; Kang Jingwan; Youli, Q.

2005-01-01

Nanosized lead oxide particles were prepared by thermal decomposition of lead hydroxycarbonate synthesized under microwave irradiation. Urea and lead nitrate were used as the starting materials. Microstructure and morphology of the products were investigated by means of XRD, AFM, TEM, and IR absorption spectra. The results indicated that well crystallized, finely dispersed and spherical α-PbO nanoparticles with a size of ca. 30 nm were obtained. Meanwhile, an orthogonal phase β-PbO with a size of ca. 38 nm was also obtained when the calcinations temperature was up to 600 deg. C. In addition, a Pb(II)-selective electrode based on cellulose acetate was prepared using nanosized α-PbO powders synthesized. The electrode exhibited a Nernstian slope of 29±1 mV per decade in a linear range of 2.5x10 -5 mol L -1 to 1.0x10 -1 mol L -1 for Pb 2+ ion. The detection limit of this electrode is down to 8.0x10 -6 mol L -1 . This sensor has a short response time of about 10 s and could be used in a pH range of 2.0-8.0. High selectivity was obtained over a wide variety of metal ions

Extraction and Determination of Pb(II by Organic Functionalisation of Graphenes Adsorbed on Surfactant Coated C18 in Environmental Sample

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A. Moghimi

2013-11-01

Full Text Available A novel, simple, sensitive and effective method has been developed for preconcentration of lead. This solid-phase extraction adsorbent was synthesized by functionalization of graphenes with covalently linked N-methyl-glycine and 3, 4-dihydroxybenzaldehyde onto the surfaces of graphite. The method is based on selective chelation of Pb (II on surfactant coated C18, modified with functionalization of graphenes (graphene-f-OH. The adsorbed ions were then eluted with 4 ml of 4 M nitric acid and determined by flame atomic absorption spectrometry (FAAS at 283.3 for Pb. The influence of flow rates of sample and eluent solutions, pH, breakthrough volume, effect of foreign ions were investigated on chelation and recovery. 1.5 g of surfactant coated C18 adsorbs 40 mg of the functionalization of graphenes (graphene-f-OH base which in turn can retain15.2±0.8mg of each of the two ions. The limit of detection (3σ for Pb(II was found to be 3.20 ng l -1. The enrichment factor for both ions is 100. The mentioned method was successfully applied on the determination of Pb in different water samples.

Extraction and Determination of Pb(II by Organic Functionalisation of Graphenes Adsorbed on Surfactant Coated C18 in Environmental Sample

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A. Moghimi

2014-05-01

Full Text Available A novel, simple, sensitive and effective method has been developed for preconcentration of lead. This solidphase extraction adsorbent was synthesized by functionalization of graphenes with covalently linked N-methyl-glycine and 3, 4-dihydroxybenzaldehyde onto the surfaces of graphite. The method is based on selective chelation of Pb (II on surfactant coated C18, modified with functionalization of graphenes (graphene-f-OH. The adsorbed ions were then eluted with 4 ml of 4 M nitric acid and determined by flame atomic absorption spectrometry (FAAS at 283.3 for Pb. The influence of flow rates of sample and eluent solutions, pH, breakthrough volume, effect of foreign ions were investigated on chelation and recovery. 1.5 g of surfactant coated C18 adsorbs 40 mg of the functionalization of graphenes (graphene-f-OH base which in turn can retain15.2±0.8mg of each of the two ions. The limit of detection (3σ for Pb(II was found to be 3.20 ng l -1. The enrichment factor for both ions is 100. The mentioned method was successfully applied on the determination of Pb in different water samples

Pb(II) adsorption by a novel activated carbon - alginate composite material. A kinetic and equilibrium study.

Science.gov (United States)

Cataldo, Salvatore; Gianguzza, Antonio; Milea, Demetrio; Muratore, Nicola; Pettignano, Alberto

2016-11-01

The adsorption capacity of an activated carbon - calcium alginate composite material (ACAA-Ca) has been tested with the aim of developing a new and more efficient adsorbent material to remove Pb(II) ion from aqueous solution. The study was carried out at pH=5, in NaCl medium and in the ionic strength range 0.1-0.75molL -1 . Differential Pulse Anodic Stripping Voltammetry (DP-ASV) technique was used to check the amount of Pb(II) ion removed during kinetic and equilibrium experiments. Different kinetic (pseudo first order, pseudo second order and Vermuelen) and equilibrium (Langmuir and Freundlich) models were used to fit experimental data, and were statistically compared. Calcium alginate (AA-Ca) improves the adsorption capacity (q m ) of active carbon (AC) in the ACAA-Ca adsorbent material (e.g., q m =15.7 and 10.5mgg -1 at I=0.25molL -1 , for ACAA-Ca and AC, respectively). SEM-EDX and thermogravimetric (TGA) measurements were carried out in order to characterize the composite material. The results of the speciation study on the Pb(II) solution and of the characterization of the ACAA-Ca and of the pristine AA-Ca and AC were evaluated in order to explain the specific contribution of AC and AA-Ca to the adsorption of the metal ion. Copyright © 2016 Elsevier B.V. All rights reserved.

Adsorption of Cu (II), Pb (II) and Cr (VI) from aqueous solutions using black wattle tannin-immobilized nanocellulose.

Science.gov (United States)

Xu, Qinghua; Wang, Yulu; Jin, Liqiang; Wang, Yu; Qin, Menghua

2017-10-05

A novel nanocomposite based on black wattle (BW) tannin and nanocellulose was prepared and applied in heavy metal ions adsorptive removal from aqueous solutions. Firstly, nanocrystalline cellulose was oxidized by sodium periodate to get dialdehyde nanocellulose (DANC). BW tannin was then covalently immobilized onto DANC, which was used as both the matrix and crosslinker, to obtain tannin-nanocellulose (TNCC) composite. The resulting nanocomposite was characterized using FTIR, AFM, and TG. The successful immobilization was confirmed by the chromogenic reaction between FeCl 3 and TNCC and FT-IR analysis. AFM images revealed that TNCC was ellipsoidal particles with lengths ranging from 100-400nm. Zeta potential measurement showed that TNCC was negative charged at a pH range from 1-12. Compared to the original tannin, the thermal stability of TNCC was slightly increased by the addition of nanocellulose. TNCC demonstrated the maximum adsorption efficiency at pH2 for Cr(VI) and pH 6 for Cu(II) and Pb(II), respectively. The adsorption for these three metal ions followed pseudo second-order kinetics, indicating the chemisorption nature. The adsorption isotherms all fitted well with the Sips model, and the calculated maximum adsorption capacities were 51.846mgg -1 , 53.371mgg -1 and 104.592mgg -1 for Cu(II), Pb(II) and Cr (VI), respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Equilibrium, thermodynamic and kinetic studies for the biosorption of aqueous lead(II), cadmium(II) and nickel(II) ions on Spirulina platensis

Energy Technology Data Exchange (ETDEWEB)

Seker, Ayseguel [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: aysegulseker@iyte.edu.tr; Shahwan, Talal [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: talalshahwan@iyte.edu.tr; Eroglu, Ahmet E. [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: ahmeteroglu@iyte.edu.tr; Yilmaz, Sinan [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: sinanyilmaz@iyte.edu.tr; Demirel, Zeliha [Department of Biology, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: zelihademirel@gmail.com; Dalay, Meltem Conk [Department of Bioengineering, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: meltemconkdalay@gmail.com

2008-06-15

The biosorption of lead(II), cadmium(II) and nickel(II) ions from aqueous solution by Spirulina platensis was studied as a function of time, concentration, temperature, repetitive reactivity, and ionic competition. The kinetic results obeyed well the pseudo second-order model. Freundlich, Dubinin Radushkevich and Temkin isotherm models were applied in describing the equilibrium partition of the ions. Freundlich isotherm was applied to describe the design of a single-stage batch sorption system. According to the thermodynamic parameters such as {delta}G{sup o}, {delta}H{sup o}and {delta}S{sup o} calculated, the sorption process was endothermic and largely driven towards the products. Sorption activities in a three metal ion system were studied which indicated that there is a relative selectivity of the biosorbent towards Pb{sup 2+} ions. The measurements of the repetitive reusability of S. platensis indicated a large capacity towards the three metal ions.

Application of functionalized nano HMS type mesoporous silica with N-(2-aminoethyl-3-aminopropyl methyldimethoxysilane as a suitable adsorbent for removal of Pb (II from aqueous media and industrial wastewater

Directory of Open Access Journals (Sweden)

Hamedreza Javadian

2017-01-01

Full Text Available In this work, adsorption characteristics of nano NH2-HMS (functionalized HMS type mesoporous silica with amine groups for the removal of Pb (II ions from aqueous solutions were investigated. The adsorbent was characterized using FE-SEM, TEM, XRD, FTIR and BET. The adsorption of Pb (II ions by batch method was applied and the optimum conditions were investigated. In optimum experimental conditions, removal efficiency was 99.08%. It was found that temperature has a positive effect on the removal efficiency. The thermodynamic parameters were evaluated, as well. The evaluated thermodynamic parameters (ΔG, ΔH and ΔS showed that the adsorption of Pb (II ions onto nano NH2-HMS was feasible, spontaneous and endothermic in nature. It can be concluded that NH2-HMS is potentially able to remove Pb (II ions from aqueous solutions. Also, more than 90% of desorption efficiency was achieved using 0.01 M HNO3.

The sorption of lead(II) ions on rice husk ash.

Science.gov (United States)

Naiya, Tarun Kumar; Bhattacharya, Ashim Kumar; Mandal, Sailendranath; Das, Sudip Kumar

2009-04-30

Present study deals with the adsorption of Pb(II) from aqueous solution on rice husk ash. Rice husk is a by-product generally obtained from rice mill. Rice husk ash is a solid obtained after burning of rice husk. Batch studies were performed to evaluate the influences of various experimental parameters like pH, initial concentration, adsorbent dosage, contact time and the effect of temperature. Optimum conditions for Pb(II) removal were found to be pH 5, adsorbent dosage 5 g/L of solution and equilibrium time 1h. Adsorption of Pb(II) followed pseudo-second-order kinetics. The effective diffusion coefficient is of the order of 10(-10)m(2)/s. The equilibrium adsorption isotherm was better described by Freuindlich adsorption isotherm model. The adsorption capacity (q(max)) of rice husk ash for Pb(II) ions in terms of monolayer adsorption was 91.74 mg/g. The change of entropy (DeltaS(0)) and enthalpy (Delta H(0)) were estimated at 0.132 kJ/(mol K) and 28.923 kJ/mol respectively. The negative value of Gibbs free energy (Delta G(0)) indicates feasible and spontaneous adsorption of Pb(II) on rice husk ash. The value of the adsorption energy (E), calculated using Dubinin-Radushkevich isotherm, was 9.901 kJ/mol and it indicated that the adsorption process was chemical in nature. Application study was also carried out to find the suitability of the process in waste water treatment operation.

Synthesis and application of novel ion-imprinted polymer coated magnetic multi-walled carbon nanotubes for selective solid phase extraction of lead(II) ions

Energy Technology Data Exchange (ETDEWEB)

Fayazi, Maryam, E-mail: maryam.fayazi@yahoo.com [Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Taher, Mohammad Ali [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Department of Environment, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Mostafavi, Ali [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Ghanei-Motlagh, Masoud, E-mail: m.ghaneimotlagh@yahoo.com [Young Researchers Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

2016-03-01

In this study, novel magnetic ion-imprinted polymer (MIIP) nanoparticles were utilized for the sensitive and selective detection of Pb(II) ions by graphite furnace atomic absorption spectrometry (GFAAS). The Pb(II)-imprinted polymer was synthesized by using 4-vinylpyridine (4VP) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,3,5,6-tetra(2-pyridyl) pyrazine (TPPZ) as the chelating agent and magnetic multi-walled carbon nanotubes (MMWCNTs) as the carrier. The synthesized MIIP materials were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). Various analytical parameters such as extraction and desorption time, eluent type and concentration, pH and sample volume were systematically examined. The selectivity of MIIP sorbent for Pb(II) ions in the presence of some cations was also evaluated. The limit of detection (LOD, 3S{sub b}) and the relative standard deviation (RSD, n = 8, c = 25 ng L{sup −1}) were found to be 2.4 ng L{sup −1} and 5.6%, respectively. The maximum sorption capacity of the MIIP for Pb(II) was found to be 48.1 mg g{sup −1}. Finally, the proposed analytical procedure was successfully applied to monitoring lead in human hair and water samples with satisfactory results for the spiked samples. - Highlights: • A selective and sensitive method based on MSPE-GFAAS was proposed. • The MIIP nanoparticles were characterized using FE-SEM, XRD, VSM and FT-IR techniques. • The synthesized MIIP material is efficient at extracting lead ions. • The method was applied to determine lead ions in several real samples.

Batch adsorptive removal of Fe(III), Cu(II) and Zn(II) ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

OpenAIRE

Aboul-Magd, Abdul-Aleem Soliman; Al-Husain, Salwa Al-Rashed; Al-Zahrani, Salma Ahmed

2016-01-01

Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III), Cd(II), Zn(II), Cu(II), Mn(II), Mg(II), and Pb(II) from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion ...

Rational assembly of Pb(II)/Cd(II)/Mn(II) coordination polymers based on flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Energy Technology Data Exchange (ETDEWEB)

Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Robbins, Julianne; Zhang, Z. John [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Yin, Hong-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Wang, Yu-Hua [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China)

2015-05-15

Six new coordination polymers, namely, [Pb(L)(H{sub 2}O)] (1), [Pb(L)(phen)] (2), [Pb{sub 2}(L){sub 2}(4,4′-bipy){sub 0.5}] (3), [Cd(L)(phen)] (4), [Cd(L)(4,4′-bipy)]·H{sub 2}O (5) and [Mn(L)(4,4′-bipy)]·H{sub 2}O (6) have been synthesized by the hydrothermal reaction of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) with Pb(II)/Cd(II)/Mn(II) in the presence of ancillary ligands 4,4′-bipyridine (4,4′-bipy) or 1,10-phenanthroline (phen). Complexes 1 and 4–6 exhibit 2-D structures, and complexes 2–3 display 3-D frameworks, of which L{sup 2−} ligands join metal ions to single-stranded helical chains of 1, 3–6 and double-stranded helical chains of 2. Complexes 2 and 3 also contain double-stranded Metal–O helices. Topology analysis reveals that complexes 1 and 4 both represent 4-connected sql net, 2 represents 6-connected pcu net, 3 exhibits a novel (3,12)-connected net, while 5 and 6 display (3,5)-connected gek1 net. The six complexes exhibit two kinds of inorganic–organic connectivities: I{sup 0}O{sup 2} for 1, 4–6, and I{sup 1}O{sup 2} for 2–3. The photoluminescent properties of 4–5 and the magnetic properties of 6 have been investigated. - Graphical abstract: Six new Pb(II)/Cd(II)/Mn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent and magnetic properties have been investigated. - Highlights: • Six novel M(II) coordination polymers with 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid and N-donor ligands. • Complexes 1–6 show diverse intriguing helical characters. • The luminescent properties of complexes 1–5 were investigated. • Complex 6 shows antiferromagnetic coupling.

Loss pattern of Pb ions with charge changing processes in the LEIR ring

CERN Document Server

Pasternak, J

2004-01-01

Avalanche like pressure rise and an associated decrease of the beam lifetime, caused by (i) beam loss due to charge exchange interactions with rest gas molecules and (ii) ion impact induced outgassing, is a potential limitation for heavy ion accelerators. The vacuum system of the LEIR ring has to be upgraded carefully to avoid that these phenomena prevent the machine from reaching design performance. The loss pattern of Pb ions having captured an electron presented in this report allows to estimate whether the low dynamic pressure needed for LEIR is reachable. Efficient interception of lost ions with low beam loss induced outgassing absorber blocks, installed at appropriate locations is promising.

Separation/preconcentration of trace Pb(II and Cd(II with 2-mercaptobenzothiazole impregnated Amberlite XAD-1180 resin and their determination by flame atomic absorption spectrometry

Directory of Open Access Journals (Sweden)

Şerife Tokalıoğlu

2017-01-01

Full Text Available A new chelating resin, 2-mercaptobenzothiazole loaded Amberlite XAD-1180 was prepared and used for separation and preconcentration of Cd(II and Pb(II ions prior to their determinations by flame atomic absorption spectrometry. The optimum pH for simultaneous retention of the elements and the best elution means for their simultaneous elution were 9.5 and 2 mol L−1 HNO3, respectively. The detection limits for Cd(II and Pb(II were 0.35 and 5.0 μg L−1, respectively. The accuracy of the method was confırmed both by analyzing the certified reference material (RM 8704 Buffalo river sediment and performing recovery studies.

Amino siloxane oligomer-linked graphene oxide as an efficient adsorbent for removal of Pb(II) from wastewater

International Nuclear Information System (INIS)

Luo, Shenglian; Xu, Xiangli; Zhou, Guiyin; Liu, Chengbin; Tang, Yanhong; Liu, Yutang

2014-01-01

Graphical abstract: A high performance sorbent, oligomer-linked graphene oxide, was prepared by using oligomeric poly3-aminopropyltriethoxysilane as crosslinking agents. The sorbent could selectively remove Pb(II) with high adsorption capacity. - Highlights: • Oligomer-linked graphene oxide sharply fattened function groups. • The sorbent exhibited high adsorption capacity toward Pb(II). • Pb, Cu and Fe were selectively removed from smelter industrial effluent. • The sorption could be conducted at a wide pH range of about 4.0–7.0. - Abstract: A high performance sorbent, oligomer-linked graphene oxide (GO) composite, was prepared through simple cross-linking reactions between GO sheets and poly3-aminopropyltriethoxysilane (PAS) oligomers as crosslinking agents. The three-dimensional PAS oligomers prevented GO sheets from aggregation, provided foreign molecules with easier access, and introduced a large amount of amino functional groups. The morphology, structure and property of the PAS-GO composite were determined by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourie transform infrared (FTIR), X-ray diffractometer (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The adsorption performance of PAS-GO was investigated in removing Pb(II) ions from water. Compared to 3-aminopropyltriethoxysilane functionalized GO (AS-GO) which was prepared by the direct reaction between 3-aminopropyltriethoxysilane and GO, PAS-GO exhibited much higher adsorptivity toward Pb(II) with the maximum adsorption capacity of 312.5 mg/g at 303 K and furthermore the maximum adsorption capacity increased with increasing temperature. The adsorption could be conducted in a wide pH range of 4.0–7.0. Importantly, PAS-GO had a priority tendency to adsorb Pb, Cu and Fe from a mixed solution of metal ions, especially from a practical industrial effluent

Competition from Cu(II), Zn(II) and Cd(II) in Pb(II) binding to Suwannee River Fulvic Acid

NARCIS (Netherlands)

Chakraborty, P.; Chakrabarti, C.L.

2008-01-01

This is a study of trace metal competition in the complexation of Pb(II) by well-characterized humic substances, namely Suwannee River Fulvic Acid (SRFA) in model solutions. It was found that Cu(II) seems to compete with Pb(II) for strong binding sites of SRFA when present at the same concentration

Flame atomic absorption spectrometric determination of trace amounts of Pb(II) and Cr(III) in biological, food and environmental samples after preconcentration by modified nano-alumina

International Nuclear Information System (INIS)

Afkhami, A.; Madrakian, T.; Saber-Tehrani, M.; Bagheri, H.

2011-01-01

A new solid-phase extraction sorbent was used for the preconcentration of Pb(II) and Cr(III) ions prior to their determination by flame atomic absorption spectrometry. It was prepared by immobilization of 2,4-dinitrophenylhydrazine on nano-alumina coated with sodium dodecyl sulfate. The sorbent was characterized by scanning electron microscopy, N 2 adsorption and Fourier transform infrared spectrometry, and used for preconcentration and separation of Pb(II) and Cr(III) from aqueous solutions. The ions on the sorbent were eluted with a mixture of nitric acid and methanol. The effects of sample pH, flow rates of samples and eluent, type of eluent, breakthrough volume and potentially interfering ions were studied. Linearity is maintained between 1.2 and 350 μg L -1 of Pb(II), and between 2.4 and 520 μg L -1 of Cr(III) for an 800-mL sample. The detection limit (3 s, N=10) for Pb(II) and Cr(III) ions is 0.43 and 0.55 μg L -1 , respectively, and the maximum preconcentration factor is 267. The method was successfully applied to the evaluation of these trace and toxic metals in various water, food, industrial effluent and urine samples. (author)

Thiopental and Phenytoin as Novel Ionophores for Potentiometric Determination of Lead (II Ions

Directory of Open Access Journals (Sweden)

Yasser M. Abd EL-Karem

2009-03-01

Full Text Available Two novel polymeric membrane sensors for the analysis of Pb(II have been developed based ontwo therapeutic drugs, thiopental (TP and phenytoin (PT as two new ionophores and potassium tetrakis(p-chlorophenyl borate (KTpClPB as a lipophilic additive, in plasticized PVC membranes. The sensors show a Nernstian response for Pb(II ions over the wide concentration ranges of 1×10-2 - 7×10-6 M and 1×10-2 - 8×10-6 M for the sensors based on thiopental and phenytoin, respectively. The proposed sensors have a fast response time and can be used for more than nine weeks without any considerable divergence in potentials. The sensors exhibit comparatively good selectivity with respect to alkaline, alkaline earth and some transition and heavy metal ions. They were employed for direct determination of lead in solder alloys and in galena rocks with a good agreement with the obtained results by atomic absorption spectroscopy.

New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative

International Nuclear Information System (INIS)

Pina-Luis, Georgina; Martínez-Quiroz, Marisela; Ochoa-Terán, Adrián; Santacruz-Ortega, Hisila; Mendez-Valenzuela, Eduardo

2013-01-01

This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb 2+ ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV–visible and fluorescence spectroscopy. Compounds 1(a–d) with different length alkyl linkers (CH 2 ) n (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5–8) and was only slightly influenced by the addition of metal ions in CH 3 CN solutions. However, derivative 1e with amino-containing spacer (CH 2 –NH–CH 2 ) showed excimer emission in aqueous solution, a wide response to pH (2.5–9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li + , Na + , K + , Cs + , Ca 2+ , Mg 2+ , Ba 2+ , Cu 2+ , Pb 2+ , Ni 2+ , Zn 2+ and Cd 2+ . The coordination chemistry of these complexes was studied by UV–Vis, fluorescence and 1 H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb 2+ ions in the presence of the metals ions mentioned in CH 3 CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb 2+ ions, results in less than ±5% fluorescence intensity changes. Linear calibration up to 1×10 −5 M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0×10 −8 M. - Highlights: ► A novel dual emission bis-1,8-naphthalimide sensor for pH and Pb 2+ ions is synthetized. ► The excimer formation depends on the spacer that links the two naphthalimide groups. ► Bis(naphthalimide) with amino-containing spacer showed a wide selective response to pH. ► This chemosensor displayed a selective fluorescence enhancement effect towards Pb 2+ ions. ► Mechanism for the fluorescence OFF�

Syntheses and characterizations of secondary Pb-O bonding supported Pb(II)-sulfonate complexes

Science.gov (United States)

Huang, Guo-Zhen; Zou, Xin; Zhu, Zhi-Biao; Deng, Zhao-Peng; Huo, Li-Hua; Gao, Shan

2018-06-01

The reaction of Pb(II) salts and mono- or disulfonates leads to the formation of eight new Pb(II)-mono/disulfonate complexes, [Pb(L1)(H2O)]2 (1), [Pb4(L2)2(AcO)2]n·5nH2O (2), [Pb(L3)(H2O)]2 (3), [Pb(HL4)(H2O)2]n·nH2O (4), [Pb(HL5)(H2O)2]n·2nH2O (5), [Pb(H2L6)(H2O)]n·nDMF·2nH2O (6), [Pb2(H3L7)4(H2O)6]·2H2O (7) and [Pb(H2L7)(H2O)]n·nH2O (8) (H2L1= 2-hydroxy-5-methyl-benzenesulfonic acid, H3L2= 2-hydroxyl-5-methyl- 1,3-benzenedisulfonic acid, H2L3= 2-hydroxy-5-nitro-benzenesulfonic acid, H3L4= 2-hydroxyl-5-bromo-1,3- benzenedisulfonic acid, H3L5= 2-hydroxyl-5-carboxyl-benzenesulfonic acid, H4L6= 2,5-dihydroxyl-3-carboxyl- benzenesulfonic acid, H4L7= 2,4-dihydroxyl-5-carboxyl-benzenesulfonic acid, DMF = N,N'-dimethyl-formamide, AcO- = acetate), which have been characterized by elemental analysis, IR, TG, PL, powder and single-crystal X-ray diffraction. In view of the primary Pb-O bonds, these eight complexes exhibit diverse dinuclear (1, 3 and 7), helical chain (4), wave-like chain (5), linear chain (6), zigzag chain (8) and layer structure (2), in which the Pb(II) cations present different hemi-directed geometries. Taking the secondary Pb-O bonds into account, chain structure for complex 7, layer motifs for complexes 1 and 3-6, as well as 3-D framework for complex 8 are observed with Pb(II) cations showing more intricate holo-directed geometries. The various coordination modes of these seven different mono/disulfonate anions are responsible for the formation of these multiple structures. Furthermore, the introduction of hydroxyl and carboxyl groups increases the coordination ability of sulfonate to the p-block metal cation. Luminescent analyses indicate that complex 7 presents purple emission at 395 nm at room temperature.

Effects of low molecular weight organic acids on the immobilization of aqueous Pb(II) using phosphate rock and different crystallized hydroxyapatite.

Science.gov (United States)

Wei, Wei; Cui, Jing; Wei, Zhenggui

2014-06-01

Understanding the effects of low molecular weight organic acids (LMWOAs) on the transformation of Pb(II) to geochemically stable pyromorphite (PY) by apatite materials (AMs), has considerable benefits for risk assessment and remediation strategies for contaminated water and soil. In this study, we systematically investigated the immobilization of Pb(II) from aqueous solution by natural phosphate rock (PR) and different crystallized hydroxyapatite (HAp) in the absence and presence of LMWOAs (oxalic, malic and citric acids). The results indicated that the effectiveness of PR and HAp in immobilizing Pb(II) followed in descending order by HAp2 (the poorly crystallized HAp), HAp1 (the well crystallized HAp) and PR, regardlessof the presence of LMWOAs. The presence of malic and citric acids significantly decreased the immobilizationefficiency of Pb(II) by HAp1 and PR, clarifying the lower adsorption affinities of Pb(II)-organic acid complexes on HAp1 and PR rather than Pb(II) ion. On thecontrary, oxalic acid could markedly enhance the removal of Pb(II) from aqueous solution by HAp1 and PR through the formation of lead oxalate, which was confirmed by FT-IR and XRDanalysis. Results also showed that LMWOAs had little promoting or inhibiting effect on the immobilization of Pb(II) by HAp2. This study suggested that the ubiquity of LMWOAs in natural environments could retard the transformation efficiency of Pb(II) to PY by AMs, especiallyin thepresenceof oxalic acid, and the poorly crystallized HAp2 had great potential to remediate Pb(II)-contaminated water and soil due to its insusceptibility to LMWOAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Artificial neural network (ANN) approach for modeling of Pb(II) adsorption from aqueous solution by Antep pistachio (Pistacia Vera L.) shells.

Science.gov (United States)

Yetilmezsoy, Kaan; Demirel, Sevgi

2008-05-30

A three-layer artificial neural network (ANN) model was developed to predict the efficiency of Pb(II) ions removal from aqueous solution by Antep pistachio (Pistacia Vera L.) shells based on 66 experimental sets obtained in a laboratory batch study. The effect of operational parameters such as adsorbent dosage, initial concentration of Pb(II) ions, initial pH, operating temperature, and contact time were studied to optimise the conditions for maximum removal of Pb(II) ions. On the basis of batch test results, optimal operating conditions were determined to be an initial pH of 5.5, an adsorbent dosage of 1.0 g, an initial Pb(II) concentration of 30 ppm, and a temperature of 30 degrees C. Experimental results showed that a contact time of 45 min was generally sufficient to achieve equilibrium. After backpropagation (BP) training combined with principal component analysis (PCA), the ANN model was able to predict adsorption efficiency with a tangent sigmoid transfer function (tansig) at hidden layer with 11 neurons and a linear transfer function (purelin) at output layer. The Levenberg-Marquardt algorithm (LMA) was found as the best of 11 BP algorithms with a minimum mean squared error (MSE) of 0.000227875. The linear regression between the network outputs and the corresponding targets were proven to be satisfactory with a correlation coefficient of about 0.936 for five model variables used in this study.

Contact angle study on the activation mechanisms of sphalerite with Cu(II) and Pb(II); Estudio de los mecanismos de activacion de la esfalerita con Cu(II) y Pb(II)

Energy Technology Data Exchange (ETDEWEB)

Davila Pulido, G. I.; Uribe Salas, A.

2011-07-01

This article presents results of an experimental study on the sphalerite activation with Cu(II) and Pb(II), whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate) is characterized making use of the contact angle technique. The results show that Cu(II) replaces the Zn of the external layers of the mineral, promoting the sulfide (S{sup 2}-) oxidation to produce a mixture of CuS, Cu{sub 2}S and S{sup o}, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II) activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX{sub 2}). It is also observed that the hydrophobicity of sphalerite activated with Pb(II) is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation. (Author) 11 refs.

Preparation of PbS and PbO nanopowders from new Pb(II)(saccharine) coordination polymers

International Nuclear Information System (INIS)

Aslani, Alireza; Musevi, Seyid Javad; Şahin, Ertan; Yilmaz, Veysel T.

2014-01-01

Highlights: • The complex of compounds “[Pb(H 2 O)(μ-OAc)(μ-sac)] n ” are synthesized at nano and bulk size structurally diverse and show interesting three-dimensional coordination polymers. • Reduction of the particle size of the coordination polymers to a few dozen nanometers results in lower thermal stability when compared to the single crystalline samples. • This study demonstrates that the metal–organic framework may be suitable precursors for the preparation of nanoscale materials with interesting morphologies. - Abstract: Nanopowders and single crystal of new Pb(II) three-dimensional coordination polymer, [Pb(H 2 O)(μ-OAc)(μ-sac)] n “PASAC” were synthesized by a sonochemical and branched tube methods (Yılmaz et al., Z. Anorg. Allg. Chem. 629 (2003) 172). The new nano-structures of Pb(II) coordination polymer were characterized by X-ray crystallography analysis, scanning electron microscopy (SEM), X-ray powder diffraction (XRD), surface analysis (BET), and IR spectroscopy. The crystal structure of these compounds consists of three-dimensional polymeric units. The thermal stability of compounds was studied by thermal gravimetric analysis (TGA) and differential thermal analyses (DTA). PbS and PbO nano-structures were obtained by calcinations of the nano-structures of this coordination polymer at 600 °C

Combination of rice husk and coconut shell activated adsorbent to adsorb Pb(II) ionic metal and it’s analysis using solid-phase spectrophotometry (sps)

Science.gov (United States)

Rohmah, D. N.; Saputro, S.; Masykuri, M.; Mahardiani, L.

2018-03-01

The purpose of this research was to know the effect and determine the mass comparation which most effective combination between rice husk and coconut shell activated adsorbent to adsorb Pb (II) ion using SPS method. This research used experimental method. Technique to collecting this datas of this research is carried out by several stages, which are: (1) carbonization of rice husk and coconut shell adsorbent using muffle furnace at a temperature of 350°C for an hour; (2) activation of the rice husk and coconut shell adsorbent using NaOH 1N and ZnCl2 15% activator; (3) contacting the adsorbent of rice husk and coconut shell activated adsorbent with liquid waste simulation of Pb(II) using variation comparison of rice husk and coconut shell, 1:0; 0:1; 1:1; 2:1; 1:2; (4) analysis of Pb(II) using Solid-Phase Spectrophotometry (SPS); (5) characterization of combination rice husk and coconut shell activated adsorbent using FTIR. The result of this research show that the combined effect of combination rice husk and coconut shell activated adsorbent can increase the ability of the adsorbent to absorb Pb(II) ion then the optimum adsorbent mass ratio required for absorbing 20 mL of Pb(II) ion with a concentration of 49.99 µg/L is a ratio of 2:1 with the absorption level of 97,06%Solid-Phase Spectrophotometry (SPS) is an effective method in the level of µg/L, be marked with the Limit of Detection (LOD) of 0.03 µg/L.

Synthesis and characterisation of nano structure lead (II) ion-imprinted polymer as a new sorbent for selective extraction and preconcentration of ultra trace amounts of lead ions from vegetables, rice, and fish samples.

Science.gov (United States)

Behbahani, Mohammad; Bagheri, Akbar; Taghizadeh, Mohsen; Salarian, Mani; Sadeghi, Omid; Adlnasab, Laleh; Jalali, Kobra

2013-06-01

This paper describes the preparation of new Pb(II)-imprinted polymeric particles using 2-vinylpyridine as a functional monomer, ethylene glycol dimethacrylate as the cross-linker, 2,2'- azobisisobutyronitrile as the initiator, diphenylcarbazone as the ligand, acetonitril as the solvent, and Pb(NO(3))(2) as the template ion, through bulk polymerisation technique. The imprinted lead ions were removed from the polymeric matrix using 5 mL of HCl (2 mol.L(-1)) as the eluting solvent. The lead ion concentration was determined by flame atomic absorption spectrometry. Optimum pH for maximum sorption was obtained at 6.0. Sorption and desorption of Pb(II) ions on the IIP particles were quite fast and achieved fully over 5 min. In the proposed method, the maximum sorbent capacity of the ion-imprinted polymer was calculated to be 75.4 mg g(-1). The preconcentration factor, relative standard deviation, and limit of detection of the method were found to be 245, 2.1%, and 0.42 ng mL(-1), respectively. The prepared ion-imprinted polymer particles have an increased selectivity toward Pb(II) ions over a range of competing metal ions with the same charge and similar ionic radius. This ion-imprinted polymer is an efficient solid phase for extraction and preconcentration of lead ions in complex matrixes. For proving that the proposed method is reliable, a wide range of food samples with different and complex matrixes was used. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stuides on a Pb2+-selective electrode with a macrocyclic liquid membrane. Potentiometric determination of Pb2+ ions

Directory of Open Access Journals (Sweden)

MARIAN ISVORANU

2006-12-01

Full Text Available This paper presents experimental and theoretical data regarding the design, characterization and analytical applications of a non-expensive, liquid-membrane ion-selective electrode for Pb2+ ions. The membrane is a solution of the active complex formed by Pb2+ ions with dibenzo-18-crown-6-ionophore (DB-[18]-C-6 extracted in propylene carbonate (PC. The sucessful application of the developed electrode for the determination of Pb2+ ions in aqueos solution samples by direct potentiometry and potentiometric titration is presented. For the presented analytical results, there are insignificant systematic errors between the direct potentiometric method with the developed ion-selective electrode and atomic absorption spectrometry.

Highly sensitive detection of lead(II) ion using multicolor CdTe quantum dots

International Nuclear Information System (INIS)

Zhong, W.; Zhang, C.; Gao, Q.; Li, H.

2012-01-01

Multicolor and water-soluble CdTe quantum dots (QDs) were synthesized with thioglycolic acid (TGA) as stabilizer. These QDs have a good size distribution, display high fluorescence quantum yield, and can be applied to the ultrasensitive detection of Pb(II) ion by virtue of their quenching effect. The size of the QDs exerts a strong effect on sensitivity, and quenching of luminescence is most effective for the smallest particles. The quenching mechanism is discussed. Fairly selective detection was accomplished by utilizing QDs with a diameter of 1. 6 nm which resulted in a detection limit of 4. 7 nmol L -1 concentration of Pb(II). The method was successfully applied to the determination of Pb(II) in spinach and citrus leaves, and the results are in good agreement with those obtained with atomic absorption spectrometry. (author)

Adsorption Kinetics and intra particulate diffusivities of Hg, As and Pb ions on unmodified and thiolated coconut fiber

International Nuclear Information System (INIS)

Igwe, J. C.; Abia, A. A.; Ibeh, C. A.

2008-01-01

As, Hg and Pb are examples of heavy metals which are present in different types of industrial effluents responsible for environmental pollution. Their removal is traditionally made by chemical precipitation, ion-exchange and so on. However, this is expensive and not completely feasible to reduce their concentrations to the levels as low as required by the environmental legislation. Bio sorption is a process in which solids of natural origin are employed for binding the heavy metal. It is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. The kinetics was studied for bio sorption experiments using coconut fiber for As (III), Hg (II) and Pb (II) ions adsorption. The specific surface area and surface charge density of the coconut fiber are 1.186x10 25 (m 2 /g) and 5.39 xI0 24 (meq/m 2 ), respectively. The maximum adsorption capacity was found to be the highest for Pb (II) followed by Hg (II) and As (Ill). The modification of the adsorbent by thiolation affected the adsorption capacity. Equilibrium sorption was reached for the metal ions at about 60 min. The equilibrium constant and free energy of the adsorption at 30 degree were calculated. The mechanism of sorption was found to obey the particle-diffusion model. The kinetic studies showed that the sorption rates could be described by both pseudo first-order and pseudo second-order models. The pseudo second-order model showed a better fit with a rate constant value of 1.16x10 -4 /min. for all three metal ions.Therefore, the results of this study show that coconut fiber, both modified and unmodified, is an efficient adsorbent for the removal of toxic and valuable metals from industrial effluents

Adsorption of Pb(II) ions from aqueous solution using lignin from ...

