Preface

Rieman, William; WALTON, HAROLD F.

doi:10.1016/b978-0-08-015511-1.50003-3

Cited by 7 publications

(6 citation statements)

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“…The DR isotherm was displayed in Figure S2. The value of E provides information about physical and chemical adsorption . It was in the range of 0.238–1.185, 0.248–0.345, and 0.008–0.010 kJ mol –1 for Cu 2+ , Pb 2+ , and Zn 2+ by MCB, respectively, which is lower than the range of adsorption reaction 8–16 kJ mol –1 , and these results also showed that the adsorption mechanism of Cu 2+ , Pb 2+ , and Zn 2+ onto MCB are the combination of chemical and physical sorption.…”

Section: Resultsmentioning

confidence: 83%

Removal of Heavy Metal Ions from Water by Magnetic Cellulose-Based Beads with Embedded Chemically Modified Magnetite Nanoparticles and Activated Carbon

Luo

Lei

Cai

et al. 2016

ACS Sustainable Chem. Eng.

199

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For heavy metal ions removal from water, new resources should be exploited to design more efficient environmentally-friendly adsorbents. To tackle this challenge, millimeterscale magnetic cellulose-based beads with micro-and nano-pore structure were fabricated via an optimal extrusion dropping technology from NaOH/urea aqueous solution. The composite beads incorported with carboxyl decorated magnetite nanoparticles and nitric acid modified activated carbon have the convenient operation based on sensitive magnetic response and the highly effective removal performance for Cu 2+ , Pb 2+ and Zn 2+ . Their structure and properties were investigated. Moreover, the adsorption equilibrium, kinetics and thermodynamics of the Cu 2+ , Pb 2+ and Zn 2+ by the prepared composite adsorbents were examined. The results revealed that these adsorption processes were spontaneous endothermic reactions, and determined by combination of physical and chemical adsorptive mechanisms.

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Section: Resultsmentioning

confidence: 83%

Removal of Heavy Metal Ions from Water by Magnetic Cellulose-Based Beads with Embedded Chemically Modified Magnetite Nanoparticles and Activated Carbon

Luo

Lei

Cai

et al. 2016

ACS Sustainable Chem. Eng.

199

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“…It is based on the capability of some materials to exchange their own positive charges with heavy-metal cations . These systems are mainly based on synthetic resins, natural zeolites, and silicates, whereas recently, several kinds of nanostructured inorganic materials have been synthesized and studied for this purpose. , In particular, metal oxides, such as iron oxides or aluminum oxides, and other nanomaterials have been already applied as pollutant sorbents due to their high surface/volume ratio, high reactivity, and ion-exchange capacity, reaching in the case of lead ions removal capacities of 100 mg/g of sorbent. − …”

Section: Introductionmentioning

confidence: 99%

Titanate Fibroin Nanocomposites: A Novel Approach for the Removal of Heavy-Metal Ions from water

Magrì

Caputo²,

Perotto³

et al. 2017

ACS Appl. Mater. Interfaces

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In this study, we report the fabrication of nanocomposites made of titanate nanosheets immobilized in a solid matrix of regenerated silk fibroin as novel heavy-metal-ion removal systems. The capacity of these nanocomposite films to remove lead, mercury, and copper cations from water was investigated, and as shown by the elemental quantitative analysis performed, their removal capacity is 73 mmol/g for all of the ions tested. We demonstrate that the nanocomposites can efficiently retain the adsorbed ions, with no release of titanate nanosheets occurring even after several exposure cycles to ionic solutions, eliminating the risk of release of potentially hazardous nanosubstances to the environment. We also prove that the introduction of sodium ions in the nanocomposite formulation makes the materials highly selective toward the lead ions. The developed biopolymer nanocomposites can be potentially used for the efficient removal of heavy-metal-ion pollutants from water and, thanks to their physical and optical characteristics, offer the possibility to be used in sensor applications.

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“…Table summarizes the slope-derived values of Δ H trans 0 for both solutes. Interestingly, the values for Δ H trans 0 are in the range often found for RPLC (−6 to −31 kJ/mol) − but are above those for the retention based purely on an ion-exchange mechanism (−8 to −12 kJ/mol). , For 1,5-NDS, Δ H trans 0 ranges from −11 kJ/mol at +200 mV to −23 kJ/mol at −200 mV. The retention of 2,6-NDS at each value of E app is consistently 7–9 kJ/mol more negative (i.e., more exothermic) than that for 1,5-NDS, changing from −19 kJ/mol at +200 mV to −31 kJ/mol at −200 mV (Figure ).…”

Section: Results and Discussionmentioning

confidence: 70%

Investigation of Adsorption Thermodynamics at Electrified Liquid–Solid Interfaces by Electrochemically Modulated Liquid Chromatography

Ponton

Keller

Siperko³

et al. 2019

J. Phys. Chem. C

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A method to investigate electrosorption thermodynamics has been developed by the examination of the temperature dependence of solute retention by means of electrochemically modulated liquid chromatography (EMLC). This hybrid technique couples electrochemistry and liquid chromatography, which enables the manipulation of solute retention through changes in the potential applied (E app) to a conductive stationary phase like glassy carbon, porous graphitic carbon, and boron-doped diamond. An understanding of the thermodynamics of the EMLC separation mechanism would further the interpretations of the rules to predict retention, which may also provide fundamental insights into sorption processes and the structure of the electrical double layer of importance to a number of other technologies (e.g., battery and fuel cells). This paper describes a study in which the dependence of retention for two naphthalene disulfonates (1,5- and 2,6-naphthalene disulfonates) was measured at different fixed values of E app [−200 to +200 mV vs Ag/AgCl (sat’d NaCl)] for a glassy carbon chromatographic packing that was held at several different thermally equilibrated column temperatures (22–55 °C). These data were analyzed using the van’t Hoff relationship to determine the enthalpic and entropic contributions to Gibb’s free energy for the transfer of a solute between the mobile and stationary phases. The results for both solutes showed that (1) the retention increased as E app moved to more positive values, (2) the retention at each value of E app became smaller as the column temperature increased, and (3) the dependence of retention on temperature was stronger as the value of E app became more negative. The first and second observations follow expectations for the dependence of the electrostatic interaction strength for anionic solutes on the charge on the electrode surface and for the temperature dependence of the exothermic transfer of a solute from the mobile phase to the stationary phase, respectively. The third observation indicates that retention actually becomes more endothermic as the value of E app becomes more positive, which should conceptually cause a decrease rather than an increase in retention. This points to the somewhat surprising importance of entropy to the overall retention mechanism. That is, the increase in retention at increasingly positive values of E app reflects the fact that the increase in the entropy for solute transfer has a stronger contribution to the transfer process than the concomitant increase in the endothermicity of transfer. The paper concludes by briefly examining mechanistic origins for the thermodynamic behavior of this system within the context of the electrical double-layer theory and the hydrophobic effect, and possible applications of this intriguing development as a tool for the investigation of electrosorption processes in energy, colloidal, and bioanalytical systems.

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Preface

Cited by 7 publications

References 0 publications

Removal of Heavy Metal Ions from Water by Magnetic Cellulose-Based Beads with Embedded Chemically Modified Magnetite Nanoparticles and Activated Carbon

Removal of Heavy Metal Ions from Water by Magnetic Cellulose-Based Beads with Embedded Chemically Modified Magnetite Nanoparticles and Activated Carbon

Titanate Fibroin Nanocomposites: A Novel Approach for the Removal of Heavy-Metal Ions from water

Investigation of Adsorption Thermodynamics at Electrified Liquid–Solid Interfaces by Electrochemically Modulated Liquid Chromatography

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