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Artículos de revistas sobre el tema "Metals Equilibrium"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 1 de febrero de 2022

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1

El Zayat, Mohamed, Sherien Elagroudy y Salah El Haggar. "Equilibrium analysis for heavy metal cation removal using cement kiln dust". Water Science and Technology 70, n.º 6 (21 de julio de 2014): 1011–18. http://dx.doi.org/10.2166/wst.2014.325.

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Ion exchange, reverse osmosis, and chemical precipitation have been investigated extensively for heavy metal uptake. However, they are deemed too expensive to meet stringent effluent characteristics. In this study, cement kiln dust (CKD) was examined for the removal of target heavy metals. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Studies showed the ability of CKD to remove the target heavy metals in a pH range below that of precipitation after an equilibrium reaction time of 24 h. A surface titration experiment indicated negative surface charge of the CKD at pH below 10, meaning that electrostatic attraction of the divalent metals can occur below the pH required for precipitation. However, surface complexation was also important due to the substantive metal removal. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the CKD surface as well as equilibria between background ions and the sorbent surface. It was concluded that the removal strength of adsorption is in the order: Pb > Cu > Cd. The experiments were also supported by Fourier transform infrared spectroscopy (FTIR).

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2

Kraftmakher, Yaakov. "On equilibrium point defects in metals". Philosophical Magazine A 74, n.º 3 (septiembre de 1996): 811–20. http://dx.doi.org/10.1080/01418619608243543.

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3

Rajfur, Małgorzata. "Algae - Heavy Metals Biosorbent / Glony - Biosorbent Metali Ciężkich". Ecological Chemistry and Engineering S 20, n.º 1 (1 de marzo de 2013): 23–40. http://dx.doi.org/10.2478/eces-2013-0002.

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Abstract The publication is a synthetic collection of information on the sorption properties of marine and freshwater algae. Kinetics and sorption equilibrium of heavy metals in algae-solution system, influence of abiotic factors on the process of sorption and desorption of analytes from biomass are discussed. In paper the results of laboratory tests conducted using different species and types of algae, which purpose was to assess their usefulness as natural sorbents, are described. The conclusions drawn from current research confirm the results from literature.

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4

Guo, Xiang Hui y Hai Yun Hu. "Non-Equilibrium Statistical Theory of Void Microstructure Evolution in Irradiated Metals". Applied Mechanics and Materials 364 (agosto de 2013): 568–72. http://dx.doi.org/10.4028/www.scientific.net/amm.364.568.

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The non-equilibrium statistical theory was used as a theoretical approach to modeling and predicting void evolution in metal materials. Fokker-Plank equation was introduced as the kinetic equation for the void evolution, from which the probability density distribution function of voids could be obtained. From the micro-mechanism of metal's irradiation damage, void growth rate equation was obtained using spherical Weilv model and control diffusion theory, and then was simplified based on appropriate assumptions. According to the probability density distribution function of void, a series of macro-mechanical characteristics caused by void growth can be calculated, such as: the critical radius of the void nucleation, the average radius of void. Thus the correlation between the void microstructure evolution and the macroscopic properties of metals can be achieved.

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5

El Zayat, Mohamed y Edward Smith. "Modeling of heavy metals removal from aqueous solution using activated carbon produced from cotton stalk". Water Science and Technology 67, n.º 7 (1 de abril de 2013): 1612–19. http://dx.doi.org/10.2166/wst.2013.037.

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Activated carbon produced from cotton stalks was examined for the removal of heavy metal contaminants. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Continuous flow experiments using the activated carbon in fixed beds were conducted to determine heavy metal breakthrough versus bed volumes treated. At given pH value in the range 5–7, the adsorption capacity was similar for copper and lead and clearly greater than for cadmium. A surface titration experiment indicated negative surface charge of the activated carbon at pH > 6, meaning that electrostatic attraction of the divalent heavy metals can occur below the pH required for precipitation. Substantive metal removal below the pH of zero charge might be due to surface complexation. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the activated carbon surface as well as equilibria between background ions used to establish ionic strength and the sorbent surface. Pb(II) adsorption edges were best modeled using inner-layer surface complexation of Pb2+, while Cd(II) and Cu(II) data were best fit by outer-layer complexes with Me2+. The full set of equilibrium constants were used as input in a dual-rate dynamic model to simulate the breakthrough curves of the target metals (Pb, Cu and Cd) from fixed bed experiments and to estimate external (or film) diffusion and internal (surface) diffusion coefficients.

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6

Kraftmakher, Y. "Equilibrium Point Defects in Metals: Unsolved Problems". Defect and Diffusion Forum 194-199 (abril de 2001): 23–28. http://dx.doi.org/10.4028/www.scientific.net/ddf.194-199.23.