African Journals Online (AJOL)

The adsorption of lead(II) ions from aqueous solution onto alkali lignin extracted from Hagenia abyssinica was investigated by electrochemical methods. The effect of solution pH, lignin dosage and contact time were investigated at room temperature in a batch system. Adsorption equilibrium was approached within 80 min.

Removal of Pb(II) from aqueous solution by seed powder of Prosopis juliflora DC.

Science.gov (United States)

Jayaram, K; Prasad, M N V

2009-09-30

Biosorption potential of Prosopis juliflora seed powder (PJSP) for Pb(II) from aqueous solution was investigated. The effects of pH, contact time and different metal concentrations were studied in batch experiments. The maximum uptake of metal ions was obtained at pH 6.0. Adsorption equilibrium was established at 360 min. The pseudo-first-order and pseudo-second-order kinetic models were applied to study the kinetics of the biosorption processes. The pseudo-second-order kinetic model provided the best correlation (R(2)=0.9992) of the experimental data compared to the pseudo-first-order kinetic model. The maximum Pb(II) adsorbed was found to be 40.322 mg/g and it was found that the biosorption of Pb(II) on PJSP has correlated well (R(2)=0.9719) with the Langmuir equation compared to Freundlich isotherm equation (R(2)=0.9282) in the concentration range studied. Negative values of DeltaG indicated that the adsorption process was spontaneous and exothermic in nature. The FTIR study revealed the presence of various functional groups which are responsible for the adsorption process. The overall results show that PJSP can be envisaged as a vibrant, biosorbent for metal cleanup operations.

New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative

Energy Technology Data Exchange (ETDEWEB)

Pina-Luis, Georgina, E-mail: gpinaluis@yahoo.com [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Martinez-Quiroz, Marisela; Ochoa-Teran, Adrian [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Santacruz-Ortega, Hisila [Departamento de investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Mendez-Valenzuela, Eduardo [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico)

2013-02-15

This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb{sup 2+} ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV-visible and fluorescence spectroscopy. Compounds 1(a-d) with different length alkyl linkers (CH{sub 2}){sub n} (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5-8) and was only slightly influenced by the addition of metal ions in CH{sub 3}CN solutions. However, derivative 1e with amino-containing spacer (CH{sub 2}-NH-CH{sub 2}) showed excimer emission in aqueous solution, a wide response to pH (2.5-9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li{sup +}, Na{sup +}, K{sup +}, Cs{sup +}, Ca{sup 2+}, Mg{sup 2+}, Ba{sup 2+}, Cu{sup 2+}, Pb{sup 2+}, Ni{sup 2+}, Zn{sup 2+} and Cd{sup 2+}. The coordination chemistry of these complexes was studied by UV-Vis, fluorescence and {sup 1}H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb{sup 2+} ions in the presence of the metals ions mentioned in CH{sub 3}CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb{sup 2+} ions, results in less than {+-}5% fluorescence intensity changes. Linear calibration up to 1 Multiplication-Sign 10{sup -5} M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0 Multiplication-Sign 10{sup -8} M. - Highlights: Black-Right-Pointing-Pointer A novel dual emission bis-1,8-naphthalimide sensor for pH and Pb{sup 2+} ions is synthetized. Black-Right-Pointing-Pointer The excimer formation depends on the spacer that links the two naphthalimide groups. Black-Right-Pointing-Pointer Bis

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

Energy Technology Data Exchange (ETDEWEB)

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.; Berrie, Barbara H. (NGA); (Bordeaux)

2016-09-23

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K⁺, Zn²⁺, Pb²⁺) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic–inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm^–1 for Pb(II) and ca. 1580 cm^–1 for Zn(II) are consistent with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. These complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.

Biosorption optimization of lead(II), cadmium(II) and copper(II) using response surface methodology and applicability in isotherms and thermodynamics modeling

International Nuclear Information System (INIS)

Singh, Rajesh; Chadetrik, Rout; Kumar, Rajender; Bishnoi, Kiran; Bhatia, Divya; Kumar, Anil; Bishnoi, Narsi R.; Singh, Namita

2010-01-01

The present study was carried out to optimize the various environmental conditions for biosorption of Pb(II), Cd(II) and Cu(II) by investigating as a function of the initial metal ion concentration, temperature, biosorbent loading and pH using Trichoderma viride as adsorbent. Biosorption of ions from aqueous solution was optimized in a batch system using response surface methodology. The values of R 2 0.9716, 0.9699 and 0.9982 for Pb(II), Cd(II) and Cu(II) ions, respectively, indicated the validity of the model. The thermodynamic properties ΔG o , ΔH o , ΔE o and ΔS o by the metal ions for biosorption were analyzed using the equilibrium constant value obtained from experimental data at different temperatures. The results showed that biosorption of Pb(II) ions by T. viride adsorbent is more endothermic and spontaneous. The study was attempted to offer a better understating of representative biosorption isotherms and thermodynamics with special focuses on binding mechanism for biosorption using the FTIR spectroscopy.

Biosorption optimization of lead(II), cadmium(II) and copper(II) using response surface methodology and applicability in isotherms and thermodynamics modeling

Energy Technology Data Exchange (ETDEWEB)

Singh, Rajesh; Chadetrik, Rout; Kumar, Rajender; Bishnoi, Kiran; Bhatia, Divya; Kumar, Anil [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India); Bishnoi, Narsi R., E-mail: nrbishnoi@gmail.com [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India); Singh, Namita [Department of Bio and Nanotechnology, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana (India)

2010-02-15

The present study was carried out to optimize the various environmental conditions for biosorption of Pb(II), Cd(II) and Cu(II) by investigating as a function of the initial metal ion concentration, temperature, biosorbent loading and pH using Trichoderma viride as adsorbent. Biosorption of ions from aqueous solution was optimized in a batch system using response surface methodology. The values of R{sup 2} 0.9716, 0.9699 and 0.9982 for Pb(II), Cd(II) and Cu(II) ions, respectively, indicated the validity of the model. The thermodynamic properties {Delta}G{sup o}, {Delta}H{sup o}, {Delta}E{sup o} and {Delta}S{sup o} by the metal ions for biosorption were analyzed using the equilibrium constant value obtained from experimental data at different temperatures. The results showed that biosorption of Pb(II) ions by T. viride adsorbent is more endothermic and spontaneous. The study was attempted to offer a better understating of representative biosorption isotherms and thermodynamics with special focuses on binding mechanism for biosorption using the FTIR spectroscopy.

Oxidation of cyclohexane catalyzed by metal-ion-exchanged zeolites.

Science.gov (United States)

Sökmen, Ilkay; Sevin, Fatma

2003-08-01

The ion-exchange rates and capacities of the zeolite NaY for the Cu(II), Co(II), and Pb(II) metal ions were investigated. Ion-exchange equilibria were achieved in approximately 72 h for all the metal ions. The maximum ion exchange of metal ions into the zeolite was found to be 120 mg Pb(II), 110 mg Cu(II), and 100 mg Co(II) per gram of zeolite NaY. It is observed that the exchange capacity of a zeolite varies with the exchanged metal ion and the amount of metal ions exchanged into zeolite decreases in the sequence Pb(II) > Cu(II) > Co(II). Application of the metal-ion-exchanged zeolites in oxidation of cyclohexane in liquid phase with visible light was examined and it is observed that the order of reactivity of the zeolites for the conversion of cyclohexane to cyclohexanone and cyclohexanol is CuY > CoY > PbY. It is found that conversion increases by increase of the empty active sites of a zeolite and the formation of cyclohexanol is favored initially, but the cyclohexanol is subsequently converted to cyclohexanone.

Accumulation of metal ions by pectinates

Science.gov (United States)

Deiana, S.; Deiana, L.; Palma, A.; Premoli, A.; Senette, C.

2009-04-01

The knowledge of the mechanisms which regulate the interactions of metal ions with partially methyl esterified linear polymers of α-1,4 linked D-galacturonic acid units (pectinates), well represented in the root inner and outer apoplasm, is of great relevance to understand the processes which control their accumulation at the soil-root interface as well as their mobilization by plant metabolites. Accumulation of a metal by pectinates can be affected by the presence of other metals so that competition or distribution could be expected depending on the similar or different affinity of the metal ions towards the binding sites, mainly represented by the carboxylate groups. In order to better understand the mechanism of accumulation in the apoplasm of several metal ions, the sorption of Cd(II), Zn(II), Cu(II), Pb(II) and Cr(III) by a Ca-polygalacturonate gel, used as model of the soil-root interface, with a degree of esterification of 18% (PGAE1) and 65% (PGAE2) was studied at pH 3.0, 4.0, 5.0 and 6.0 in the presence of CaCl2 2.5 mM.. The results show that sorption increases with increasing both the initial metal concentration and pH. A similar sorption trend was evidenced for Cu(II) and Pb(II) and for Zn(II) and Cd(II), indicating that the mechanism of sorption for these two ionic couples is quite different. As an example, at pH 6.0 and an initial metal concentration equal to 2.0 mM, the amount of Cu(II) and Pb(II) sorbed was about 1.98 mg-1 of PGAE1 while that of Cd(II) and Zn(II) was about 1.2 mg-1. Cr(III) showed a rather different sorption trend and a much higher amount (2.8 mg-1of PGAE1 at pH 6.0) was recorded. The higher affinity of Cr(III) for the polysaccharidic matrix is attributable to the formation of Cr(III) polynuclear species in solution, as shown by the distribution diagrams obtained through the MEDUSA software. On the basis of these findings, the following affinity towards the PGAE1 can be assessed: Cr(III) > Cu(II) ? Pb(II) > Zn (II) ? Cd(II

Luminescence and photothermally stimulated defects creation processes in PbWO4:La3+, Y3+ (PWO II) crystals

International Nuclear Information System (INIS)

Auffray, E.; Korjik, M.; Zazubovich, S.

2015-01-01

Photoluminescence and thermally stimulated luminescence (TSL) are studied for a PbWO 4 crystal grown by the Czochralski method at Bogoroditsk Technical Chemical Plant, Russia from the melt with a precise tuning of the stoichiometry and co-doped with La 3+ and Y 3+ ions (the PWO II crystal). Photothermally stimulated processes of electron and hole centers creation under selective UV irradiation of this crystal in the 3.5–5.0 eV energy range and the 85–205 K temperature range are clarified and the optically created electron and hole centers are identified. The electrons in PWO II are mainly trapped at the (WO 4 ) 2− groups located close to single La 3+ and Y 3+ ions, producing the electron {(WO 4 ) 3− –La 3+ } and {(WO 4 ) 3− –Y 3+ } centers. The holes are mainly trapped at the regular oxygen ions O 2− located close to La 3+ and Y 3+ ions associated with lead vacancies, producing the hole O − (I)-type centers. No evidence of single-vacancy-related centers has been observed in PWO II. The data obtained indicate that excellent scintillation characteristics of the PWO II crystal can be explained by a negligible concentration of single (non-compensated) oxygen and lead vacancies as the traps for electrons and holes, respectively. - Highlights: • Photoluminescence of the PbWO 4 :La 3+ , Y 3+ (PWO II) crystal is investigated. • Creation of defects under UV irradiation of PWO II is studied by TSL. • Origin of dominating electron and hole centers is ascertained. • Concentration of single-vacancy-related centers is found to be negligible. • Excellent scintillation characteristics of the PWO II crystal are explained.

One step synthesis of polyacrylamide functionalized graphene and its application in Pb(II) removal

International Nuclear Information System (INIS)

Xu, Zhiwei; Zhang, Yaoyao; Qian, Xiaoming; Shi, Jie; Chen, Lei; Li, Baodong; Niu, Jiarong; Liu, Liangsen

2014-01-01

Highlights: • PAM-g-graphene is synthesized by the co-irradiation between GO and AM monomers. • PAM graft on GO has led to the exfoliation of GO into individual sheets. • The γ-ray induced reduction of GO. • PAM-g-graphene exhibits high adsorption capacities toward Pb(II) ions. • PAM-g-graphene provides a new idea for heavy metal pollutants’ removal in water. - Abstract: Polyacrylamide grafted graphene (PAM-g-graphene) from graphite oxide (GO) was successfully prepared by γ-ray irradiation with acrylamide monomers in aqueous at room temperature in this paper. Our strategy involves the PAM chains graft on the surface and between the layers of GO by in situ radical polymerization which led to the exfoliation of GO into individual sheets. Results show that the degree of grafting of PAM-g-graphene samples is 24.2%, and the thickness is measured to be 2.59 nm. Moreover, the as-prepared PAM-g-graphene with some amino from PAM and little oxygen functional groups exhibit superior adsorption of Pb(II) ions. The adsorption processes reach equilibrium in just 30 min and the adsorption isotherms are described well by Langmuir and Freundlich classical isotherms models. The determined adsorption capacity of PAM-g-graphene is 819.67 mg g −1 (pH 6) for Pb(II), which is 20 times and 8 times capacities of that for graphene nanosheets and carbon nanotubes according to reports, respectively. This chemically modified graphene synthesized by this fast one-step approach, featuring a good versatility and adaptability, excellent adsorption capacity and rapid extraction, may provide a new idea for the global problem of heavy metal pollutants’ removal in water

Thermodynamics of Pb(ii) and Zn(ii) binding to MT-3, a neurologically important metallothionein.

Science.gov (United States)

Carpenter, M C; Shami Shah, A; DeSilva, S; Gleaton, A; Su, A; Goundie, B; Croteau, M L; Stevenson, M J; Wilcox, D E; Austin, R N

2016-06-01

Isothermal titration calorimetry (ITC) was used to quantify the thermodynamics of Pb(2+) and Zn(2+) binding to metallothionein-3 (MT-3). Pb(2+) binds to zinc-replete Zn7MT-3 displacing each zinc ion with a similar change in free energy (ΔG) and enthalpy (ΔH). EDTA chelation measurements of Zn7MT-3 and Pb7MT-3 reveal that both metal ions are extracted in a tri-phasic process, indicating that they bind to the protein in three populations with different binding thermodynamics. Metal binding is entropically favoured, with an enthalpic penalty that reflects the enthalpic cost of cysteine deprotonation accompanying thiolate ligation of the metal ions. These data indicate that Pb(2+) binding to both apo MT-3 and Zn7MT-3 is thermodynamically favourable, and implicate MT-3 in neuronal lead biochemistry.

EDTA-functionalized clinoptilolite nanoparticles as an effective adsorbent for Pb(II) removal.

Science.gov (United States)

Eshraghi, Farahnaz; Nezamzadeh-Ejhieh, Alireza

2018-03-08

An efficient Pb(II) adsorbent was prepared by the modification of clinoptilolite nanoparticles (CpN) with ethylenediaminetetraacetic acid (EDTA). Samples were characterized by XRD, FT-IR, SEM, BET, TG-DTG, CHNS analyzer, and energy dispersive analysis X-ray spectroscopy (EDX). The experiments were designed by response surface methodology (RSM) based on central composite design (CCD) that suggested a quadratic model to predict the conditions and the interactions between the variables including adsorbent dosage, removal time, C Pb , and its solution pH. Adequacy of the suggested quadratic model was judged by ANOVA. The maximum Pb(II) removal of 0.27 mmol Pb(II) /g ads was achieved in optimal run including adsorbent dosage 2 g L -1 , removal time 271 min, C Pb 22.51 mmol L -1 , and Pb(II) solution pH 5.88. In binary metal cation systems including 1000 mg L -1 with respect to both Pb(II) and interfering cations, good selectivity of CpN-EDTA adsorbent was observed towards Pb(II) among the tested cations except Fe(III). Adsorption isotherm of lead removal by the adsorbent was well modeled by Langmuir equation, indicating a monolayer sorption of Pb(II) onto the adsorbent. The pseudo-second-order rate equation, indicating chemical reaction rate limiting step for the process, well modeled the kinetic of the process. An exothermic and spontaneous process was confirmed by the negative ∆H and ∆G.

Ion microprobe U-Pb dating of a dinosaur tooth

International Nuclear Information System (INIS)

Sano, Yuji; Terada, Kentaro; Ly, Chi V.; Park, Eun Ju

2006-01-01

Ion microprobe U-Pb dating of apatite is applied to a fossil tooth of a Allosaurid derived from the Hasandong Formation in the Gyeongsang basin, southeastern Korea. Twelve spots on a single fragment of the fossil dentine yield a Tera-Wasserburg concordia intercept age of 115±10 Ma (2σ, MSWD=0.59) on a 238 U/ 206 Pb- 207 Pb/ 206 Pb- 204 Pb/ 206 Pb diagram. The age provides a constraint on the depositional age of the fossil in its host Hassandong Formation as Early Aptian. The success of the ion microprobe dating depends on the heterogeneities of diagenetically incorporated U and Pb at the few hundred μm scale, the consequent variations in Pb isotopic compositions due to radioactive decay and the closed-system behavior of U and Pb. There are at least three end-members to explain the variations of minor chemical components such as FeO, SiO 2 and Al 2 O 3 , and trace elements as Th, U and rare earth elements (REE) in the sample by a simple mixing model. They are (1) very low minor and REE, very high common Pb with variable U abundances, (2) low common Pb, high minor, REE, and U abundances, and (3) low minor, common Pb, and U with intermediate REE abundances, even though groups (2) and (3) may consist of a larger group. Various contributions of the three (and/or two) end-members during diagenetic processes may cause the elemental fractionation of U and Pb in a fossil tooth. (author)

Sequestering of Fe and Pb ions from Wastewater by Canarium ...

African Journals Online (AJOL)

In this paper agricultural waste; Canarium schweinfurthii was explored for the sequestering of Fe and Pb ions from wastewater solution after carbonization and chemical treatment at 400oC. Optimum time of 30 and 150 min with percentage removal of 95 and 98% at optimum pH of 2 and 6 was obtained for Fe and Pb ions.

Equilibrium, kinetic and thermodynamic studies of adsorption of Pb(II) from aqueous solution onto Turkish kaolinite clay

International Nuclear Information System (INIS)

Sari, Ahmet; Tuzen, Mustafa; Citak, Demirhan; Soylak, Mustafa

2007-01-01

The adsorption of Pb(II) onto Turkish (Bandirma region) kaolinite clay was examined in aqueous solution with respect to the pH, adsorbent dosage, contact time, and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 31.75 mg/g at pH 5 and 20 deg. C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (13.78 kJ/mol) indicated that the adsorption of Pb(II) onto kaolinite clay may be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, free energy (ΔG o ), enthalpy (ΔH o ) and entropy (ΔS o ) of adsorption were also calculated. These parameters showed that the adsorption of Pb(II) onto kaolinite clay was feasible, spontaneous and exothermic process in nature. Furthermore, the Lagergren-first-order, pseudo-second-order and the intraparticle diffusion models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetics

Stabilization of Pb(II) accumulated in biomass through phosphate-pretreated pyrolysis at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Li, Saijun; Zhang, Tao; Li, Jianfa, E-mail: ljf@usx.edu.cn; Shi, Lingna; Zhu, Xiaoxiao; Lü, Jinhong; Li, Yimin

2017-02-15

Highlights: • Phosphate-pretreated pyrolysis can stabilize Pb(II) accumulated in biomass. • More than 95% of Pb(II) in celery and wood biomass was stabilized. • Pb from biomass was almost totally retained in char. • Most Pb was transformed into phosphates according to XRD and SEM/EDX analyses. - Abstract: The remediation of heavy metal-contaminated soil and water using plant biomass is considered to be a green technological approach, although the harmless disposal of biomass accumulated with heavy metals remains a challenge. A potential solution to this problem explored in this work involves combining phosphate pretreatment with pyrolysis. Pb(II) was accumulated in celery biomass with superior sorption capacity and also in ordinary wood biomass through biosorption. The Pb(II)-impregnated biomass was then pretreated with phosphoric acid or calcium dihydrogen phosphate (CaP) and pyrolyzed at 350 or 450 °C. Pb(II) from biomass was in turn almost totally retained in chars, and the percentage of DTPA-extractable Pb(II) was reduced to less than 5% of total Pb(II) in chars through CaP pretreatment. Pb(II) stabilization was further confirmed through a sequential extraction test, which showed that more than 95% of Pb(II) was converted into stable species composed mainly of lead phosphates according to X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analyses. Overall, phosphate-pretreated pyrolysis can stabilize both Pb(II) and degradable biomass, so as to control efficiently the hazards of heavy metal-contaminated biomass.

Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II Ions

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Radka Opatrilova

2009-06-01

Full Text Available In this study, the influence of lead (II ions on sunflower growth and biochemistry was investigated from various points of view. Sunflower plants were treated with 0, 10, 50, 100 and/or 500 µM Pb-EDTA for eight days. We observed alterations in growth in all experimental groups compared with non-treated control plants. Further we determined total content of proteins by a Bradford protein assay. By the eighth day of the experiment, total protein contents in all treated plants were much lower compared to control. Particularly noticeable was the loss of approx. 8 µg/mL or 15 µg/mL in shoots or roots of plants treated with 100 mM Pb-EDTA. We also focused our attention on the activity of alanine transaminase (ALT, aspartate transaminase (AST and urease. Activity of the enzymes increased with increasing length of the treatment and applied concentration of lead (II ions. This increase corresponds well with a higher metabolic activity of treated plants. Contents of cysteine, reduced glutathione (GSH, oxidized glutathione (GSSG and phytochelatin 2 (PC2 were determined by high performance liquid chromatography with electrochemical detection. Cysteine content declined in roots of plants with the increasing time of treatment of plants with Pb-EDTA and the concentration of toxic substance. Moreover, we observed ten times higher content of cysteine in roots in comparison with shoots. The observed reduction of cysteine content probably relates with its utilization for biosynthesis of GSH and phytochelatins, because the content of GSH and PC2 was similar in roots and shoots and increased with increased treatment time and concentration of Pb-EDTA. Moreover, we observed oxidative stress caused by Pb-EDTA in roots where the GSSG/GSH ratio was about 0.66. In shoots, the oxidative stress was less distinctive, with a GSSG/GSH ratio 0.14. We also estimated the rate of phytochelatin biosynthesis from the slope of linear equations plotted with data measured in the

Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II) Ions

Science.gov (United States)

Krystofova, Olga; Shestivska, Violetta; Galiova, Michaela; Novotny, Karel; Kaiser, Jozef; Zehnalek, Josef; Babula, Petr; Opatrilova, Radka; Adam, Vojtech; Kizek, Rene

2009-01-01

In this study, the influence of lead (II) ions on sunflower growth and biochemistry was investigated from various points of view. Sunflower plants were treated with 0, 10, 50, 100 and/or 500 μM Pb-EDTA for eight days. We observed alterations in growth in all experimental groups compared with non-treated control plants. Further we determined total content of proteins by a Bradford protein assay. By the eighth day of the experiment, total protein contents in all treated plants were much lower compared to control. Particularly noticeable was the loss of approx. 8 μg/mL or 15 μg/mL in shoots or roots of plants treated with 100 mM Pb-EDTA. We also focused our attention on the activity of alanine transaminase (ALT), aspartate transaminase (AST) and urease. Activity of the enzymes increased with increasing length of the treatment and applied concentration of lead (II) ions. This increase corresponds well with a higher metabolic activity of treated plants. Contents of cysteine, reduced glutathione (GSH), oxidized glutathione (GSSG) and phytochelatin 2 (PC2) were determined by high performance liquid chromatography with electrochemical detection. Cysteine content declined in roots of plants with the increasing time of treatment of plants with Pb-EDTA and the concentration of toxic substance. Moreover, we observed ten times higher content of cysteine in roots in comparison with shoots. The observed reduction of cysteine content probably relates with its utilization for biosynthesis of GSH and phytochelatins, because the content of GSH and PC2 was similar in roots and shoots and increased with increased treatment time and concentration of Pb-EDTA. Moreover, we observed oxidative stress caused by Pb-EDTA in roots where the GSSG/GSH ratio was about 0.66. In shoots, the oxidative stress was less distinctive, with a GSSG/GSH ratio 0.14. We also estimated the rate of phytochelatin biosynthesis from the slope of linear equations plotted with data measured in the particular

Determination of Mercury (II Ion on Aryl Amide-Type Podand-Modified Glassy Carbon Electrode

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Sevgi Güney

2011-01-01

Full Text Available A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy-3,6-dioxaoctane, (AAP modified glassy carbon electrode, was described for the determination of trace level of mercury (II ion by cyclic voltammetry (CV and differential pulse voltammetry (DPV. A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1 NaCl. Mercury (II ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ ions were also studied at two different concentration ratios with respect to mercury (II ions. The modified electrode was applied to the determination of mercury (II ions in seawater sample.

Characterization of hydroxybenzoic acid chelating resins: equilibrium, kinetics, and isotherm profiles for Cd(II and Pb(II uptake

Directory of Open Access Journals (Sweden)

BHAVNA A. SHAH

2011-06-01

Full Text Available Chelating ion-exchange resins were synthesized by polycondensation of ortho/para hydroxybenzoic acid with resorcinol/catechol employing formaldehyde as cross-linking agent at 80±5 °C in DMF. The resins were characterized by FTIR and XRD. The uptake behaviour of synthesized resins for Cd(II and Pb(II ions have been studied depending on contact time, pH, metal ion concentration and temperature. The sorption data obtained at optimized conditions were analyzed by the Langmuir and Freundlich isotherms. Experimental data of all metal–resin system were best represented by the Freundlich isotherm. The maximum obtained sorption capacity for cadmium was 69.53 mg g-1 and 169.32 mg g-1 for Lead. The adsorption process follows first order kinetics and the specific rate constant Kr was obtained by the application of the Lagergan equation. Thermodynamic parameters ∆Gads, ∆Sads and ∆Hads were calculated for the metal–resin systems. The external diffusion rate constant (KS and the intra-particle diffusion rate constant (Kid were calculated by the Spahn–Schlunder and Weber–Morris models, respectively. The sorption process was found to follow an intra-particle diffusion phenomenon.

Selective and Efficient Solvent Extraction of Copper(II Ions from Chloride Solutions by Oxime Extractants

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Zahra Kaboli Tanha

2016-06-01

Full Text Available Oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (HL1 and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (HL2 were synthesized and characterized by conventional spectroscopic methods. Suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated metal ions by performing competitive extraction experiments of Cu(II, Co(II, Ni(II, Zn(II, Cd(II and Pb(II ions from chloride solutions. Both ligands transfer selectively the copper ions into dichloromethane by a cation exchange mechanism. Conventional log-log analysis and isotherm curves showed that Cu(II ions are extracted as the complexes with 1:2 metal to ligand ratio by both extractants. Verification of the effect of the organic diluent used in the extraction of copper ions by HL1 and HL2 demonstrated that the extraction efficiency varies as: dichloromethane ~ dichloroethane > toluene > xylene > ethylacetate. Time dependency investigation of the extraction processes revealed that the kinetics of the extraction of copper by HL2 is more rapid than that of HL1. The application of the ligands for extraction-separation of copper ions from leach solutions of cobalt and nickel-cadmium filter-cakes of a zinc production plants was evaluated.

Stability of binary complexes of Pb(II, Cd(II and Hg(II with maleic acid in TX100-water mixtures

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M. Ramanaiah

2014-09-01

Full Text Available Binary complexes of maleic acid with toxic metal ions such as Pb(II, Cd(II and Hg(II have been studied in 0.0-2.5% v/v tritonX-100 (TX100 - water media at 303 K at an ionic strength of 0.16 M. The active forms of the ligand are LH2, LH- and L2-. The derived ‘best fit’ chemical speciation models are based on crystallographic R-factors, χ2 and Skewness and Kurtosis factors. The predominant species formed are of the type ML2, ML2H and ML3. The trend in variation of complex stability constants with change in the mole fraction of the medium is explained on the basis of prevailing electrostatic and non-electrostatic forces. The species distribution as a function of pH at different compositions of TX100-water mixtures and plausible speciation equilibria are presented and discussed. DOI: http://dx.doi.org/10.4314/bcse.v28i3.7

Fabrication and characterization of mesoporous activated carbon from Lemna minor using one-step H3PO4 activation for Pb(II) removal

International Nuclear Information System (INIS)

Huang, Yang; Li, Shunxing; Lin, Haibin; Chen, Jianhua

2014-01-01

Graphical abstract: - Highlights: • Activated carbon was prepared from Lemna minor using H 3 PO 4 activation. • Materials have higher mesoporosity (92.2%) and more oxygen and nitrogen-containing functional groups. • Materials can remove Pb(II) rapidly with monolayer adsorption capacity (170.9 mg/g). • The adsorption process fitted to Langmuir isotherm and pseudo-first-order kinetic. • Materials could be used as an economical, efficient adsorbent to remove Pb(II) ions. - Abstract: A low cost and locally available material, Lemna minor, was used to fabricate activated carbon using H 3 PO 4 activation. After H 3 PO 4 activation, the L. minor activated carbons (LACs) possess high mesoporosity (92.2%) and a surface area of 531.9 m 2 /g according to Brunauer–Emmett–Teller (BET) analysis. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses reveal the presence of rich hydroxyl, carboxyl, amide and phosphate functional groups on the LACs surface, leading to facile Pb(II) binding to the surface through strong chemisorptive bonds or ion-exchange. The kinetic and equilibrium data were well described by pseudo-first-order model and Langmuir isotherm, with the maximum monolayer adsorption capacity (q m ) 170.9 mg/g at 25 °C. The intra-particle diffusion mechanism was partially responsible for the adsorption. The adsorption process was spontaneous and endothermic with negative ΔG and positive ΔH. The Pb(II)-loaded LACs could be easily regenerated using 0.1-M HCl and reused for seven cycles without significant adsorption capacity reduction. The maximum percentage removal rate for Pb(II) (20 mg/L) was found to be 91.8% within 30 min, at optimum conditions of pH 6.0 and 25 °C. These suggested that the low-cost LACs could be used as a potential adsorbent in the treatment of lead-contaminated water

Rapid adsorption of copper(II) and lead(II) by rice straw/Fe₃O₄ nanocomposite: optimization, equilibrium isotherms, and adsorption kinetics study.

Science.gov (United States)

Khandanlou, Roshanak; Ahmad, Mansor B; Fard Masoumi, Hamid Reza; Shameli, Kamyar; Basri, Mahiran; Kalantari, Katayoon

2015-01-01

Rice straw/magnetic nanocomposites (RS/Fe3O4-NCs) were prepared via co-precipitation method for removal of Pb(II) and Cu(II) from aqueous solutions. Response surface methodology (RSM) was utilized to find the optimum conditions for removal of ions. The effects of three independent variables including initial ion concentration, removal time, and adsorbent dosage were investigated on the maximum adsorption of Pb (II) and Cu (II). The optimum conditions for the adsorption of Pb(II) and Cu(II) were obtained (100 and 60 mg/L) of initial ion concentration, (41.96 and 59.35 s) of removal time and 0.13 g of adsorbent for both ions, respectively. The maximum removal efficiencies of Pb(II) and Cu(II) were obtained 96.25% and 75.54%, respectively. In the equilibrium isotherm study, the adsorption data fitted well with the Langmuir isotherm model. The adsorption kinetics was best depicted by the pseudo-second order model. Desorption experiments showed adsorbent can be reused successfully for three adsorption-desorption cycles.

Study of the Adsorbent-Adsorbate Interactions from Cd(II) and Pb(II) Adsorption on Activated Carbon and Activated Carbon Fiber

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae Ho; Kim, Doo Won; Kim, Bohye; Yang, Kap Seung [Chonnam National Univ., Gwangju (Korea, Republic of); Lim, Yongkyun; Park, Eun Nam [Microfilter Co., Ltd, Seoul (Korea, Republic of)

2013-02-15

The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents.

Study of the Adsorbent-Adsorbate Interactions from Cd(II) and Pb(II) Adsorption on Activated Carbon and Activated Carbon Fiber

International Nuclear Information System (INIS)

Kim, Dae Ho; Kim, Doo Won; Kim, Bohye; Yang, Kap Seung; Lim, Yongkyun; Park, Eun Nam

2013-01-01

The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents

Pb(II), Cd(II) and Zn(II) adsorption on low grade manganese ore ...

African Journals Online (AJOL)

Low grade manganese ore (LMO) of Orissa containing 58.37% SiO2, 25.05% MnO2, 8.8% Al2O3, and 5.03% Fe2O3 as the main constituents was taken to study its adsorption behaviour for Pb(II), Cd(II) and Zn(II) from aqueous solutions. The XRD studies showed the crystalline phases to be quartz, ß-MnO2, d-MnO2 and ...

Removal of aqueous Pb(II) by adsorption on Al{sub 2}O{sub 3}-pillared layered MnO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Haipeng; Gu, Liqin; Zhang, Ling; Zheng, Shourong; Wan, Haiqin; Sun, Jingya [State Key Laboratory of Pollution Control and Resource Reuse, Jiangsu Key Laboratory of Vehicle Emissions Control, School of the Environment, Nanjing University, Nanjing 210023 (China); Zhu, Dongqiang [School of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Xu, Zhaoyi, E-mail: zhaoyixu@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, Jiangsu Key Laboratory of Vehicle Emissions Control, School of the Environment, Nanjing University, Nanjing 210023 (China)

2017-06-01

Highlights: • Al{sub 2}O{sub 3}-pillared layered MnO{sub 2} (p-MnO{sub 2}) was prepared from δ-MnO{sub 2} precursor. • p-MnO{sub 2} showed markedly higher Pb(II) adsorption capacity than pristine δ-MnO{sub 2.}. • Pillaring of Al{sub 2}O{sub 3} into the layer of δ-MnO{sub 2} enhanced the Pb(II) adsorption. - Abstract: In the present study, Al{sub 2}O{sub 3}-pillared layered MnO{sub 2} (p-MnO{sub 2}) was synthesized using δ-MnO{sub 2} as precursor and Pb(II) adsorption on p-MnO{sub 2} and δ-MnO{sub 2} was investigated. To clarify the adsorption mechanism, Al{sub 2}O{sub 3} was also prepared as an additional sorbent. The adsorbents were characterized by X-ray fluorescence analysis, powder X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and N{sub 2} adsorption-desorption. Results showed that in comparison with pristine δ-MnO{sub 2}, Al{sub 2}O{sub 3} pillaring led to increased BET surface area of 166.3 m{sup 2} g{sup −1} and enlarged basal spacing of 0.85 nm. Accordingly, p-MnO{sub 2} exhibited a higher adsorption capacity of Pb(II) than δ-MnO{sub 2}. The adsorption isotherms of Pb(II) on δ-MnO{sub 2} and Al{sub 2}O{sub 3} pillar fitted well to the Freundlich model, while the adsorption isotherm of Pb(II) on p-MnO{sub 2} could be well described using a dual-adsorption model, attributed to Pb(II) adsorption on both δ-MnO{sub 2} and Al{sub 2}O{sub 3}. Additionally, Pb(II) adsorption on δ-MnO{sub 2} and p-MnO{sub 2} followed the pseudo second-order kinetics, and a lower adsorption rate was observed on p-MnO{sub 2} than δ-MnO{sub 2}. The Pb(II) adsorption capacity of p-MnO{sub 2} increased with solution pH and co-existing cation concentration, and the presence of dissolved humic acid (10.2 mg L{sup −1}) did not markedly impact Pb(II) adsorption. p-MnO{sub 2} also displayed good adsorption capacities for aqueous Cu(II) and Cd(II). Findings in this study indicate that p-MnO{sub 2} could be used as a highly effective

Toxicity assessment of Chlorella vulgaris and Chlorella protothecoides following exposure to Pb(II).

Science.gov (United States)

Zhang, Wei; Xiong, Bang; Chen, Lin; Lin, Kuangfei; Cui, Xinhong; Bi, Huasong; Guo, Meijin; Wang, Weiliang

2013-07-01

The short- and long-term toxic effects of Pb(II) exposure on Chlorella vulgaris (C. vulgaris) and Chlorella protothecoides (C. protothecoides) were not well understood. The lab study was performed to observe the Pb(II) exposure induced changes. Results of the observations show: (1) higher level of Pb(II) (50 or 80mgL(-1)) could significantly inhibit the growth and chlorophyll a synthesis of both algae in almost all the treatments and dose-response relationships could be clearly observed, (2) the range of EC50 values (24-120h, 67.73-172.45mgL(-1)) indicated that Pb(II) had a relatively limited short-term toxicity to the two algae, while long-term tests (7-28d, 50.41-63.91mgL(-1)) displayed higher toxicity and (3) SOD and CAT activities of both algae after exposed to medium level of Pb(II) were significantly promoted, and their response might be more susceptible in short-term exposure. This research provides a basic understanding of Pb(II) toxicity to aquatic organisms. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultrasound-assisted xanthation of cellulose from lignocellulosic biomass optimized by response surface methodology for Pb(II) sorption.

Science.gov (United States)

Wang, Chongqing; Wang, Hui; Gu, Guohua

2018-02-15

Alkali treatment of lignocellulosic biomass is conducted to remove hemi-cellulose and lignin, further increasing the reactivity and accessibility of cellulose. Ultrasound-assisted xanthation of alkali cellulose is optimized by response surface methodology (RSM) with a Box-Behnken design. A predicting mathematical model is obtained by fitting experimental data, and it is verified by analysis of variance. Response surface plots and the contour plots obtained from the model are applied to determine the interactions of experimental variables. The optimum conditions are NaOH concentration 1.3mol/L, ultrasonic time 71.6min and CS 2 dosage 1.5mL. FTIR, SEM and XPS characterizations confirm the synthesis and sorption mechanism of cellulose xanthate (CX). Biosorption of Pb (II) onto CX obeys pseudo-second order model and Langmuir model. The sorption mechanism is attributed to surface complexation or ion exchange. CX shows good reusability for Pb (II) sorption. The maximum sorption capacity of Pb(II) is 134.41mg/g, higher than that of other biosorbents. CX has great potential as an efficient and low-cost biosorbent for wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption of Pb(II) present in aqueous solution on calcium, strontium and barium hydroxy apatites; Adsorcion de Pb(II) presente en solucion acuosa sobre hidroxiapatitas de calcio, estroncio y bario

Energy Technology Data Exchange (ETDEWEB)

Vilchis G, J.

