Analysis of Cr(III) ions adsorption on the surface of algae: implications for the removal of heavy metal ions from water

For purposeful control of the adsorption process, a comprehensive study of the properties of the original cells and the effect of metal ions on them is necessary. In this regard, the features of the adsorption of Cr(III) ions on the cell surface of Spirulina platensis algae were studied. FTIR spectroscopy revealed that the main functional groups responsible for the binding of Cr(III) ions are carboxyl, hydroxyl, amino, and phosphate groups on the surface of algae. The adsorption data were processed using the Langmuir and Freundlich models. It is shown that the maximum adsorption of Cr(III) ions on the surface of algae cells is 31.25 mg/g. The Freundlich constant 1/n is 0.65. The study of the effect of the concentration of Cr(III) ions on the Zeta-potential of algae cells revealed an abnormal increase in the negative value of the ζ – potential at 10–5 mol/L, caused by the release of an additional amount of anionic functional groups to the surface. A further increase in the concentration of Cr(III) ions in the algae suspension leads to a decrease in the ζ – potential and recharge of the surface at C>10–2 mol/L. It was found that the adsorption of Cr(III) ions also affects the morphology of the cell surface. If before contact with Cr(III) ions, the surface of algae cells is represented as a uniform green grid, after adsorption of Cr(III) ions, the surface becomes green-brown, with swollen spirals. The study of the effect of pH on the adsorption and desorption processes shows an increase in the desorption of Cr(III) ions from the surface of algae during acidification of the medium. The adsorption reaches a maximum value in the pH range of 6–7. In the region of optimal Cr(III)/biosorbent ion ratios, the recovery rate of Cr(III) reaches 98.5–99.3 %.

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Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material

Solid Earth ◽

10.5194/se-6-337-2015 ◽

2015 ◽

Vol 6 (1) ◽

pp. 337-346 ◽

Cited By ~ 12

Author(s):

N. Seco-Reigosa ◽

L. Cutillas-Barreiro ◽

J. C. Nóvoa-Muñoz ◽

M. Arias-Estévez ◽

E. Álvarez-Rodríguez ◽

...

Keyword(s):

Food Chain ◽

Soluble Fraction ◽

Mussel Shell ◽

Weakly Bound ◽

Retention Capacity ◽

Adsorption Data ◽

Water Courses ◽

Ph Range ◽

Adsorption Desorption ◽

Langmuir And Freundlich Models

Abstract. As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the unamended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always <19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH <6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreased as pH increased. Desorption varying pH was always <26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). The granitic material did not show high As(V) retention capacity, which could facilitate As(V) transfer to water courses and to the food chain in case of As(V) compounds being applied on this material; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

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Use of Fly Ash in the Removal of Copper, Nickel and Zinc from Wastewater

Water Quality Research Journal ◽

10.2166/wqrj.1993.018 ◽

1993 ◽

Vol 28 (2) ◽

pp. 369-384 ◽

Cited By ~ 11

Author(s):

T. Viraraghavan ◽

Murali M. Dronamraju

Keyword(s):

Fly Ash ◽

Thermodynamic Parameters ◽

Contact Time ◽

Adsorption Process ◽

Initial Concentration ◽

Copper Nickel ◽

Adsorption Data ◽

Ph Range ◽

Langmuir And Freundlich Models

Abstract The effectiveness of fly ash in adsorbing copper, nickel and zinc was studied by conducting batch kinetic and isotherm studies. The effect of contact time, pH, initial concentration of the adsorbate, and temperature on the adsorption process was studied. Fly ash was found to be an effective adsorbent. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 3.0 to 3.5. The Langmuir and Freundlich models were found to be applicable to the adsorption data of copper, nickel and zinc. Thermodynamic parameters suggested the exothermic nature of the adsorption process.

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Selective Cu(II) Adsorption from Aqueous Solutions Including Cu(II), Co(II), and Ni(II) by Modified Acrylic Acid Grafted PET Film

ISRN Polymer Science ◽

10.1155/2013/536314 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Nazia Rahman ◽

Nobuhiro Sato ◽

Satoru Yoshioka ◽

Masaaki Sugiyama ◽

Hirotaka Okabe ◽

...

Keyword(s):

Experimental Data ◽

Aqueous Solution ◽

Acrylic Acid ◽

Metal Ions ◽

Functional Groups ◽

Metal Ion ◽

Second Order ◽

Isotherm Models ◽

Adsorption Data ◽

Pseudo Second Order

Acrylic acid (AAc) grafted polyethylene terephthalate (PET) films were prepared by γ irradiation. The graft films showed little metal ion adsorption due to compact structure of the graft chains as shown by the scanning electron microscopy (SEM) images which restricted the access of metal ions to the functional groups. Therefore, the graft films were modified with KOH treatment for expansion of the graft chains to facilitate the access of metal ions to the functional groups. The modified films were used to study the selective Cu2+ adsorption from aqueous solution containing Cu2+, Co2+, and Ni2+. Langmuir and Freundlich isotherm models were used for interpretation of selective equilibrium adsorption data and Langmuir model showed better fitting with experimental data. Again pseudo-first-order and pseudo-second-order equations were used for interpretation of selective kinetic adsorption data and pseudo-second-order equation showed better prediction of experimental data. The adsorbent film showed high selectivity towards Cu2+ in presence of Cu2+, Co2+, and Ni2+ in the pH range of 1.5 to 4.5. Desorption and reuse of the adsorbent film were also studied which indicated that the film can be used repeatedly for selective Cu2+ sorption from aqueous solution.