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7

Kraftmakher, Yaakov. "Equilibrium vacancies and thermophysical properties of metals". Physics Reports 299, n.º 2-3 (junio de 1998): 79–188. http://dx.doi.org/10.1016/s0370-1573(97)00082-3.

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8

Zyuzin, A. A. y A. Yu. Zyuzin. "Non-equilibrium spin waves in paramagnetic metals". EPL (Europhysics Letters) 90, n.º 6 (1 de junio de 2010): 67007. http://dx.doi.org/10.1209/0295-5075/90/67007.

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9

Gerasimov, K. B., A. A. Gusev, E. Y. Ivanov y V. V. Boldyrev. "Tribochemical equilibrium in mechanical alloying of metals". Journal of Materials Science 26, n.º 9 (1991): 2495–500. http://dx.doi.org/10.1007/bf01130201.

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10

Salgansky, E. A., D. N. Podlesniy, M. V. Tsvetkov y A. Yu Zaichenko. "Thermodynamically Equilibrium Compositions of the Products Formed During the Filtration Combustion of the Metal-Containing Mixtures". Eurasian Chemico-Technological Journal 22, n.º 4 (30 de diciembre de 2020): 263. http://dx.doi.org/10.18321/ectj998.

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Thermodynamic calculations for describing the compositions of the products formed in conditions of the filtration combustion of the metal-containing mixtures were carried out. The analysis of the equilibrium compositions of the products was carried out using the TERRA high-temperature thermochemical equilibrium calculation program. According to the results of calculations, the metals were divided into two groups. First one forms both the condensed and gaseous phases and in the second one ‒ metals that are only in the condensed phase. In case of the presence of metal compounds in the gas phase, as a rule, these are the following compounds: metals, oxides, hydroxides, hydrides, sulfides and metal sulfates. Metals of the second group cannot be subjected to mass transfer under conditions of the filtration combustion wave and will remain in solid combustion products (in ash).

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11

Sridhar, Vaishnavi y J. K. Verma. "Recovery of Copper, Nickel and Zinc from Sulfate Solutions by Solvent Extraction Using LIX 984N". E-Journal of Chemistry 8, s1 (2011): S434—S438. http://dx.doi.org/10.1155/2011/108628.

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Recovery of valuable metals such as copper, nickel and zinc from synthetic sulfate solutions using LIX 984N as the extractant dissolved in kerosene was investigated. The metals get extracted at different equilibrium pH of the aqueous phase and thus the pH of the aqueous solutions forms the basis of their separation. Copper was extracted at an equilibrium pH of 3.5, while nickel and zinc get extracted at an equilibrium pH of 7.3 and 8.8 respectively. The extraction isotherms of copper, nickel and zinc were obtained by contacting the respective metal solutions and 0.05 M LIX 984N at different A:O phase ratio at their respective equilibrium pH of maximum extraction. A two-stage counter- current extraction simulation was done to achieve quantitative extraction of the metals. Furthermore, a two-stage counter- current stripping simulation yielded quantitative recovery of the individual metals, from their loaded organic phases. On the basis of the results, a flow sheet of the process has been developed.

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12

VIDALI, GIANFRANCO. "ISLAND AND MULTILAYER GROWTH OF METALS ON METALS: EXPERIMENTS AND COMPUTER SIMULATIONS". Surface Review and Letters 04, n.º 04 (agosto de 1997): 709–19. http://dx.doi.org/10.1142/s0218625x97000717.

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We review the current understanding of growth of metals on metal films prepared in far-from-equilibrium conditions. Recent experimental and computational studies of metal-on-metal growth are presented and physical/chemical factors controlling this type of growth are identified and discussed. The technique of atom beam scattering to probe thin film growth in situ and in real time is illustrated in detail with selected results of a study of metal-on-metal heteroepitaxial growth.

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13

Haytogiu, B., G. N. Demirer y U. Yetis. "Effectiveness of anaerobic biomass in adsorbing heavy metals". Water Science and Technology 44, n.º 10 (1 de noviembre de 2001): 245–52. http://dx.doi.org/10.2166/wst.2001.0632.