2013-07-01

Calcium, strontium and barium hydroxy apatites were successfully synthesized by chemical precipitation method, the obtained powders were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (Sem), semi-quantitative elemental analysis (EDS), infrared spectroscopy (IR), and N{sub 2} physisorption studies, complementary to these analytical techniques, was determined the surface fractal dimension (Df), and the amount of surface active sites of the materials, in order to know application as ceramic for water remediation. The ability of Pb(II) ion adsorption present in aqueous solution on the hydroxy apatites synthesized by batch type experiments was studied as a function of contact time, concentration of the adsorbate and temperature. The maximum lead adsorption efficiencies obtained were 0.31, 0.32 and 0.26 mg/g for calcium, strontium and barium hydroxy apatites respectively, achieved an equilibrium time of 20 minutes in the three solid-liquid systems studied. Experimental data were adequately adjusted at the adsorption kinetic model pseudo-second order, for the three cases. Moreover, experimental data of the strontium and calcium hydroxy apatites were adjusted to the Langmuir adsorption isotherm, indicating that the adsorption was through a monolayer, whereas barium hydroxyapatite was adjusted to the Freundlich adsorption isotherm, indicating a multilayer adsorption. The thermodynamic parameters obtained during adsorption studies as a function of temperature showed physisorption, exothermic and spontaneous processes respectively. The results showed that the calcium hydroxyapatite, strontium and barium are an alternative for the Pb(II) ion adsorption present in wastewaters. (Author)

Estudio de los mecanismos de activación de la esfalerita con Cu(II y Pb(II

Directory of Open Access Journals (Sweden)

Dávila Pulido, G. I.

2011-08-01

Full Text Available This article presents results of an experimental study on the sphalerite activation with Cu(II and Pb(II, whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate is characterized making use of the contact angle technique. The results show that Cu(II replaces the Zn of the external layers of the mineral, promoting the sulfide (S^2– oxidation to produce a mixture of CuS, Cu₂S and S°, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX₂. It is also observed that the hydrophobicity of sphalerite activated with Pb(II is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation.

Este artículo presenta los resultados de un estudio experimental sobre la activación de esfalerita (ZnS con Cu(II y Pb(II, cuyo objetivo principal consistió en investigar los mecanismos de activación y en evaluar la magnitud relativa de la hidrofobización alcanzada con ambas especies químicas. La hidrofobicidad que la superficie mineral adquiere como resultado de la interacción con los activadores y colectores tipo xantato (ditiocarbonatos alquílicos, R-O-CS₂ –, se caracteriza mediante la técnica del ángulo de contacto. Los resultados muestran que el Cu(II es intercambiado por el Zn de las capas exteriores del cristal, promoviendo la oxidación de sulfuro (S^2– para producir una mezcla de

Possibility of Modification of Zeolites by Iron Oxides and its Utilization for Removal of Pb(II from Water Solutions

Directory of Open Access Journals (Sweden)

Michal Lovás

2004-12-01

Full Text Available Ion-exchange properties of cations from lattice and ions from solutions are characteristic for zeolites. Zeolites as sorbents are used in many branches of industry. Ion-exchange reactions of cations on zeolites have been a theme of many works. With the exception of using natural zeolites as the sorbent, a modification of surface of zeolites and preparation of synthetic zeolites has received interest lately. One of the common modification of zeolites is modification by iron oxides, which increases capacity of adsorption. In this work, we prepared a modified zeolite by the precipitation of magnetite on the surface of zeolite. This new adsorbent was used to remove of Pb(II from waste water. The maximum adsorption capacity was 73,25 mg/g from the solution of Pb with the concentration of 400 mg/l.

Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent

Energy Technology Data Exchange (ETDEWEB)

Ronda, A., E-mail: alirg@ugr.es [Department of Chemical Engineering, University of Granada, 18071 Granada (Spain); Della Zassa, M. [Department of Industrial Engineering, University of Padua, 35131 Padova (Italy); Martín-Lara, M.A.; Calero, M. [Department of Chemical Engineering, University of Granada, 18071 Granada (Spain); Canu, P. [Department of Industrial Engineering, University of Padua, 35131 Padova (Italy)

2016-05-05

Highlights: • The fate of Pb during combustion at two scales of investigation was studied. • Results from combustion in a flow reactor and in the thermobalance were consistent. • The Pb contained in the solid remained in the ashes. • The Pb does not interfere in the use of OTP as fuel. • The combustion of Pb(II)-loaded OTP does not cause environmental hazards. - Abstract: The olive tree pruning is a specific agroindustrial waste that can be successfully used as adsorbent, to remove Pb(II) from contaminated wastewater. Its final incineration has been studied in a thermobalance and in a laboratory flow reactor. The study aims at evaluating the fate of Pb during combustion, at two different scales of investigation. The flow reactor can treat samples approximately 10{sup 2} larger than the conventional TGA. A detailed characterization of the raw and Pb(II)-loaded waste, before and after combustion is presented, including analysis of gas and solids products. The Pb(II)-loaded olive tree pruning has been prepared by a previous biosorption step in a lead solution, reaching a concentration of lead of 2.3 wt%. Several characterizations of the ashes and the mass balances proved that after the combustion, all the lead presents in the waste remained in ashes. Combustion in a flow reactor produced results consistent with those obtained in the thermobalance. It is thus confirmed that the combustion of Pb(II)-loaded olive tree pruning is a viable option to use it after the biosorption process. The Pb contained in the solid remained in the ashes, preventing possible environmental hazards.

Luminescence and photothermally stimulated defects creation processes in PbWO{sub 4}:La{sup 3+}, Y{sup 3+} (PWO II) crystals

Energy Technology Data Exchange (ETDEWEB)

Auffray, E. [CERN, Geneva 23, Geneva (Switzerland); Korjik, M. [Institute for Nuclear Problems, 11 Bobruiskaya, 220020 Minsk (Belarus); Zazubovich, S., E-mail: svetlana.zazubovits@ut.ee [Institute of Physics, University of Tartu, Ravila 14 c, 50411 Tartu (Estonia)

2015-12-15

Photoluminescence and thermally stimulated luminescence (TSL) are studied for a PbWO{sub 4} crystal grown by the Czochralski method at Bogoroditsk Technical Chemical Plant, Russia from the melt with a precise tuning of the stoichiometry and co-doped with La{sup 3+} and Y{sup 3+} ions (the PWO II crystal). Photothermally stimulated processes of electron and hole centers creation under selective UV irradiation of this crystal in the 3.5–5.0 eV energy range and the 85–205 K temperature range are clarified and the optically created electron and hole centers are identified. The electrons in PWO II are mainly trapped at the (WO{sub 4}){sup 2−} groups located close to single La{sup 3+} and Y{sup 3+} ions, producing the electron {(WO_4)"3"−–La"3"+} and {(WO_4)"3"−–Y"3"+} centers. The holes are mainly trapped at the regular oxygen ions O{sup 2−} located close to La{sup 3+} and Y{sup 3+} ions associated with lead vacancies, producing the hole O{sup −}(I)-type centers. No evidence of single-vacancy-related centers has been observed in PWO II. The data obtained indicate that excellent scintillation characteristics of the PWO II crystal can be explained by a negligible concentration of single (non-compensated) oxygen and lead vacancies as the traps for electrons and holes, respectively. - Highlights: • Photoluminescence of the PbWO{sub 4}:La{sup 3+}, Y{sup 3+} (PWO II) crystal is investigated. • Creation of defects under UV irradiation of PWO II is studied by TSL. • Origin of dominating electron and hole centers is ascertained. • Concentration of single-vacancy-related centers is found to be negligible. • Excellent scintillation characteristics of the PWO II crystal are explained.

Adsorption of Pb2+ on Thiol-functionalized Mesoporous Silica, SH-MCM-48

Science.gov (United States)

Taba, P.; Mustafa, R. D. P.; Ramang, L. M.; Kasim, A. H.

2018-03-01

Modification of mesoporous silica, MCM-48, by using 3- mercaptopropyltrimethoxysilane has been successfully conducted. MCM-48 and SH-MCM-48 were characterized using XRD and FTIR. SH-MCM-48 was used as an adsorbent of Pb2+ ions from solution. A number of Pb2+ ions adsorbed were studied as the function of time, pH, and concentration. The concentration of the ions after adsorption was determined by an Atomic Absorption Spectrophotometer. The removal of the adsorbed ions from the SH-MCM-48 was also studied using several desorbing agents. The result showed that the optimum time was 20 minutes and optimum pH was 4. The adsorption of Pb(II) ion followed the pseudo-second-order with the rate constant of 0,2632 g•mg-1•min-1. Adsorption of Pb(II) ion fitted the Langmuir isotherm with the adsorption capacity of 0,1088 mmol/g. The best desorbing agent to remove the adsorbed ion from SH-MCM-48 was 0.3 M HCl solution with the desorption percentage of 58.6%.

Intrinsic Lead Ion Emissions in Zero-Dimensional Cs4PbBr6 Nanocrystals

KAUST Repository

Yin, Jun

2017-11-07

We investigate the intrinsic lead ion (Pb2+) emissions in zero-dimensional (0D) perovskite nanocrystals (NCs) using a combination of experimental and theoretical approaches. The temperature-dependent photoluminescence experiments for both “nonemissive” (highly suppressed green emission) and emissive (bright green emission) Cs4PbBr6 NCs show a splitting of emission spectra into high- and low-energy transitions in the ultraviolet (UV) spectral range. In the nonemissive case, we attribute the high-energy UV emission at approximately 350 nm to the allowed optical transition of 3P1 to 1S0 in Pb2+ ions and the low-energy UV emission at approximately 400 nm to the charge-transfer state involved in the 0D NC host lattice (D-state). In the emissive Cs4PbBr6 NCs, in addition to the broad UV emission, we demonstrate that energy transfer occurs from Pb2+ ions to green luminescent centers. The optical phonon modes in Cs4PbBr6 NCs can be assigned to both Pb–Br stretching and rocking motions from density functional theory calculations. Our results address the origin of the dual broadband Pb2+ ion emissions observed in Cs4PbBr6 NCs and provide insights into the mechanism of ionic exciton–optical phonon interactions in these 0D perovskites.

Adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II), and As(V) on bacterially produced metal sulfides.

Science.gov (United States)

Jong, Tony; Parry, David L

2004-07-01

The adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II) and As(V) onto bacterially produced metal sulfide (BPMS) material was investigated using a batch equilibrium method. It was found that the sulfide material had adsorptive properties comparable with those of other adsorbents with respect to the specific uptake of a range of metals and, the levels to which dissolved metal concentrations in solution can be reduced. The percentage of adsorption increased with increasing pH and adsorbent dose, but decreased with increasing initial dissolved metal concentration. The pH of the solution was the most important parameter controlling adsorption of Cd(II), Cu(II), Fe(II), Ni(II), Pb(II), Zn(II), and As(V) by BPMS. The adsorption data were successfully modeled using the Langmuir adsorption isotherm. Desorption experiments showed that the reversibility of adsorption was low, suggesting high-affinity adsorption governed by chemisorption. The mechanism of adsorption for the divalent metals was thought to be the formation of strong, inner-sphere complexes involving surface hydroxyl groups. However, the mechanism for the adsorption of As(V) by BPMS appears to be distinct from that of surface hydroxyl exchange. These results have important implications to the management of metal sulfide sludge produced by bacterial sulfate reduction.

SPECIATION OF BINARY COMPLEXES OF Pb(II) AND Cd(II) WITH ...

African Journals Online (AJOL)

ABSTRACT. Chemical speciation of L-Asparagine complexes of Pb(II) and Cd(II) in presence of (0-50% v/v) dimethyl sulfoxide(DMSO)-water mixtures has been studied potentiometrically at 303.0 K and at an ionic strength of 0.16 mol L-1. The models containing different number of species were refined by using the ...

Electrospun Zeolite/Cellulose Acetate Fibers for Ion Exchange of Pb2+

Directory of Open Access Journals (Sweden)

Daniel N. Tran

2014-12-01

Full Text Available The ion exchange capability of electrospun cellulose acetate (CA fibers containing zeolite A nanoparticles is reported. Solid and porous CA fibers were used to make a zeolite-embedded filter paper, which was then used to ion exchange Na+ with Cu2+ and Pb2+. The composite Linde Type A (LTA zeolite CA fibers exchanged 0.39 mmol/g more Pb2+ than LTA nanoparticles in the solid CA fibers. These fibers could provide a simple and effective method for heavy metal ion removal in water.

Prediction of equilibrium parameters of adsorption of lead (II) ions onto diatomite

Science.gov (United States)

Salman, Taylan; Ardalı, Yüksel; Gamze Turan, N.

2013-04-01

Heavy metals from industrial wastewaters are one of the most important environmental issues to be solved today. Due to their toxicity and nonbiodegradable nature, heavy metals cause environmental and public health problems. Various techniques have been developed to remove heavy metals from aqueous solutions. These include chemical precipitation, reverse osmosis, ion Exchange and adsorption. Among them, adsorption is considered to be a particularly competitive and effective process for the removal of heavy metals from aqueous solutions. There is growing interest in using low cost, commercially available materials for the adsorption of heavy metals. Diatomite is a siliceous sedimentary rock having an amorphous form of silica (SiO2. nH2O) containing a small amount of microcrystalline material. It has unique combination of physical and chemical properties such as high porosity, high permeability, small particle size, large surface area, and low thermal conductivity. In addition, it is available in Turkey and in various locations around the world. Therefore, diatomite has been successfully used as adsorbent for the removal of heavy metals. The aim of the study is to investigate the adsorption properties of diatomite. The equilibrium adsorption data were applied to the Langmuir, Freundlich and Dubinin-Radushkevic (D-R) isotherm models. Adsorption experiments were performed under batch process, using Pb (II) initial concentration, pH of solution and contact time as variables. The results demonstrated that the adsorption of Pb (II) was strongly dependent on pH of solution. The effect of pH on adsorption of Pb(II) on diatomite was conducted by varying pH from 2 to 12 at 20 oC. In the pH range of 2.0-4.0, the adsorption percentage increases slightly as the pH increasing. At pH>4, the adsorption percentage decreases with increasing pH because hydrolysis product and the precipitation begin to play an important role in the sorption of Pb (II). At pH4, the maximum adsorption

[Preparation of Pb2+ imprinted acrylic acid-co-styrene and analysis of its adsorption properties by FAAS].

Science.gov (United States)

Shawket, Abliz; Abdiryim, Supahun; Wang, Ji-De; Ismayil, Nurulla

2011-06-01

With lead ion template, acrylic acid as functional monomer, potassium persulfate as initiator, strytrene as framework monomer, lead ion imprinted polymers (Pb(II)-IIPs) were prepared using free emulsion polymerization method. The structure and morphology of the polymers were analyzed by UV-spectra, FTIR and scanning electron microscopy. The adsorption/ desorption and selectivity for Pb2+ were investigated by flame atomic absorption spectrometry (FAAS) as the detection means. The results show that compared with non-imprinted polymers(NIPs), the Pb(II)-IIPs had higher specific adsorption properties and selective recognition ability for Pb(II). The relative selectivity coefficient of Pb(II)-IIPs for Pb(II) was 6.25, 6.18, 6.25 and 6.38 in the presence of Cd(II), Cu(II), Mn(II) and Zn(II) interferences, respectively. The absorption rate was the best at the pH of adsorbent solution of 6, Adsorption rate reached 96% during the 2.5 h static adsorption time. Using 3.0 mol x L(-1) HCI as the best desorption solvent to desorb the adsorbents, the desorbtion rate reached 98%. Under the best adsorption conditions, the adsorption capacity of Pb(II)-IIPs for Pb(II) was found to be 40. mg x g(-1).

Evaluation of Dacryodes edulis (native pear) seed biomass for Pb (II ...

African Journals Online (AJOL)

Dacryodes edulis (Native pear) seed is herein evaluated as a promising biomass for Pb(II) removal from aqueous solution. The Pb(II) adsorption onto Dacryodes edulis seed biomass was influenced by the solution pH, time, biomass dose and initial adsorbate concentration. The Freundlich model fitted better than the ...

Batch adsorptive removal of Fe(III, Cu(II and Zn(II ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

Directory of Open Access Journals (Sweden)

Abdul-Aleem Soliman Aboul-Magd

2016-09-01

Full Text Available Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III, Cd(II, Zn(II, Cu(II, Mn(II, Mg(II, and Pb(II from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion concentration, different proportions of some organic solvents, H+-ion concentrations and reaction temperature on the partition coefficients. The metal adsorption for the cation exchanger was found to be significant in different media for both nitric and hydrochloric acids, i.e., the adsorption up take of metal ions presented in this work is very significant depending on the characteristics of ions and on the external concentrations of solute. The presence of low ionic strength or low concentration of acids does have a significant adsorption of metal ions on ion-exchange resin. The results show that the ion exchanger could be employed for the preconcentration, separation and the determination.

Effect of Crop-Straw Derived Biochars on Pb(II) Adsorption in Two Variable Charge Soils

Institute of Scientific and Technical Information of China (English)

JIANG Tian-yu; XU Ren-kou; GU Tian-xia; JIANG Jun

2014-01-01

Two variable charge soils were incubated with biochars derived from straws of peanut, soybean, canola, and rice to investigate the effect of the biochars on their chemical properties and Pb(II) adsorption using batch experiments. The results showed soil cation exchange capacity (CEC) and pH signiifcantly increased after 30 d of incubation with the biochars added. The incorporation of the biochars markedly increased the adsorption of Pb(II), and both the electrostatic and non-electrostatic adsorption mechanisms contributed to Pb(II) adsorption by the variable charge soils. Adsorption isotherms illustrated legume-straw derived biochars more greatly increased Pb(II) adsorption on soils through the non-electrostatic mechanism via the formation of surface complexes between Pb(II) and acid functional groups of the biochars than did non-legume straw biochars. The adsorption capacity of Pb(II) increased, while the desorption amount slightly decreased with the increasing suspension pH for the studied soils, especially in a high suspension pH, indicating that precipitation also plays an important role in immobilizing Pb(II) to the soils.

Adsorption of lead and cadmium ions in aqueous solutions onto modified lignin from alkali glycerol delignication

International Nuclear Information System (INIS)

Demirbas, Ayhan

2004-01-01

Adsorptions of toxic metal ions (Pb(II) and Cd(II)) onto modified lignin from beech and poplar woods by alkali glycerol delignification are presented in this paper. The material exhibits good adsorption capacity and the adsorption data follow the Langmuir model. The maximum adsorption capacities are 8.2-9.0 and 6.7-7.5 mg/g of the modified lignin for Pb(II) and Cd(II), respectively. The maximum adsorption percentage is 95.8 for Pb(II) for 4 h at 330 K and is 95.0 for Cd(II) for 10 h at 290 K. The adsorption of both the metal ions increased with increasing temperature indicating endothermic nature of the adsorption process. The maximum adsorption percentages of Pb(II) and Cd(II) ions decrease with time till 48 and 42 h and then again increase slightly with time. The adsorption of both heavy metal ions increases with pH. The adsorption of Pb(II) ions reached a maximum at a 5.0 value of pH

Detection of lead(II) ions with a DNAzyme and isothermal strand displacement signal amplification.

Science.gov (United States)

Li, Wenying; Yang, Yue; Chen, Jian; Zhang, Qingfeng; Wang, Yan; Wang, Fangyuan; Yu, Cong

2014-03-15

A DNAzyme based method for the sensitive and selective quantification of lead(II) ions has been developed. A DNAzyme that requires Pb(2+) for activation was selected. An RNA containing DNA substrate was cleaved by the DNAzyme in the presence of Pb(2+). The 2',3'-cyclic phosphate of the cleaved 5'-part of the substrate was efficiently removed by Exonuclease III. The remaining part of the single stranded DNA (9 or 13 base long) was subsequently used as the primer for the strand displacement amplification reaction (SDAR). The method is highly sensitive, 200 pM lead(II) could be easily detected. A number of interference ions were tested, and the sensor showed good selectivity. Underground water samples were also tested, which demonstrated the feasibility of the current approach for real sample applications. It is feasible that our method could be used for DNAzyme or aptazyme based new sensing method developments for the quantification of other target analytes with high sensitivity and selectivity. © 2013 Elsevier B.V. All rights reserved.

Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent.

Science.gov (United States)

Ronda, A; Della Zassa, M; Martín-Lara, M A; Calero, M; Canu, P

2016-05-05

The olive tree pruning is a specific agroindustrial waste that can be successfully used as adsorbent, to remove Pb(II) from contaminated wastewater. Its final incineration has been studied in a thermobalance and in a laboratory flow reactor. The study aims at evaluating the fate of Pb during combustion, at two different scales of investigation. The flow reactor can treat samples approximately 10(2) larger than the conventional TGA. A detailed characterization of the raw and Pb(II)-loaded waste, before and after combustion is presented, including analysis of gas and solids products. The Pb(II)-loaded olive tree pruning has been prepared by a previous biosorption step in a lead solution, reaching a concentration of lead of 2.3 wt%. Several characterizations of the ashes and the mass balances proved that after the combustion, all the lead presents in the waste remained in ashes. Combustion in a flow reactor produced results consistent with those obtained in the thermobalance. It is thus confirmed that the combustion of Pb(II)-loaded olive tree pruning is a viable option to use it after the biosorption process. The Pb contained in the solid remained in the ashes, preventing possible environmental hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Adsorption of heavy metal ions on molybdenum and molybdenum trioxide from dilute aqueous solution

International Nuclear Information System (INIS)

Utsunomiya, Taizo; Hoshino, Yoshio; Sakabe, Ken-ichi

1984-01-01

The adsorption of heavy metal ions such as Co(II), Cu(II) and Pb(II) on molybdenum powder has been investigated by the batch technique as a function of soaking time, concentration of heavy metal ions and coexisting salts, pH etc. Molybdenum trioxide was also used as an adsorbent for a comparison to discuss the adsorption mechanism. The amount of these heavy metal ions adsorbed was highly pH and coexisting salts dependent. These adsorbents have features of selective adsorption for Pb(II) and large adsorption rate. The adsorption of heavy metal ions on these adsorbents proceeds independently or concurrently by following complex mechanism; (1) cation exchange reaction by hydroxyl radical on the surface of Mo and MoO 3 is predominant for most of heavy metal ions except Pb(II) [Co(II), Mn(II), Fe(III), Ni(II), Zn(II), Cd(II) and Sr(II)], (2) reduction (electron exchange reaction) to low ionic or metallic state after cation exchange reaction [Cu(II) and Ag(I) on Mo] and (3) formation of a compound [Pb(II) on both Mo and MoO 3 ]. (author)

Kinetics and thermodynamics of Pb(II) adsorption onto modified spent grain from aqueous solutions

International Nuclear Information System (INIS)

Li Qingzhu; Chai Liyuan; Yang Zhihui; Wang Qingwei

2009-01-01

Spent grain, a main by-product of the brewing industry, is available in large quantities, but its main application has been limited to animal feeding. Nevertheless, in this study, spent grain modified with 1 M NaCl solution as a novel adsorbent has been used for the adsorption of Pb(II) in aqueous solutions. Isotherms, kinetics and thermodynamics of Pb(II) adsorption onto modified spent grain were studied. The equilibrium data were well fitted with Langmuir, Freundlich and Dubinin-Radushkevick (D-R) isotherm models. The kinetics of Pb(II) adsorption followed pseudo-second-order model, using the rate constants of pseudo-second-order model, the activation energy (E a ) of Pb(II) adsorption was determined as 12.33 kJ mol -1 according to the Arrhenius equation. Various thermodynamic parameters such as ΔG ads , ΔH ads and ΔS ads were also calculated. Thermodynamic results indicate that Pb(II) adsorption onto modified spent grain is a spontaneous and endothermic process. Therefore, it can be concluded that modified spent grain as a new effective adsorbent has potential for Pb(II) removal from aqueous solutions.

Development of complexation ion chromatography for the determination of metal ions

OpenAIRE

Bashir, Wasim

2002-01-01

A simple ion chromatographic method was developed for the determination of Pb(II) in river and polluted water samples. The method was based upon the use of a colourforming complexing eluent and direct visible detection of the eluting Pb(II) complex. Using the combination of a strong cation exchange column and an eluent consisting of 20 mM sodium acetate-acetic acid buffer and 0.2 mM xylenol orange (XO) (~pH = 4.2), Pb(II) was detected at 572 nm eluting in under 6.5 min. The developed method p...

A fluorescent nanosensor based on graphene quantum dots-aptamer probe and graphene oxide platform for detection of lead (II) ion.

Science.gov (United States)

Qian, Zhao Sheng; Shan, Xiao Yue; Chai, Lu Jing; Chen, Jian Rong; Feng, Hui

2015-06-15

The sensitive detection of heavy metal ions in the organism and aquatic ecosystem using nanosensors based on environment friendly and biocompatible materials still remains a challenge. A fluorescent turn-on nanosensor for lead (II) detection based on biocompatible graphene quantum dots and graphene oxide by employment of Pb(2+)-induced G-quadruplex formation was reported. Graphene quantum dots with high quantum yield, good biocompatibility were prepared and served as the fluorophore of Pb(2+) probe. Fluorescence turn-off of graphene quantum dots is easily achieved through efficient photoinduced electron transfer between graphene quantum dots and graphene oxide, and subsequent fluorescence turn-on process is due to the formation of G-quadraplex aptamer-Pb(2+) complex triggered by the addition of Pb(2+). This nanosensor can distinguish Pb(2+) ion from other ions with high sensitivity and good reproducibility. The detection method based on this nanosensor possesses a fast response time of one minute, a broad linear span of up to 400.0 nM and ultralow detection limit of 0.6 nM. Copyright © 2015 Elsevier B.V. All rights reserved.

Redetermination of (d-penicillaminatolead(II

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Adam C. Schell

2012-04-01

Full Text Available In the title coordination polymer, [Pb(C5H9NO2S]n {systematic name: catena-poly[(μ-2-amino-3-methyl-3-sulfidobutanoatolead(II]}, the d-penicillaminate ligand coordinates to the metal ion in an N,S,O-tridentate mode. The S atom acts as a bridge to two neighbouring PbII ions, thereby forming a double thiolate chain. Moreover, the coordinating carboxylate O atom forms bridges to the PbII ions in the adjacent chain. The overall coordination sphere of the PbII ion can be described as a highly distorted pentagonal bipyramid with a void in the equatorial plane between the long Pb—S bonds probably occupied by the stereochemically active inert electron pair. The amino H atoms form N—H...S and N—H...O hydrogen bonds, resulting in a cluster of four complex units, giving rise to an R44(16 ring lying in the ab plane. The crystal structure of the title compound has been reported previously [Freeman et al. (1974. Chem. Soc. Chem. Commun. pp. 366–367] but the atomic coordinates have not been deposited in the Cambridge Structural Database (refcode DPENPB. Additional details of the hydrogen bonding are presented here.

BIOSSORÇÃO DE Pb(II POR CASCA DE URUCUM (Bixa orellana EM SOLUÇÕES AQUOSAS: ESTUDO CINÉTICO, EQUILÍBRIO E TERMODINÂMICO

Directory of Open Access Journals (Sweden)

Klaiani B. Fontana

Full Text Available This study describes the application of new and low cost biosorbent, shells of urucum (Bixa Orellana, for removal of lead ions (Pb(II from water solution. The urucum shells were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Batch adsorption experiments were performed in order to evaluate the effect of pH, agitation speed, adsorbent dosage, contact time, temperature, presence of interfering ions and matrix effect on the adsorption of process. The kinetics of biosorption followed pseudo-second-order model. Langmuir and Freundlich isotherm models were applied to describe the biosorption of Pb(II by urucum shells. The Langmuir model showed better fit and the estimated biosorption capacity was 43.6 mg g-1. The negative Gibbs free energy, ΔG°, confirms the spontaneous nature and positive value of enthalpy, ΔH°, the endothermic character of the process. Furthermore, we also performed an evaluation of matrix and others ions effect on the biosorption process.

Properties of coherent vortex motion in Pb-Nb-Pb ion implant variable thickness bridges

International Nuclear Information System (INIS)

Crozat, P.; Vernet, G.; Adde, R.

1980-01-01

We report here on the dc and microwave properties of variable thickness ion implant Pb-Nb-Pb bridges which present characteristic feature of coherent vortex motion. These results follow from a choice of particular microbridge parameters which altogether constitute favorable conditions to have one row of vortices in the central part of the bridge: a/ Large Pb bank thickness D (500-800 nm) > lambdasub(Pb) such that vortices are strongly repelled by the banks. b/ The implantation of the Nb bridge brings film uniformity compared to the coherent length (inhomogeneities due to defects approx. equal to 5 nm), a large increase of lambdasub(eff) (400%) and resistance (200%) while xi drops only very slightly (10-15%). c/ As a consequence of b/bridges with micrometric dimensions are much smaller than lambdasub(eff). Therefore a single row of vortices is strongly repelled by both banks. (orig./WRI)

High-Frequency H-1 NMR Chemical Shifts of Sn-II and Pb-II Hydrides Induced by Relativistic Effects: Quest for Pb-II Hydrides

Czech Academy of Sciences Publication Activity Database

Vícha, J.; Marek, R.; Straka, Michal

2016-01-01

Roč. 55, č. 20 (2016), s. 10302-10309 ISSN 0020-1669 Institutional support: RVO:61388963 Keywords : hydrides of TlI and PbII * high-frequency 1H chemical shifts * relativistic effects Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.857, year: 2016

Fabrication and characterization of mesoporous activated carbon from Lemna minor using one-step H{sub 3}PO{sub 4} activation for Pb(II) removal

Energy Technology Data Exchange (ETDEWEB)

Huang, Yang, E-mail: zzsfxyhy@163.com; Li, Shunxing; Lin, Haibin; Chen, Jianhua

2014-10-30

Graphical abstract: - Highlights: • Activated carbon was prepared from Lemna minor using H{sub 3}PO{sub 4} activation. • Materials have higher mesoporosity (92.2%) and more oxygen and nitrogen-containing functional groups. • Materials can remove Pb(II) rapidly with monolayer adsorption capacity (170.9 mg/g). • The adsorption process fitted to Langmuir isotherm and pseudo-first-order kinetic. • Materials could be used as an economical, efficient adsorbent to remove Pb(II) ions. - Abstract: A low cost and locally available material, Lemna minor, was used to fabricate activated carbon using H{sub 3}PO{sub 4} activation. After H{sub 3}PO{sub 4} activation, the L. minor activated carbons (LACs) possess high mesoporosity (92.2%) and a surface area of 531.9 m{sup 2}/g according to Brunauer–Emmett–Teller (BET) analysis. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses reveal the presence of rich hydroxyl, carboxyl, amide and phosphate functional groups on the LACs surface, leading to facile Pb(II) binding to the surface through strong chemisorptive bonds or ion-exchange. The kinetic and equilibrium data were well described by pseudo-first-order model and Langmuir isotherm, with the maximum monolayer adsorption capacity (q{sub m}) 170.9 mg/g at 25 °C. The intra-particle diffusion mechanism was partially responsible for the adsorption. The adsorption process was spontaneous and endothermic with negative ΔG and positive ΔH. The Pb(II)-loaded LACs could be easily regenerated using 0.1-M HCl and reused for seven cycles without significant adsorption capacity reduction. The maximum percentage removal rate for Pb(II) (20 mg/L) was found to be 91.8% within 30 min, at optimum conditions of pH 6.0 and 25 °C. These suggested that the low-cost LACs could be used as a potential adsorbent in the treatment of lead-contaminated water.

A new Pb{sup II}(ethylenediaminetetraacetate) coordination polymer with a two-dimensional layer structure

Energy Technology Data Exchange (ETDEWEB)

Zhao, D., E-mail: iamzd@hpu.edu.cn; Zhang, R. H.; Li, F. F. [Henan Polytechnic University, Department of Physics and Chemistry (China)

2016-12-15

A new Pb{sup II}−edta{sup 4–} coordination polymer, Pb{sub 2}(edta)(H{sub 2}O){sub 0.76} (edta{sup 4–} = ethylenediaminetetraacetate) was synthesized under hydrothermal condition. Single crystal X-ray analysis reveals that it represents a novel two-dimensional (2D) Pb{sup 2+}–edta{sup 4–} layer structure with a (4,8{sup 2})-topology. Each edta{sup 4–} ligand employs its four carboxylate O and two N atoms to chelate one Pb{sup II} atom (hexa-coordinated) and connects five Pb{sup II} atoms (ennea-coordinated) via its four carboxylate groups to form 2D layer framework. Adjacent layers are packed into the overall structure through vander Waals interactions.

What is the role of Pb(II) in high Tc superconductors

International Nuclear Information System (INIS)

Raveau, B.; Hervieu, M.; Michel, C.; Groult, D.; Provost, J.

1990-01-01

An overview of the layered lead cuprates is presented here. The structure of these oxides and their non-stoichiometry are studied in connection with their superconducting properties. The phenomena involving a modulation of the structure, characterized by the presence of satellites on E.D. patterns are described and the particular role of the 6s 2 lone pair of Pb(II) is discussed. Divalent lead is, owing to its size intermediate between that of strontium and barium, a potential cation for superconductive cuprates. Moreover, this interest for Pb(II), is supported by its electronic structure which involves an electronic 6s 2 lone pair well known for its ability to form layered structures. In spite of these characteristics, few superconductive layered suprates were isolated at the beginning of the rush to high Tc superconductors. This is probably due to the possibility of existence of redox reactions involving the couple Pb(II)/Pb(IV), which require very particular experimental conditions. The authors report here on the recent development of the crystal chemistry of those materials and on their corresponding superconducting properties

Improved selectivity for Pb(II) by sulfur, selenium and tellurium analogues of 1,8-anthraquinone-18-crown-5: synthesis, spectroscopy, X-ray crystallography and computational studies.

Science.gov (United States)

Mariappan, Kadarkaraisamy; Alaparthi, Madhubabu; Hoffman, Mariah; Rama, Myriam Alcantar; Balasubramanian, Vinothini; John, Danielle M; Sykes, Andrew G

2015-07-14

We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene-9,10-dione in a 1 : 1 ratio. The optical properties of the new compounds are examined and the sulfur and selenium analogues produce an intense green emission enhancement upon association with Pb(II) in acetonitrile. Selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was also competitive for Ca(II) ion. UV-Visible and luminescence titrations reveal that 2 and 3 form 1 : 1 complexes with Pb(II), confirmed by single-crystal X-ray studies where Pb(II) is complexed within the macrocycle through coordinate covalent bonds to neighboring carbonyl, ether and heteroether donor atoms. Cyclic voltammetry of 2-8 showed classical, irreversible oxidation potentials for sulfur, selenium and tellurium heteroethers in addition to two one-electron reductions for the anthraquinone carbonyl groups. DFT calculations were also conducted on 1, 2, 3, 6, 6 + Pb(II) and 6 + Mg(II) to determine the trend in energies of the HOMO and the LUMO levels along the series.

Chitosan-stabilized Silver Nanoparticles for Colorimetric Assay of Mercury (II) Ions in aqueous system

Science.gov (United States)

Zarlaida, Fitri; Adlim, M.; Syukri Surbakti, M.; Fairuz Omar, Ahmad

2018-05-01

Mercury is considered as dangerous pollutant. Among the many form of mercury, the most stable and soluble in water is mercury (II) ions which it cause threat to human health and surroundings. Silver nanoparticles (AgNPs) used in this method were prepared by chitosan (chi) which act as stabilizing agent. The Chi-AgNPs has good dispersity with size ranging from 2.50 to 6.00 nm as shown by transmission electron microscopy (TEM) analysis and it is stable for 3 months. Color of Chi-AgNPs fades from brownish-yellow to colorless only with Hg2+ ions, but it shows no significant changes upon addition of other metal ions such as Al3+, Ba2+, Ca2+, Cd2+, Cr3+, Co2+, Cu2+, Fe2+, K+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, and Zn2+. The detection limit for Hg2+ ions by bare-eye is estimated to be ∼1µM. This method can be used for sensing mercury(II) ions in numerous water samples.

Adsorption of Pb(II) present in aqueous solution on calcium, strontium and barium hydroxy apatites

International Nuclear Information System (INIS)

Vilchis G, J.