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Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material

Solid Earth Discussions ◽

10.5194/sed-6-3419-2014 ◽

2014 ◽

Vol 6 (2) ◽

pp. 3419-3444

Author(s):

N. Seco-Reigosa ◽

L. Cutillas-Barreiro ◽

J. C. Nóvoa-Muñoz ◽

M. Arias-Estévez ◽

E. Álvarez-Rodríguez ◽

...

Keyword(s):

Water Pollution ◽

Food Chain ◽

Soluble Fraction ◽

Mussel Shell ◽

Weakly Bound ◽

Retention Capacity ◽

Adsorption Data ◽

Ph Range ◽

Adsorption Desorption ◽

Langmuir And Freundlich Models

Abstract. As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell, and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH, as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the un-amended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always < 19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH < 6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreasing as pH increased. Desorption varying pH was always < 26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). Globally, the granitic material did not show high As(V) retention capacity, which implies risks of water pollution and transfer to the food chain; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

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Efficient Preconcentration of Cu2+, Zn2+ and Fe3+ with an Agarose-Schiff Base Sorbent

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20070908 ◽

2007 ◽

Vol 72 (7) ◽

pp. 908-916 ◽

Cited By ~ 3

Author(s):

Payman Hashemi ◽

Hatam Hassanvand ◽

Hossain Naeimi

Keyword(s):

Schiff Base ◽

Metal Ions ◽

Metal Ion ◽

Good Accuracy ◽

Kinetic Studies ◽

Sample Volume ◽

Effects Of Ph ◽

Glass Column ◽

High Concentrations ◽

Ph Range

Sorption and preconcentration of Cu2+, Zn2+ and Fe3+ on a salen-type Schiff base, 2,2'- [ethane-1,2-diylbis(nitrilomethylidyne)]bis(2-methylphenol), chemically immobilized on a highly crosslinked agarose support, were studied. Kinetic studies showed higher sorption rates of Cu2+ and Fe3+ in comparison with Zn2+. Half-times (t1/2) of 31, 106 and 58 s were obtained for sorption of Cu2+, Zn2+ and Fe3+ by the sorbent, respectively. Effects of pH, eluent concentration and volume, ionic strength, buffer concentration, sample volume and interferences on the recovery of the metal ions were investigated. A 5-ml portion of 0.4 M HCl solution was sufficient for quantitative elution of the metal ions from 0.5 ml of the sorbent packed in a 6.5 mm i.d. glass column. Quantitative recoveries were obtained in a pH range 5.5-6.5 for all the analytes. The volumes to be concentrated exceeding 500 ml, ionic strengths as high as 0.5 mol l-1, and acetate buffer concentrations up to 0.3 mol l-1 for Zn2+ and 0.4 mol l-1 for Cu2+ and Fe3+ did not have any significant effect on the recoveries. The system tolerated relatively high concentrations of diverse ions. Preconcentration factors up to 100 and detection limits of 0.31, 0.16 and 1.73 μg l-1 were obtained for Cu2+, Zn2+ and Fe3+, respectively, for their determination by a flame AAS instrument. The method was successfully applied to the metal ion determinations in several river water samples with good accuracy.

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Ideal pH for the adsorption of metal ions Cr6+, Ni2+, Pb2+ in aqueous solution with different adsorbent materials

Open Agriculture ◽

10.1515/opag-2021-0225 ◽

2021 ◽

Vol 6 (1) ◽

pp. 115-123

Author(s):

Luísa P. Cruz-Lopes ◽

Morgana Macena ◽

Bruno Esteves ◽

Raquel P. F. Guiné

Keyword(s):