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This study focuses on the effectiveness of waste anaerobic dead biomass (ADB) in adsorbing heavy metals, namely Pb(II), Cr(VI), Cu(II), Ni(II) and Zn(II). The metal uptake capacity of ADB was investigated and compared with the values for various biomass types from the literature. The biomass, which was grown under laboratory conditions using a synthetic wastewater, was used throughout the study after sterilization. The maximum metal adsorptive capacities were evaluated by running isotherm tests at 25°C and initial pH of 4. It was observed that Pb(II) was adsorbed with the highest capacity. The maximum adsorptive capacity of ADB for Pb(II), Zn(II), Cu(II), Ni(II) and Cr(VI) was determined as 1250, 625, 357, 227 and 384 mg/g dry biomass, respectively. These values were significantly higher than the corresponding capacities reported in the literature for other types of biomass. In describing the adsorption equilibrium, both the Langmuir and Freundlich isotherm models were examined. The experimental data for Pb(II), Zn(II), Cr(VI), and Ni(II) fitted both the Langmuir and Freundlich models with correlation coefficients of 0.80-0.99 while Cu(II) only fitted the Langmuir model with a correlation coefficient of 0.99. Therefore, different and distinct aspects of the interactions between the cell surfaces and the metal ions might have occurred for Cu(II) and the rest of the metals. The equilibrium pH values attained were all higher than the initial pH value of 4.0, and this indicated that both the type and the initial concentration of the metal influenced the equilibrium pH. Furthermore, there was a decrease in equilibrium pH with increasing initial metal concentration at varying levels.

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14

Jodra, Y. y F. Mijangos. "Ion exchange selectivities of calcium alginate gels for heavy metals". Water Science and Technology 43, n.º 2 (1 de enero de 2001): 237–44. http://dx.doi.org/10.2166/wst.2001.0095.

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An equilibrium model has been proposed and verified, based on the conditions in the gel phase and Donnan equilibrium theory, for the analysis of the experimental data on the recovery of lead, copper, cadmium, cobalt, nickel and zinc from synthetic, nonmetallic aqueous solutions on calcium alginate gels. This equilibrium model considers that the system behaves as an ion-exchange process between the calcium in the gels and the divalent metals in solution, and that the metallic portion enclosed in gel fluid is supposed an important quantitative contribution to the total amount of metal uptake by gels. According to the equilibrium constants calculated, it is deduced that the selectivity order is: Pb>Cu>Cd>Ni>Zn>Co.

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15

Kraftmakher, Y. "An Opposite View on Equilibrium Vacancies in Metals". Defect and Diffusion Forum 143-147 (enero de 1997): 37–42. http://dx.doi.org/10.4028/www.scientific.net/ddf.143-147.37.

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16

Matłok, Magdalena, Roman Petrus y Jolanta K. Warchoł. "Equilibrium Study of Heavy Metals Adsorption on Kaolin". Industrial & Engineering Chemistry Research 54, n.º 27 (6 de julio de 2015): 6975–84. http://dx.doi.org/10.1021/acs.iecr.5b00880.

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17

Schwab, P. y R. Raimondi. "Coherent transport in disordered metals out of equilibrium". European Physical Journal B 24, n.º 4 (diciembre de 2001): 525–40. http://dx.doi.org/10.1007/s10051-001-8706-1.

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18

Lee, Dae Haeng y Hee Moon. "Adsorption equilibrium of heavy metals on natural zeolites". Korean Journal of Chemical Engineering 18, n.º 2 (marzo de 2001): 247–56. http://dx.doi.org/10.1007/bf02698467.

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19

Yang, K. y M. Z. Cao. "Hydrogen trapping in metals under local equilibrium assumption". Scripta Metallurgica et Materialia 25, n.º 9 (septiembre de 1991): 2139–42. http://dx.doi.org/10.1016/0956-716x(91)90288-c.

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20

Dai, Jianhong, Dongye He y Yan Song. "Correlations of Equilibrium Properties and Electronic Structure of Pure Metals". Materials 12, n.º 18 (11 de septiembre de 2019): 2932. http://dx.doi.org/10.3390/ma12182932.

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First principles calculations were carried out to study the equilibrium properties of metals, including the electrons at bonding critical point; ebcp; cohesive energy; Ecoh; bulk modulus; B; and, atomic volume; V. 44 pure metals, including the s valence (alkali), p valence (groups III to V), and d valence (transition) metals were selected. In the present work, the electronic structure parameter ebcp has been considered to be a bridge connecting with the equilibrium properties of metals, and relationships between ebcp and equilibrium properties (V; Ecoh; and B) are established. It is easy to estimate the equilibrium properties (Ecoh; V, and B) of pure metals through proposed formulas. The relationships that were derived in the present work might provide a method to study the intrinsic mechanisms of the equilibrium properties of alloys and to develop new alloys.

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21

Popov, Vladimir V. "Mössbauer Spectroscopy of Internal Interfaces in Metals". Defect and Diffusion Forum 333 (enero de 2013): 157–73. http://dx.doi.org/10.4028/www.scientific.net/ddf.333.157.

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A brief review on various possibilities of studying internal interfaces in metals by various methods of Mössbauer (nuclear gamma-resonance) spectroscopy is presented. Specific features of investigations of different interfaces in various materials are considered, such as equilibrium boundaries of recrystallization origin in coarse-grained materials, non-equilibrium boundaries in submicro-and nanocrystalline materials and interlayer boundaries in multilayered structures.