2013-01-01

Calcium, strontium and barium hydroxy apatites were successfully synthesized by chemical precipitation method, the obtained powders were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (Sem), semi-quantitative elemental analysis (EDS), infrared spectroscopy (IR), and N 2 physisorption studies, complementary to these analytical techniques, was determined the surface fractal dimension (Df), and the amount of surface active sites of the materials, in order to know application as ceramic for water remediation. The ability of Pb(II) ion adsorption present in aqueous solution on the hydroxy apatites synthesized by batch type experiments was studied as a function of contact time, concentration of the adsorbate and temperature. The maximum lead adsorption efficiencies obtained were 0.31, 0.32 and 0.26 mg/g for calcium, strontium and barium hydroxy apatites respectively, achieved an equilibrium time of 20 minutes in the three solid-liquid systems studied. Experimental data were adequately adjusted at the adsorption kinetic model pseudo-second order, for the three cases. Moreover, experimental data of the strontium and calcium hydroxy apatites were adjusted to the Langmuir adsorption isotherm, indicating that the adsorption was through a monolayer, whereas barium hydroxyapatite was adjusted to the Freundlich adsorption isotherm, indicating a multilayer adsorption. The thermodynamic parameters obtained during adsorption studies as a function of temperature showed physisorption, exothermic and spontaneous processes respectively. The results showed that the calcium hydroxyapatite, strontium and barium are an alternative for the Pb(II) ion adsorption present in wastewaters. (Author)

Facile and green preparation of novel adsorption materials by combining sol-gel with ion imprinting technology for selective removal of Cu(II) ions from aqueous solution

Science.gov (United States)

Ren, Zhongqi; Zhu, Xinyan; Du, Jian; Kong, Delong; Wang, Nian; Wang, Zhuo; Wang, Qi; Liu, Wei; Li, Qunsheng; Zhou, Zhiyong

2018-03-01

A novel green adsorption polymer was prepared by ion imprinted technology in conjunction with sol-gel process under mild conditions for the selective removal of Cu(II) ions from aqueous solution. Effects of preparation conditions on adsorption performance of prepared polymers were studied. The ion-imprinted polymer was prepared using Cu(II) ion as template, N-[3-(2-aminoethylamino) propyl] trimethoxysilane (AAPTMS) as functional monomer and tetraethyl orthosilicate (TEOS) as cross-linker. Water was used as solvent in the whole preparation process. The imprinted and non-imprinted polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM), Brunauer, Emmett and Teller (BET) and zeta potential. Three-dimensional network structure was formed and functional monomer was successfully cross-linked into the network structure of polymers. Effects of adsorption conditions on adsorption performance of prepared polymers were studied too. The pH value is of great influence on adsorption behavior. Adsorption by ion-imprinted polymer was fast (adsorption equilibrium was reached within 60 min). The adsorption capacity of Cu(II) ion-imprinted polymer was always larger than that of non-imprinted polymer. Pseudo-second-order kinetics model and Freundlich isotherm model fitted well with adsorption data. The maximum adsorption capacity of Cu(II) ion-imprinted polymer was 39.82 mg·g-1. However, the preparation conditions used in this work are much milder than those reported in literatures. The Cu(II) ion-imprinted polymer showed high selectivity and relative selectivity coefficients for Pb(II), Ni(II), Cd(II) and Co(II). In addition, the prepared ion-imprinted polymer could be reused several times without significant loss of adsorption capacity.

Pb, Cu, and Zn distributions at humic acid-coated metal-oxide surfaces

Science.gov (United States)

Wang, Yingge; Michel, F. Marc; Choi, Yongseong; Eng, Peter J.; Levard, Clement; Siebner, Hagar; Gu, Baohua; Bargar, John R.; Brown, Gordon E.

2016-09-01

Mineral surfaces are often coated by natural organic matter (NOM), which has a major influence on metal-ion sorption and sequestration because of the abundance of binding sites in such coatings and the changes they cause in local nanoscale environments. The effects of NOM coatings on mineral surfaces are, however, still poorly understood at the molecular level due to the complexity of these systems. In this study, we have applied long-period X-ray standing wave-fluorescence yield (LP-XSW-FY) spectroscopy to measure the partitioning of naturally present Cu(II) (0.0226%), Zn(II) (0.009%), and Pb(II) (∼0.0004%) between Elliott Soil Humic Acid (ESHA) coatings and three model single-crystal metal-oxide substrates: α-Al2O3 (0 0 0 1), α-Al2O3 (1 -1 0 2), and α-Fe2O3 (0 0 0 1). The competitive sorption effects among these metal ions for binding sites in the ESHA coatings and on the metal-oxide surfaces were investigated as a function of reaction time, calcium content, and solution pH. Pb(II) ions present in the ESHA coatings were found to redistribute to reactive α-Al2O3 (1 -1 0 2) and α-Fe2O3 (0 0 0 1) surfaces after 3 h of reaction (pH = 6.0, [Ca(II)] = 2 mM). Pb(II) partitioning onto these reactive metal-oxide surfaces increased with increasing reaction time (up to 7 d). In addition, the partitioning of Cu(II) and Zn(II) from the ESHA coating to the α-Fe2O3 (0 0 0 1) substrate increased slightly with reaction time (2.4% and 3.7% for Cu(II) and Zn(II), respectively, after 3 h and 6.4% and 7.7% for Cu(II) and Zn(II), respectively, after 72 h of reaction time). However, no changes in the partitioning of Cu(II) and Zn(II) onto the α-Al2O3 (1 -1 0 2) surface were observed with increasing reaction time, suggesting that these ions strongly complex with functional groups in the ESHA coatings. Similar results were obtained for Cu(II) and Zn(II) on the ESHA-coated α-Al2O3 (1 -1 0 2) surfaces in samples without the addition of calcium. However, the amounts of Pb(II

Levels of Cd (II, Mn (II, Pb (II, Cu (II, and Zn (II in Common Buzzard (Buteo buteo from Sicily (Italy by Derivative Stripping Potentiometry

Directory of Open Access Journals (Sweden)

P. Licata

2010-01-01

Full Text Available The purpose of this study was to determine the concentrations of heavy metals (Cd, Pb, Cu, Mn, and Zn in different organs (liver, kidney, muscle, lung, skin, and feathers of buzzards (Buteo buteo, utilized as a “biological indicator” for environmental contamination, from different areas of Sicily and to investigate the relationships between birds sex, age, and weight and metal levels in these samples. All samples of common buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. Potentiometric stripping analysis (PSA was used to determine the content of Cd(II, Cu(II, Mn(II, Pb(II, and Zn(II in bird tissues. For toxic metals, the highest levels of Pb were in liver and those of Cd in lung; Zn levels were higher than Cu and Mn in all tissues analyzed. The concentrations in liver, lung, kidney, and muscle could be considered as an indicative of chronic exposure to metals while the presence of metals in skin could be consequential to storing and elimination processes. The found concentrations of metals in the studied matrices required a highly sensitive method for their determination and a simple sample preparation procedure, and the proposed method was well suited for this purpose.

Adsorption kinetics of ion of Pb2+ using Tricalcium Phosphate particles

Science.gov (United States)

Fadli, A.; Yenti, S. R.; Akbar, F.; Maihendra; Mawarni, F.

2018-04-01

One of the heavy metals that can pollute water is Pb2+. The concentration of ion Pb2+ can be removed using the adsorption method. The purpose of this research is to determine the adsorption kinetics model of ions Pb2+ using tricalcium phosphate (TCP) particles with variation of the temperature and adsorbent dosage. Five hundred mililiter Pb2+ solution with of 3 mg/L were added 0,5 gr, 1 gr and 1,5 gr of TCP in a glass beaker and stirred with rate of 300 rpm at a temperature of 30 °C, 40 °C and 50 °C. Pb2+ concentration in solution was analyzed by AAS (Atomic Adsorption Spectroscopy). The results showed that the rate of adsorption increased with the increasing of the temperature and adsorbent dosage. Minimum constant value of adsorption kinetic was 1,720 g/mg.min obtained at temperature of 30 °C and adsorbent dosageof 0,5 gr. The maximum value of adsorption kinetic constant was 9,755 g/mg.min obtained at temperature of 50 °C and adsorbent dosage of 1,5 gr. The appropriate model for adsorption kinetics followed the pseudo second order.

Ion imprinted activated carbon solid-phase extraction coupled to flame atomic absorption spectrometry for selective determination of lead ions in environmental samples

International Nuclear Information System (INIS)

Naraghi, Kiyana; Panahi, Homayon Ahmad; Hassani, Amir Hesam; Moniri, Elham

2014-01-01

A simple lead ion imprinted sorbent was synthesized by coupling activated carbon with a known metal chelating compound, iminodiacetic acid. The ion imprinted sorbent has been characterized using Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis and subjected for the extraction and determination of trace Pb(II) in environmental water samples. The optimum pH value for sorption of the lead ion was 6.5. The sorption capacity of lead imprinted sorbent was 42.2 mg g"−"1. The chelating imprinted sorbent can be reused for five cycles of sorption-desorption without any significant change in sorption capacity. Compared with non-imprinted polymer particles, the lead ion imprinted sorbent showed high adsorption capacity, significant selectivity, good site accessibility for Pb(II). The equilibrium adsorption data of Pb(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models

The SPS as accelerator of Pb$^{82+}$ ions

CERN Document Server

Faugier, A; Bailey, R; Blanchard, R R; Bohl, T; Brouzet, E; Burkhardt, H; Collier, Paul; Cornelis, Karel; de Rijk, G; Ferioli, F; Hilaire, A; Lamont, M; Linnecar, Trevor Paul R; Jonker, M; Niquille, C; Roy, G; Schmickler, Hermann

1996-01-01

In 1994 the CERN SPS was used for the first time to accelerate fully stripped ions of the Pb208 isotope from the equivalent proton momentum of 13 GeV/c to 400 GeV/c. In the CERN PS, which was used as injector, the lead was accelerated as Pb53+ ions and then fully stripped in the transfer line from PS to SPS. The radio frequency swing which is needed in order to keep the synchronism during acceleration is too big to have the SPS cavities deliver enough voltage for all frequencies. For that reason a new technique of fixed frequency acceleration was used. With this technique up to 70% of the injected beam could be captured and accelerated up to the extraction energy, the equivalent of 2.2 1010 charges. The beam was extracted over a 5 sec. long spill and was then delivered to different experiments at the same time.

Optimization of simultaneous electrochemical determination of Cd(II), Pb(II), Cu(II) and Hg(II) at carbon nanotube-modified graphite electrodes.

Science.gov (United States)

Pikna, L'ubomír; Heželová, Mária; Kováčová, Zuzana

2015-01-01

The health of the environment is worsening every day. Monitoring of potentially toxic elements and remediation of environmental pollution are necessary. Therefore, the research and development of simple, inexpensive, portable and effective sensors is important. Electrochemistry is a useful component of the field of environment monitoring. The present study focuses on evaluating and comparing three types of electrodes (PIGE, PIGE/MWCNT/HNO3 and PIGE/MWCNT/EDTA/HNO3) employed for the simultaneous electrochemical determination of four potentially toxic elements: Cd(II), Pb(II), Cu(II) and Hg(II). Cyclic voltammograms were measured in an acetate buffer. The LOD, LOQ, the standard and relative precisions of the method and a prediction intervals were calculated (according to the technical procedure DIN 32 645) for the three electrodes and for each measured element. The LOD for PIGE/CNT/HNO3 (the electrode with narrowest calculated prediction intervals) was 2.98 × 10(-7) mol L(-1) for Cd(II), 4.83 × 10(-7) mol L(-1) for Pb(II), 3.81 × 10(-7) mol L(-1) for Cu(II), 6.79 × 10(-7) mol L(-1) for Hg(II). One of the benefits of this study was the determination of the amount of Hg(II) in the mixture of other elements.

Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls.

Science.gov (United States)

Rao, M Madhava; Ramana, D K; Seshaiah, K; Wang, M C; Chien, S W Chang

2009-07-30

Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g(-1) for Pb(II), 21.2 mg g(-1) for Zn(II), 19.5 mg g(-1) for Cu(II), and 15.7 mg g(-1) for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls

International Nuclear Information System (INIS)

Rao, M. Madhava; Ramana, D.K.; Seshaiah, K.; Wang, M.C.; Chien, S.W. Chang

2009-01-01

Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g -1 for Pb(II), 21.2 mg g -1 for Zn(II), 19.5 mg g -1 for Cu(II), and 15.7 mg g -1 for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium.

Science.gov (United States)

Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

2016-02-23

In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O8(2-) system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01-100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

International Nuclear Information System (INIS)

Xue Yongjie; Hou Haobo; Zhu Shujing

2009-01-01

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO 3 . In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH 50 (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

Energy Technology Data Exchange (ETDEWEB)

Xue Yongjie [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China); Wuhan Kaidi Electric Power Environmental Protection Co. Ltd., Hubei, Wuhan (China)], E-mail: xueyj@mail.whut.edu.cn; Hou Haobo; Zhu Shujing [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China)

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO{sub 3}. In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH{sub 50} (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag.

Science.gov (United States)

Xue, Yongjie; Hou, Haobo; Zhu, Shujing

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01M NaNO(3). In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84mM in the single element system and 0.21mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH(50) (the pH at which 50% adsorption occurs) was found to follow the sequence Zn>Cu>Pb>Cd in single-element systems, but Pb>Cu>Zn>Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

A new insight on the core–shell structure of zerovalent iron nanoparticles and its application for Pb(II) sequestration

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yalei, E-mail: zhangyalei@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China); Key Laboratory of Yangtze Water Environment for Ministry of Education, Tongji University, Shanghai 200092 (China); Su, Yiming [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China); Zhou, Xuefei, E-mail: zhouxuefei@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China); Dai, Chaomeng [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China); College of Civil Engineering, Tongji University, Shanghai 200092 (China); Keller, Arturo A. [Bren School of Environmental Science and Management, University of California, Santa Barbara (United States)

2013-12-15

Highlights: • The shell of nZVI is composed of 45.5% Fe(OH){sub 3} and 54.5% FeOOH. • Fe(OH){sub 3} shell suppresses the reduction of Pb(II). • Fe(OH){sub 3} shell greatly promotes the co-precipitation and adsorption of Pb(II). • pH < 4.5 favors Fe dissolution, while pH > 4.5 promotes Pb(II) adsorption. • A reaction between Fe{sup 0} core, Fe(OH){sub 3} and Pb(II) is proposed. -- Abstract: Nanoscale zerovalent iron (nZVI) has shown a high efficacy for removing heavy metals from liquid solution. However, its removal capacity has not been fully explored due to its common shell composition (FeOOH). In this study, a much higher removal capacity of Pb(II) is observed (1667 mg Pb(II)/g Fe), which is over 100% higher than the highest removal capacity of nZVI reported before. High-resolution X-ray photoelectron spectroscopy (HR-XPS) reveals that through restricting the dehydration process of Fe(OH){sub 3}, nZVI can acquire a unique shell, which is composed of 45.5% Fe(OH){sub 3} and 54.5% FeOOH. The presence of Fe(OH){sub 3} suppresses the reduction of Pb(II), but greatly promotes the co-precipitation and adsorption of Pb(II). Combining the ratio of Fe-released to Pb-immobilized and the result of HR-XPS, a reaction between Fe{sup 0} core, Fe(OH){sub 3}, and Pb(II) is proposed. The Fe released from the Fe{sup 0} core leads to the core depletion, observed by transmission electron microscopy (TEM) under high Pb(II) loading. While temperature has little influence on the removal capacity, pH affects the removal capacity greatly. pH < 4.5 favors Fe dissolution, while pH > 4.5 promotes Pb(II) adsorption. Given the high Pb removal capacity via the Fe(OH){sub 3} shell, nZVI can be used to remedy Pb(II) contamination.

Ion imprinted activated carbon solid-phase extraction coupled to flame atomic absorption spectrometry for selective determination of lead ions in environmental samples

Energy Technology Data Exchange (ETDEWEB)

Naraghi, Kiyana; Panahi, Homayon Ahmad; Hassani, Amir Hesam [Islamic Azad University, Tehran (Korea, Republic of); Moniri, Elham [Islamic Azad University, Varamin (Iran, Islamic Republic of)

2014-10-15

A simple lead ion imprinted sorbent was synthesized by coupling activated carbon with a known metal chelating compound, iminodiacetic acid. The ion imprinted sorbent has been characterized using Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis and subjected for the extraction and determination of trace Pb(II) in environmental water samples. The optimum pH value for sorption of the lead ion was 6.5. The sorption capacity of lead imprinted sorbent was 42.2 mg g{sup −1}. The chelating imprinted sorbent can be reused for five cycles of sorption-desorption without any significant change in sorption capacity. Compared with non-imprinted polymer particles, the lead ion imprinted sorbent showed high adsorption capacity, significant selectivity, good site accessibility for Pb(II). The equilibrium adsorption data of Pb(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models.

Low-cost nanoparticles sorbent from modified rice husk and a copolymer for efficient removal of Pb(II) and crystal violet from water.

Science.gov (United States)

Masoumi, Arameh; Hemmati, Khadijeh; Ghaemy, Mousa

2016-03-01

In this work, preparation of adsorbent nanoparticles based on treated low-value agricultural by-product rice husk (TARH), and poly(methylmethacrylate-co-maleic anhydride), poly(MMA-co-MA), is reported for the removal of Pb(II) ion and Crystal violet dye from water. The prepared adsorbent was characterized by FT-IR, SEM, AFM, DLS, BET and Zeta potential. The metal ion adsorption capability was determined for rice husk (RH), TARH, crosslinked poly(MMA-co-MA) (CNR), and CNR@TARH nanoparticles. Different factors affecting the adsorption of Pb(II) such as pH, contact time, initial metal ion concentration and also temperature were studied to investigate adsorption isotherms, kinetics and thermodynamics. For the four tested adsorption isotherm models, the equilibrium sorption data for CNR@TARH nanoparticles obeyed the Langmuir isotherm equation with maximum sorption capacity of 93.45 mg g(-1). The kinetic adsorption data fitted best the Lagergren pseudo-second order model. Regeneration of adsorbent was easily performed by adsorption/desorption experiments followed for 4 cycles. Finally, the ability of the nanoparticles to remove Crystal violet dye from aqueous solution was also investigated by varying the initial dye concentration, pH and immersion time and the adsorption mechanism followed the second-order kinetic model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Propyl phthalimide-modified thiacalixphenyl[4]arene as a “turn on” chemosensor for Hg(II) ions

Energy Technology Data Exchange (ETDEWEB)

Modi, Krunal; Panchal, Urvi; Mehta, Viren; Panchal, Manthan; Kongor, Anita; Jain, V.K., E-mail: drvkjain@hotmail.com

2016-11-15

Thiacalixphenyl[4]arene tetra N-(3-propyl) phthalimide (TPTN3PPh), a novel thiacalixarene bearing a N-(3-bromopropyl) phthalimide group, was synthesized and characterized by Electrospray Ionization Mass Spectrometry (ESI-MS) and NMR. The ability of TPTN3PPh to recognize the cations Fe(III), Cu(II), Cd(II), Zn(II), Cr(II), Ca(II), Co(II), Mg(II), Ag(I), Pb(II), Sr(II), Hg (II), Th(II), Ba(II), Bi(II), K(I), and Na(I) was evaluated. Only Hg(II) was selectively and sensitively detected using a spectrofluorimetric method, with a detection limit as low as 3.10×10{sup −9} M. Analysis of the binding behavior of TPTN3PPh with Hg(II) revealed 1:2 complex formation. Real sample analysis detected nano levels of mercury ions in a waste water samples.

Melamine-based dendrimer amine-modified magnetic nanoparticles as an efficient Pb(II) adsorbent for wastewater treatment: Adsorption optimization by response surface methodology.

Science.gov (United States)

Jiryaei Sharahi, Fatemeh; Shahbazi, Afsaneh

2017-12-01

Magnetic Fe 3 O 4 nanoparticles with an average diameter of 64 nm was synthesized solvothermically and subsequently modified with melamine-based dendrimer amine (MDA-Fe 3 O 4 ) via grafting method. The synthesized materials were characterized using DLS, SEM, XRD, FTIR, VSM, TGA and elemental analysis techniques. The MDA-Fe 3 O 4 was employed for the efficient removal of Pb(II) ions from an aqueous solution. The adsorption efficiency was investigated in relation to the independent variables of Pb(II) concentration (80-250 mg L -1 ), pH of the solution (3-7), adsorbent dosage (0.1-0.5 g L -1 ) and temperature (10-40 °C) via a central composite design (CCD) using response surface methodology (RSM). The significance of independent variables and their interactions was tested using ANOVA at a 95% confidence limit (α = 0.05). A second-order quadratic model was established to predict the adsorption efficiency. Under the optimum condition (initial Pb(II) concentration = 110 mg L -1 , MDA-Fe 3 O 4 dosage = 0.49 g L -1 , pH = 5 and temperature = 30 °C) a removal percentage of 85.6% was obtained. The isotherm data fitted well to the Freundlich model within the concentration range of the experimental study. A maximum adsorption capacity of 333.3 mg g -1 was predicted by the Langmuir model. The adsorption rate of Pb(II) ions onto MDA-Fe 3 O 4 was in good agreement with the pseudo-second-order model (R 2  = 0.999; k 2  = 4.7 × 10 -4  g mg -1 min -1 ). Thermodynamically, adsorption was spontaneous and endothermic. The MDA-Fe 3 O 4 was successfully regenerated using 0.3 M HCl with little loss of adsorption capacity (≈7%) for five successive adsorption cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Formation of nanodots and enhancement of thermoelectric power induced by ion irradiation in PbTe:Ag composite thin films

Energy Technology Data Exchange (ETDEWEB)

Bala, Manju, E-mail: manjubala474@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Meena, Ramcharan; Gupta, Srashti; Pannu, Compesh [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Tripathi, Tripurari S. [Aalto University, Värmemansgränden 2, 02150 Espoo (Finland); Varma, Shikha [Institute of Physics, Bhubaneshwar, Odisha 751005 (India); Tripathi, Surya K. [Department of Physics, Panjab University, Chandigarh 160 014 (India); Asokan, K., E-mail: asokaniuac@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Avasthi, Devesh K. [Amity University, Noida 201313, Uttar Pradesh (India)

2016-07-15

Present study demonstrates an enhancement in thermoelectric power of 10% Ag doped PbTe (PbTe:Ag) thin films when irradiated with 200 keV Ar ion. X-ray diffraction showed an increase in crystallinity for both PbTe and PbTe:10Ag nano-composite films after Ar ion irradiation due to annealing of defects in the grain boundaries. The preferential sputtering of Pb and Te ions in comparison to Ag ions resulted in the formation of nano-dots. This was further confirmed by X-ray photoelectron spectroscopy (XPS). Such an enhancement in thermoelectric power of irradiated PbTe:10Ag films in comparison to pristine PbTe:10Ag film is attributed to the decrease in charge carrier concentration that takes part in the transport process via restricting the tunneling of carriers through the wider potential barrier formed at the interface of nano-dots.

Iminodiacetic acid functionalized polypyrrole modified electrode as Pb(II) sensor: Synthesis and DPASV studies

International Nuclear Information System (INIS)

Joseph, Alex; Subramanian, Sankaran; Ramamurthy, Praveen C.; Sampath, Srinivasan; Kumar, R. Vasant; Schwandt, Carsten

2014-01-01

Graphical abstract: - Abstract: An electrochemical lead ion sensor has been developed by modification of carbon paste electrode (CPE) using polypyrrole functionalized with iminodiacetic acid (IDA-PPy) containing carboxyl group. The electrochemical response of Pb 2+ ion on the IDA-PPy modified CPE has been evaluated and the controling parameters have been optimized using differential pulse anodic stripping voltammetry (DPASV). The IDA-PPy modified CPE shows a linear correlation for Pb 2+ concentrations in the range of 1 × 10 −6 to 5 × 10 −9 M and the lower detection limit of Pb 2+ has been found to be 9.6 × 10 −9 M concentration. Other tested metal ions, namely Cu 2+ , Cd 2+ , Co 2+ , Hg 2+ , Ni 2+ and Zn 2+ , do not exhibit any voltammetric stripping response below 1 × 10 −7 M concentration. However, the Pb 2+ response is affected in the presence of molar equivalents or higher concentrations of Cu 2+ , Cd 2+ and Co 2+ ions in binary systems with Pb 2+ , consequent to their ability to bind with iminodiacetic acid, while Hg 2+ , Ni 2+ and Zn 2+ do not interfere at all. A good correlation has been observed between the lead concentrations as analyzed by DPASV using IDA-PPy modified CPE and atomic absorption spectrophotometry for a lead containing industrial effluent sample

A novel magnetic ion imprinted polymer as a selective magnetic solid phase for separation of trace lead(II) ions from agricultural products, and optimization using a Box-Behnken design.

Science.gov (United States)

Dahaghin, Zohreh; Mousavi, Hassan Zavvar; Sajjadi, S Maryam

2017-12-15

In this work, a magnetic ion-imprinted polymer (Fe 3 O 4 @SiO 2 @IIP) as a novel and selective nanosorbent for selective extraction of Pb(II) ions from various agricultural products is presented. The novel lead magnetic ion-imprinted polymer was synthesized by imidazole as a new ligand and grafted onto the surface of Fe 3 O 4 @SiO 2 NPs. A Box-Behnken (BBD) design was used for optimization of the extraction and elution steps. In the selected conditions, the limit of detection was 0.48ngmL -1 , preconcentration factor was 300, the sorption capacity of this new magnetic ion-imprinted polymer was 105mgg -1 , and the precision of the method (RSD%) for six replicate measurements was found 3.2%. Finally, the feasibility of the new magnetic ion-imprinted polymer was evaluated by extraction and determination of trace Pb 2+ ions in different agricultural products including (orange, mango, apple, kiwi, lettuce, broccoli, carrot, squash, eggplant, radish, mushroom, cucumber, and tomato). Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

Science.gov (United States)

Gündüz, Z. Yurtman; Gündüz, C.; Özpınar, C.; Urucu, O. Aydın

2015-02-01

A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5‧-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, 1H NMR, 13C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K+, Na+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu2+ ions were also investigated using quantum chemical computations.

Crystal and morphological phase transformation of Pb(II) to Pb(IV) in chlorinated water

International Nuclear Information System (INIS)

Lytle, Darren A.; White, Colin; Nadagouda, Mallikarjuna N.; Worrall, Adam

2009-01-01

Herein, we show an important transformation of Pb(II) to Pb(IV) in chlorinated water under laboratory conditions. The study results will give an insight toward understanding how corrosion by-products on lead materials found in drinking water distribution systems develop and breakdown with time. The experiments were conducted to elucidate the morphology of lead (IV) oxide mineral transformation from hydrocerussite and its relationship to color change over a period of time. Scanning electron microscopy and transmission electron microscopy were used to describe the surface morphology, shape and size of lead solids. X-ray diffraction (XRD) analysis was performed to determine the mineral structure of lead solids. Solids analysis results were compared over a 14-day period of time to define changes in the crystal structure and morphology of lead solids. XRD analysis results of freshly synthesized lead solids showed that hydrocerussite, [Pb 3 (CO 3 ) 2 (OH) 2 ], was the only lead mineral present. After 14 days, a mixture of cerussite (PbCO 3 ) and α-PbO 2 and β-PbO 2 was present. Lead precipitates, i.e. hydrocerussite changed color from white to reddish brown confirming a transformation of the lead phase with time. This was correlated to a change in morphology from flower shaped crystals to hexagonal bars and submicron particles.

Investigation of Pb(II Removal from Synthetic Wastewater by Using Azolla Filiculoides Biomass

Directory of Open Access Journals (Sweden)

Davoud Balarak

2015-06-01

Full Text Available Background and Aim: Discharge of industrial wastewater containing Pb into the environment can have harmful effects in the live organisms. Therefore, Pb must be removed from polluted water using an effective method before being discharged into the environment. The purpose of the present study was to examine Pb removal using alga Azolla biomass. Materials and Methods: In this experimental study, removal of Pb(II was performed using Azolla biomass considering changes in time, pH, adsorbent dose, initial concentration of Pb and mixing speed. Experiments were performed in batch reactor in flasks on Shaker. , Atomic absorption spectrophotometry was used for Pb determination. All experiments were conducted in triplicate and the mean removal percent was reported. Finally, biosorption kinetic and equilibrium isotherms of adsorbent was investigated. Results: It was found that the higher removal efficiency of Pb occurred in pH 6 and aoptimum dsorbent dose 7 g/L. With increase in the initial concentration of Pb, removal efficincy decreased and with increasing of contact time and mixing speed,efficincy increased. Data also showed that the Langmuir isotherm and pseudo second-order kinetic are compliance. Conclusion: Azolla biomass is an efficient and low-cost adsorbent for removing of Pb (II from water and wastewater.

Highly selective and sensitive coumarin-triazole-based fluorometric 'turn-off' sensor for detection of Pb2+ ions.

Science.gov (United States)

Shaily; Kumar, Ajay; Parveen, Iram; Ahmed, Naseem

2018-06-01

Exposure to even very low concentrations of Pb 2+ is known to cause cardiovascular, neurological, developmental, and reproductive disorders, and affects children in particular more severely. Consequently, much effort has been dedicated to the development of colorimetric and fluorescent sensors that can selectively detect Pb 2+ ions. Here, we describe the development of a triazole-based fluorescent sensor L5 for Pb 2+ ion detection. The fluorescence intensity of chemosensor L5 was selectively quenched by Pb 2+ ions and a clear color change from colorless to yellow could be observed by the naked eye. Chemosensor L5 exhibited high sensitivity and selectivity towards Pb 2+ ions in phosphate-buffered solution [20 mM, 1:9 DMSO/H 2 O (v/v), pH 8.0] with a 1:1 binding stoichiometry, a detection limit of 1.9 nM and a 6.76 × 10 6  M -1 binding constant. Additionally, low-cost and easy-to-prepare test strips impregnated with chemosensor L5 were also produced for efficient of Pb 2+ detection and proved the practical use of this test. Copyright © 2018 John Wiley & Sons, Ltd.

The Role of Pectin in Pb Binding by Carrot Peel Biosorbents: Isoterm Adsorption Study

Science.gov (United States)

Hastuti, B.; Totiana, F.; Winiasih, R.

2018-04-01

Cheaply and abundantly biosorption available materials such as carrot peels can be a cost-efficient method for removing heavy metals from wastewater. To investigate the role pectin plays in metal binding by carrot peels, commerce pectin was compared. FTIR spectra confirmed the presence of carboxyl and hydroxyl groups in commerce pectin and carrot pectin. Isoterm experiments showed that all materials could remove Pb (II) ion. All of materials binding Pb (II) follow Freundlich models adsorption. The commerce pectin bindsPb (II) by involving energy 16.6 KJ/mole whereas pectin from carrot peel involves energy 21.09 KJ/mole. It indicates that commerce pectin binds the Pb (II) by physics adsorption whereas pectin from carrot peel by physics and chemical adsorption.

Modeling the adsorption of metal ions (Cu 2+, Ni 2+, Pb 2+) onto ACCs using surface complexation models

Science.gov (United States)

Faur-Brasquet, Catherine; Reddad, Zacaria; Kadirvelu, Krishna; Le Cloirec, Pierre

2002-08-01

Activated carbon cloths (ACCs), whose efficiency has been demonstrated for microorganics adsorption from water, were here studied in the removal of metal ions from aqueous solution. Two ACCs are investigated, they are characterized in terms of porosity parameters (BET specific surface area, percentage of microporosity) and chemical characteristics (acidic surface groups, acidity constants, point of zero charge). A first part consists in the experimental study of three metal ions removal (Cu 2+, Ni 2+ and Pb 2+) in a batch reactor. Isotherms modeling by Freundlich and Brunauer-Emmett-Teller (BET) equations enables the following adsorption order: Cu 2+>Ni 2+>Pb 2+ to be determined for adsorption capacities on a molar basis. It may be related to adsorbates characteristics in terms of electronegativity and ionic radius. The influence of adsorbent's microporosity is also shown. Adsorption experiments carried out for pH values ranging from 2 to 10 demonstrate: (i) an adsorption occurring below the precipitation pH; (ii) the strong influence of pH, with a decrease of electrostatic repulsion due to the formation of less charged hydrolyzed species coupled with a decrease of activated carbon surface charge as pH increases. The second part focuses on the modeling of adsorption versus the pH experimental data by the diffuse layer model (DLM) using Fiteql software. The model is efficient to describe the system behavior in the pH range considered. Regarding complexation constants, they show the following affinity for ACC: Pb 2+>Cu 2+>Ni 2+. They are related to initial concentrations used for the three metal ions.

Continuous adsorption of Pb(II) and methylene blue by engineered graphite oxide coated sand in fixed-bed column

Energy Technology Data Exchange (ETDEWEB)

Gong, Ji-Lai, E-mail: jilaigong@gmail.com [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zhang, Yong-Liang; Jiang, Yan [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zeng, Guang-Ming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Cui, Zhi-Hui; Liu, Ke; Deng, Can-Hui; Niu, Qiu-Ya; Deng, Jiu-Hua [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Huan, Shuang-Yan [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

2015-03-01

Highlights: • GO-sand was prepared by coating GO on the surface of sand. • Pb(II) and MB were efficiently removed by GO-sand filter in column. • The removal of MB was enhanced with the presence of Pb(II). • GO-sand is low-cost and convenient for its application as packed bed filter. - Abstract: The mixture of several effluents, caused by the improper handling and management of effluents, generated multi-component wastewater containing both metals and dyes, leading to the complicated treatment process. In this study, a continuous adsorption of Pb(II) and methylene blue (MB) has been studied in single and binary solutions by using graphite oxide coated sand (GO-sand) as an adsorbent in a fixed-bed column. GO-sand was analyzed by X-ray photoelectron spectroscopy before and after analyte adsorption. Compared with sand filter, adsorption quantity and capacity for Pb(II) and MB by GO-sand filter were greatly increased. In Pb(II) and MB single solutions, the experimental parameters were investigated in detail including initial concentration, flow rate, bed depth and pH. Exhaustion time decreased with increasing initial concentration and flow rate, and increased with increasing bed depth and pH. In the Pb(II)-MB binary solution, exhaustion time significantly decreased for Pb(II) adsorption, but increased for MB adsorption. The reason was explained that the more favorable adsorption for MB onto the surface of GO-sand than that for Pb(II), which was derived from π–π interaction between MB and GO on sand surface in packed filter. The Yoon–Nelson model was applied at different concentration of Pb(II) and MB to predict the breakthrough curves. The experimental data were well fit with the model indicating that it was suitable for this column design.

Adsorption efficiencies of calcium (II ion and iron (II ion on activated carbon obtained from pericarp of rubber fruit

Directory of Open Access Journals (Sweden)

Orawan Sirichote

2008-03-01

Full Text Available Determination of adsorption efficiencies of activated carbon from pericarp of rubber fruit for calcium (II ion and iron (II ion has been performed by flowing the solutions of these ions through a column of activated carbon. The weights of activated carbon in 500 mL buret column (diameter 3.2 cm for flowing calcium (II ion and iron (II ion solutions were 15 g and 10 g, respectively. The initial concentration of calcium ion was prepared to be about eight times more diluted than the true concentration found in the groundwater from the lower part of southern Thailand. Calcium (II ion concentrations were analysed by EDTA titration and its initial concentration was found to be 23.55 ppm. With a flow rate of 26 mL/min, the adsorption efficiency was 11.4 % with passed through volume 4.75 L. Iron (II ion concentrations were analysed by spectrophotometric method; its initial concentration was found to be 1.5565 ppm. At a flow rate of 22 mL/min, the adsorption efficiency was 0.42 % with passed through volume of 34.0 L.

Ultrafast exciton decay in PbS quantum dots through simultaneous electron and hole recombination with a surface-localized ion pair

Energy Technology Data Exchange (ETDEWEB)

Edme, Kedy; Bettis Homan, Stephanie; Nepomnyashchii, Alexander B.; Weiss, Emily A., E-mail: e-weiss@northwestern.edu

2016-06-01

Highlights: • We synthesize complexes of PbS quantum dots (QDs) and tetracyanoquinodimethane (TCNQ). Each PbS QD spontaneously reduces up to 17 TCNQ molecules. • The photoluminescence of the PbS QDs is quenched in the presence of the reduced TCNQ species through ultrafast non-radiative, simultaneous decay of the electron and hole. • We assign this decay to a four-carrier, concerted charge recombination mechanism with the surface localized sulfur–TCNQ{sup x−} ion pair. - Abstract: This paper describes the ultrafast decay of the band-edge exciton in PbS quantum dots (QDs) through simultaneous recombination of the excitonic hole and electron with the surface localized ion pair formed upon adsorption of tetracyanoquinodimethane (TCNQ). Each PbS QD (R = 1.8 nm) spontaneously reduces up to 17 TCNQ molecules upon adsorption of the TCNQ molecule to a sulfur on the QD surface. The photoluminescence of the PbS QDs is quenched in the presence of the reduced TCNQ species through ultrafast (⩽15-ps) non-radiative decay of the exciton; the rate constant for the decay process increases approximately linearly with the number of adsorbed, reduced TCNQ molecules. Near-infrared and mid-infrared transient absorption show that this decay occurs through simultaneous transfer of the excitonic electron and hole, and is assigned to a four-carrier, concerted charge recombination mechanism based on the observations that (i) the PL of the QDs recovers when spontaneously reduced TCNQ{sup 1−} desorbs from the QD surface upon addition of salt, and (ii) the PL of the QDs is preserved when another spontaneous oxidant, ferrocinium, which cannot participate in charge transfer in its reduced state, is substituted for TCNQ.

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingjing [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China); Li, Zhengkui, E-mail: zhkuili@nju.edu.cn [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China)

2015-12-30

Highlights: • A novel ion-imprinted poly(polyethylenimine/hydroxyethyl acrylate) hydrogel was synthesized. • The prepared hydrogel enhanced the selectivity of Cu(II) removal. • The material had high adsorption capacity and excellent regeneration property for copper. • The adsorption mechanism was the chelate interaction between functional groups and Cu(II) ions. - Abstract: A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by {sup 60}Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption–desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater.