Heavy Metals ◽

Metal Ions ◽

Walnut Shell ◽

Lead Adsorption ◽

Viable Solution ◽

Chestnut Shell ◽

Adsorption Processes ◽

Irreversible Effects ◽

Optimal Values ◽

Ph Range

Abstract Industrialization increases the number of heavy metals released into the environment. Lead (Pb2+), nickel (Ni2+) and chromium (Cr6+) are among these toxic metals and cause irreversible effects on ecosystems and human health due to their bio-accumulative potential. The decontamination through adsorption processes using lignocellulosic wastes from agricultural and/or forestry processes is a viable solution. Hence, this work aimed at studying the effect of pH on the biosorption of the metal ions using four different by-product materials: walnut shell, chestnut shell, pinewood and burnt pinewood. These experiments were conducted with solutions of the three heavy metals in which the adsorbents were immersed to measure the rate of adsorption. A range of pH values from 3.0 to 7.5 was used in the experiments, and the concentrations were determined by atomic absorption. The results showed different behaviour of the biosorbent materials when applied to the different metals. The lead adsorption had an ideal pH in the range of 5.5–7.5 when the walnut shell was used as an adsorbent, corresponding to values of adsorption greater than 90%, but for the other materials, maximum adsorption occurred for a pH of 7.5. For the adsorption of chromium, the pH was very heterogeneous with all adsorbents, with optimal values of pH varying from 3.0 (for chestnut shell) to 6.5 (for walnut shell and wood). For nickel, the best pH range was around pH 5, with different values according to the lignocellulosic material used. These results indicate that the tested biosorbents have the potential to decontaminate wastewater in variable extensions and that by controlling the pH of the solution; a more efficient removal of the heavy metals can be achieved.

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The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

International Journal of Molecular Sciences ◽

10.3390/ijms22126458 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6458

Author(s):

Aleksandra Pieniężna ◽

Weronika Witak ◽

Aneta Szymańska ◽

Justyna Brasuń

Keyword(s):

Metal Ions ◽

Coordination Mode ◽

Transition Metal Ions ◽

Disulfide Bridge ◽

Chain Flexibility ◽

Vis Spectroscopy ◽

Ph Range ◽

Cd Studies ◽

Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

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Study on desorption of Mn, Fe, and Mg from TMP and evaluation of the complexing strength of different chelating agents using side reaction coefficients 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽

10.1515/hf.2009.105 ◽

2009 ◽

Vol 63 (6) ◽

Cited By ~ 3

Author(s):

Kim Granholm ◽

Pingping Su ◽

Leo Harju ◽

Ari Ivaska

Keyword(s):

Citric Acid ◽

Metal Ions ◽

Chelating Agents ◽

Side Reaction ◽

Sodium Dithionite ◽

Thermomechanical Pulp ◽

Peroxide Bleaching ◽

Ph Values ◽

Reducing Environment ◽

Ph Range

Abstract Chelation of thermomechanical pulp (TMP) was studied in this work. The desorption of Mn, Fe, and Mg due to their impact on peroxide bleaching was investigated. The desorption experiments were performed with EDTA, citric acid, oxalic acid, and formic acid as chelating agents at different pH. Chelation experiments with EDTA were carried out at pH 3–11. Sodium dithionite was used as the reducing agent in studying chelation with EDTA in a reducing environment. Mn was very effectively desorbed with EDTA from TMP at pH <10 and the reducing environment further improved the removal of all the studied metal ions from TMP with EDTA. Citric acid also removed Mn effectively from TMP at pH 5. The thermodynamic stability constants of different metal chelates do not present the correct picture of how strongly the metal ions are bound by the chelating agents in different conditions. But by means of the side reaction coefficients (α M(L)-coefficients) it is also theoretically possible to evaluate and compare the real binding strengths between the metal ions and different chelating agents at varying pH values and other solution conditions. In this study, a theory is given for the calculation of side reaction coefficients. Values of the α M(L)-coefficients, for the pH range 0–14, are presented for EDTA, DTPA, and also for some other new potential environmentally friendly chelating agents.

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Reduction of COD from Micro-Polluted Water through Adsorption of Activated Carbon-Attapulgite Composite Adsorbent

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.450.445 ◽

2010 ◽

Vol 450 ◽

pp. 445-448

Author(s):

Zheng Wang ◽

Zhao Qian Jing ◽

Yu Kong ◽

Wei Shen

Keyword(s):

Activated Carbon ◽

Oxygen Demand ◽

Polluted Water ◽

Adsorption Model ◽

Batch Mode ◽

Composite Adsorbent ◽

Adsorption Data ◽

Complete Study ◽

Ph Range ◽

Optimum Ph Range

The aim of this study was the assessment of reduction of chemical oxygen demand (COD) from micro-polluted water using activated carbon-attapulgite composite adsorbent prepared using activated carbon and natural attapulgite through compounding, granulation and calcination. The complete study was done in batch mode to investigate the effect of operating parameters. Adsorption of COD was found to be dependent on contact time, pH, temperature and initial COD concentration. Adsorption equilibrium attained within 80 minutes time. The optimum pH range for adsorption of organics was found to be 8. The sorption of organics decreased with rise of temperature because adsorption process was exothermic. The studied adsorption data fitted well to Langmuir adsorption model with the correlation coefficient 0.9947. The activated carbon-attapulgite composite adsorbent in this study shows very good promise for practical applicability on removal of COD from micro-polluted water.

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