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22

Slaveykova, Vera I. y Kevin J. Wilkinson. "Predicting the Bioavailability of Metals and Metal Complexes: Critical Review of the Biotic Ligand Model". Environmental Chemistry 2, n.º 1 (2005): 9. http://dx.doi.org/10.1071/en04076.

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Environmental Context. The chemical speciation of trace metals greatly influences their biological effects. Nonetheless, no clear consensus currently exists as to when metal complexes are bioavailable, especially for field conditions. Recently, the USA EPA has incorporated the biotic ligand model (BLM) into their regulatory framework and many other countries are now examining the implications of following suit. This review examines the fundamental basis of the BLM in order to provide the reader with an understanding of its potential uses and limitations. Abstract. The biotic ligand model is a useful construct both for predicting the effects of metals to aquatic biota and for increasing our mechanistic understanding of their interactions with biological surfaces. Since biological effects due to metals are always initiated by metal bioaccumulation, the fundamental processes underlying bio-uptake are examined in this review. The model assumes that the metal of interest, its complexes, and metal bound to sensitive sites on the biological surface are in chemical equilibrium. Therefore, many of the equilibrium constants required for the model have been compiled and their methods of determination evaluated. The underlying equilibrium assumption of the BLM is also examined critically. In an attempt to identify which conditions are appropriate for its application, several documented examples of failures of the BLM are discussed. Finally, the review is concluded by identifying some important future research directions.

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23

Gopalapillai, Yamini, Chuni L. Chakrabarti y David R. S. Lean. "Assessing toxicity of mining effluents: equilibrium- and kinetics-based metal speciation and algal bioassay". Environmental Chemistry 5, n.º 4 (2008): 307. http://dx.doi.org/10.1071/en08027.

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Environmental context. The release of mining effluents exposes natural waters to excess metals and thereby threatens both human and environmental health. The present study explores the toxicity of aqueous mining effluents collected from a mining area in Sudbury (Ontario, Canada), using two different methods for determination of metal speciation, and an algal toxicity study. The results show reasonable correlation between metal speciation and the observed toxicity and suggest the importance of taking into account other factors related to water quality criteria such as nutrient concentrations, diluent water and presence of other toxic metals that can greatly influence the toxicological result. Abstract. The present study explores the toxicity of aqueous mining and municipal effluents from the Sudbury area (Canada) using equilibrium- and kinetics-based estimates of metal speciation and chronic toxicity studies using algae (Pseudokirchneriella subcapitata). Free metal ion concentration was determined by the Ion Exchange Technique (IET) and a computer speciation code, Windermere Humic Aqueous Model (WHAM) VI. Labile metal concentration was determined using the Competing Ligand Exchange Method. In general, no correlation was found between the observed IC25 (concentration of test substance that inhibits growth of organism by 25%) and the [Ni]labile, [Ni2+]IET or [Ni2+]WHAM, probably because of contributions by other metals such as Cu and Zn being also significant. Reasonable correlation (r2 = 0.7575) was found when the observed toxicity was compared with the sum of free metal ions of Cu, Ni, and Zn predicted by WHAM. The results of the present study reveal the importance of taking into account other factors related to water quality criteria such as nutrient concentrations, diluent water, and the presence of other toxic metals, which greatly influence the toxicological result in complex, multi-metal contaminated waters.

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24

Efimova, Natalya V., Alla P. Krasnopyorova, Galina D. Yuhno y Anastasia A. Scheglovskaya. "Sorption of heavy metals by natural biopolymers". Adsorption Science & Technology 35, n.º 7-8 (25 de abril de 2017): 595–601. http://dx.doi.org/10.1177/0263617417703113.

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The sorption properties of modified hydrolysis lignin towards Cu[Formula: see text], Zn[Formula: see text], Ni[Formula: see text], Co[Formula: see text] ions in the pH range from 2 to 8 at temperature of 298.15 K solution are studied. The analysis of kinetic curves of ions sorption on modified lignin at pH 7 shows that sorption equilibrium in heterogenic system ion–metal–sorbent is attained in 30–60 min. Obtained results indicate good equilibrium kinetic properties of sorbent. Supposed that reaction between sorbate and functional group of sorbent are the second-order reaction and they interact between each other in ratio 1:1. The character of the obtained electrokinetic curve suggests that the zeta potential of modified lignin strongly depends on the pH. The dependencies of cations metals sorption coefficients on the pH value of water phase are S-shaped. Maximal extraction of studied cations is observed at pH values of equilibrium solutions close to neutral ones.

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25

Yıldız Yiğit, Merve, Esra Sultan Baran y Çiğdem Kıvılcımdan Moral. "A polymer – zeolite composite for mixed metal removal from aqueous solution". Water Science and Technology 83, n.º 5 (10 de febrero de 2021): 1152–66. http://dx.doi.org/10.2166/wst.2021.057.