Investigation of Pb(II Removal from Aqueous Solutions Using Modified Nano Zero-Valent Iron Particles

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Amirhossein Ramezanpoor

2014-05-01

Full Text Available This research was conducted in experimental scale with the aim of investigation effect of polyacrylic acid-stabilized zero-valent iron nanoparticles (PAA-nZVI on lead removal from aqueous solution. In this regards, NZVI was synthesized with polyacrylic acid and their size and morphological characteristics were examined via X-ray diffraction (XRD, Scanning Electron Microscopy (SEM and Fourier Transmission Infrared Spectroscopy (FTIR. To study the effect of PAA-nZVI on lead removal, pH of aqueous solution, contact time, PAA-NZVI concentration  and initial Pb(II concentration were considered as variables. Furthermore, the experimental data of Pb(II  removal were fitted using three kinetic models, namely Zero-order, First-order and Second-order.The results of experiments showed that maximum Pb(II removal efficiency was observed at pH=5, 15 min contact time and 5 g/L PAA-nZVI concentration. Moreover, the results of kinetic studies indicated that among all applied kinetic models, First-order kinetic model had more better prediction than other kinetic models ofPb(II removal. Based on the results of present research, PAA-NZVI is an efficient agent to remove Pb(II from aqueous solutions.

Comparative results on collimation of the SPS beam of protons and Pb ions with bent crystals

CERN Document Server

Scandale, W.; Assmann, R.; Bracco, C.; Cerutti, F.; Christiansen, J.; Gilardoni, S.; Laface, E.; Losito, R.; Masi, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Previtali, V.; Redaelli, S.; Valentino, G.; Schoofs, P.; Smirnov, G.; Tlustos, L.; Bagli, E.; Baricordi, S.; Dalpiaz, P.; Guidi, V.; Mazzolari, A.; Vincenzi, D.; Dabagov, S.; Murtas, F.; Carnera, A.; Della Mea, G.; De Salvador, D.; Lombardi, A.; Lytovchenko, O.; Tonezzer, M.; Cavoto, G.; Ludovici, L.; Santacesaria, R.; Valente, P.; Galluccio, F.; Afonin, A.G.; Bulgakov, M.K.; Chesnokov, Yu.A.; Maisheev, V.A.; Yazynin, I.A.; Kovalenko, A.D.; Taratin, A.M.; Uzhinskiy, V.V.; Gavrikov, Yu.A.; Ivanov, Yu.M.; Lapina, L.P.; Skorobogatov, V.V.; Ferguson, W.; Fulcher, J.; Hall, G.; Pesaresi, M.; Raymond, M.; Rose, A.; Ryan, M.; Zorba, O.; Robert-Demolaize, G.; Markiewicz, T.; Oriunno, M.; Wienands, U.

2011-01-01

New experiments on crystal assisted collimation have been carried out at the CERN SPS with stored beams of 120 Gev/c protons and Pb ions. Bent silicon crystals of 2 mm long with about 170 mu rad bend angle and a small residual torsion were used as primary collimators. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with the crystal nuclei is minimal. The loss reduction was about 6 for protons and about 3 for Pb ions. Lower reduction value for Pb ions can be explained by their considerably larger ionization losses in the crystal. In one of the crystals, the measured fraction of the Pb ion beam halo deflected in channeling conditions was 74\\%, a value very close to that for protons. The intensity of the off-momentum halo leaking out from the collimation station was measured in the first high dispersion area downstream. The particle population in the shadow of the secondary collimator-absorber was considerably smaller in channeling conditions than for amorphous orienta...

Lattice thermal transport in group II-alloyed PbTe

Science.gov (United States)

Xia, Yi; Hodges, James M.; Kanatzidis, Mercouri G.; Chan, Maria K. Y.

2018-04-01

PbTe, one of the most promising thermoelectric materials, has recently demonstrated a thermoelectric figure of merit (ZT) of above 2.0 when alloyed with group II elements. The improvements are due mainly to significant reduction of lattice thermal conductivity (κl), which was in turn attributed to nanoparticle precipitates. However, a fundamental understanding of various phonon scattering mechanisms within the bulk alloy is still lacking. In this work, we apply the newly-developed density-functional-theory-based compressive sensing lattice dynamics approach to model lattice heat transport in PbTe, MTe, and Pb0.94M0.06Te (M = Mg, Ca, Sr, and Ba) and compare our results with experimental measurements, with focus on the strain effect and mass disorder scattering. We find that (1) CaTe, SrTe, and BaTe in the rock-salt structure exhibit much higher κl than PbTe, while MgTe in the same structure shows anomalously low κl; (2) lattice heat transport of PbTe is extremely sensitive to static strain induced by alloying atoms in solid solution form; (3) mass disorder scattering plays a major role in reducing κl for Mg/Ca/Sr-alloyed PbTe through strongly suppressing the lifetimes of intermediate- and high-frequency phonons, while for Ba-alloyed PbTe, precipitated nanoparticles are also important.

Synthesis, characterization and application of Lanthanide metal-ion-doped TiO2/bentonite nanocomposite for removal of Lead (II and Cadmium (II from aquatic media

Directory of Open Access Journals (Sweden)

Susan Samadi

2016-07-01

Full Text Available The efficient application of the photocatalytic activity and superficial adsorption on removing heavy metals from water, two types of sorbents, Nd-TiO2/bentonite and Ce-TiO2/bentonite nanocomposites, were synthesized by sol-gel method. The crystalline nanocomposites were obtained after heat treatment at 500 °C for 3 hours. The results of scanning electron microscopy (SEM indicates that Nd-TiO2/bentonite and Ce-TiO2/bentonite were produced on a nanoscale. The phase change of both nanocomposite from amorphous to anatase has been investigated by X- ray diffraction. Removal of lead (II and cadmium (II were studied through adsorption on these nanocomposites by letting them float in the bulk of sample for a definite time in presence and absence of light. The effective parameters in removal process were studied and optimized. The optimum pH, removal time and sorbent dosage in the absence and presence of light for Pb2+ ion were 7, 0.3 g, 15 min and for Cd2+ ion were 7, 0.4 g, 20 min, respectively. Subsequently, the effect of interfering ions in removal process was investigated at optimum conditions and no evidence of interference was observed. The study showed that reproducibility of method (n=9 is good and suitable. The results further indicated that the removal efficiency of Pb2+ ion with Nd-TiO2/bentonite in the presence of light was more than that in the absence of light. Finally, the equilibrium adsorption data fitted Freundlich and Langmuir adsorption models.

A dip-and-read test strip for the determination of mercury(II) ion in aqueous samples based on urease activity inhibition.

Science.gov (United States)

Shi, Guo-Qing; Jiang, Guibin

2002-11-01

A sensitive dip-and-read test strip for the determination of mercury in aqueous samples based on the inhibition of urease reaction by the ion has been developed. The strip has a circular sensing zone that containing two layers: the top layer is a cellulose acetate membrane where urease is immobilized on it; the bottom layer is a pH indicator wafer that is impregnated with urea. The principle of the measurement is based on the disappearance of a yellow spot on the pH indicator wafer. The elapsing time until the disappearance of the spot which depends on the concentration of mercury(II) ion is measured with a stopwatch. Under the experimental conditions, as low as 0.2 ng/ml mercury can be observed with the detection range from 0.2 to 200 ng/ml in water. Organomercury compounds give essentially the same response as inorganic mercury. Heavy-metal ions such as Ag(I), Cu(II), Cd(II), Ni(II), Zn(II), and Pb(II) as well as other sample matrixes basically do not interfere with the mercury measurement.

Doppler-shift assisted fast ion spectroscopy: a case study for X-ray emission from 277 MeV/u Pb[81+] ions

International Nuclear Information System (INIS)

Mokler, P.H.; Stoehlker, T.; Kozhuharov, C.; Moshammer, R.; Rymuza, P.; Stachura, Z.; Warczak, A.

1994-09-01

Utilizing the different information from spatially separated segments of high-granular photon detectors the measured (LAB) energy of photons emitted by fast moving ions can be corrected individually for the Doppler effect according to the particular observation angles of each detector segment. By a redundant fitting procedure the center of mass photon energy can be determined with high precision. This new Doppler-shift assisted spectroscopy is explained for the case study of 277.4 MeV/u Pb 82+ ions colliding with a N 2 -gas target at the heavy ion storage ring ESR. Spectroscopic information for hydrogenic Pb 81+ ions is given for the ground-state transitions, for the Balmer transitions, as well as for the total K-binding energy. (orig.)

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms.

Science.gov (United States)

Wang, Jingjing; Li, Zhengkui

2015-12-30

A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by (60)Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption-desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

Solid phase extraction of heavy metal ions based on a novel functionalized magnetic multi-walled carbon nanotube composite with the aid of experimental design methodology

International Nuclear Information System (INIS)

Taghizadeh, Mohsen; Asgharinezhad, Ali Akbar; Samkhaniany, Noorallah; Tadjarodi, Azadeh; Abbaszadeh, Abolfazl; Pooladi, Mohsen

2014-01-01

We report that magnetic multiwalled carbon nanotubes functionalized with 8-aminoquinoline can be applied to the preconcentration of Cd(II), Pb(II) and Ni(II) ions. The parameters affecting preconcentration were optimized by a Box-Behnken design through response surface methodology. Three variables (extraction time, magnetic sorbent amount, and pH value) were selected as the main factors affecting sorption, and four variables (type, volume and concentration of the eluent; elution time) were selected for optimizing elution. Following sorption and elution, the ions were quantified by FAAS. The LODs are 0.09, 0.72, and 1.0 ng mL −1 for Cd(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations are <5.1 % for five separate batch determinations at 30 ng mL −1 level of Cd(II), Ni(II), and Pb(II) ions. The sorption capacities (in mg g −1 ) of this new sorbent are 201 for Cd(II), 150 for Pb(II), and 172 Ni(II). The composite was successfully applied to the rapid extraction of trace quantities of heavy metal ions in fish, sediment, soil, and water samples. (author)

A novel magnetic metal organic framework nanocomposite for extraction and preconcentration of heavy metal ions, and its optimization via experimental design methodology

International Nuclear Information System (INIS)

Taghizadeh, Mohsen; Asgharinezhad, Ali Akbar; Pooladi, Mohsen; Barzin, Mahnaz; Abbaszadeh, Abolfazl; Tadjarodi, Azadeh

2013-01-01

We describe a novel magnetic metal-organic framework (MOF) prepared from dithizone-modified Fe 3 O 4 nanoparticles and a copper-(benzene-1,3,5-tricarboxylate) MOF and its use in the preconcentration of Cd(II), Pb(II), Ni(II), and Zn(II) ions. The parameters affecting preconcentration were optimized by a Box-Behnken design through response surface methodology. Three variables (extraction time, amount of the magnetic sorbent, and pH value) were selected as the main factors affecting adsorption, while four variables (type, volume and concentration of the eluent; desorption time) were selected for desorption in the optimization study. Following preconcentration and elution, the ions were quantified by FAAS. The limits of detection are 0.12, 0.39, 0.98, and 1.2 ng mL −1 for Cd(II), Zn(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations were −1 of Cd(II), Zn(II), Ni(II), and Pb(II) ions. The adsorption capacities (in mg g −1 ) of this new MOF are 188 for Cd(II), 104 for Pb(II), 98 Ni(II), and 206 for Zn(II). The magnetic MOF nanocomposite has a higher capacity than the Fe 3 O 4 /dithizone conjugate. This magnetic MOF nanocomposite was successfully applied to the rapid extraction of trace quantities of heavy metal ions in fish, sediment, soil, and water samples. (author)

U and Pb isotope analysis of uraninite and galena by ion microprobe

Energy Technology Data Exchange (ETDEWEB)

Evins, L.Z.; Sunde, T.; Schoeberg, H. [Swedish Museum of Natural History, Stockholm (Sweden). Laboratory for Isotope Geology; Fayek, M. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences

2001-10-01

Accurate isotopic analysis of minerals by ion microprobe, or SIMS (Secondary Ion Mass Spectrometry) usually requires a standard to correct for instrumental mass bias effects that occur during analysis. We have calibrated two uraninite crystals and one galena crystal to be used as ion probe standards. As part of this study we describe the analytical procedures and problems encountered while trying to establish fractionation factors for U and Pb isotopes measured in galena and uraninite. Only the intra-element isotopic mass fractionation is considered and not the interelement fractionation. Galena and uraninite were analysed with TIMS (Thermal Ionisation Mass Spectrometry) prior to SIMS. One uraninite crystal (P88) comes from Sweden and is ca 900 Ma old, the other from Maine, USA (LAMNH-30222) and is ca 350 Ma old. The galena sample comes from the Paleoproterozoic ore district Bergslagen in Sweden. SIMS analyses were performed at two different laboratories: the NORDSM facility in Stockholm, which has a high resolution Cameca IMS 1270 ion microprobe, and the Oak Ridge National Laboratory (ORNL) in Tennessee, which has a Cameca IMS 4f ion microprobe. The results show that during the analysis of galena, Pb isotopes fractionate in favour of the lighter isotope by as much as 0.5%/amu. A Pb isotope fractionation factor for uraninite was more difficult to calculate, probably due to the formation of hydride interferences encountered during analysis with the Cameca IMS 1270 ion microprobe. However, drying the sample in vacuum prior to analysis, and using high-energy filtering and a cold trap during analysis can minimise these hydride interferences. A large fractionation of U isotopes of ca 1.4%/amu in favour of the lighter isotope was calculated for uraninite.

U and Pb isotope analysis of uraninite and galena by ion microprobe

International Nuclear Information System (INIS)

Evins, L.Z.; Sunde, T.; Schoeberg, H.; Fayek, M.

2001-10-01

Accurate isotopic analysis of minerals by ion microprobe, or SIMS (Secondary Ion Mass Spectrometry) usually requires a standard to correct for instrumental mass bias effects that occur during analysis. We have calibrated two uraninite crystals and one galena crystal to be used as ion probe standards. As part of this study we describe the analytical procedures and problems encountered while trying to establish fractionation factors for U and Pb isotopes measured in galena and uraninite. Only the intra-element isotopic mass fractionation is considered and not the interelement fractionation. Galena and uraninite were analysed with TIMS (Thermal Ionisation Mass Spectrometry) prior to SIMS. One uraninite crystal (P88) comes from Sweden and is ca 900 Ma old, the other from Maine, USA (LAMNH-30222) and is ca 350 Ma old. The galena sample comes from the Paleoproterozoic ore district Bergslagen in Sweden. SIMS analyses were performed at two different laboratories: the NORDSM facility in Stockholm, which has a high resolution Cameca IMS 1270 ion microprobe, and the Oak Ridge National Laboratory (ORNL) in Tennessee, which has a Cameca IMS 4f ion microprobe. The results show that during the analysis of galena, Pb isotopes fractionate in favour of the lighter isotope by as much as 0.5%/amu. A Pb isotope fractionation factor for uraninite was more difficult to calculate, probably due to the formation of hydride interferences encountered during analysis with the Cameca IMS 1270 ion microprobe. However, drying the sample in vacuum prior to analysis, and using high-energy filtering and a cold trap during analysis can minimise these hydride interferences. A large fractionation of U isotopes of ca 1.4%/amu in favour of the lighter isotope was calculated for uraninite

Silver-bearing minerals in the Xinhua hydrothermal vein-type Pb-Zn deposit, South China

Science.gov (United States)

Wang, Minfang; Zhang, Xubo; Guo, Xiaonan; Pi, Daohui; Yang, Meijun

2018-02-01

Electron probe microanalysis (EPMA) results are reported for newly identified silver-bearing minerals from the Xinhua deposit, Yunkaidashan area, South China. The Xinhua deposit is a hydrothermal vein-type Pb-Zn deposit and is hosted in the Pubei Complex, which consists of a cordierite-biotite granite with a U-Pb zircon age of 244.3 ± 1.8-251.9 ± 2.2 Ma. The mineralization process is subdivided into four mineralization stages, characterized by the following mineral associations: mineralization stage I with quartz, pyrite, and sphalerite; mineralization stage II with siderite, galena, and tetrahedrite; mineralization stage III with quartz and galena; and mineralization stage IV with quartz, calcite, and baryte. Tetrahedrite series minerals, such as freibergite, argentotetrahedrite, and tennantite are the main Ag-bearing minerals in the Xinhua deposit. The greatest concentration of silver occurs in phases from mineralization stage II. Microscopic observations reveal close relationship between galena and tetrahedrite series minerals that mostly occur as irregular inclusions within galena. The negative correlation between Cu and Ag in the lattices of tetrahedrite series minerals suggests that Cu sites are occupied by Ag atoms. Zn substitution for Fe in argentotetrahedrite and Cd substitution for Pb in tetrahedrite are also observed. Micro-thermometric data reveal that both homogenization temperatures and calculated salinities of hydrothermal fluids decrease progressively from the early to the later mineralization stages. The metal ions, such as Ag+, Cu+, Pb2+, and Zn2+, are transported as chlorine complex ions in the early mineralization stage and as bisulfide complex ions in the late mineralization stage, caused by changes in oxygen fugacity, temperature, and pH of the hydrothermal fluids. Because of the varying solubility of different metal ions, Pb2+, Zn2+, and Cu2+ ions are initially precipitated as galena, sphalerite, and chalcopyrite, respectively. With

Removal of Pb(II) from wastewater using Al2O3-NaA zeolite composite hollow fiber membranes synthesized from solid waste coal fly ash.

Science.gov (United States)

Zhu, Li; Ji, Jiayou; Wang, Shulin; Xu, Chenxi; Yang, Kun; Xu, Man

2018-09-01

Al 2 O 3 -NaA zeolite composite hollow fiber membranes were successfully fabricated via hydrothermal synthesis by using industrial solid waste coal fly ash and porous Al 2 O 3 hollow fiber supports. The as-synthesized Al 2 O 3 -NaA zeolite composite hollow fiber membranes were then characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The hollow fiber membranes were used to remove lead ions (Pb(II), 50 mg L -1 ) from synthetic wastewater with a removal efficiency of 99.9% at 0.1 MPa after 12 h of filtration. This study showed that the Al 2 O 3 -NaA zeolite composite hollow fiber membranes (the pore size of the membrane was about 0.41 nm in diameter) synthesized from coal fly ash could be efficiently used for treating low concentration Pb(II) wastewater. It recycled solid waste coal fly ash not only to solve its environment problems, but also can produce high-value Al 2 O 3 -NaA zeolite composite hollow fiber membranes for separation application in treating wastewater containing Pb(II). Copyright © 2018 Elsevier Ltd. All rights reserved.

Adsorption of Pb(II by Activated Pyrolytic Char from Used Tire

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Lu Ping

2016-01-01

Full Text Available As a renewable resource, the pyrolytic char derived from used tire has promising adsorption capacities owing to its similar structure and properties with active carbon. The purification and activation of the pyrolytic char from used tire, as well as the application of this material in the adsorption of Pb(II in water is conducted. The influences on the adsorption capacity by temperature and pH value are investigated and discussed; the adsorption thermodynamics and kinetics are also studied. The results show that the pyrolytic char from used tire has remarkable adsorption capacity for Pb(II, and the adsorption is an endothermic process complying with the Langmuir isotherm. The adsorption kinetics is a pseudo second-order reaction.

Intrinsic Lead Ion Emissions in Zero-Dimensional Cs4PbBr6 Nanocrystals

KAUST Repository

Yin, Jun; Zhang, Yuhai; Bruno, Annalisa; Soci, Cesare; Bakr, Osman; Bredas, Jean-Luc; Mohammed, Omar F.

2017-01-01

-energy UV emission at approximately 350 nm to the allowed optical transition of 3P1 to 1S0 in Pb2+ ions and the low-energy UV emission at approximately 400 nm to the charge-transfer state involved in the 0D NC host lattice (D-state). In the emissive Cs4PbBr6

Chemically-modified activated carbon with ethylenediamine for selective solid-phase extraction and preconcentration of metal ions.

Science.gov (United States)

Li, Zhenhua; Chang, Xijun; Zou, Xiaojun; Zhu, Xiangbing; Nie, Rong; Hu, Zheng; Li, Ruijun

2009-01-26

A new method that utilizes ethylenediamine-modified activated carbon (AC-EDA) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The new sorbent was prepared by oxidative surface modification. Experimental conditions for effective adsorption of trace levels of Cr(III), Fe(III), Hg(II) and Pb(II) were optimized with respect to different experimental parameters using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.0. Complete elution of absorbed metal ions from the sorbent surface was carried out using 3.0 mL of 2% (%w/w) thiourea and 0.5 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.4, 28.9, 60.5 and 49.9 mg g(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The time for 94% adsorption of target metal ions was less than 2 min. The detection limits of the method was found to be 0.28, 0.22, 0.09 and 0.17 ng mL(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The precision (R.S.D.) of the method was lower 4.0% (n=8). The prepared sorbent as solid-phase extractant was successfully applied for the preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) in natural and certified samples with satisfactory results.

An Electrochemical Sensor Based on Novel Ion Imprinted Polymeric Nanoparticles for Selective Detection of Lead Ions

Directory of Open Access Journals (Sweden)

Masoud Ghanei-Motlagh

1999-11-01

Full Text Available In this study, the novel surface ion-imprinted polymer (IIP particles were prepared and applied as a electrode modifier in stripping voltammetric detection of lead(II ion. A carbon paste electrode (CPE modified with IIP nanoparticles and multi-walled carbon nanotubes (MWCNTs was used for accumulation of toxic lead ions. Various factors that govern on electrochemical signals including carbon paste composition, pH of the preconcentration solution, supporting electrolyte, stirring time, reduction potential and time were studied in detail. The best electrochemical response for Pb(II ions was obtained with a paste composition of 7% (w/w of lead IIP, 10% MWCNTs, 53% (w/w of graphite powder and 30% (w/w of paraffin oil using a solution of 0.1 mol L-1 acetat buffer solution (pH=4.5 with a extraction time of 15 min. A sensitive response for Pb(II ions in the concentration range of 3 to 55 µg L-1 was achived. The proposed electrochemical sensor showed low detection limit (0.5 µg L-1, remarkable selectivity and good reproducibility (RSD = 3.1%. Determination of lead(II content in different environmental water samples was also realized adopting graphite furnace atomic absorptions spectrometry (GF-AAS and the obtained results were satisfactory.

Removal of industrial dyes and heavy metals by Beauveria bassiana: FTIR, SEM, TEM and AFM investigations with Pb(II).

Science.gov (United States)

Gola, Deepak; Malik, Anushree; Namburath, Maneesh; Ahammad, Shaikh Ziauddin

2017-10-01

Presence of industrial dyes and heavy metal as a contaminant in environment poses a great risk to human health. In order to develop a potential technology for remediation of dyes (Reactive remazol red, Yellow 3RS, Indanthrene blue and Vat novatic grey) and heavy metal [Cu(II), Ni(II), Cd(II), Zn(II), Cr(VI) and Pb(II)] contamination, present study was performed with entomopathogenic fungi, Beauveria bassiana (MTCC no. 4580). High dye removal (88-97%) was observed during the growth of B. bassiana while removal percentage for heavy metals ranged from 58 to 75%. Further, detailed investigations were performed with Pb(II) in terms of growth kinetics, effect of process parameters and mechanism of removal. Growth rate decreased from 0.118 h -1 (control) to 0.031 h -1 , showing 28% reduction in biomass at 30 mg L -1 Pb(II) with 58.4% metal removal. Maximum Pb(II) removal was observed at 30 °C, neutral pH and 30 mg L -1 initial metal concentration. FTIR analysis indicated the changes induced by Pb(II) in functional groups on biomass surface. Further, microscopic analysis (SEM and atomic force microscopy (AFM)) was performed to understand the changes in cell surface morphology of the fungal cell. SEM micrograph showed a clear deformation of fungal hyphae, whereas AFM studies proved the increase in surface roughness (RSM) in comparison to control cell. Homogenous bioaccumulation of Pb(II) inside the fungal cell was clearly depicted by TEM-high-angle annular dark field coupled with EDX. Present study provides an insight into the mechanism of Pb(II) bioremediation and strengthens the significance of using entomopathogenic fungus such as B. bassiana for metal and dye removal.

Biosorption of copper(II) and lead(II) onto potassium hydroxide treated pine cone powder.

Science.gov (United States)

Ofomaja, A E; Naidoo, E B; Modise, S J

2010-08-01

Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures. As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g(-1) for copper(II) and from 23.74 to 26.27 for lead(II). Activation energy was higher for lead(II) (22.40 kJ mol(-1)) than for copper(II) (20.36 kJ mol(-1)). The free energy of activation was higher for lead(II) than for copper(II) and the values of DeltaH* and DeltaS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption. Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin-Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

Effectively simultaneous naked-eye detection of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin extracted from red cabbage as chelating agent

Science.gov (United States)

Khaodee, Warangkhana; Aeungmaitrepirom, Wanlapa; Tuntulani, Thawatchai

Simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin as a chelating agent was investigated in terms of both quantitative and qualitative detections. Cyanidin was extracted and purified from red cabbage which is a local plant in Thailand. The selectivity of this method was examined by regulating the pH of cyanidin solution operated together with masking agents. It was found that Cu(II), Pb(II), Al(III) and Fe(III) simultaneously responded with the color change at pH 7, pH 6, pH 5 and pH 4, respectively. KF, DMG and the mixture of KF and DMG were used as masking agents for the determination of Fe(III), Al(III) and Pb(II), respectively. Results from naked-eye detection were evaluated by comparing with those of inductively coupled plasma (ICP), and there was no significant difference noticed. Cyanidin using as a multianalyte reagent could be employed for simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) at the lowest concentration at 50, 80, 50 and 200 μM, respectively, by slightly varying pHs. Moreover, the proposed method could be potentially applied for real water samples with simplicity, rapidity, low cost and environmental safety.

Adsorption of aqueous Cd(II) and Pb(II) on activated carbon nanopores prepared by chemical activation of doum palm shell.

Science.gov (United States)

Gaya, Umar Ibrahim; Otene, Emmanuel; Abdullah, Abdul Halim

2015-01-01

Non-uniformly sized activated carbons were derived from doum palm shell, a new precursor, by carbonization in air and activation using KOH, NaOH and ZnCl2. The activated carbon fibres were characterised by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, particle size analysis and evaluated for Cd(II) and Pb(II) removal. The 40-50 nm size, less graphitic, mesoporous NaOH activated carbon yielded high adsorption efficiency, pointing largely to the influence surface area. The performance of the KOH based activated carbon was arguably explained for the first time in terms of crystallinity. The efficiencies of the mesoporous ZnCl2-formulated activated carbon diminished due to the presence of larger particles. Batch adsorption of divalent metals revealed dependence on adsorbent dose, agitation time, pH and adsorbate concentrations with high adsorption efficiencies at optimum operating parameters. The equilibrium profiles fitted Langmuir and Freundlich isotherms, and kinetics favoured pseudo-second order model. The study demonstrated the practicability of the removal of alarming levels of cadmium and lead ions from industrial effluents.

1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions

Energy Technology Data Exchange (ETDEWEB)

Tu Zhifeng; He Qun [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chang, Xijun, E-mail: tuzhf07@lzu.cn [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Hu Zheng; Gao Ru; Zhang Lina; Li Zhenhua [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

2009-09-07

A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L{sup -1} HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g{sup -1} for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL{sup -1} for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n = 8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.

1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions.

Science.gov (United States)

Tu, Zhifeng; He, Qun; Chang, Xijun; Hu, Zheng; Gao, Ru; Zhang, Lina; Li, Zhenhua

2009-09-07

A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.

1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions

International Nuclear Information System (INIS)

Tu Zhifeng; He Qun; Chang, Xijun; Hu Zheng; Gao Ru; Zhang Lina; Li Zhenhua

2009-01-01

A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L -1 HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g -1 for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL -1 for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n = 8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.

A Bacillus sp. isolated from sediments of the Sarno River mouth, Gulf of Naples (Italy) produces a biofilm biosorbing Pb(II)

Energy Technology Data Exchange (ETDEWEB)

Pepi, Milva; Borra, Marco [Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli (Italy); Tamburrino, Stella [Consiglio Nazionale delle Ricerche, Istituto per l' Ambiente Marino Costiero UOS Capo Granitola, Palermo (Italy); Saggiomo, Maria [Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli (Italy); Viola, Alfio [Università di Catania, Corso Italia 57, I-95129 Catania (Italy); Biffali, Elio; Balestra, Cecilia [Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli (Italy); Sprovieri, Mario [Consiglio Nazionale delle Ricerche, Istituto per l' Ambiente Marino Costiero UOS Capo Granitola, Palermo (Italy); Casotti, Raffaella, E-mail: raffaella.casotti@szn.it [Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli (Italy)

2016-08-15

A Pb-resistant bacterial strain (named hereinafter Pb15) has been isolated from highly polluted marine sediments at the Sarno River mouth, Italy, using an enrichment culture to which Pb(II) 0.48 mmol l{sup −1} were added. 16S rRNA gene sequencing (Sanger) allowed assignment of the isolate to the genus Bacillus, with Bacillus pumilus as the closest species. The isolate is resistant to Pb(II) with a minimum inhibitory concentration (MIC) of 4.8 mmol l{sup −1} and is also resistant to Cd(II) and Mn(II) with MIC of 2.22 mmol l{sup −1} and 18.20 mmol l{sup −1}, respectively. Inductively coupled plasma atomic emission spectrometry (ICP-AES) showed that Pb inoculated in the growth medium is absorbed by the bacterial cells at removal efficiencies of 31.02% and 28.21% in the presence of 0.48 mmol l{sup −1} or 1.20 mmol l{sup −1} Pb(II), respectively. Strain Pb15 forms a brown and compact biofilm when grown in presence of Pb(II). Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) confirm that the biofilm contains Pb, suggesting an active biosorption of this metal by the bacterial cells, sequestering 14% of inoculated Pb as evidenced by microscopic analyses. Altogether, these observations support evidence that strain Pb15 has potentials for being used in bioremediation of its native polluted sediments, with engineering solutions to be found in order to eliminate the adsorbed Pb before replacement of sediments in situ. - Highlights: • The strain is able to sequester Pb by biosorption in a biofilm. • A Pb-resistant Bacillus sp. isolated from marine polluted sediments. • The strain is proposed as a tool for bioremediation of Pb-polluted marine sediments.

A Bacillus sp. isolated from sediments of the Sarno River mouth, Gulf of Naples (Italy) produces a biofilm biosorbing Pb(II)

International Nuclear Information System (INIS)

Pepi, Milva; Borra, Marco; Tamburrino, Stella; Saggiomo, Maria; Viola, Alfio; Biffali, Elio; Balestra, Cecilia; Sprovieri, Mario; Casotti, Raffaella

2016-01-01

A Pb-resistant bacterial strain (named hereinafter Pb15) has been isolated from highly polluted marine sediments at the Sarno River mouth, Italy, using an enrichment culture to which Pb(II) 0.48 mmol l −1 were added. 16S rRNA gene sequencing (Sanger) allowed assignment of the isolate to the genus Bacillus, with Bacillus pumilus as the closest species. The isolate is resistant to Pb(II) with a minimum inhibitory concentration (MIC) of 4.8 mmol l −1 and is also resistant to Cd(II) and Mn(II) with MIC of 2.22 mmol l −1 and 18.20 mmol l −1 , respectively. Inductively coupled plasma atomic emission spectrometry (ICP-AES) showed that Pb inoculated in the growth medium is absorbed by the bacterial cells at removal efficiencies of 31.02% and 28.21% in the presence of 0.48 mmol l −1 or 1.20 mmol l −1 Pb(II), respectively. Strain Pb15 forms a brown and compact biofilm when grown in presence of Pb(II). Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) confirm that the biofilm contains Pb, suggesting an active biosorption of this metal by the bacterial cells, sequestering 14% of inoculated Pb as evidenced by microscopic analyses. Altogether, these observations support evidence that strain Pb15 has potentials for being used in bioremediation of its native polluted sediments, with engineering solutions to be found in order to eliminate the adsorbed Pb before replacement of sediments in situ. - Highlights: • The strain is able to sequester Pb by biosorption in a biofilm. • A Pb-resistant Bacillus sp. isolated from marine polluted sediments. • The strain is proposed as a tool for bioremediation of Pb-polluted marine sediments.

Alumina physically loaded by thiosemicarbazide for selective preconcentration of mercury(II) ion from natural water samples

International Nuclear Information System (INIS)

Ahmed, Salwa A.

2008-01-01

The multifunctional ligand, thiosemicarbazide, was physically loaded on neutral alumina. The produced alumina-modified solid phase (SP) extractor named, alumina-modified thiosemicarbazide (AM-TSC), experienced high thermal and medium stability. This new phase was identified based on surface coverage determination by thermal desorption method to be 0.437 ± 0.1 mmol g -1 . The selectivity of AM-TSC phase towards the uptake of different nine metal ions was checked using simple, fast and direct batch equilibration technique. AM-TSC was found to have the highest capacity in selective extraction of Hg(II) from aqueous solutions all over the range of pH used (1.0-7.0), compared to the other eight tested metal ions. So, Hg(II) uptake was 1.82 mmol g -1 (distribution coefficient log K d = 5.658) at pH 1.0 or 2.0 and 1.78, 1.73, 1.48, 1.28 and 1.28 mmol g -1 (log K d = 4.607, 4.265, 3.634, 3.372 and 3.372), at pH 3.0, 4.0, 5.0, 6.0 and 7.0, respectively. On the other hand, the metal ions Ca(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) showed low uptake values in range 0.009-0.720 mmol g -1 (log K d < 3.0) at their optimum pH values. A mechanism was suggested to explain the unique uptake of Hg(II) ions based on their binding as neutral and chloroanionic species predominate at pH values ≤3.0 of a medium rich in chloride ions. Application of the new phase for the preconcentration of ultratrace amounts of Hg(II) ions spiked natural water samples: doubly distilled water (DDW), drinking tap water (DTW) and Nile river water (NRW) using cold vapor atomic absorption spectroscopy (CV-AAS) was studied. The high recovery values obtained using AM-TSC (98.5 ± 0.5, 98.0 ± 0.5 and 103.0 ± 1.0) for DDW, DTW and NRW samples, respectively based on excellent enrichment factor 1000, along with a good precision (R.S.D.% 0.51-0.97%, n 3) demonstrate the accuracy and validity of the new modified alumina sorbent for preconcentrating ultratrace amounts of Hg(II) with no

In situ immobilization on the silica gel surface and adsorption capacity of polymer-based azobenzene on toxic metal ions

Science.gov (United States)

Savchenko, Irina; Yanovska, Elina; Sternik, Dariusz; Kychkyruk, Olga; Ol'khovik, Lidiya; Polonska, Yana

2018-03-01

In situ immobilization of poly[(4-methacryloyloxy-(4'-carboxy)azobenzene] on silica gel surface has been performed by radical polymerization of monomer. The fact of polymer immobilization is confirmed by IR spectroscopy. TG and DSC-MS analysis showed that the mass of the immobilized polymer was 10.61%. The SEM-microphotograph-synthesized composite analysis showed that the immobilized polymer on the silica gel surface is placed in the form of fibers. It has been found that the synthesized composite exhibits the sorption ability in terms of microquantities of Cu(II), Cd(II), Pb(II), Mn(II) and Fe(III) ions in a neutral aqueous medium. The quantitative sorption of microquantities of Pb(II) and Fe(III) ions has been recorded. It has been found that immobilization of the silica gel surface leads to an increase in its sorption capacitance for Fe(III), Cu(II) and Pb(II) ions by half.

CRYSTAL-QUASICHEMICAL ANALYSIS OF DEFECT SUBSYSTEM OF DOPED PbTe: Sb CRYSTALS AND Pb-Sb-Te SOLID SOLUTIONS

Directory of Open Access Journals (Sweden)

D.M. Freik

2014-05-01

Full Text Available Within crystalquasichemical formalism models of point defects of crystals in the Pb-Sb-Te system were specified. Based on proposed crystalquasichemical formulae of antimony doped crystals PbTe:Sb amphoteric dopant effect was explained. Mechanisms of solid solution formation for РbТе-Sb2Те3: replacement of antimony ions lead sites  with the formation of cation vacancies  (I or neutral interstitial tellurium atoms  (II were examined. Dominant point defects in doped crystals PbTe:Sb and РbТе-Sb2Те3 solid solutions based on p-PbTe were defined. Dependences of concentration of dominant point defects, current carriers and Hall concentration on content of dopant compound and the initial deviation from stoichiometry in the basic matrix were calculated.

Commissioning of the LEIR electron cooler with Pb$^{+54}$ ions

CERN Document Server

Tranquille, G; Carly, Ch; Prieto, V; Sautier, R; Bubley, A; Parkhomchuk, V; Reva, V; Brizgunov, M; Vedenev, M; Panasyuk, V

2006-01-01

The new LEIR cooler with a variable profile of the electron beam and electrostatic bending was commissioned in 2005-2006. In this paper we present our experience with the commissioning of the new device as well as the first results of the ion beam Pb +54 cooling with a high-intensity variable-density electron beam.

New thiamine functionalized silica microparticules as a sorbent for the removal of lead, mercury and cadmium ions in aqueous media

Directory of Open Access Journals (Sweden)

Deniz Sabahattin

2017-01-01

Full Text Available The existence of heavy metal ions in aqueous media is one of the biggest environmental pollution problems and thus the removal of heavy metals is a very important procedure. In this work, a new adsorbent was synthesized by modifying 3-aminopropyl-functionalized silica gel with thiamine (vitamin B1 and characterized. The influence of the uptake conditions, such as pH, contact time, initial feed concentration and foreign metal ions, on the binding capacity of thiamine-functionalized silica gel sorbent (M3APS were investigated. Maximum obtained adsorption capacities for Pb(II, Hg(II and Cd(II were 39.4±0.2, 30.9±0.5 and 9.54±0.4 mg g-1 M3APS, respectively, at pH 5.0. The observed selectivity of M3APS for these metal ions was the following: Pb(II > Hg(II > Cd(II. Adsorption isotherm models were also applied to the adsorption process. As a result, the Langmuir isotherm model gave the best fit for the adsorption of metal ions on M3APS. The Gibbs energy change (ΔG for the adsorption of Pb(II, Hg(II and Cd(II were calculated to predict the nature of adsorption process. Having such satisfactory adsorption results, M3APS is a potential candidate adsorbent for Pb(II and Hg(II removal from aqueous media.