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Abstract Heavy metals become inevitable pollutants that are toxic to life. Lots of treatment methods are available; adsorption is a cheap option. Metals are mostly found as mixtures in wastewaters. Taking this into account, a natural composite adsorbent aims to remove multiple heavy metals (Pb2+, Cu2+, Cd2+). Alginate was combined with clinoptilolite to form alginate – clinoptilolite (A–C) beads. First, factors influencing the removal efficiency of metals were investigated. Then, continuous column experiments were performed to evaluate the real application potential of the adsorbent. A–C beads preferably adsorbed Pb2+. Batch experiments showed metal uptake reached equilibrium after 24 hours and kinetics were compatible with the first-order. Also, pH values near neutral levels were observed to increase heavy metal removal. On the other hand, adsorption equilibrium was well described by the Langmuir model for Cu2+ and Cd2+ and by the Freundlich model for Pb2+. The highest heavy metal uptake was calculated as 2,145 mg /g A–C beads for Pb2+. Continuous column operations were suggested to apply low flow rates (<2 mL/min) and heavy metal concentration (<10 mg/L) for effectiveness. A–C beads can be a good candidate for mixed heavy metal removal composed of environmentally friendly and low-cost materials.

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26

Elizondo, Martínez, Martínez Nájera, Rodríguez Pérez, Hinojosa Reyes y Del Río. "Polyaza macroligands as potential agents for heavy metal removal from wastewater". Journal of the Serbian Chemical Society 78, n.º 4 (2013): 591–602. http://dx.doi.org/10.2298/jsc120228050e.

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Two polyaza macroligands N,N?-bis(2-aminobenzyl)-1,2- ethanediamine (L1) and 3,6,9,12-tetraaza-4(1,2),11(1,2)-dibenzo-1(1,3)- piridinaciclotridecafano (L2) were characterized and investigated for their metal ion extraction capabilities. The nature of all complexes was established by spectroscopic techniques. The equilibrium constants were determined by spectrophotometric and potentiometric techniques and the residual concentration of metals in the solutions by Atomic Absorption Spectrometry (AAS). The capacity of the ligands to remove heavy metals such as Cu(II), Ni(II), Cd(II), Zn(II) and Pb(II) as insoluble complexes was evaluated in wastewater from industrial effluents. These agents showed high affinity for the studied metals. The values of equilibrium constants of the isolated complexes (between 1 x 104 and 2 x 107) demonstrated the feasibility of applying these chelating agents as an alternative to remove heavy metals from industrial effluents.

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27

Alhamzan, Abdulrahman G. "Using of Sukary and Khlass Date Pits as a Bio-adsorbents for Adsorption of Lead and Copper Ions from Waste Water". Oriental Journal Of Chemistry 37, n.º 2 (30 de abril de 2021): 302–7. http://dx.doi.org/10.13005/ojc/370206.

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In this study date pits of two types of date-palm trees (Phoenix Dactylifera L.), in Saudi Arabia were used as bio-sorbents for heavy metals (e.g. lead and copper) from aqueous solutions. Investigation of equilibrium time and the effect of different concentrations of metals were performed. Adsorption capacity of bio-sorbents increased when increasing concentration of metal ions. Maximum adsorption capacity at room temperature of Sukary date pits was 17.53 mg g-1 and 9.86 mg g-1 for lead and copper ions, respectively. Whereas, Khlass date pits showed maximum adsorption capacity at 14.1 mg g-1 and 7.91 mg g-1 for lead and copper ions, respectively at room temperature. Equilibrium isotherm models, (Langmuir and Freundlich models), were used for analysis of equilibrium experimental results. these models describe the experimental data well.

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28

Mattigod, S. V., P. F. Pratt y E. B. Schalscha. "Trace Metal Speciation in a Soil Profile Irrigated with Waste Waters". Water Science and Technology 17, n.º 9 (1 de septiembre de 1985): 133–42. http://dx.doi.org/10.2166/wst.1985.0087.

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A chemical equilibrium computer model: GEOCHEM, was used to predict the trace metal behavior in a soil profile if subjected to a long-term irrigation with waste waters. Various categories of interactions such as acid-base equilibria, soluble complex formation of metals with organic and inorganic ligands, dissolution-precipitation reactions and ion-exchange reactions were included in simulation. The metal-soluble organic interactions were accounted for by a mixture model. The computations included a 10 metal - 15 ligand system with 262 soluble complex species and 21 possible solid phases. The results predicted that a major fraction of alkali elements in solution tend to be in free ionic forms, whereas, major fractions of the alkaline earths were predicted to be present in adsorbed and/or precipitated forms. In marked contrast, significant soluble fractions of transition series metals were predicted to be in adsorbed and/or complexed forms. The degree of attenuation of these transition series elements moving through the soil profile seems to be governed mainly by the degree of adsorption on soil surfaces and the tendency of these elements to form soluble organic complexes. The predicted mobilities of these elements in this soil profile was Cu > Ni > Zn > Cd. Application of this equilibrium model appears to provide a first approximation approach to simulate the trace element behavior in soil profiles.