Separation and recovery of lead from a low concentration solution of lead(II) and zinc(II) using the hydrolysis production of poly styrene-co-maleic anhydride

Energy Technology Data Exchange (ETDEWEB)

Liang, Xing; Su, Yibing [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China); Yang, Ying, E-mail: Yangying@lzu.edu.cn [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China); Qin, Wenwu [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Separation and recovery of Pb(II) from a solution of Pb(II) and Zn(II) was performed. Black-Right-Pointing-Pointer Pb(II) can be recovered using the hydrolysis production of poly styrene-co-maleic anhydride. Black-Right-Pointing-Pointer The adsorption capacity of the PSMA resin for Pb(II) is 641.62 mg g{sup -1}. Black-Right-Pointing-Pointer Pb(II) can be recovered through desorption of Pb-PSMA into Pb(II) ion and the solid PSMA resin. Black-Right-Pointing-Pointer The resin can be repeatedly used through desorption by an inorganic acid condition (6 M H{sub 2}SO{sub 4}). - Abstract: The Pb-Zn separation/preconcentration technique, based on the complex formation reaction of Pb(II) and Zn(II), using a copolymer poly(styrene-co-maleic anhydride) (PSMA), without adding any carrier element was developed. The effects of several experimental parameters such as solution pH, temperature and adsorption time were studied. The experimental results show that the PSMA resin-Pb equilibrium was achieved in 2 min and the Pb(II) loading capacity is up to 641.62 mg g{sup -1} in aqueous solution under optimum conditions, which is much higher than the Zn(II) loading capacity within 80 min. The adsorption test for Pb(II) indicates that PSMA can recover Pb(II) from a mixed solution of Pb(II), Zn(II) and light metals such as Ca(II) and Mg(II) with higher adsorption rate and larger selective coefficient. A further study indicates that PSMA as chelating resins recovering Pb(II) can be regenerated via mineral acid (6 M H{sub 2}SO{sub 4}). PSMA was synthesized by radical polymerization and tested as an adsorbent for the selective recovery of Pb(II). In addition, the formation procedure and structure of Pb-PSMA complex were also studied. Both the PSMA and the Pb-PSMA complex were characterized by means of FTIR spectroscopy, elemental analysis, gel permeation chromatography (GPC) and atomic absorption spectrometry (AAS).

Biosorción de Cd (II) y Pb (II) en columna de lecho fijo con cáscara de cacao

OpenAIRE

Vera, L.; Bermejo, D.; Uguña, M.F.; García, N.; Flores, M.; Brazales, D.

2018-01-01

En este trabajo se presentan los resultados de la biosorcion de Pb (II) y Cd (II) de aguas sintéticas con cáscara de cacao en columnas de lecho fijo. Los datos experimentales fueron ajustados a varios modelos que describen la curva de ruptura para sistemas monocomponentes y bicomponentes. Los porcentajes de remoción de plomo y cadmio en sistemas monocomponentes son 91% y 90% respectivamente. En sistemas bicomponentes Pb-Cd el porcentaje de remoción de plomo 88% y cadmio 90%. El modelo de Dosi...

The impact of auxins used in assisted phytoextraction of metals from the contaminated environment on the alterations caused by lead(II) ions in the organization of model lipid membranes.

Science.gov (United States)

Hąc-Wydro, Katarzyna; Sroka, Aleksandra; Jabłońska, Klaudia

2016-07-01

Auxins are successfully used to improve phytoextraction efficiency of metal ions from the contaminated environment, however, the mechanism of their activity in this field is not explained. Auxins are known to exert various biochemical alterations in the plant membranes and cells, but their activity involves also direct interactions with lipids leading to changes in membrane organization. Following the suggestion that the auxins-induced modifications in membrane properties alleviate toxic effect of metal ions in this paper we have undertaken the comparative studies on the effect of metal ions and metal ions/auxins mixtures on model membrane systems. The experiments were done on lipid monolayers differing in their composition spread on water subphase and on Pb(2+), Indole-3-acetic acid (IAA), 1-Naphthaleneacetic acid (NAA) and Pb(2+)/IAA and Pb(2+)/NAA water solutions. The analysis of the collected data suggests that metal ions and auxins can change fluidity of the lipid systems and weaken the interactions between monolayer components. This manifested in the increase of the mean area per molecule and the excess area per molecule values for the films on Pb(2+), auxins as well as Pb(2+)/auxin solutions as compared to the values on pure water subphase. However, the presence of auxin in the mixture with lead(II) ions makes the alterations induced by sole metal ions weaker. This effect was more pronounced for the membranes of a higher packing. Thus it was proposed that auxins may enhance phytoextraction of metal ions by weakening their destabilizing effect on membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

Smart responsive microcapsules capable of recognizing heavy metal ions.

Science.gov (United States)

Pi, Shuo-Wei; Ju, Xiao-Jie; Wu, Han-Guang; Xie, Rui; Chu, Liang-Yin

2010-09-15

Smart responsive microcapsules capable of recognizing heavy metal ions are successfully prepared with oil-in-water-in-oil double emulsions as templates for polymerization in this study. The microcapsules are featured with thin poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)) membranes, and they can selectively recognize special heavy metal ions such as barium(II) or lead(II) ions very well due to the "host-guest" complexation between the BCAm receptors and barium(II) or lead(II) ions. The stable BCAm/Ba(2+) or BCAm/Pb(2+) complexes in the P(NIPAM-co-BCAm) membrane cause a positive shift of the volume phase transition temperature of the crosslinked P(NIPAM-co-BCAm) hydrogel to a higher temperature, and the repulsion among the charged BCAm/Ba(2+) or BCAm/Pb(2+) complexes and the osmotic pressure within the P(NIPAM-co-BCAm) membranes result in the swelling of microcapsules. Induced by recognizing barium(II) or lead(II) ions, the prepared microcapsules with P(NIPAM-co-BCAm) membranes exhibit isothermal and significant swelling not only in outer and inner diameters but also in the membrane thickness. The proposed microcapsules in this study are highly attractive for developing smart sensors and/or carriers for detection and/or elimination of heavy metal ions. Copyright 2010 Elsevier Inc. All rights reserved.

Application of Hydrothermal and Non-Hydrothermal TiO2 Nanoporous Materials as New Adsorbents for Removal of Heavy Metal Ions from Aqueous System

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Mansoor Anbia

2016-06-01

Full Text Available Hydrothermal and non-hydrothermal spherical TiO2 nanoporous with crystalline framework were prepared by sol-gel method. The Crystalline structures, morphologies and surface texturing of materials were determined by X-ray diffraction (XRD, scanning electron microscopy (SEM and N2 adsorption-desorption isotherms. The Hydrothermal spherical TiO2 nanoporous was found to have a narrow and strong pore size distribution peaks with average of 37.8 Å and pore volume of 0.41 cm3/g and the (Brunauer–Emmett–TellerBET specific surface area of 365 m2/g. Hydrothermal and non-hydrothermal spherical TiO2 nanoporous have been used as adsorbent to study of the adsorption behavior of Pb(II, Co(II and Ni(II ions from aqueous system in a batch system. Effect of equilibrium time on adsorption Pb(II, Co(II and Ni(II ions on these adsorbent was studied The results show that the shaking time 0.5 to 10h has no serious effect on the percentage of ions removal, and the adsorption is fast in all cases. The maximum uptake capacities of Hydrothermal and non-hydrothermal spherical TiO2 nanoporous was calculated. Both hydrothermal and non-hydrothermal TiO2 nanoporous materials were found to have very good potential as new adsorbents in removal of these ions. In batch systems the maximum uptake capacities of Pb(II, Ni(II and Co(II on the hydrothermal and non-hydrothermal TiO2 nanoporous materials was Co(II > Pb(II > Ni(II and Co(II > Ni(II > Pb(II, respectively.

Optimal synthesis of a Ni(II)-dimethylglyoxime ion-imprinted polymer ...

African Journals Online (AJOL)

A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was optimised by the uniform design experimental method and used to adsorb Ni(II) ions from water, soil and mine tailing samples. This aimed to improve the performance of this ion-imprinted polymer in trapping Ni(II) ions from soil and mine tailing samples ...

Fabrication and characterization of mesoporous activated carbon from Lemna minor using one-step H3PO4 activation for Pb(II) removal

Science.gov (United States)

Huang, Yang; Li, Shunxing; Lin, Haibin; Chen, Jianhua

2014-10-01

A low cost and locally available material, Lemna minor, was used to fabricate activated carbon using H3PO4 activation. After H3PO4 activation, the L. minor activated carbons (LACs) possess high mesoporosity (92.2%) and a surface area of 531.9 m2/g according to Brunauer-Emmett-Teller (BET) analysis. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses reveal the presence of rich hydroxyl, carboxyl, amide and phosphate functional groups on the LACs surface, leading to facile Pb(II) binding to the surface through strong chemisorptive bonds or ion-exchange. The kinetic and equilibrium data were well described by pseudo-first-order model and Langmuir isotherm, with the maximum monolayer adsorption capacity (qm) 170.9 mg/g at 25 °C. The intra-particle diffusion mechanism was partially responsible for the adsorption. The adsorption process was spontaneous and endothermic with negative ΔG and positive ΔH. The Pb(II)-loaded LACs could be easily regenerated using 0.1-M HCl and reused for seven cycles without significant adsorption capacity reduction. The maximum percentage removal rate for Pb(II) (20 mg/L) was found to be 91.8% within 30 min, at optimum conditions of pH 6.0 and 25 °C. These suggested that the low-cost LACs could be used as a potential adsorbent in the treatment of lead-contaminated water.

Poly[μ-aqua-di-μ-benzoato-lead(II

Directory of Open Access Journals (Sweden)

Jiantong Li

2009-08-01

Full Text Available The reaction of lead(II nitrate and benzoic acid in aqueous solution yields the title polymer, [Pb(C7H5O22(H2O]n. The asymmetric unit contains one PbII ion, two benzoate ligands and one water molecule. The Pb—O bond distances are in the range 2.494 (4–2.735 (4 Å. The Pb...Pb distance is 4.0683 (4 Å, indicating an insignificant metal–metal interaction. The PbII atom has a distorted pentagonal-bipyramidal geometry chelated by two carboxylate O atoms. The Pb atoms are bridged through a coordinating water molecule and two carboxylate O atoms from another two benzoate ligands, giving an infinite three-dimensional supramolecular structure. O—H...O hydrogen-bonding interactions involved the coordinating water and carboxylate O atoms enhance the stability of the supramolecular arrangement.

Adsorption of Pb(II) from fish sauce using carboxylated cellulose nanocrystal: Isotherm, kinetics, and thermodynamic studies.

Science.gov (United States)

Wang, Nan; Jin, Ru-Na; Omer, A M; Ouyang, Xiao-Kun

2017-09-01

In the present study, a new adsorbent based on carboxylated cellulose nanocrystal (CCN) was developed for the adsorption of Pb(II) from fish sauce. The prepared adsorbent material was characterized by zeta potential, FT-IR, XRD, and XPS tools. The changes in the morphological structure of the developed CCN surface were evidenced by SEM and TEM. The favorable adsorption conditions were selected by studying the contact time, initial concentration, temperature, and concentration of the used glutamic acid and NaCl. The results indicated that the Langmuir isotherm model agrees very well with experimental adsorption data (R 2 =0.9962) with a maximum adsorption capacity 232.56mg/g of Pb(II) at 293.2K. Additionally, data of the adsorption kinetics follow the pseudo-second-order kinetics (R 2 >0.9990). On the other hand, the thermodynamics studies show that the adsorption process is spontaneous and endothermic. Furthermore, the developed CCN could be regenerated using acid treatment with a good reusability for Pb(II) adsorption. The results clearly indicated that the synthesized CCN could be effectively applied as a new material for Pb(II) adsorption from fish sauce solutions. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

Directory of Open Access Journals (Sweden)

M. Padma Latha

2007-04-01

Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

Liquid crystal based optical platform for the detection of Pb2+ ions using NiFe2O4 nanoparticles

Science.gov (United States)

Zehra, Saman; Gul, Iftikhar Hussain; Hussain, Zakir

2018-06-01

A simple, sensitive, selective and real time detection protocol was developed for Pb2+ ions in water using liquid crystals (LCs). In this method, NiFe2O4 nanoparticles were synthesized using chemical co-precipitation method. Crystallite size, morphological, functional groups and magnetization studies were confirmed using X-ray diffraction, Scanning Electron Microscopy, and Fourier transform infrared spectroscopy techniques, respectively. The nanoparticles were mono dispersed with average particle size of 20 ± 2 nm. The surfactant stabilized magnetic nanoparticles were incubated in liquid crystal based sensor system for the detection of Pb+2 ions. The bright to dark transition of LC was observed through optical microscope. When this system was further immersed with a solution containing Pb2+ ions, it caused homeotropic to planar orientation of LC. This interaction is attributed to the presence of abundant hydroxyl groups in such as M-OH, Fe-OH on the surface of spinel ferrites nanoparticles. These groups interact with metal ions at aqueous interface, causing disruption in LCs orientation giving bright texture. This sensor showed higher selectivity towards Pb2+ ions. The detection limit was estimated to be 100 ppb. The cheap and effective protocol reported here should make promising development of LC based sensor for lead ion detection.

Experimental study of Pb (II) solution sorption behavior onto Coffee Husk Bioactivated Carbon

Science.gov (United States)

Fona, Z.; Habibah, U.

2018-04-01

Coffee husk which is abundantly produced in the coffee plantations is potential to be a challenging adsorbent. The fate of Pb (II) solution in the sorption mechanism onto the adsorbent has been investigated. This paper aimed to study the efficiency of Pb (II) aqueous solution removal using activated carbon from coffee husk (CAC). The sorption characteristics were using two isotherm models, Langmuir and Freundlich, were also reported. The coffee husk from local plantations in Middle Aceh was carbonized and sieved to 120/140 mesh. The charcoal was activated using hydrochloric acid before contacted with the different initial concentrations of Pb (II) solution. The remaining concentrations of the metal in the specified contact times were determined using Atomic Adsorption Spectrophotometer at 283.3 wavelength. The result showed that the equilibrium concentrations were obtained in about 30 minutes which depended on the initial concentration. The sorption mechanism followed Freundlich isotherm model where the adsorption constant and capacity were accordingly 1.353 and 1.195 mgg‑1. The iodine sorption was up to 1,053 mgg‑1. Based on the ash and moisture content, as well as iodine sorption, the activated carbon met the national standard.

Characterization and application of Mucuna urens seed husk as novel biosorbent for sequestration of some divalent metal ions from solution

Directory of Open Access Journals (Sweden)

Linda Obiageli ELUKE

2017-07-01

Full Text Available The utilization of Horse-Eye Bean (Mucuna urens Seed Husk (HEBSH as low cost biosorbent for the abstraction of Co (II, Pb (II and Zn (II ions from water was performed. The biosorbent was characterized by the Fourier Transform Infrared (FTIR spectroscopy, X-ray diffraction (XRD and Scanning Electron Microscopy (SEM. The influence of pH, initial metal ion concentration, biosorbent dosage and contact time on the biosorption was studied. Four isotherm and four kinetic models were used to determine the mechanism of biosorption. FTIR showed the presence of some functional groups such as OH, C=O, C=C, C-O, C-Cl on the surface of HEBSH, while XRD and SEM showed amorphous and non-porous surface structure respectively. Optimum biosorption of the metal ions was obtained at pH 6.0, biosorbent dosage 0.1 g, metal concentration 400 mg/L and contact time of 30, 40, and 60 min for Co (II, Zn (II and Pb (II respectively. The Freundlich gave the best fit for the three metal ions (R2 > 0.95 than the Langmuir, Tempkin and Dubinin-Radushkevich models indicating a multilayer biosorption on a heterogenous surface of HEBSH. Kinetic analysis showed the pseudo first order model presented good fits for Zn (II and Pb (II while the pseudo second order model for Co (II. The initial sorption rate h (mg/g min was 2.35 × 10-3, 2.1 × 10-4 and 6.3 × 10-7 for Co (II, Zn (II and Pb (II ions respectively. Liquid film diffusion was found to be the diffusion mechanism of biosorption rather than the intraparticle diffusion. The experimental investigation showed that HEBSH is effective as a low cost alternative biosorbent for the sequestration of heavy metal ions from aqueous stream.

Physico - chemical investigation on Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO2+2 and VO+2 ions-O-(-N-3,5-dichloro-α-pyridone imino)

International Nuclear Information System (INIS)

Mathur, Praveen; Trivedi, Pradeep; Mehta, R.K.

1983-01-01

Studies on the interaction of newly synthesised ligand, O-(N-3, 5-dichloro-α-pyridone imino) benzene sulphonic acid (H 2 PB) with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO 2 +2 and VO +2 have been carried out potentiometrically. Many physico-chemical studies on thermodynamics, elemental analysis, molecular weight, magnetic moment, conductance, electronic and IR spectra have also been made on the solid chelates and their adducts. The dissociation constants of H 2 PB and stabilities of its bivalent chelates have been evaluated potentiometrically at 25deg, 35deg and 45degC in aqueous medium (0.01M, 0.05M and 0.1M NaClO 4 ) by Bjerrum's method. The stability sequence is in agreement with the Irving-William's rule. (author)

Lithium ion beam driven hohlraums for PBFA II

International Nuclear Information System (INIS)

Dukart, R.J.

1994-01-01

In our light ion inertial confinement fusion (ICF) program, fusion capsules are driven with an intense x-ray radiation field produced when an intense beam of ions penetrates a radiation case and deposits energy in a foam x-ray conversion region. A first step in the program is to generate and measure these intense fields on the Particle Beam Fusion Accelerator II (PBFA II). Our goal is to generate a 100-eV radiation temperature in lithium ion beam driven hohlraums, the radiation environment which will provide the initial drive temperature for ion beam driven implosion systems designed to achieve high gain. In this paper, we describe the design of such hohlraum targets and their predicted performance on PBFA II as we provide increasing ion beam intensities

Absorbed Pb2+ and Cd2+ Ions in Water by Cross-Linked Starch Xanthate

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Kai Feng

2017-01-01

Full Text Available A cross-linked starch xanthate was prepared by graft copolymerization of acrylamide and sodium acrylate onto starch xanthate using potassium persulfate and sodium hydrogen sulfite initiating system and N,N′-methylenebisacrylamide as a cross-linker. As this kind of cross-linked potato starch xanthate can effectively absorb heavy metal ions, it was dispersed in aqueous solutions of divalent heavy metal ions (Pb2+ and Cd2+ to investigate their absorbency by the polymer. Factors that can influence absorbency were investigated, such as the ratio of matrix to monomers, the amount of initiator and cross-linker, pH, and the concentration of metal ions. Results were reached and conclusion was drawn that the best synthetic conditions for the polymer adsorbing Pb2+ and Cd2+ were as follows: the quality ratio of matrix to monomers was 1 : 12 and 1 : 11, the amount of initiator was 2.4% and 3.2% of matrix, and the amount of cross-linker was 12 mg and 13 mg. When the initial concentration of ions was 10 mg/L, the highest quantities of adsorption of Pb2+ and Cd2+ were 47.11 mg/g and 36.55 mg/g. Adsorption mechanism was discussed by using Fourier transform infrared (FTIR spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, Energy Dispersive X-Ray Spectroscopy (EDS test, and adsorption kinetic simulation.

A Strangelet and Particle Search in Pb-Pb Collisions

CERN Multimedia

Lohmann, K-D; Linden, T

2002-01-01

%NA52 %title\\\\ \\\\The NA52 experiment aims to detect strangelets, \\textit{i.e.} small drops of strange quark matter, which might result from the extreme energy and baryon densities attained in Pb+Pb collisions at a beam momentum of 158~A GeV/c. The experiment uses the H6 beam line as a spectrometer equipped with wire chambers, time of flight measurements over a path of 524~m and a hadronic calorimeter which is placed at the end of the setup.\\\\ \\\\During the 17 day run in fall of 1994 we accumulated data of 1.8~\\cdot~10$^{12}$~Pb ions on our Pb targets. The average beam intensity was 2~\\cdot~10$^{7}$~ions per spill for the NA52 experiment. We were running mainly with a 40~mm target at spectrometer rigidities of $\\pm$100 and $-$200~GeV/c and with a 16~mm target at $+$200~GeV/c. Per setting 10$^{11}$ Pb+Pb collisions were recorded. During the Pb-ion run in 1995 the statistics for the strangelet search at a rigidity of $-$200~GeV/c has been improved by about one order of magnitude. This was mainly due to a factor o...

Liquid crystal based optical platform for the detection of Pb2+ ions using NiFe2O4 nanoparticles

Directory of Open Access Journals (Sweden)

Saman Zehra

2018-06-01

Full Text Available A simple, sensitive, selective and real time detection protocol was developed for Pb2+ ions in water using liquid crystals (LCs. In this method, NiFe2O4 nanoparticles were synthesized using chemical co-precipitation method. Crystallite size, morphological, functional groups and magnetization studies were confirmed using X-ray diffraction, Scanning Electron Microscopy, and Fourier transform infrared spectroscopy techniques, respectively. The nanoparticles were mono dispersed with average particle size of 20 ± 2 nm. The surfactant stabilized magnetic nanoparticles were incubated in liquid crystal based sensor system for the detection of Pb+2 ions. The bright to dark transition of LC was observed through optical microscope. When this system was further immersed with a solution containing Pb2+ ions, it caused homeotropic to planar orientation of LC. This interaction is attributed to the presence of abundant hydroxyl groups in such as M-OH, Fe-OH on the surface of spinel ferrites nanoparticles. These groups interact with metal ions at aqueous interface, causing disruption in LCs orientation giving bright texture. This sensor showed higher selectivity towards Pb2+ ions. The detection limit was estimated to be 100 ppb. The cheap and effective protocol reported here should make promising development of LC based sensor for lead ion detection. Keywords: Chemical co-precipitation method, Fourier transform infrared spectroscopy, Liquid crystals, Nanoparticles, Sensor, X-ray diffraction

o-Vanillin functionalized mesoporous silica - coated magnetite nanoparticles for efficient removal of Pb(II) from water

Science.gov (United States)

Culita, Daniela C.; Simonescu, Claudia Maria; Patescu, Rodica-Elena; Dragne, Mioara; Stanica, Nicolae; Oprea, Ovidiu

2016-06-01

o-Vanillin functionalized mesoporous silica - coated magnetite (Fe3O4@MCM-41-N-oVan) was synthesized and fully characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N2 adsorption-desorption technique and magnetic measurements. The capacity of Fe3O4@MCM-41-N-oVan to adsorb Pb(II) from aqueous solutions was evaluated in comparison with raw mesoporous silica - coated magnetite (Fe3O4@MCM-41) and amino - modified mesoporous silica coated magnetite (Fe3O4@MCM-41-NH2). The effect of adsorption process parameters such us pH, contact time, initial Pb(II) concentration was also investigated. The adsorption data were successfully fitted with the Langmuir model, exhibiting a maximum adsorption capacity of 155.71 mg/g at pH=4.4 and T=298 K. The results revealed that the adsorption rate was very high at the beginning of the adsorption process, 80-90% of the total amount of Pb(II) being removed within the first 60 min, depending on the initial concentration. The results of the present work suggest that Fe3O4@MCM-41-N-oVan is a suitable candidate for the separation of Pb(II) from contaminated water.

The Influence of Mg(II and Ca(II Ions on Rutin Autoxidation in Weakly Alkaline Aqueous Solutions

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Živanović Slavoljub C.

2016-09-01

Full Text Available Rutin (quercetin-3-O-rutinoside is one of the most abundant bioflavonoids with various biological and pharmacological activities. Considering the ubiquitous presence of Mg(II and Ca(II ions in biological systems we decided to investigate their influence on the autoxidation of rutin in weakly alkaline aqueous solutions. Changes in UV-Vis spectra recorded during the rutin autoxidation in aqueous solution at pH 8.4 revealed that this process was very slow in the absence of metal ions. The presence of Mg(II and, especially Ca(II ion, increased the transformation rate of rutin. UV-Vis spectra recorded after prolonged autoxidation indicated the formation of humic acidlike products in the presence of Mg(II and Ca(II ions. Four new compounds formed during the initial stage of rutin autoxidation in the presence of Mg(II and Ca(II ions were detected by HPLCDAD. Based on the analysis of their DAD UV-Vis spectra and comparison of their retention times with the retention time value for rutin, we concluded that the initial rutin transformation products were formed by the water addition on double bond in ring C and hydroxylation of ring B. A very small decrease of the initial rutin concentration (4% was observed by HPLC-DAD in the absence of metal ions for the period of 90 minutes. However, rutin concentration decrease was much larger in the presence of Mg(II and Ca(II ions (14% and 24%, respectively. The more pronounced effect of Ca(II ion on the rutin autoxidation may be explained by the stronger binding of Mg(II ion to rutin and thus greater stabilizing effect on reaction intermediates caused by its higher ionic potential (charge/ionic radius ratio in comparison to Ca(II ion. The results of this study may contribute to the better understanding of interactions of Mg(II and Ca(II ions with natural phenolic antioxidants which are important for their various biological activities.

Biosorption of Fe (II) and Cd (II) ions from aqueous solution using a ...

African Journals Online (AJOL)

ADOWIE PERE

Biosorption of Fe (II) and Cd (II) ions from aqueous solution using a low cost ... human activities in the environment poses a lot of risk ... ion exchange or reverse osmosis, electrochemical treatment ..... is the adsorption coefficient, n indicates the.

Biosorption kinetics of Cd (II), Cr (III) and Pb (II) in aqueous solutions by olive stone

OpenAIRE

M. Calero; F. Hernáinz; G. Blázquez; M. A. Martín-Lara; G. Tenorio

2009-01-01

A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II), Cr (III) and Pb (II) from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is th...

Poly(hydroxyethyl methacrylate) nanobeads containing imidazole groups for removal of Cu(II) ions

Energy Technology Data Exchange (ETDEWEB)

Tuerkmen, Deniz; Yilmaz, Erkut [Department of Chemistry, Hacettepe University, Ankara (Turkey); Oztuerk, Nevra; Akgoel, Sinan [Department of Chemistry, Adnan Menderes University, Aydin (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Department of Chemistry, Hacettepe University, Ankara (Turkey)

2009-08-01

Poly(hydroxyethyl methacrylate) (PHEMA) nanobeads with an average size of 300 nm in diameter and with a polydispersity index of 1.156 were produced by a surfactant free emulsion polymerization. Specific surface area of the PHEMA nanobeads was found to be 996 m{sup 2}/g. Imidazole containing 3-(2-imidazoline-1-yl)propyl(triethoxysilane) (IMEO) was used as a metal-chelating ligand. IMEO was covalently attached to the nanobeads. PHEMA-IMEO nanobeads were used for the removal of copper(II) ions from aqueous solutions. To evaluate the degree of IMEO loading, the PHEMA nanobeads were subjected to Si analysis by using flame atomizer atomic absorption spectrometer and it was estimated as 973 {mu}mol IMEO/g of polymer. The PHEMA nanobeads were characterized by transmission electron microscopy and fourier transform infrared spectroscopy. Adsorption equilibrium was achieved in about 8 min. The adsorption of Cu{sup 2+} ions onto the PHEMA nanobeads was negligible (0.2 mg/g). The IMEO attachment into the PHEMA nanobeads significantly increased the Cu{sup 2+} adsorption capacity (58 mg/g). Adsorption capacity of the PHEMA-IMEO nanobeads increased significantly with increasing concentration. The adsorption of Cu{sup 2+} ions increased with increasing pH and reached a plateau value at around pH 5.0. Competitive heavy metal adsorption from aqueous solutions containing Cu{sup +}, Cd{sup 2+}, Pb{sup 2+} and Hg{sup 2+} was also investigated. The adsorption capacities are 61.4 mg/g (966.9 {mu}mol/g) for Cu{sup 2+}; 180.5 mg/g (899.8 {mu}mol/g) for Hg{sup 2+}; 34.9 mg/g (310.5 {mu}mol/g) for Cd{sup 2+} and 14.3 mg/g (69 {mu}mol/g) for Pb{sup 2+}. The affinity order in molar basis is observed as Cu{sup 2+} > Hg{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. These results may be considered as an indication of higher specificity of the PHEMA-IMEO nanobeads for the Cu{sup 2+} comparing to other ions. Consecutive adsorption and elution operations showed the feasibility of repeated use for PHEMA

A transferable force field for CdS-CdSe-PbS-PbSe solid systems

Science.gov (United States)

Fan, Zhaochuan; Koster, Rik S.; Wang, Shuaiwei; Fang, Changming; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.; van Huis, Marijn A.; Vlugt, Thijs J. H.

2014-12-01

A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., "Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth," Nano Lett. 14, 3661-3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

A transferable force field for CdS-CdSe-PbS-PbSe solid systems

Energy Technology Data Exchange (ETDEWEB)

Fan, Zhaochuan; Vlugt, Thijs J. H., E-mail: t.j.h.vlugt@tudelft.nl [Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands (Netherlands); Koster, Rik S.; Fang, Changming; Huis, Marijn A. van [Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht (Netherlands); Wang, Shuaiwei [Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, Henan 450006 (China); Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

2014-12-28

A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

Biosorption of aqueous lead (II) on rice straws (oryza sativa) by flash column process

International Nuclear Information System (INIS)

Khalid, H.N.; Hassan, M.U.; Jamil, N.; Ahmad, D.; Bushra, H.; Khatoon, S.

2010-01-01

Biosorption of Pb (II) on rice straws has been studied with the variation in the parameters and on modified rice straws by flash column process. Different parameters like particle size of adsorbent, initial concentration of metal ions, length and width of columns were studied. A comparative study of modification of adsorbent was also done for which rice straws were modified with EDTA, acids, bases, and volatile organic solvents. Base modified adsorbents have shown an increase in adsorption capacity while acid modified adsorbents proved to be the poor adsorbents for metal ions similarly ash of rice straws used as adsorbent given higher adsorption and EDTA modified adsorbents have shown least adsorption of metal ions. Polar volatile organic solvents modified adsorbent gave less adsorption efficiency and non polar adsorbent shown no influence on Pb (II) uptake capacity of rice straws. Rice straws proved to be the best biosorbent for Pb(II) in aqueous solution. The biosorption characteristics fit well with Langmuir and Freundlich isotherm. (author)

Ion bombardment induced topography evolution on low index crystal surfaces of Cu and Pb

International Nuclear Information System (INIS)

Tanovic, L.; Tanovic, N.; Carter, G.; Nobes, M.J.

1993-01-01

(100), (110) and (111) oriented single crystal surfaces of Cu and Pb have been bombarded with inert gas ions, self ions, ions of the other substrate species and Bi in the energy range 50-150 keV and in the fluence range 10 15 -10 18 ions.cm 2 . The evolving surface topography was observed by scanning electron microscopy. This topography was observed to be strongly influenced by ion species and surface orientation but the habit of the topography was delineated at low fluences and the features increased in size and density with increasing fluence with some mutation to the more stable of the features. As an example Bi and Pb bombardment of (100) Cu leads to little topographic evolution, (110) Cu develops a system of parallel ridges with (100) facets and (111) Cu develops a prismatic surface, each prism possessing (100) facets. These, and the more general, results cannot be explained by surface erosion by sputtering theory alone (this predicts surface stability of the lowest sputtering yield orientation (110), nor by surface free energy density minimisation criteria (this predicts stability of (111) surfaces). It is proposed that the observed topography is most strongly related to the crystallographic form of precipitates of implanted species. (orig.)

Use of Aloe vera shell ash supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles for removal of Pb (II from aqueous solutions

Directory of Open Access Journals (Sweden)

Samira Namavari

2016-03-01

easily separated from them with the aid of an external magnet after adsorption. The process for purifying water presented here is clean and safe. Therefore, this adsorbent is applicable to managing water pollution caused by Pb (II ions.