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29

Kraftmakher, Y. "How to Reliably Determine Equilibrium Vacancy Concentrations in Metals". Defect and Diffusion Forum 194-199 (abril de 2001): 17–22. http://dx.doi.org/10.4028/www.scientific.net/ddf.194-199.17.

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30

Bringa, E. M., B. D. Wirth, M. J. Caturla, J. Stölken y D. Kalantar. "Metals far from equilibrium: From shocks to radiation damage". Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 202 (abril de 2003): 56–63. http://dx.doi.org/10.1016/s0168-583x(02)01831-1.

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31

Yakibchuk, P. M. "Equilibrium atomic properties of transition and rare-earth metals". Journal of Physical Studies 1, n.º 2 (1997): 279–81. http://dx.doi.org/10.30970/jps.01.279.

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32

Kraftmakher,, Y. "Equilibrium Vacancies and Properties of Metals at High Temperatures". High Temperature Materials and Processes 15, n.º 3 (julio de 1996): 171–78. http://dx.doi.org/10.1515/htmp.1996.15.3.171.

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33

Vidali, Gianfranco y Hong Zeng. "Recent advances in island and multilayer growth of metals on metals far from equilibrium". Applied Surface Science 92 (febrero de 1996): 11–19. http://dx.doi.org/10.1016/0169-4332(95)00195-6.

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34

Yong, Raymond N., Rosa Galvez-Cloutier y Yuwaree Phadungchewit. "Selective sequential extraction analysis of heavy-metal retention in soil". Canadian Geotechnical Journal 30, n.º 5 (1 de octubre de 1993): 834–47. http://dx.doi.org/10.1139/t93-074.

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The selective sequential extraction method of analysis is used in this study to determine the distribution of heavy metals in some clay soils, to assist in evaluation of the role of the various clay soil solids (clay minerals, organics, amorphous materials, and carbonates) in heavy-metal retention capability as a function of acidity of the leachate. The chemical speciation model MINTEQ (metal speciation equilibrium model for surface and groundwater) is used to calculate the probable percent distribution of different species of heavy metals present in the leachate used. The selective sequential extraction method is based on the fact that different forms of heavy metals that are retained in soil (e.g., as oxides, hydroxides, carbonates, bound with organic matter) can be extracted selectively by using appropriate reagents. The results show that heavy metals can be retained in the four clay soils studied by several soil phases or mechanisms such as exchangeable, carbonate, hydroxide, and organic phases. The retention of heavy metals in any phase depends on soil solution pH, soil constituents, and the type of heavy metal. At high soil solution pH values, retention of heavy metal by precipitation mechanisms prevails, whereas at low soil solution pH, retention by cation exchange mechanisms becomes dominant. The results from the selective sequential extraction analysis support the conclusion of the significance of soil buffer capacity with regard to heavy-metal retention. The capacity of the soils to retain high amounts of heavy metals as they receive increasing amounts of acid (i.e., as the pH is reduced) depends directly on the soil initial pH values and on their buffer capacities. Key words : selective sequential analysis, exchangeable cations, heavy metals, equilibrium models, oxides.

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35

Marukovich, E. I., V. Yu Stetsenko y A. V. Stetsenko. "Nanostructural crystallization of metals". Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), n.º 2 (9 de julio de 2021): 23–26. http://dx.doi.org/10.21122/1683-6065-2021-2-23-26.

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Based on thermodynamic calculations, it is shown that metal crystallization is an equilibrium nanostructural process. At the beginning, trigonal or tetragonal structure-forming nanocrystals are formed from elementary nanocrystals. Then crystallization centers are formed from them. Further, tetragonal or hexagonal dendrites are formed from them and tetragonal or trigonal structure-forming nanocrystals. Their forms depend on the degree of branching of dendrites. The most branched of them (compact dendrites) are tetragonal or hexagonal crystals.

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36

Jin, Hak Son y An Du. "End Processing of MAEAM Pair Potential for BCC Metals". Advanced Materials Research 424-425 (enero de 2012): 568–72. http://dx.doi.org/10.4028/www.scientific.net/amr.424-425.568.