arXiv Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS

CERN Document Server

Sirunyan, A.M.; CMS Collaboration; Adam, Wolfgang; Ambrogi, Federico; Asilar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Grossmann, Johannes; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krammer, Natascha; Krätschmer, Ilse; Liko, Dietrich; Madlener, Thomas; Mikulec, Ivan; Pree, Elias; Rabady, Dinyar; Rad, Navid; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Spanring, Markus; Spitzbart, Daniel; Strauss, Josef; Waltenberger, Wolfgang; Wittmann, Johannes; Wulz, Claudia-Elisabeth; Zarucki, Mateusz; Chekhovsky, Vladimir; Mossolov, Vladimir; Suarez Gonzalez, Juan; De Wolf, Eddi A; Janssen, Xavier; Lauwers, Jasper; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; De Bruyn, Isabelle; De Clercq, Jarne; Deroover, Kevin; Flouris, Giannis; Lowette, Steven; Moortgat, Seth; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Skovpen, Kirill; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Parijs, Isis; Brun, Hugues; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Luetic, Jelena; Maerschalk, Thierry; Marinov, Andrey; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Vannerom, David; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Cimmino, Anna; Cornelis, Tom; Dobur, Didar; Fagot, Alexis; Gul, Muhammad; Khvastunov, Illia; Poyraz, Deniz; Roskas, Christos; Salva Diblen, Sinem; Tytgat, Michael; Verbeke, Willem; Zaganidis, Nicolas; Bakhshiansohi, Hamed; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Francois, Brieuc; Giammanco, Andrea; Jafari, Abideh; Komm, Matthias; Krintiras, Georgios; Lemaitre, Vincent; Magitteri, Alessio; Mertens, Alexandre; Musich, Marco; Piotrzkowski, Krzysztof; Quertenmont, Loic; Vidal Marono, Miguel; Wertz, Sébastien; Beliy, Nikita; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hensel, Carsten; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; Da Silveira, Gustavo Gil; De Jesus Damiao, Dilson; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Melo De Almeida, Miqueias; Mora Herrera, Clemencia; Mundim, Luiz; Nogima, Helio; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Torres Da Silva De Araujo, Felipe; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Misheva, Milena; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Shopova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Gao, Xuyang; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Chen, Ye; Jiang, Chun-Hua; Leggat, Duncan; Liu, Zhenan; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Yazgan, Efe; Zhang, Huaqiao; Zhao, Jingzhou; Ban, Yong; Chen, Geng; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; González Hernández, Carlos Felipe; Ruiz Alvarez, José David; Courbon, Benoit; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Sculac, Toni; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Ferencek, Dinko; Kadija, Kreso; Mesic, Benjamin; Susa, Tatjana; Ather, Mohsan Waseem; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Finger, Miroslav; Finger Jr, Michael; Carrera Jarrin, Edgar; Abdelalim, Ahmed Ali; Mohammed, Yasser; Salama, Elsayed; Dewanjee, Ram Krishna; Kadastik, Mario; Perrini, Lucia; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Jarvinen, Terhi; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Ghosh, Saranya; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Kucher, Inna; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Negro, Giulia; Rander, John; Rosowsky, André; Sahin, Mehmet Özgür; Titov, Maksym; Abdulsalam, Abdulla; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Charlot, Claude; Davignon, Olivier; Granier de Cassagnac, Raphael; Jo, Mihee; Lisniak, Stanislav; Lobanov, Artur; Martin Blanco, Javier; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Stahl Leiton, Andre Govinda; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Zghiche, Amina; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Jansová, Markéta; Le Bihan, Anne-Catherine; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Finco, Linda; Gascon, Susan; Gouzevitch, Maxime; Grenier, Gérald; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Popov, Andrey; Sordini, Viola; Vander Donckt, Muriel; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Feld, Lutz; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Preuten, Marius; Schomakers, Christian; Schulz, Johannes; Verlage, Tobias; Albert, Andreas; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hamer, Matthias; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Mukherjee, Swagata; Olschewski, Mark; Padeken, Klaas; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Teyssier, Daniel; Thüer, Sebastian; Flügge, Günter; Kargoll, Bastian; Kress, Thomas; Künsken, Andreas; Lingemann, Joschka; Müller, Thomas; Nehrkorn, Alexander; Nowack, Andreas; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Arndt, Till; Asawatangtrakuldee, Chayanit; Beernaert, Kelly; Behnke, Olaf; Behrens, Ulf; Bin Anuar, Afiq Aizuddin; Borras, Kerstin; Botta, Valeria; Campbell, Alan; Connor, Patrick; Contreras-Campana, Christian; Costanza, Francesco; Diez Pardos, Carmen; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Eren, Engin; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Grados Luyando, Juan Manuel; Grohsjean, Alexander; Gunnellini, Paolo; Harb, Ali; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Kasemann, Matthias; Keaveney, James; Kleinwort, Claus; Korol, Ievgen; Krücker, Dirk; Lange, Wolfgang; Lelek, Aleksandra; Lenz, Teresa; Leonard, Jessica; Lipka, Katerina; Lohmann, Wolfgang; Mankel, Rainer; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Ntomari, Eleni; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Savitskyi, Mykola; Saxena, Pooja; Shevchenko, Rostyslav; Spannagel, Simon; Stefaniuk, Nazar; Van Onsem, Gerrit Patrick; Walsh, Roberval; Wen, Yiwen; Wichmann, Katarzyna; Wissing, Christoph; Zenaiev, Oleksandr; Bein, Samuel; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Dreyer, Torben; Garutti, Erika; Gonzalez, Daniel; Haller, Johannes; Hoffmann, Malte; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Kurz, Simon; Lapsien, Tobias; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Niedziela, Marek; Nowatschin, Dominik; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Scharf, Christian; Schleper, Peter; Schmidt, Alexander; Schumann, Svenja; Schwandt, Joern; Sonneveld, Jory; Stadie, Hartmut; Steinbrück, Georg; Stober, Fred-Markus Helmut; Stöver, Marc; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baur, Sebastian; Butz, Erik; Caspart, René; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Dierlamm, Alexander; Freund, Benedikt; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Kassel, Florian; Kudella, Simon; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Schröder, Matthias; Shvetsov, Ivan; Sieber, Georg; Simonis, Hans-Jürgen; Ulrich, Ralf; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Williamson, Shawn; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Topsis-Giotis, Iasonas; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Triantis, Frixos A; Csanad, Mate; Filipovic, Nicolas; Pasztor, Gabriella; Bencze, Gyorgy; Hajdu, Csaba; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Makovec, Alajos; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Choudhury, Somnath; Komaragiri, Jyothsna Rani; Bahinipati, Seema; Bhowmik, Sandeep; Mal, Prolay; Mandal, Koushik; Nayak, Aruna; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Bhawandeep, Bhawandeep; Chawla, Ridhi; Dhingra, Nitish; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Kumari, Priyanka; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Shah, Aashaq; Bhardwaj, Ashutosh; Chauhan, Sushil; Choudhary, Brajesh C; Garg, Rocky Bala; Keshri, Sumit; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhardwaj, Rishika; Bhattacharya, Rajarshi; Bhattacharya, Satyaki; Dey, Sourav; Dutt, Suneel; Dutta, Suchandra; Ghosh, Shamik; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukhopadhyay, Supratik; Nandan, Saswati; Purohit, Arnab; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Thakur, Shalini; Behera, Prafulla Kumar; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Netrakanti, Pawan Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Dugad, Shashikant; Mahakud, Bibhuprasad; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sur, Nairit; Sutar, Bajrang; Banerjee, Sudeshna; Bhattacharya, Soham; Chatterjee, Suman; Das, Pallabi; Guchait, Monoranjan; Jain, Sandhya; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Sarkar, Tanmay; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Hegde, Vinay; Kapoor, Anshul; Kothekar, Kunal; Pandey, Shubham; Rane, Aditee; Sharma, Seema; Chenarani, Shirin; Eskandari Tadavani, Esmaeel; Etesami, Seyed Mohsen; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Errico, Filippo; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Sharma, Archana; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Albergo, Sebastiano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Chatterjee, Kalyanmoy; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Russo, Lorenzo; Sguazzoni, Giacomo; Strom, Derek; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Brivio, Francesco; Ciriolo, Vincenzo; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Govoni, Pietro; Malberti, Martina; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pauwels, Kristof; Pedrini, Daniele; Pigazzini, Simone; Ragazzi, Stefano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Fienga, Francesco; Iorio, Alberto Orso Maria; Khan, Wajid Ali; Lista, Luca; Meola, Sabino; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Checchia, Paolo; Dall'Osso, Martino; De Castro Manzano, Pablo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Michelotto, Michele; Montecassiano, Fabio; Pantano, Devis; Pozzobon, Nicola; Ronchese, Paolo; Rossin, Roberto; Simonetto, Franco; Torassa, Ezio; Zanetti, Marco; Zotto, Pierluigi; Zumerle, Gianni; Braghieri, Alessandro; Fallavollita, Francesco; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Ressegotti, Martina; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Leonardi, Roberto; Mantovani, Giancarlo; Mariani, Valentina; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Spiga, Daniele; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Borrello, Laura; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Fedi, Giacomo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Cipriani, Marco; Daci, Nadir; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Longo, Egidio; Margaroli, Fabrizio; Marzocchi, Badder; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bartosik, Nazar; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Cenna, Francesca; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Monteno, Marco; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Shchelina, Ksenia; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Traczyk, Piotr; Belforte, Stefano; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Zanetti, Anna; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Lee, Jeongeun; Lee, Sangeun; Lee, Seh Wook; Oh, Young Do; Sekmen, Sezen; Son, Dong-Chul; Yang, Yu Chul; Lee, Ari; Kim, Hyunchul; Moon, Dong Ho; Oh, Geonhee; Brochero Cifuentes, Javier Andres; Goh, Junghwan; Kim, Tae Jeong; Cho, Sungwoong; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Ha, Seungkyu; Hong, Byung-Sik; Jo, Youngkwon; Kim, Yongsun; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Lim, Jaehoon; Park, Sung Keun; Roh, Youn; Almond, John; Kim, Junho; Kim, Jae Sung; Lee, Haneol; Lee, Kyeongpil; Nam, Kyungwook; Oh, Sung Bin; Radburn-Smith, Benjamin Charles; Seo, Seon-hee; Yang, Unki; Yoo, Hwi Dong; Yu, Geum Bong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Choi, Young-Il; Hwang, Chanwook; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Zolkapli, Zukhaimira; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Lopez-Fernandez, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Oropeza Barrera, Cristina; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Uribe Estrada, Cecilia; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Saddique, Asif; Shah, Mehar Ali; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bozena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Pyskir, Andrzej; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Voytishin, Nikolay; Zarubin, Anatoli; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Stepennov, Anton; Toms, Maria; Vlasov, Evgueni; Zhokin, Alexander; Aushev, Tagir; Bylinkin, Alexander; Chadeeva, Marina; Popova, Elena; Rusinov, Vladimir; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Terkulov, Adel; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Demiyanov, Andrey; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Vardanyan, Irina; Blinov, Vladimir; Skovpen, Yuri; Shtol, Dmitry; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Elumakhov, Dmitry; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Dordevic, Milos; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Barrio Luna, Mar; Cerrada, Marcos; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; 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Paganis, Efstathios; Psallidas, Andreas; Tsai, Jui-fa; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Adiguzel, Aytul; Bakirci, Mustafa Numan; Boran, Fatma; Cerci, Salim; Damarseckin, Serdal; Demiroglu, Zuhal Seyma; Dozen, Candan; Dumanoglu, Isa; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Hos, Ilknur; Kangal, Evrim Ersin; Kara, Ozgun; Kayis Topaksu, Aysel; Kiminsu, Ugur; Oglakci, Mehmet; Onengut, Gulsen; Ozdemir, Kadri; Tali, Bayram; Turkcapar, Semra; Zorbakir, Ibrahim Soner; Zorbilmez, Caglar; Bilin, Bugra; Karapinar, Guler; Ocalan, Kadir; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Tekten, Sevgi; Yetkin, Elif Asli; Nazlim Agaras, Merve; Atay, Serhat; Cakir, Altan; Cankocak, Kerem; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Burns, Douglas; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Smith, Dominic; Smith, Vincent J; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Williams, Thomas; Baber, Mark; Bainbridge, Robert; Breeze, Shane; Buchmuller, Oliver; Bundock, Aaron; Casasso, Stefano; Citron, Matthew; Colling, David; Corpe, Louie; Dauncey, Paul; Davies, Gavin; De Wit, Adinda; Della Negra, Michel; Di Maria, Riccardo; Dunne, Patrick; Elwood, Adam; Futyan, David; Haddad, Yacine; Hall, Geoffrey; Iles, Gregory; James, Thomas; Lane, Rebecca; Laner, Christian; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Mastrolorenzo, Luca; Matsushita, Takashi; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Raymond, David Mark; 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Paulini, Manfred; Russ, James; Sun, Menglei; Vogel, Helmut; Vorobiev, Igor; Weinberg, Marc; Cumalat, John Perry; Ford, William T; Jensen, Frank; Johnson, Andrew; Krohn, Michael; Leontsinis, Stefanos; Mulholland, Troy; Stenson, Kevin; Wagner, Stephen Robert; Alexander, James; Chaves, Jorge; Chu, Jennifer; Dittmer, Susan; Mcdermott, Kevin; Mirman, Nathan; Patterson, Juliet Ritchie; Rinkevicius, Aurelijus; Ryd, Anders; Skinnari, Louise; Soffi, Livia; Tan, Shao Min; Tao, Zhengcheng; Thom, Julia; Tucker, Jordan; Wittich, Peter; Zientek, Margaret; Abdullin, Salavat; Albrow, Michael; Apollinari, Giorgio; Apresyan, Artur; Apyan, Aram; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Canepa, Anadi; Cheung, Harry; Chlebana, Frank; Cremonesi, Matteo; Duarte, Javier; Elvira, Victor Daniel; Freeman, Jim; Gecse, Zoltan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Lincoln, Don; Lipton, Ron; Liu, Miaoyuan; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Magini, Nicolo; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Ristori, Luciano; Schneider, Basil; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strait, James; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Wang, Michael; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Brinkerhoff, Andrew; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Field, Richard D; Furic, Ivan-Kresimir; Konigsberg, Jacobo; Korytov, Andrey; Kotov, Khristian; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Mitselmakher, Guenakh; Rank, Douglas; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Joshi, Yagya Raj; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Todd; Askew, Andrew; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Kolberg, Ted; Perry, Thomas; Prosper, Harrison; Santra, Arka; Yohay, Rachel; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Cavanaugh, Richard; Chen, Xuan; Evdokimov, Olga; Gerber, Cecilia Elena; Hangal, Dhanush Anil; Hofman, David Jonathan; Jung, Kurt; Kamin, Jason; Sandoval Gonzalez, Irving Daniel; Tonjes, Marguerite; Trauger, Hallie; Varelas, Nikos; Wang, Hui; Wu, Zhenbin; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; You, Can; Al-bataineh, Ayman; Baringer, Philip; Bean, Alice; Boren, Samuel; Bowen, James; Castle, James; Khalil, Sadia; Kropivnitskaya, Anna; Majumder, Devdatta; Mcbrayer, William; Murray, Michael; Royon, Christophe; Sanders, Stephen; Schmitz, Erich; Stringer, Robert; Tapia Takaki, Daniel; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Hadley, Nicholas John; Jabeen, Shabnam; Jeng, Geng-Yuan; Kellogg, Richard G; Kunkle, Joshua; Mignerey, Alice; Ricci-Tam, Francesca; Shin, Young Ho; Skuja, Andris; Tonwar, Suresh C; Abercrombie, Daniel; Allen, Brandon; Azzolini, Virginia; Barbieri, Richard; Baty, Austin; Bi, Ran; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; D'Alfonso, Mariarosaria; Demiragli, Zeynep; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hsu, Dylan; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Maier, Benedikt; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Tatar, Kaya; Velicanu, Dragos; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Benvenuti, Alberto; Chatterjee, Rajdeep Mohan; Evans, Andrew; 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Walker, Matthew; Foerster, Mark; Heideman, Joseph; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Kamon, Teruki; Mueller, Ryan; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Perniè, Luca; Rathjens, Denis; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Damgov, Jordan; De Guio, Federico; Dudero, Phillip Russell; Faulkner, James; Gurpinar, Emine; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Peltola, Timo; Undleeb, Sonaina; Volobouev, Igor; Wang, Zhixing; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Melo, Andrew; Ni, Hong; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Barria, Patrizia; Cox, Bradley; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Sturdy, Jared; Zaleski, Shawn; Buchanan, James; Caillol, Cécile; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Hussain, Usama; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Savin, Alexander; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

2017-12-05

For the first time a principal-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from $\\sqrt{s_{\\mathrm{NN}}} = $ 2.76 TeV PbPb and $\\sqrt{s_{\\mathrm{NN}}} = $ 5.02 TeV pPb collisions collected by the CMS experiment at the LHC. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it has been shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ("leading" and "subleading") of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of $ p_{\\mathrm{T}} $ over a wide range of event activity. The leading mode is found to be essentially equivalent to...

Effect of metal ion concentration on the biosorption of Pb2+ and ...

African Journals Online (AJOL)

The influence of initial metal ion concentration of the batch sorption of Pb2+ and Cd2+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were ...

U-Pb dating by zircon dissolution method using chemical abrasion

Energy Technology Data Exchange (ETDEWEB)

Takehara, Lucy, E-mail: lucytakehara@gmail.com.br [Servico Geologico do Brasil (CPRM), Brasilia, DF (Brazil); Chemale Junior, Farid [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Inst. de Geociencias. Lab. de Geocronologia; Hartmann, Leo A. [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Inst. de Geociencias; Dussin, Ivo A.; Kawashita, Koji [Universidade de Sao Paulo (USP), SP, (Brazil). Centro de Pesquisa Geocronologicas

2012-06-15

Chemical abrasion was carried out on zircons grains of the Temora II standard for U-Pb dating prior to analyses using in situ Laser Ablation-Multi Collector Ion Coupled Plasma Mass Spectrometer (LA-ICPMS) followed by the Isotope Dissolution Thermal Ionization Mass Spectrometer (ID-TIMS) method. The proposed methodology was herein applied in order to reduce primarily the effects of secondary Pb loss, the presence of common lead and/or silicate impurities. Nine Temora II zircon grains were analyzed by the laser ablation method yielding an age of 418.3 +- 4.3 Ma. Zircon grains of a same population were separated for chemical abrasion before dissolution and mass spectrometry analyses. Six fractions of them were separated for isotope dissolution using {sup 235}U-{sup 205}Pb mixed spike after we have checked and assured the laboratory conditions of low blank values for total Pb of less than 2 pg/g. The obtained U-Pb zircon age by the ID-TIMS method was 415.7 +- 1.8 Ma (error 0.43 %) based on four successful determinations. The results are consistent with the published ages for the Temora diorite (Temora I - 416.75 +- 1.3 Ma; Temora II - 416.78 +- 0.33 Ma) and established as 416 +- 0.33 Ma. The technique is thus recommended for high precision U-Pb zircon analyses (error < 1 %), mainly for high resolution stratigraphic studies of Phanerozoic sequences. (author)

Inorganic-organic Ag-rhodamine 6G hybrid nanorods: "turn on" fluorescent sensors for highly selective detection of Pb2+ ions in aqueous solution.

Science.gov (United States)

Tyagi, A K; Ramkumar, Jayshree; Jayakumar, O D

2012-02-07

Lead metal ions are of great concern and the monitoring of their concentration in the environment has become extremely important. In the present study, a new inorganic-organic hybrid assay of Ag nanorods (AgNR)-Rhodamine 6G (R6G) was developed for the sensitive and selective determination of Pb(2+) ions in aqueous solutions. To the best of our knowledge there is almost no literature on the use of silver nanorod sensors for determination of lead ions in aqueous solutions. The sensor is developed by the coating of R6G on the surface of AgNRs. The sensing is based on the photoluminescence of R6G. The sensor was rapid as the measurements were carried out within 3 min of addition of the test solution to the AgNR-R6G hybrid. Moreover, the system showed excellent stability at tested concentration levels of Pb(2+) ions. The naked eye detection of the colour was possible with 1 mg L(-1) of Pb(2+) ions. The present method has a detection limit of 50 μg L(-1) of Pb(2+) (for a signal/noise (S/N) ratio > 3). The selectivity toward Pb(2+) ions against other metal ions was improved using chelating agents. The proposed method was validated by analysis using different techniques.

Computer augumented modelling studies of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid in 1,2-propanediol–water mixtures

Directory of Open Access Journals (Sweden)

MAHESWARA RAO VEGI

2008-12-01

Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid was studied at 303 K in 0–60 vol. % 1,2-propanediol–water mixtures, whereby the ionic strength was maintained at 0.16 mol dm-3. The active forms of the ligand are LH3+, LH2 and LH–. The predominant detected species were ML, ML2, MLH, ML2H and ML2H2. The trend of the variation in the stability constants with changing dielectric constant of the medium is explained based on the cation stabilizing nature of the co-solvents, specific solvent–water interactions, charge dispersion and specific interactions of the co-solvent with the solute. The effect of systematic errors in the concentrations of the substances on the stability constants is in the order alkali > > acid > ligand > metal. The bioavailability and transportation of metals are explained based on distribution diagrams and stability constants.

Electrochemical study and recovery of Pb using 1:2 choline chloride/urea deep eutectic solvent: A variety of Pb species PbSO4, PbO2, and PbO exhibits the analogous thermodynamic behavior

International Nuclear Information System (INIS)

Liao, Yu-Shun; Chen, Po-Yu; Sun, I-Wen

2016-01-01

Water-insoluble PbSO 4 , PbO 2 , and PbO are fairly soluble in choline chloride/urea deep eutectic solvent (ChCl/urea DES) in 1:2 molar ratio. Very interestingly, solution prepared from PbO 2 exhibits the almost identical electrochemical behavior as those from PbSO 4 and PbO, indicating that Pb(II) is formed in the DES regardless of what Pb compound is introduced. The electrochemical reduction of the Pb(II) species is determined as an irreversible process, and involves the three-dimensional (3D) instantaneous nucleation with diffusion-controlled growth. From the dependence of the diffusion coefficient on temperature, the activation energy for diffusion of PbSO 4 and PbO 2 is determined to be 33.7 and 34.1 kJ mol −1 , respectively. Electrodeposition of Pb was achieved potentiostatically and galvanostatically. The surface morphology of Pb deposits significantly depends on the applied potential and current. The coulombic efficiency of Pb electrodeposition is higher than 90%. Electrodeposition of Pb from a wet DES containing a mixture of three different Pb sources is also investigated. The XRD analysis confirmed that the electrodeposits consisted of metallic Pb.

Biosorption of lead(II) and cadmium(II) by protonated Sargassum glaucescens biomass in a continuous packed bed column

International Nuclear Information System (INIS)

Naddafi, Kazem; Nabizadeh, Ramin; Saeedi, Reza; Mahvi, Amir Hossein; Vaezi, Forough; Yaghmaeian, Kamyar; Ghasri, Azar; Nazmara, Shahrokh

2007-01-01

Biosorption of lead(II) and cadmium(II) from aqueous solutions by protonated Sargassum glaucescens biomass was studied in a continuous packed bed column. The selective uptake of Pb 2+ and Cd 2+ was investigated in a binary system with initial concentration of 1 mM for each metal ion. The selective uptake capacities of Pb 2+ and Cd 2+ at complete exhaustion point were obtained 1.18 and 0.22 mmol/g, respectively; therefore, the biosorbent showed much higher relative affinity for Pb 2+ than for Cd 2+ . The optimum range of empty bed contact time (EBCT) was identified as 5-10 min in the packed bed column. The efficiency of biosorbent regeneration by 0.1 M HCl was achieved about 60%, so that the maximum uptake capacity of Pb 2+ by the regenerated biomass was determined to be 0.75 mmol/g while the same value for the original biomass was 1.24 mmol/g. The Thomas model was found in a suitable fitness with the experimental data (R 2 > 0.90 and ε% + with the uptake of heavy metals; hence, ion exchange was confirmed to be one of the main biosorption mechanisms

REMOVAL OF LEAD(II) IONS FROM AQUEOUS SOLUTIONS ...

African Journals Online (AJOL)

a

The adsorption followed the first order kinetics and was found to be pH ... metals from wastewater is with inadequate efficiencies at law metal ..... The thermodynamic quantities ∆H, ∆S, ∆G of Pb(II) adsorption on activated carbon were.

An insight into the removal of Cu (II) and Pb (II) by aminopropyl-modified mesoporous carbon CMK-3: Adsorption capacity and mechanism

Energy Technology Data Exchange (ETDEWEB)

Hamad, Hussein, E-mail: hussein.hamad@ul.edu.lb [Platform for Research and Analysis in Environmental Sciences (PRASE), Lebanese University, Beirut (Lebanon); Ezzeddine, Zeinab; Lakis, Fatima; Rammal, Hassan [Platform for Research and Analysis in Environmental Sciences (PRASE), Lebanese University, Beirut (Lebanon); Srour, Mortada [Lebanese University, Faculty of Sciences (I), Hadath, Beirut (Lebanon); Hijazi, Akram [Platform for Research and Analysis in Environmental Sciences (PRASE), Lebanese University, Beirut (Lebanon)

2016-08-01

In this study, the adsorption of heavy metal ions onto ordered mesoporous carbon CMK-3 was investigated. CMK-3 has been synthesized using SBA-15 as the hard template and then directly amino-functionalized by the treatment with 3-aminopropyltrimethoxysilane (APTMS) without the need of oxidation before. The thus obtained modified mesoporous carbon has been characterized by nitrogen sorption, X-ray diffraction and infrared spectroscopy. Its adsorption efficiency for the removal of Cu{sup 2+} and Pb{sup 2+} from aqueous solutions was tested. The effects of contact time, pH and initial metal ions concentration were investigated as well. The adsorption capacities were very high (3.5 mmol g{sup −1} and 8.6 mmol g{sup −1} for Pb{sup 2+} and Cu{sup 2+} respectively). These values depend largely on the speciation of metal ions as a function of pH. The selectivity was also dependent on the nature of metal ions rather than the adsorbent used. The mechanism of adsorption is complex where several types of interaction between metal ions and the adsorbent surface are involved. - Highlights: • Mesoporous carbon CMK-3 was successfully synthesized and functionalized. • No oxidation treatment was done prior to aminopropyl functionalization. • The adsorbent adsorption capacity is high (3.5 mmol g{sup −1} for Cu{sup 2+} and 8.6 mmol g{sup −1} for Pb{sup 2+}). • The maximum Cu{sup 2+} adsorption capacity is related to its speciation as a function of pH. • The mechanism of adsorption is complex including different types of interaction.

Removal of Pb (II from Aqueous Solutions Using Mixtures of Bamboo Biochar and Calcium Sulphate, and Hydroxyapatite and Calcium Sulphate

Directory of Open Access Journals (Sweden)

Ahmed Hassan

2016-01-01

Full Text Available Sorption characteristics of Pb(II from aqueous solutions through a low-cost adsorbent mixture comprising of Bamboo biochar (BB and Calcium Sulphate (CS, and a more expensive mixture of Hydroxyapatite (HAP and Calcium Sulphate (CS, were investigated. The effects of equilibrium contact time, and adsorbate concentration conducted in batch experiments were studied. Adsorption equilibrium was established in 40 (min. The adsorption mechanism of Pb(II from these two adsorbent mixtures was carried out through a kinetic rate order. A pseudo second-order kinetic model was applied for the adsorption processes. The model yielded good correlation (R2 >0.999 of the experimental data. Adsorption of Pb(II using (BB&CS and (HAP&CS correlated well (R2 >0.99 with both the Langmuir and Freundlich isotherm equations under the concentration range studied. Hence, the effectiveness of an inexpensive natural material (BB&CS mixture in Pb(II removal is established, and is promising for use in other heavy metal adsorptions.

Investigation on Pleurotus ferulae potential for the sorption of Pb(II ...

African Journals Online (AJOL)

Pleurotus ferulae obtained from rotten tree was collected, washed, dried, ground and sieved to appropriate particle size. Infra-red spectrometry was used to determine functional groups on the biomass while biosorption of Pb(II) from aqueous solution was studied using the biomass in a batch system. The effect of pH (1-7.5), ...

Selective removal for Pb2+ in aqueous environment by using novel macroreticular PVA beads

International Nuclear Information System (INIS)

Zhang Yun; Li Yanfeng; Li Xiaoli; Yang Liuqing; Bai Xue; Ye Zhengfang; Zhou Lincheng; Wang Liyuan

2010-01-01

Batch sorption experiments were conducted using macroreticular poly(vinyl alcohol) (MR-PVA) beads as a adsorbent to adsorb Pb(II) from both single component system and multi-metal solution in which experimental parameters were studied including solution pH, contact time, adsorbent dose, initial concentration of metal ions and ionic strength. The equilibrium isotherms were determined at pH 6 under constant ionic strength and at different temperatures. The results showed that the maximum adsorption capacity of Pb(II) (213.98 mg g -1 ) with 1 g L -1 of adsorbent was observed at 300 mg L -1 at an initial pH value of 6.0 under temperature of 288 K. Removals of about 60% occurred in 30 min, and equilibrium was attained at around 150 min. The equilibrium data for the adsorption of Pb(II) on MR-PVA beads was tested with various adsorption isotherm models among which three models were found to be suitable for the Pb(II) adsorption. In addition, the kinetic adsorption fitted well to the pseudo-second-order model and the corresponding rate constants were obtained. Thermodynamic aspects of the adsorption process were also investigated.

A study on complex formation of cadmium(II) ions, 8

International Nuclear Information System (INIS)

Matsui, Haruo; Hirabayashi, Yoshihiro

1984-01-01

In the potentiometric titration of the solution containing a cadmium(II) ion and an amino acid, white precipitates often appear in the test solution, and they disturb the emf measurements. Such precipitates were formes in the solutions, pH ranging 7.5--8.5, during the course of titrations of the test solutions containing cadmium(II) ion and amino acid such as glycine, α-alanine. 2-aminobutanoic acid, 3-aminobutanoic acid, 4-aminobutanoic acid, 2-aminopentanoic acid, 5-aminopentanoic acid, 2-aminohexanoic acid, 6-aminohexanoic acid, aspartic acid, glutamic acid, asparagine, or glutamine. The identification of the precipitates obtained from the solutions containing cadmium(II) ion and L-aspartic acid, 4-aminobutanoic acid, or 6-aminohexanoic acid were carried out by both of elemental analysis and the infrared spectroscopy. These results indicated that the precipitate obtained from the solution containing cadmium(II) ion and L-aspartic acid was 1:1 cadmium(II)-L-aspartic acid complex and did not contain any cadmium(II) hydroxide, and other two precipitates were mostly cadmium(II) hydroxide and contained a little cadmium(II)-amino acid complexes. (author)

Highly effective removal of mercury and lead ions from wastewater by mercaptoamine-functionalised silica-coated magnetic nano-adsorbents: Behaviours and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Bao, Shuangyou; Li, Kai; Ning, Ping [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, YunNan, KunMing, 650500 (China); Peng, Jinhui [Faculty of Metallurgical and Energy, Kunming University of Science and Technology, YunNan, KunMing 650500 (China); Jin, Xu [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, YunNan, KunMing, 650500 (China); Tang, Lihong, E-mail: luckyman@163.com [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, YunNan, KunMing, 650500 (China)

2017-01-30

Highlights: • Highly effective removal of Hg(II) and Pb(II) ions from wastewater. • This adsorbent had multiple adsorption sites (sulfur and amine sites) on the surface. • This adsorbent had better tolerance to low pH for removal of Hg(II). • This new hybrid material was much cheaper and no secondary pollution. • This adsorbent shows notable advantages including easy separation and recyclability. - Abstract: A novel hybrid material was fabricated using mercaptoamine-functionalised silica-coated magnetic nanoparticles (MAF-SCMNPs) and was effective in the extraction and recovery of mercury and lead ions from wastewater. The properties of this new magnetic material were explored using various characterisation and analysis methods. Adsorbent amounts, pH levels and initial concentrations were optimised to improve removal efficiency. Additionally, kinetics, thermodynamics and adsorption isotherms were investigated to determine the mechanism by which the fabricated MAF-SCMNPs adsorb heavy metal ions. The results revealed that MAF-SCMNPs were acid-resistant. Sorption likely occurred by chelation through the amine group and ion exchange between heavy metal ions and thiol functional groups on the nanoadsorbent surface. The equilibrium was attained within 120 min, and the adsorption kinetics showed pseudo-second-order (R{sup 2} > 0.99). The mercury and lead adsorption isotherms were in agreement with the Freundlich model, displaying maximum adsorption capacities of 355 and 292 mg/g, respectively. The maximum adsorptions took place at pH 5–6 and 6–7 for Hg(II) and Pb(II), respectively. The maximum adsorptions were observed at 10 mg and 12 mg adsorbent quantities for Hg(II) and Pb(II), respectively. The adsorption process was endothermic and spontaneous within the temperature range of 298–318 K. This work demonstrates a unique magnetic nano-adsorbent for the removal of Hg(II) and Pb(II) from wastewater.

Anti-inflammatory drugs interacting with Zn(II), Cd(II) and Pt(II) metal ions.

Science.gov (United States)

Dendrinou-Samara, C; Tsotsou, G; Ekateriniadou, L V; Kortsaris, A H; Raptopoulou, C P; Terzis, A; Kyriakidis, D A; Kessissoglou, D P

1998-09-01

Complexes of Zn(II), Cd(II) and Pt(II) metal ions with the anti-inflammatory drugs, 1-methyl-5-(p-toluoyl)-1H-pyrrole-2-acetic acid (Tolmetin), alpha-methyl-4-(2-methylpropyl)benzeneacetic acid (Ibuprofen), 6-methoxy-alpha-methylnaphthalene-2-acetic acid (Naproxen) and 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid (indomethacin) have been synthesized and characterized. In the structurally characterized Cd(naproxen)2 complex the anti-inflammatory drugs acts as bidentate chelate ligand coordinatively bound to metal ions through the deprotonated carboxylate group. Crystal data for 1: [C32H26O8Cd], orthorhombic, space group P22(1)2(1), a = 5.693(2) (A), b = 8.760(3) (A), c = 30.74(1) (A), V = 1533(1) A3, Z = 2. Antibacterial and growth inhibitory activity is higher than that of the parent ligands or the platinum(II) diamine compounds.

Pb(II) and Cd(II) removal from aqueous solution, shipyard wastewater, and landfill leachate by modified Rhizopus oryzae biomass

Science.gov (United States)

Naeimi, Behrouz; Foroutan, Rauf; Ahmadi, Bahram; Sadeghzadeh, Farzaneh; Ramavandi, Bahman

2018-04-01

This study was designed to remove Pb(II) and Cd(II) from aqueous solution, shipyard wastewater, and sanitary landfill leachate using an alkaline-modified Rhizopus oryzae biomass. According to the Fourier transform infrared test, different functional groups like O–H, N–H, C=O, and P–O were detected in the bioadsorbent. The x-ray fluorescence (XRF) analysis showed that CaO, P2O3, and SO3 oxides have the highest content in the bioadsorbent. The surface area of modified Rhizopus oryzae was obtained as 20.32 m2 g‑1. The effect of initial pH, temperature, contact time, and bioadsorbent dose on the metals removal was discussed. At optimal conditions, maximum Pb(II) and Cd(II) removal was obtained 95.66% and 94.55%, respectively. Freundlich model was well- accurately described the equilibrium data. Among four studied models, the pseudo-second-order was better able to describe the kinetic behavior of the bioadsorption process. The amount of enthalpy, free energy of Gibbs, and entropy parameters indicated that the bioadsorption process of studied heavy metals is negative, exothermic, and spontaneous. The amount of heavy metals in a shipyard wastewater and sanitary landfill leachate was significantly decreased by using the developed bioadsorbent.

ethane as ionophore in potentiometric sensor for Pb(II) ions

Indian Academy of Sciences (India)

solvent media up to 30% (v/v) non-aqueous contents. Selectivity of the ... PVC; neutral carrier; ionophore; liquid membrane; lead ions; selectivity coefficients; Nernstian ... Health Organization (WHO) and US Environmental ... The first new tripo-.

Cellulose bearing Schiff base and carboxylic acid chelating groups: a low cost and green adsorbent for heavy metal ion removal from aqueous solution.

Science.gov (United States)

Saravanan, R; Ravikumar, L

2016-10-01

Chemically modified cellulose bearing metal binding sites like Schiff base and carboxylic acid groups was synthesized and characterized through Fourier transform infrared and solid state 13 C-nuclear magnetic resonance (NMR) analysis. The chemically modified cellulose (Cell-PA) adsorbent was examined for its metal ion uptake ability for Cu(II) and Pb(II) ions from aqueous solution. Kinetic and isotherm studies were carried out under optimum conditions. Pseudo-second-order kinetics and Langmuir isotherm fit well with the experimental data. Thermodynamic studies were also performed along with adsorption regeneration performance studies. The adsorbent (Cell-PA) shows high potential for the removal of Cu(II) and Pb(II) metal ions, and it shows antibacterial activity towards selected microorganisms.

Results on ultra-peripheral interactions in Pb-Pb and p-Pb collisions in ALICE

CERN Document Server

Scapparone, E

2013-01-01

Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study $\\gamma$-nucleus and $\\gamma$-proton interactions at the LHC in the so called ultra-peripheral collisions (UPC). Here we report ALICE results on J/psi photoproduction measured in Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV and in p-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 5.02 TeV.

Hydrogen diffusion in Pb β''-alumina

International Nuclear Information System (INIS)

Bates, J.B.; Dudney, N.J.; Wang, J.C.

1985-01-01

The mobile Na + ions in Na β''-alumina can be completely exchanged with Pb 2+ ions by treatment in molten PbCl 2 . When this exchange was carried out in the presence of air, protons in the form of OH - were introduced into the conduction layers along with lead ions. Although the concentration of OH - was low, on the order of 5 x 10 -3 per formula unit of Pb/sub 0.84/Mg/sub 0.67/Al/sub 10.33/O_1_7, the distribution of OH - after ion exchange indicated that the proton mobility in Pb β''-alumina is high. The potential use of Pb β''-alumina as a fast proton conductor that is stable at 400 0 C motivated further studies of hydrogen diffusion. In this report, the results of tracer diffusion measurements by isotope exchange will be presented

Design concepts for PBFA-II's applied-B ion diode

International Nuclear Information System (INIS)

Rovang, D.C.

1985-01-01

The lithium ion diode to be used at the center of Particle Beam Fusion Accelerator-II (PBFA-II) at Sandia National Laboratories is an applied-B ion diode. The center section of the PBFA-II accelerator is where the electrical requirements of the accelerator, the design requirements of the diode, and the operational requirements must all be satisfied simultaneously for a successful experiment. From an operational standpoint, the ion diode is the experimental hub of the accelerator and needs to be easily and quickly installed and removed. Because of the physical size and geometry of the PBFA-II center section, achieving the operational requirements has presented an interesting design challenge. A discussion of the various design requirements and the proposed concepts for satisfying them is presented

Removal of Pb(II) from aqueous solution by natural and synthetic ...

African Journals Online (AJOL)

The point of zero charge values of 9.57 and 8.20 were obtained by mass titration method for synthetic and natural calcite, respectively. The maximum adsorption capacities of 200 mg/g and 150 mg/g Pb(II) of synthetic calcite and natural calcite were obtained at initial lead loading of 1200 mg/L at 25±2 °C, respectively.

Separation of 210 Pb, 210 Bi and 210 Po by ion exchange and their liquid scintillation standardization

International Nuclear Information System (INIS)

Rodriguez, L.; Jimenez, A.; Grau, A.

1996-01-01

We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210 Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''tm II, HiSafe''tmIII, Ultima-Gold''tm, Ultima-Gold''tmXR, Ultima-Gold''tmAB, Insta-Gel and e Insta-Gel II. Also we analyzed the disequilibrium of the radioactive chain ''210Pb+''210Bi+''210Po, achieving and excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs

Spectroscopic, Elemental and Thermal Analysis, and Positron Annihilation Studies on Ca(II), Sr(II), Ba(II), Pb(II), and Fe(III) Penicillin G Potassium Complexes

Science.gov (United States)

Refat, M. S.; Sharshara, T.

2015-11-01

The [Pb(Pin)2] · 3H2O, [M(Pin)(H2O)2(Cl)] · nH2O (M = SrII, CaII or BaII; n = 0-1), and [Fe(Pin)2(Cl)(H2O)] · H2O penicillin G potassium (Pin) complexes were synthesized and characterized using elemental analyses, molar conductivity, thermal analysis and electronic spectroscopy techniques. The positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques have been employed to probe the defects and structural changes of Pin ligand and its complexes. The PAL and DB line-shape parameters were discussed in terms of the structure, molecular weight, ligand-metal molar ratio, and other properties of the Pin complexes.

$Z^0$ boson measurement in the dimuon channel in PbPb collisions with the CMS experiment

CERN Document Server

Robles, Jorge A

2011-01-01

The unprecedented center of mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions. This QCD matter is created at extreme temperatures, intermediate momentum fractions and large Q2 values. With its high precision, large acceptance for tracking, and a trigger scheme that allows analysis of each minimum-bias PbPb events, CMS is especially suited to measure high-pT dimuons, even in the high multiplicity environment of heavy-ion collisions. Electroweak probes are accessible for the first time in heavy-ion collisions. The Z0 boson is cleanly reconstructed in the dimuon channel with the CMS detector. Precise measurements of Z0 production in heavy-ion collisions can help to constrain the nuclear parton distribution functions (PDF) as well as serve as a standard candle of the initial state in PbPb collisions at the LHC energies. From the PbPb run at $\\sgrt{s_{NN}}$ = 2.76 TeV, the inclusive and differential measurement...

Continuous preparation of Fe3O4 nanoparticles through Impinging Stream-Rotating Packed Bed reactor and their electrochemistry detection toward heavy metal ions

International Nuclear Information System (INIS)

Fan, Hong-Lei; Zhou, Shao-Feng; Gao, Jing; Liu, You-Zhi

2016-01-01

We reported the continuous preparation and electrochemical behavior toward heavy metal ions of the Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs). This Fe 3 O 4 NPs were fabricated through a novel Impinging Stream-Rotating Packed Bed reactor with a high production rate of 2.23 kg/hour. The as-prepared Fe 3 O 4 NPs were quasi-spherical with a mean diameter of about 10 nm and shown the characteristics of superparamagnetism with the saturated magnetization of 60.5 emu/g. The electrochemical characterization of the as-prepared Fe 3 O 4 NPs toward heavy metal ions were evaluated using square wave anodic stripping voltammetry (SWASV) analysis. The results indicated that the modified electrode could be used to individual detection of Pb(II), Cu(II), Hg(II) and Cd(II). In particular, the modified electrode exhibited the selective detection toward Pb(II) with higher sensitivity of 14.9 μA/μM, while the response to Cu(II), Hg(II) and Cd(II) were negligible. Besides, the modified electrode shown good stability and potential practical applicability in the electrochemical determination of Pb(II). This above results offered a simple method for continuous preparation sensing materials in the application field of electrochemical detection of toxic metal ions through the technology of process intensification. - Highlights: • Fe 3 O 4 nanoparticles were continuous prepared through IS-RPB reactor. • The Fe 3 O 4 nanoparticles showed selective detection of heavy metal ions. • It exhibited favorable sensitivity (14.9 μA μM −1 ) and LOD (0.119 μM) for Pb(II). • The as-prepared nanoparticles showed favorable potential application.