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An end processing function of the pair-potential of modified analytical embedded atom method (MAEAM) was suggested for bcc metals. Through fitting the elastic constants, cohesive energy and an equilibrium condition of bcc metal crystals correctly, we changed the pair-potential parameters and the modification term parameter of the multi-body potential. The model calculations fully demonstrate the structure stabilities and the phonon dispersion curves of seven bcc transition metals: Cr, Fe, Mo, Nb, Ta, V and W.

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37

Makrovets, L. A., O. V. Samoilova, G. G. Mikhailov y I. V. Bakin. "Phase equilibrium occurring during low-carbon iron-based melt deoxidation with silicostrontium". Izvestiya. Ferrous Metallurgy 64, n.º 6 (21 de julio de 2021): 413–19. http://dx.doi.org/10.17073/0368-0797-2021-6-413-419.

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At the moment, to improve quality of metal (especially low-alloyed), out-of-furnace steel processing technologies are used with complex alloys utilization, which include alkaline earth metals (ALM) in addition to silicon. Study of strontium additives effect on deoxidation and liquid steel modification processes is one of the promising areas of research in field of metallurgical technologies. Thermodynamic modeling of phase equilibria in Fe – Sr – Si –C– O system melt was carried out using method of constructing surface of components solubility in metal. Solubility surface determines stability limits of non-metallic phases formed during deoxidation, depending on composition of liquid metal of the studied system. The calculation was carried out using equilibrium constants of reactions occurring in the melt during deoxidation, as well as the first order interaction parameters (according to Wagner) of elements in liquid iron. Activity of the oxide melt components was determined using theory of subregular ionic solutions. Activity of the gas phase was calculated taking into account partial pressures. Simulations were performed for two temperatures (1550 and 1600 °C) for fixed carbon concentrations (0 (no carbon in liquid iron) and 0.1 % (low-carbon metal melt)). It has been shown that, in comparison with silicon, strontium is stronger deoxidizing agent in liquid metal. According to the simulation results, liquid oxide non-metallic inclusions of variable composition or strontium ortho- and metasilicates Sr2SiO4 and SrSiO3 (with an increase in strontium concentration) should be the main oxide phases in deoxidation products. Decrease in the temperature of liquid metal leads to changes in phase formation (formation of SrSiO3 silicate becomes possible).

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38

Belyanchikov, L. N. "Thermodynamic calculations for solid alloys produced under equilibrium, quasi-equilibrium, and nonequilibrium solidification conditions". Russian Metallurgy (Metally) 2007, n.º 8 (diciembre de 2007): 682–87. http://dx.doi.org/10.1134/s0036029507080095.

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39

Kan, Shi-Hong, Bai-Ye Sun, Fang Xu, Qi-Xue Song y Sui-Fang Zhang. "Biosorption of aquatic copper (II) by mushroom biomass Pleurotus eryngii: kinetic and isotherm studies". Water Science and Technology 71, n.º 2 (13 de diciembre de 2014): 283–88. http://dx.doi.org/10.2166/wst.2014.511.

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Biosorption is an effective method for removing heavy metals from effluent. This work mainly aimed to evaluate the adsorption performance of the widely cultivated novel mushroom, Pleurotus eryngii, for the removal of Cu(II) from single aqueous solutions. Kinetics and equilibria were obtained using a batch technique. The sorption kinetics follows the pseudo-second-order model, whereas the adsorption equilibria are best described by the Langmuir model. The adsorption process is exothermic because both the Langmuir-estimated biosorption capacity and the heat of adsorption estimated from the Temkin model decreased with increasing tested temperature. Based on the adsorption intensity estimated by the Freundlich model and the mean adsorption free energy estimated by the Dubinin–Radushkevich model, the type of adsorption is defined as physical adsorption. The biomass of the macro-fungus P. eryngii has the potential to remove Cu(II) from a large-scale wastewater contaminated by heavy metals, because of its favorable adsorption, short biosorption equilibrium time of 20 min and remarkable biosorption capacity (15.19 mg g−1 as calculated by the Langmuir model). The adsorbed metal-enriched mushroom is a high-quality bio-ore by the virtue of its high metal content of industrial mining grade and easy metal extractability.

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40

Tyurin, Y. "Non-equilibrium release of atomic hydrogen from metals under irradiation". International Journal of Hydrogen Energy 27, n.º 7-8 (agosto de 2002): 829–37. http://dx.doi.org/10.1016/s0360-3199(01)00153-7.

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41

KHALZOV, I. V., A. I. SMOLYAKOV y V. I. ILGISONIS. "Equilibrium magnetohydrodynamic flows of liquid metals in magnetorotational instability experiments". Journal of Fluid Mechanics 644 (27 de enero de 2010): 257–80. http://dx.doi.org/10.1017/s0022112009992394.