Determination of Pb2+ metal ion level in liquid waste from adsorption process by combination adsorbent of rice husk and water hyacinth charcoal using solid-phase spectrophotometry (sps)

Science.gov (United States)

Saputro, S.; Masykuri, M.; Mahardiani, L.; Hidayah, AN

2018-03-01

This research are to find out the influence of adsorbent composition between rice husk and water hyacinth in decreasing of Pb2+ ion in simulation liquid waste; the optimumcomposition of combination adsorbent of rice husk and water hyacinth charcoal on Pb2+ ion adsorption; and theeffectivenessof SPS as a method to determine the decreasing level of Pb2+ ion in simulation liquid waste by combination adsorbent of rice husk and water hyacinth charcoal in µg/L level. Rice husk and water hyacinth carbonization using muffle furnace at 350°C for 1 hour. Rice husk charcoal activation in a 2 N NaOH solution and water hyacinth charcoal activated in a 5 M HCl solution. Contacting the combination adsorbent of rice husk and water hyacinth charcoal with a Pb2+ solution with variation of mass composition, 1:0 ; 0:1 ; 1:1 ; 1:2 and 2:1. Analysis of the Pb2+ ion level using SPS method. Characterization of rice husk and water hyacinth charcoal using the FTIR. The results showed that the combination adsorbent composition of rice husk and water hyacinth charcoal have an impact on decreasing Pb2+ ion level. The optimum composition of combination adsorbent of rice husk and water hyacinth charcoal on the adsorption Pb2+ ion is 1:2. SPS is an effective method to determine the decreasing Pb2+ ion in simulation liquid waste from the adsorption process by combination adsorbent of rice husk and water hyacinth in µg/L, with Limit of Detection (LOD) was 0,06 µg/L.

Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

Science.gov (United States)

Sharma, Surendra; Weiden, Norbert; Weiss, Alarich

1991-04-01

The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion

Binding Affinity of a Highly Sensitive Au/Ag/Au/Chitosan-Graphene Oxide Sensor Based on Direct Detection of Pb2+ and Hg2+ Ions

Directory of Open Access Journals (Sweden)

Nur Hasiba Kamaruddin

2017-10-01

Full Text Available The study of binding affinity is essential in surface plasmon resonance (SPR sensing because it allows researchers to quantify the affinity between the analyte and immobilised ligands of an SPR sensor. In this study, we demonstrate the derivation of the binding affinity constant, K, for Pb2+ and Hg2+ ions according to their SPR response using a gold/silver/gold/chitosan–graphene oxide (Au/Ag/Au/CS–GO sensor for the concentration range of 0.1–5 ppm. The higher affinity of Pb2+ to binding with the CS–GO sensor explains the outstanding sensitivity of 2.05 °ppm−1 against 1.66 °ppm−1 of Hg2+. The maximum signal-to-noise ratio (SNR upon detection of Pb2+ is 1.53, and exceeds the suggested logical criterion of an SNR. The Au/Ag/Au/CS–GO SPR sensor also exhibits excellent repeatability in Pb2+ due to the strong bond between its functional groups and this cation. The adsorption data of Pb2+ and Hg2+ on the CS–GO sensor fits well with the Langmuir isotherm model where the affinity constant, K, of Pb2+ and Hg2+ ions is computed. The affinity of Pb2+ ions to the Au/Ag/Au/CS–GO sensor is significantly higher than that of Hg2+ based on the value of K, 7 × 105 M−1 and 4 × 105 M−1, respectively. The higher shift in SPR angles due to Pb2+ and Hg2+ compared to Cr3+, Cu2+ and Zn2+ ions also reveals the greater affinity of the CS–GO SPR sensor to them, thus supporting the rationale for obtaining K for these two heavy metals. This study provides a better understanding on the sensing performance of such sensors in detecting heavy metal ions.

Optical diagnostics of lead and PbGa2S4 layered crystal laser plasmas

International Nuclear Information System (INIS)

Shuaibov, A.K.; Dashchenko, A.I.; Shevera, I.V.

2001-01-01

Paper presents the results of the optic diagnostics of plasma of laser flames formed from lead surface and PbGa 2 S 4 laminar crystal using a neodymium laser. It is shown that the most intensive lines in the lead laser plasma are as follows: 405.7, 368.3, 364.0 nm PbI and 220.4 nm PbII while for the laminar crystal base plasma - the combination of the most intensive lines of PbI and GaI emission. One determined the narrow point of recombination fluxes for the ion and the atomic components of laser plasma of lead and of PbGa 2 S 4 crystal. One conducted comparison study of emission dynamics of PbI and GaI lines in laser plasma of the respective metals and of PbGa 2 S 4 crystal [ru

Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS

Energy Technology Data Exchange (ETDEWEB)

Sirunyan, Albert M; et al.

2017-08-23

For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from sqrt(s[NN]) = 2.76 TeV PbPb and sqrt(s[NN]) = 5.02 TeV pPb collisions collected by the CMS experiment at the LHC. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it has been shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ("leading" and "subleading") of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of pt over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique has also been applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.

Removal of lead and phosphate ions from aqueous solutions by organo-smectite.

Science.gov (United States)

Bajda, Tomasz; Szala, Barbara; Solecka, Urszula

2015-01-01

Smectite has been modified using hexadecyltrimethyl ammonium bromide in an amount of double cationic exchange capacity. This alteration makes it possible to use organo-smectite as a sorbent to remove anionic forms. The experiment consisted of the interchangeable sorption of phosphate(V) and lead(II) by organo-smectite. Research was carried out with varying pH (2-5) and various concentrations (0.1-5 mmol/L). Organo-smectite with previously adsorbed lead ions removed more phosphate than the untreated organo-smectite. Experimental data show that lead is more likely to absorb on the organo-smectite than on the organo-smectite with previously adsorbed phosphate ions. It follows that the most effective use of the organo-smectite is through the sorption of first - Pb cations and then PO4 anions. With an increasing concentration of Pb(II) or P(V), the sorption efficiency increases. The maximum sorption efficiency of lead and phosphate ions is observed at pH 5. This enables the removal of harmful lead and phosphorus compounds from waste water and immobilizes them on the sorbent's surface. The alternating reactions of lead and phosphorus ions result in the crystallization of brompyromorphite Pb5(PO4)3Br.

Titania-Coated Silica Alone and Modified by Sodium Alginate as Sorbents for Heavy Metal Ions

Science.gov (United States)

Kołodyńska, D.; Gęca, M.; Skwarek, E.; Goncharuk, O.

2018-04-01

The novel organic-inorganic biohybrid composite adsorbent was synthesized based on nanosized silica-titania modified with alginate within the development of effective adsorbent for heavy metal ions. Effects of metal species Cu(II), Zn(II), Cd(II), and Pb(II); concentrations; pH; temperature; and adsorption onto titania-coated silica (ST20) initial or modified by sodium alginate (ST20-ALG) were studied. The equilibrium and kinetic data of metal ions adsorption were analyzed using Langmuir and Freundlich adsorption models and kinetic models: pseudo first order, pseudo second order, intraparticle kinetic model, and Elovich. The maximum sorption capacities observed were higher for the ST20-ALG composite compared to the initial ST20 oxide for all studied metal ions, namely their values for ST20-ALG were 22.44 mg g- 1 for Cu(II) adsorption, 19.95 mg g- 1 for Zn(II), 18.85 mg g- 1 for Cd(II), and 32.49 mg g- 1 for Pb(II). Structure and properties of initial silica-titania ST20 and modified by sodium alginate ST20-ALG adsorbents were analyzed using nitrogen adsorption/desorption isotherms, ATR-FTIR, SEM-EDS, and pHpzc techniques.

U-Pb geochronology of zircons form lunar Breccia 73217 using a sensitive high mass-resolution ion microprobe

International Nuclear Information System (INIS)

Compston, W.; Williams, I.S.

1984-01-01

U-Pb age determinations on four lunar zircons from existing thin-sections of one highland breccia, 73217, using the recently constructed ion microprobe SHRIMP, are reported. The analytical reproducibility of SHRIMP is demonstrated, and procedures for measuring Pb/U, Th/U, and corecting for initial Pb are explained. Electron microprobe analyses for the zircons are also reported. The results show that the four zircons survived the lunar cataclysm without any identifiable effects on their U-Pb systematics. All four indicate a single age of 4356 +23 or -14 m.y. The zircons have experienced small variable amounts of Pb loss since crystallization, from almost zero up to about 10 percent. If this occurred during one later event, then age of the latter is between 1100 and 2300 m.y. 18 references

Dithizone-modified graphene oxide nano-sheet as a sorbent for pre-concentration and determination of cadmium and lead ions in food.

Science.gov (United States)

Moghadam Zadeh, Hamid Reza; Ahmadvand, Parvaneh; Behbahani, Ali; Amini, Mostafa M; Sayar, Omid

2015-01-01

Graphene oxide nano-sheet was modified with dithizone as a novel sorbent for selective pre-concentration and determination of Cd(II) and Pb(II) in food. The sorbent was characterised by various analytical methods and the effective parameters for Cd(II) and Pb(II) adsorption were optimised during this work. The high adsorption capacity and selectivity of this sorbent makes the method capable of fast determinations of the Cd(II) and Pb(II) content in complicated matrices even at μg l(-1) levels using commonly available instrumentation. The precision of this method was < 1.9% from 10 duplicate determinations and its accuracy verified using standard reference materials. Finally, this method was applied to the determination of Cd(II) and Pb(II) ions in common food samples and satisfactory results were obtained.

Open-charm production measurements in pp, 1 p-Pb and Pb-Pb collisions with ALICE at the LHC

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Meninno Elisa

2017-01-01

Full Text Available ALICE (A Large Ion Collider Experiment is designed to study the strongly in teracting matter, the Quark-Gluon Plasma (QGP, created in heavy-ion collisions at LHC energies. Charm and beauty quarks are powerful probes to study the QGP. Produced in hard partonic scattering processes on a short time scale, they are expected to traverse the QCD medium, interacting with its constituents and losing energy through radiative and collisional processes. In ALICE, open-charm production is studied through the reconstruction of the hadronic decays of D0, D+, D*+ and Ds+ mesons at mid-rapidity. High precision tracking, good vertexing capabilities and excellent particle identification offered by ALICE allow for the measurement of particles containing heavy quarks (particularly D mesons in a wide transverse momentum range in pp, p-Pb and Pb-Pb collisions. A review of the main results on D-meson production in pp collisions at √s = 7 TeV, p-Pb collisions at √sNN = 5.02 TeV and Pb-Pb collisions at √sNN = 2.76 TeV will be presented.

Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

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Jacek Rożnowski

Full Text Available ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS. Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II and copper(II ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C were observed. Fortified native spelt starch with copper(II ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II ions in samples caused reduced its final viscosity by 170 (spelt starch and 103 mPa·s (monostarch phosphate. Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II ions and to 59.9% in case of iron(II ions.

The promise of a specially-designed graft copolymer of acrylic acid onto cellulose as selective sorbent for heavy metal ions.

Science.gov (United States)

Essawy, Hisham A; Mohamed, Magdy F; Ammar, Nabila S; Ibrahim, Hanan S

2017-10-01

A specially-designed graft copolymer of acrylic acid onto in-situ formed cellulose-fulvate hybrid showed privileged tendency for uptake of Pb(II) during competitive removal from a mixture containing Cd(II) and Ni(II) within 5min at pH 5. This novel trend is attributed mainly to the crowded high content of coordinating centers within the designed graft copolymer along with the acquired superabsorbency. This provides an outstanding tool to separate some metal ions selectively from mixtures containing multiple ions on kinetic basis. Thus, the designed graft copolymer structure exhibited superior efficiency that reached ∼95% for sole removal of Pb(II). Kinetic modeling for Pb(II) individual removal showed excellent fitting with a pseudo second-order model. Intraparticle diffusion model on the other hand ensured governance of boundary layer effect over diffusion during the removal process due to the superabsorbency feature of the graft copolymer. The experimental findings were described with models such as Freundlich, Langmuir, and Dubinin-Radushkevich. The Langmuir and Freundlich models showed convenience with the adsorption isotherm of Pb(II) onto the developed graft copolymer. Copyright © 2017 Elsevier B.V. All rights reserved.

Biorsopsi Ion Logam Zink (II dalam Larutan Menggunakan Daun Kari (Murraya Koenigii

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Bhayu Gita Bhernama

2017-06-01

Full Text Available Penyerapan ion logam Zn (II menggunakan daun kari (murraya koenigii telah dilakukan, Penelitian ini bertujuan untuk menentukan kadar ion logam Zn (II yang dapat diserap oleh daun kari (murraya koenigii. Kemampuan daun kari untuk menyerap ion logam Zn (II telah dievaluasi dengan variasi pH larutan, kosentrasi, ukuran partikel berat biomaterial. Kadar ion logam yang terserap diukur menggunakan spektrofotometer serapan atom (SSA. Hasil penelitian menunjukan kondisi optimum penyerapan ion logam Zn 9II menggunakan daun kari dengan pH 5 kapasitas penyerapan 0,611 mg/g, ukuran partikel 150 µm kapasitas penyerapan 0,689 mg/g, konsentrasi 50 ppm dengan kapasitas penyerapan 0,443 mg/g dan berat material 0,5 g kapasitas penyerapan 1,505 mg/g. Berdasarkan persamaan isoterm Langmuir didapatkan kapasitas penyerapan maksimum Qmax -0,127. Hasil analisis FTIR memperlihatkan adanya gugus hidroksil yang dapat mengikat ion logam Zn (II. Kata kunci : logam berat Zn (II, penyerapan, daun kari

Thiol-functionalized polysilsesquioxane as efficient adsorbent for adsorption of Hg(II) and Mn(II) from aqueous solution

International Nuclear Information System (INIS)

Niu, Yuzhong; Qu, Rongjun; Liu, Xiguang; Mu, Lei; Bu, Baihui; Sun, Yuting; Chen, Hou; Meng, Yangfeng; Meng, Lina; Cheng, Lin

2014-01-01

Highlights: • PMPSQ was promising adsorbent for the removal of Hg(II) and Mn(II). • The adsorption kinetics followed the pseudo-second-order model. • The adsorption isotherms can be described by the monolayer Langmuir model. • The adsorption was controlled by film diffusion and chemical ion-exchange mechanism. - Abstract: Thiol-functionalized polysilsesquioxane was synthesized and used for the adsorption of Hg(II) and Mn(II) from aqueous solution. Results showed that the optimal pH was about 6 and 5 for Hg(II) and Mn(II), respectively. Adsorption kinetics showed that the adsorption equilibriums were established within 100 min and followed pseudo-second-order model. Adsorption isotherms revealed that the adsorption capacities increased with the increasing of temperature. The adsorption was found to be well described by the monolayer Langmuir isotherm model and took place by chemical ion-exchange mechanism. The thermodynamic properties indicated the adsorption processes were spontaneous and endothermic nature. Selectively adsorption showed that PMPSQ can selectively adsorb Hg(II) from binary ion systems in the presence of the coexistent ions Mn(II), Cu(II), Pb(II), Co(II), and Ni(II). Based on the results, it is concluded that PMPSQ had comparable high adsorption efficiency and could be potentially used for the removal of Hg(II) and Mn(II) from aqueous solution

Adsorption of Pb(II and Cu(II by Ginkgo-Leaf-Derived Biochar Produced under Various Carbonization Temperatures and Times

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Myoung-Eun Lee

2017-12-01

Full Text Available Ginkgo trees are common street trees in Korea, and the large amounts of leaves that fall onto the streets annually need to be cleaned and treated. Therefore, fallen gingko leaves have been used as a raw material to produce biochar for the removal of heavy metals from solutions. Gingko-leaf-derived biochar was produced under various carbonization temperatures and times. This study evaluated the physicochemical properties and adsorption characteristics of gingko-leaf-derived biochar samples produced under different carbonization conditions regarding Pb(II and Cu(II. The biochar samples that were produced at 800 °C for 90 and 120 min contained the highest oxygen- and nitrogen-substituted carbons, which might contribute to a high metal-adsorption rate. The intensity of the phosphate bond was increased with the increasing of the carbonization temperature up to 800 °C and after 90 min of carbonization. The Pb(II and Cu(II adsorption capacities were the highest when the gingko-leaf-derived biochar was produced at 800 °C, and the removal rates were 99.2% and 34.2%, respectively. The highest removal rate was achieved when the intensity of the phosphate functional group in the biochar was the highest. Therefore, the gingko-leaf-derived biochar produced at 800 °C for 90 min can be used as an effective bio-adsorbent in the removal of metals from solutions.

Selective solid-phase extraction using oxidized activated carbon modified with triethylenetetramine for preconcentration of metal ions

Science.gov (United States)

Zhang, Li; Chang, Xijun; Li, Zhenhua; He, Qun

2010-02-01

A new selective solid-phase extractant using activated carbon as matrix which was purified, oxidized and modified by triethylenetetramine (AC-TETA) was prepared and characterized by FT-IR spectroscopy. At pH 4, quantitative extraction of trace Cr(III), Fe(III) and Pb(II) was obtained and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Complete elution of the adsorbed metal ions from the sorbent surface was carried out using 0.5 mol L -1 HCl. The maximum static adsorption capacity of sorbent for Cr(III), Fe(III) and Pb(II) was 34.6, 36.5 and 51.9 mg g -1, respectively. The time of quantitative adsorption was less than 2 min. The detection limits of the method was found to be 0.71, 0.35 and 0.45 ng mL -1 for Cr(III), Fe(III) and Pb(II), and the relative standard deviation (RSD) was 3.7%, 2.2% and 2.5%, respectively. Moreover, the method was free from interference with common coexiting ions. The method was also successfully applied to the preconcentration of trace Cr(III), Fe(III) and Pb(II) in synthetic samples and a real sample with satisfactory results.

Synthesis and physicochemical characterization of two lead(II) complexes with O-, N-donor ligands. Lone pair functionality and crystal structure

Science.gov (United States)

Masternak, Joanna; Barszcz, Barbara; Hodorowicz, Maciej; Khavryuchenko, Oleksiy V.; Majka, Alina

2015-02-01

A dinuclear [Pb2(4-CHO-5-MeIm)6(NO3)2](NO3)2 (1) and a polynuclear [Pb(2-pzc)2(H2O)]n (2) complexes (where 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm) and pyrazine-2-carboxylic acid (2-pzcH)) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species [Pb(4-CHO-5-MeIm)3]2+ connected through bridging nitrate(V) ions. There are also an uncoordinated nitrate ions as counterions. Complex 2 is a three-dimensional architecture consisting of Pb6O12 building units. The pyrazine-2-carboxylato ligand behaves as a chelating agent and a bi-connective bridge. The coordination polyhedra around lead(II) ion could be described as a distorted docecahedron (1) or monocapped trigonal prism (2). The luminescent properties of 1 and 2 investigated in the solid state at room temperature indicate structure-dependent photoluminescent properties. The DFT calculations and the X-ray structural data point on rather hemidirected type of coordination around Pb(II) ions of 1 and 2.

Oxidation of Pb-Sn and Pb-Sn-In alloys

International Nuclear Information System (INIS)

Sluzewski, D.A.; Chang, Y.A.; Marcotte, V.C.

1990-01-01

Air oxidized Pb-Sn and Pb-Sn-In single phase alloys have been studied with scanning Auger microscopy. Line scans across grain boundaries combined with argon ion sputter etching revealed grain boundary oxidation. In the Pb-Sn samples, tin is preferentially oxidized with the grain boundary regions having a much higher percentage of tin oxide than the bulk surface oxide. In the Pb-Sn-In alloys, both tin and indium are preferentially oxidized with the grain boundary regions being enriched with tin and indium oxides

Surface modification of glass beads with glutaraldehyde: Characterization and their adsorption property for metal ions

Energy Technology Data Exchange (ETDEWEB)

Ozmen, Mustafa; Can, Keziban; Akin, Ilker; Arslan, Gulsin [Department of Chemistry, Selcuk University, 42031, Konya (Turkey); Tor, Ali, E-mail: ali.alitor@gmail.com [Department of Environmental Engineering, Selcuk University, Engineering Faculty, Campus, 42031, Konya (Turkey); Cengeloglu, Yunus; Ersoz, Mustafa [Department of Chemistry, Selcuk University, 42031, Konya (Turkey)

2009-11-15

In this study, a new material that adsorbs the metal ions was prepared by modification of the glass beads surfaces with glutaraldehyde. First, the glass beads were etched with 4 M NaOH solution. Then, they were reacted with 3-aminopropyl-triethoxysilane (APTES). Finally, silanized glass beads were treated with 25% of glutaraldehyde solution. The characterization studies by using Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA), elemental analysis and Scanning Electron Microscopy (SEM) indicated that modification of the glass bead surfaces was successfully performed. The adsorption studies exhibited that the modified glass beads could be efficiently used for the removal of the metal cations and anion (chromate ion) from aqueous solutions via chelation and ion-exchange mechanisms. For both Pb(II) and Cr(VI), selected as model ions, the adsorption equilibrium was achieved in 60 min and adsorption of both ions followed the second-order kinetic model. It was found that the sorption data was better represented by the Freundlich isotherm in comparison to the Langmuir and Redlich-Peterson isotherm models. The maximum adsorption capacities for Pb(II) and Cr(VI) were 9.947 and 11.571 mg/g, respectively. The regeneration studies also showed that modified glass beads could be re-used for the adsorption of Pb(II) and Cr(VI) from aqueous solutions over three cycles.

Search for superconductivity in ion-implanted Pb-Ge films

International Nuclear Information System (INIS)

Zawislak, F.C.; Bernas, H.; Mendoza-Zelis, L.; Travers, A.; Chaumont, J.; Dumoulin, L.

1980-01-01

We have studied the dose and the temperature dependence of the resistivity in thin coevaporated films (500-600 A) of Pbsub(0.3) Gesub(0.7) and Pbsub(0.7) Gesub(0.3) implanted at 6K with up to 2x10 15 Ge/cm 2 of 90 and 140 keV. The composition and uniformity of the films were controlled via in situ Rutherford backscattering (RBS) measurements, as functions of the implanted dose and the annealing temperature. The following results were obtained: a) a sharp Tsub(c) very close to the Tsub(c) of pure Pb was measured for the Pbsub(0.7) Gesub(0.3) film and no change in Tsub(c) was observed as a function of dose; b) for the Pbsub(0.3)Gesub(0.7) film the Tsub(c) decreased from about 6.8K before implantation to about 3.5 K after implantation of 2x10 15 ions/cm 2 ; c) the RBS spectra revealed that the alloy homogeneity was larger implantation at 6 K than before implantation and that precipitation for Pb occured during annealing

Tetranuclear cluster-based Pb(II)-MOF: Synthesis, crystal structure and luminescence sensing for CS2

Science.gov (United States)

Dong, Yanli

2018-05-01

A new Pb(II) coordination polymer, namely [Pb2(bptc)(DMA)]n (1, H4bptc = biphenyl-3,3‧,5,5‧-tetracarboxylic acid, DMA = N, N‧- dimethylacetamide), has been synthesized by the combination of H4bptc with Pb(NO3)2 under solvothermal conditions. Single crystal X-ray diffraction analysis revealed that compound 1 features a 3D framework based on tetranuclear [Pb4(COO)6] subunits, and topological analysis revealed that compound represents a binodal (4, 8)-connected scu-type topological network with the point symbol of {416,612}{44,62}2. Luminescence studies indicated that 1 and 1' (1‧ represents the desolvated samples) showed intense yellow emissions. Significantly, 1‧ exhibited sensitive luminescence sensing for CS2 solvent molecules at a low concentration.

A novel lead imprinted polymer as the selective solid phase for extraction and trace detection of lead ions by flame atomic absorption spectrophotometry: Synthesis, characterization and analytical application

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Homeira Ebrahimzadeh

2017-05-01

Full Text Available A novel ion imprinted polymer as the selective solid phase combined with flame atomic absorption spectrometry (FAAS was applied for preconcentration and determination of lead in real samples. In the first step, Pb(II-IIP was synthesized by copolymerization of 2-vinyl pyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, 2,2-azobisisobutyronitrile as the initiator that imprinted with Pb(II as the template ion, 2-amino pyridine as the ligand. Subsequently, the imprinted Pb(II was completely removed by leaching the dried and powdered imprinted polymer with HCl (2 mol L−1. This polymer was characterized by Fourier Transform Infrared (FT-IR spectrometer. The effect of different variables on the extraction efficiency such as type and volume of eluent for extraction, solution’s pH for adsorption, sorption and desorption times was evaluated. Under the optimum conditions: type of eluent, HCl (2 mol L−1; volume of eluent, 5 mL; solution’s pH for sorption, 5; sorption time, 90 min; desorption time, 125 min and breakthrough volume of 750 mL were obtained. Preconcentration factor of the method was about 150. The limit of detection was obtained 0.75 μg L−1 and a dynamic linear range (DLR of 3–150 μg L−1 was found. The maximum sorption retention capacity of Pb(II ions on the imprinted polymer was 85.6 mg g−1. The prepared ion-imprinted polymer particles have an increased selectivity toward Pb(II ions over a range of competing metal ions with the same charge and similar ionic radius. Performance of the present method was evaluated for extraction and determination of Pb(II in water samples at microgram per liter concentration and satisfactory results were obtained (RSD = 2.7%.

Removal of lead ions from industrial waste water by using biomaterials – a novel method

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Malairajan Singanan

2005-12-01

Full Text Available A simple cost effective and eco-friendly method for the remediation of lead from industrial wastewater has been investigated. A novel biomaterial, Tridax procumbens (Asteraceae a medicinal plant, was used for the removal of lead ions from synthetic wastewater and the method was also applied for real sample analysis. The operational pH of the experimental solution was fixed as 4.5. The optimum amount of bioadsorbent was 3.5 g. The Pb(II ions removal efficiency of the raw bioadsorbent was also determined. The removal efficiency of the activated carbon of the bioadsorbent was excellent. 98 % removal of Pb(II ions was achieved at the dose rate of 3.5 g. The optimum contact time was estimated to be 160 minutes.

COMPOSITIONS BASED ON PALLADIUM(II AND COPPER(II COMPOUNDS, HALIDE IONS, AND BENTONITE FOR OZONE DECOMPOSITION

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T. L. Rakitskaya

2017-05-01

bromide ion. For Cu(II-KBr/N-Bent composition, kinetic and calculation data show that, in the presence of bromide ions, copper(II inhibits the ozone decomposition. For Pd(II-KBr/NBent composition, it has been found that the maximum activity is attained at СPd(II = 1.02·10-5 mol/g. For bimetallic Pd(II- Cu(II-KBr/N-Bent composition, changes in τ0, τ1/2, k1/2, and Q1/2 parameters depending on a Pd(II content are similar to those for monometallic Pd(II-KBr/NBent composition; however, values of the parameters are higher for the monometallic system. Thus, the inhibiting effect of Cu(II is observed even in the presence of palladium(II.

Ion Exchange Kinetics of some Heavy Metals from Aqueous Solutions onto Poly(Acrylic Acid-Acrylo nitrle) Potassium Titanate

International Nuclear Information System (INIS)

El-Shorbagy, M.M.; El-Sadek, A.A.

2012-01-01

Composite inorganic-organic absorbers represent a group of inorganic ion exchangers modified using binding organic materials for preparation of larger size particles heaving higher granular strength. Such modification of originally powdered or microcrystalline inorganic ion exchangers makes their application in peaked beds possible-modified polyacrylonitrile (PAN) has been used as a universal binding polymer for a number of inorganic ion exchangers. The kinetic of ion exchange and sorption capacity of such composite absorbers is not influenced by the binding polymer mentioned above. These composites have been tested for separation and concentration of various contaminants from aqueous solutions. Their high selectivity and sorption efficiency are advantageous for treatment of various industrial waste waters. Removal of natural or artificial and the heavy metals, Pb, Cd and Zn ions. the influence of initial metal ion concentration and ph on metal ion removal has been studied. The process was found to follow a first order rate kinetics. The intra-particle diffusion of ions through pores in the adsorbent was to be the main rate limiting step. The selectivity order towards the ions was Pb(II) > Cd(II) > Zn(II)

Pb/Pb isochron ages and Pb isotope geochemistry of Bambui Group carbonate rocks from the southern portion of the Sao Francisco Basin

International Nuclear Information System (INIS)

Babinski, M.

1993-01-01

This study involves the establishment of chemical and analytical procedure for Pb/Pb dating of Neo proterozoic carbonate rocks and their application to obtaining isochron ages of Bambui Group rocks from the southern portion of the Sao Francisco Basin, Minas Gerais State. The Pb isotopic compositions and U and Pb concentrations determined on more than 90 samples (≅ 600 analyses) from Sete Lagoas do Jacare formations, Bambui Group, from different parts of the basin, showed four distinct types of Pb, here called types I, II, III and IV. Type I Pb was found in samples with low Pb concentrations and relatively high U concentrations. Type II Pb is present in samples with relatively high Pb concentrations and low U concentrations it is non-radiogenic crustal Pb. Type III Pb is also found in samples with high Pb concentrations and low U concentrations but it is radiogenic crustal Pb. Type IV Pb occurs in samples with U/Pb ratios lower than 1 and is intermediate in composition between Type III and Type I Pb. According to the data presented in this paper it is suggested that carbonate rocks from Sete Lagoas Formations were deposited before 686±69 Ma. Rocks from the Lagoa do Jacare Formation, contained only Type II Pb, which does not permit determination of a Pb/Pb age. During the interval from 690 to 500 Ma, the Pb isotope system of the carbonate rocks from the Sao Francisco Basin was disturbed, and in some areas it was totally reset. The imprecise U/Pb ages of 550-600 Ma obtained from some of the carbonate rocks reflect this disturbance. The ages determined in this study are in agreement with most of the published ages of the tectonism from the Brasiliano fold belts marginal to Sao Francisco Craton, showing that the isotopic systems of Sao Francisco Basin rocks were largely affected by brasiliano tectonism. (author)

ethane as ionophore in potentiometric sensor for Pb(II) ions

Indian Academy of Sciences (India)

tiometric sensors have attracted attention for their simple construction, low-cost, good ... of lead can cause serious health problems, includ- ing nervous system ... tripodal ionophore as a copper (II) selective electrode.16. Several studies have ...

Removal of Zn(II) and Pb (II) ions Using Rice Husk in Food Industrial ...

African Journals Online (AJOL)

Michael Horsfall

The removal of mentioned heavy metal ions from aqueous solutions was studied by batch ... The binding process was strongly affected by pH and the optimum. pH for Zn2+ and .... on the rice husks are protonated and positively-charged, their.

Renewable Modified Cellulose Bearing Chelating Schiff Base for Adsorptive Removal of Heavy Metal Ions and Antibacterial Action.

Science.gov (United States)

Saravanan, R; Ravikumar, L

2017-07-01

  A novel approach toward chemically modified cellulose bearing active chelating Schiff base with hydroxyl group (Cell-Hy) was synthesized. The modified cellulose was examined for its heavy metal ion uptake potential from aqueous solution. The chemical and structural features of the adsorbent were characterized by Fourier transform infrared spectroscopy (FT-IR), solid state 13C-NMR, Scanning Electron Microscopy (SEM), and energy dispersive analysis of X-ray (EDAX) observations. The experimental conditions and adsorption parameters, including pH, initial metal ion concentration, adsorbent dosage, temperature, and contact time were optimized for the removal of Cu(II) and Pb(II) ions. Kinetic parameters, equilibrium adsorption capacities, and correlation coefficients for pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were carried out. The data obtained from the adsorption of Cu(II) and Pb(II) onto Cell-Hy were subjected to Langmuir and Freundlich isotherm models. Thermodynamic parameters have also been evaluated. The antibacterial activity of modified cellulose was tested toward specific bacterial species.

W and Z bosons in pp, pPb and PbPb with CMS

CERN Document Server

AUTHOR|(CDS)2079475

2016-01-01

Electroweak boson production is an important benchmark process in high-energy heavy-ion collisions at the LHC. W and Z bosons do not participate in the strong interaction and their leptonic decays provide medium-blind probes of the initial state of the collisions. The final results on the W and Z production in pPb collisions at 5.02 TeV, combining both the muon and electron channels, will be presented. When compared to theory calculations that include nuclear modifications to the parton distributions, data show a clear sensitivity to this type of effects. The final results in PbPb collisions at 2.76 TeV, compared to pp collisions at the same center of mass energy, will also be presented. The centrality dependence confirms the binary scaling of hard probes in heavy-ion collisions, while the differential cross sections points to initial state effects small compared to the statistical precision of the available data.

Optimal synthesis of a Ni(II)-dimethylglyoxime ion-imprinted polymer ...

African Journals Online (AJOL)

A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was optimised by the uniform design experimental ... The bonds formed between the template and the functional monomers in ion- imprinted polymerisation reactions are weaker, non-covalent. (Arshady and Mosbach, 1981; ..... where the polymer did not form.

On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry.

Science.gov (United States)

Ensafi, Ali A; Shiraz, A Zendegi

2008-02-11

Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL(-1) Pb(II). The adsorption capacity of the solid phase was 0.20mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method.

On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry

International Nuclear Information System (INIS)

Ensafi, Ali A.; Shiraz, A. Zendegi

2008-01-01

Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL -1 Pb(II). The adsorption capacity of the solid phase was 0.20 mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method

On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ensafi, Ali A. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: Ensafi@cc.iut.ac.ir; Shiraz, A. Zendegi [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2008-02-11

Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL{sup -1} Pb(II). The adsorption capacity of the solid phase was 0.20 mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method.

Adsorption of Zn(II) and Cd(II) ions in batch system by using the Eichhornia crassipes.

Science.gov (United States)

Módenes, A N; Espinoza-Quiñones, F R; Borba, C E; Trigueros, D E G; Lavarda, F L; Abugderah, M M; Kroumov, A D

2011-01-01

In this work, the displacement effects on the sorption capacities of zinc and cadmium ions of the Eichornia crassipes-type biosorbent in batch binary system has been studied. Preliminary single metal sorption experiments were carried out. An improvement on the Zn(II) and Cd(II) ions removal was achieved by working at 30 °C temperature and with non-uniform biosorbent grain sizes. A 60 min equilibrium time was achieved for both Zn(II) and Cd(II) ions. Furthermore, it was found that the overall kinetic data were best described by the pseudo second-order kinetic model. Classical multi-component adsorption isotherms have been tested as well as a modified extended Langmuir isotherm model, showing good agreement with the equilibrium binary data. Around 0.65 mequiv./g maximum metal uptake associated with the E. crassipes biosorbent was attained and the E. crassipes biosorbent has shown higher adsorption affinity for the zinc ions than for the cadmium ones in the binary system.

Pb-ions in harmonic number 4653 at SPS flat bottom

CERN Document Server

Bartosik, H; Huschauer, A

2017-01-01

Pb-ion beams suer from strong beam degradation suchas transverse emittance growth and losses on the long flatbottom of the SPS cycles used for LHC filling. A possiblecontribution to the losses could come from RF noise, espe-cially due to the frequency and amplitude modulation duringeach revolution period of the fixed frequency accelerationmode required for the acceleration of these beams. A ma-chine development session in 2016 was devoted to a directcomparison of a cycle with fixed harmonic number at flatbottom and a cycle with the usually used fixed frequencymode. The main results are reported here.

Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin

International Nuclear Information System (INIS)

Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

2007-01-01

The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L -1 HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 μg L -1 for aqueous samples and in the range of 2.5-9.4 ng g -1 for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results

J/ψ photoproduction in ultra-peripheral Pb-Pb and p-Pb collisions with the ALICE detector

Directory of Open Access Journals (Sweden)

Adam Jaroslav

2014-04-01

Full Text Available Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study gamma-gamma, gamma-nucleus and gamma-proton processes at the LHC in ultra-peripheral Pb-Pb and p-Pb collisions. Exclusive photoproduction of J/ψ vector mesons is sensitive to the gluon distribution of the target. Here we report on the ALICE measurement of J/ψ coherent photoproduction in Pb-Pb ultra-peripheral collisions at √sNN = 2.76 TeV for the rapidity ranges -3.6 < y < -2.6 and |y| < 0.9, and on preliminary results on the J/ψ photoproduction in p-Pb at √sNN = 5.02 TeV. The J/ψ mesons have been identified through their leptonic decays.

Adsorption of aqueous Cd(II) and Pb(II) on activated carbon nanopores prepared by chemical activation of doum palm shell

OpenAIRE

Gaya, Umar Ibrahim; Otene, Emmanuel; Abdullah, Abdul Halim

2015-01-01

Non-uniformly sized activated carbons were derived from doum palm shell, a new precursor, by carbonization in air and activation using KOH, NaOH and ZnCl2. The activated carbon fibres were characterised by X-ray diffraction, N2 adsorption–desorption, scanning electron microscopy, particle size analysis and evaluated for Cd(II) and Pb(II) removal. The 40–50 nm size, less graphitic, mesoporous NaOH activated carbon yielded high adsorption efficiency, pointing largely to the influence surface ar...