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A theoretical analysis of equilibrium magnetohydrodynamic flows in annular channels is performed from the perspective of establishing required conditions for liquid metal magnetorotational instability (MRI) experiments. Two different types of fluid rotation are considered: electrically driven flow in an annular channel and Taylor–Couette flow between rotating cylinders. The structure of these flows is studied within a unified approach as a function of the Hartmann and Reynolds numbers. The parameters appropriate for realization of MRI experiments are determined.

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42

Schaefer, H. E. "Investigation of Thermal Equilibrium Vacancies in Metals by Positron Annihilation". Physica Status Solidi (a) 102, n.º 1 (16 de julio de 1987): 47–65. http://dx.doi.org/10.1002/pssa.2211020104.

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43

Domenech-Garret, J. L., S. P. Tierno y L. Conde. "Non-equilibrium thermionic electron emission for metals at high temperatures". Journal of Applied Physics 118, n.º 7 (21 de agosto de 2015): 074904. http://dx.doi.org/10.1063/1.4929150.

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44

Zhang, X. Y., B. Li y Q. Liu. "Non-equilibrium basal stacking faults in hexagonal close-packed metals". Acta Materialia 90 (mayo de 2015): 140–50. http://dx.doi.org/10.1016/j.actamat.2015.02.036.

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45

Kaibyshev, O. A. y R. Z. Valiev. "NON-EQUILIBRIUM STRUCTURE OF GRAIN BOUNDARIES AND PROPERTIES OF METALS". Le Journal de Physique Colloques 46, n.º C4 (abril de 1985): C4–641—C4–644. http://dx.doi.org/10.1051/jphyscol:1985469.

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46

Guy, A. G. "Analysis of diffusion in metals based on non-equilibrium thermodynamics". Journal of Materials Science 21, n.º 1 (enero de 1986): 188–92. http://dx.doi.org/10.1007/bf01144719.

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47

Simeonidis, Konstantinos y Manassis Mitrakas. "Technologies Developing in Heavy Metals’ Removal from Water". Water 13, n.º 6 (22 de marzo de 2021): 860. http://dx.doi.org/10.3390/w13060860.

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48

Marukovich, E. I. y V. Yu Stetsenko. "Scientific problem of metal melts. Solutions". Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), n.º 2 (9 de agosto de 2019): 9–12. http://dx.doi.org/10.21122/1683-6065-2019-2-9-12.

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In the existing theories of liquid state of metals and alloys the basic structural element is atom. It creates a serious problem in scientific understanding of the mechanism of process of melt and properties of metal melts. For the solution of this problem it is necessary to consider that the basic structural element of liquid metals and alloys is the nanocrystal. As a result of researches it was set that metal melts are the equilibrium two-phase systems consisting on average of 97% from nanocrystals and of 3% from atoms, which form an unstructured zone.

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49

Jin, Hak Son y An Du. "Stiffening and End Processing of MAEAM Pair Potential for FCC Metals". Advanced Materials Research 424-425 (enero de 2012): 718–22. http://dx.doi.org/10.4028/www.scientific.net/amr.424-425.718.

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A stiffening function and a truncated function of the pair-potential of the modified analytical embedded atom method (MAEAM) were suggested for fcc metals. Through fitting the mono-vacancy migration energy, the elastic constants, the cohesive energy and an equilibrium condition of fcc metal crystals correctly, we determined the stiffening parameter and changed the pair-potential parameters and the modification term parameter of the multi-body potential for fcc metals: Ag, Al, Au, Cu, Ir, Ni, Pd, Pt, and Rh. The model calculations fully demonstrate the phonon dispersion curves and the unrelaxed mono-vacancy properties of the nine fcc metals.

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50

Desta, Mulu Berhe. "Batch Sorption Experiments: Langmuir and Freundlich Isotherm Studies for the Adsorption of Textile Metal Ions onto Teff Straw (Eragrostis tef) Agricultural Waste". Journal of Thermodynamics 2013 (17 de septiembre de 2013): 1–6. http://dx.doi.org/10.1155/2013/375830.

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Adsorption of heavy metals (Cr, Cd, Pb, Ni, and Cu) onto Activated Teff Straw (ATS) has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the low-cost adsorbent ATS for the removal of heavy metals from textile effluents. The influence of contact time, pH, Temperature, and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly, and the optimal removal efficiency was reached within about 1 hour. Further increase in contact time did not show significant change in equilibrium concentration; that is, the adsorption phase reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The value in the present investigation was less than one, indicating that the adsorption of the metal ion onto ATS is favorable. After treatment with ATS the levels of heavy metals were observed to decrease by 88% (Ni), 82.9% (Cd), 81.5% (Cu), 74.5% (Cr), and 68.9% (Pb). Results indicate that the freely abundant, locally available, low-cost adsorbent, Teff straw can be treated as economically viable for the removal of metal ions from textile effluents.

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