scholarly journals Sorption of cobalt and zinc from single and binary metal solutions by Evernia prunastri

2022 ◽  
Vol 7 (1) ◽  
pp. 23-31
Author(s):  
Martin Pipíška ◽  
Miroslav Horník ◽  
Ľuboš Vrtoch ◽  
Soňa Šnirclová ◽  
Jozef Augustín
Keyword(s):  
Binary Systems ◽  
Three Dimensional ◽  
Terrestrial Ecosystems ◽  
Evernia Prunastri ◽  
Sorption Data ◽  
Sorption System ◽  
Freundlich Isotherms ◽  
Binary Metal ◽  
Cobalt Removal ◽  
Maximum Sorption

Non-living lichen Evernia prunastri was studied as biosorbent material for zinc and cobalt removal from single and binary metal solutions. Sorption equilibrium of Zn2+ and Co2+ ions was reached within 1 hour. Both cobalt and zinc biosorption was not pH dependent within the range pH 4-6 and negligible at pH 2. The experimental results were fitted to the Langmuir, Freundlich, Redlich-Peterson and Langmuir-Freundlich adsorption isotherms to obtain the characteristic parameters of each model. The Langmuir, Redlich-Peterson and Langmuir-Freundlich isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the maximum sorption capacities of metal ions onto lichen biomass were 112 μmol/g Zn and 97.2 μmol/g Co from single metal solutions. E. prunastri exhibited preferential uptake of zinc from equimolar binary Zn2+ - Co2+ mixtures within the range 50 – 4000 μM. Even thought mutual interference was seen in all Co-Zn binary systems. To evaluate the two-metal sorption system, simple curves had to be replaced by three-dimensional sorption surface. These results can be used to elucidate the behavior of lichens as bioindicators of cobalt and zinc pollution in water and terrestrial ecosystems.

scholarly journals Cadmium and zinc uptake by dried activated sludge: Equilibrium and experimental design study

2021 ◽  
Vol 10 (2) ◽  
pp. 117-130
Author(s):  
Lucia Remenárová ◽  
Martin Pipíška ◽  
Miroslav Horník ◽  
Jana Marešová ◽  
Jozef Augustín
Keyword(s):  
Activated Sludge ◽  
Binary Systems ◽  
Metal Removal ◽  
Solution Ph ◽  
Sorption Data ◽  
Competitive Effects ◽  
Concentration Maximum ◽  
Component Systems ◽  
Maximum Sorption ◽  
Simple Extrapolation

Removal of Cd2+ and Zn2+ ions from single and binary solutions by dried activated sludge was studied in batch experiments. It was shown that the metal removal is a rapid process significantly influenced by solution pH. Maximum uptake of both Cd and Zn was reached at pH 6.0 and negligible uptake was observed at pH 2.0. The Langmuir isotherm was found to well represent the measured equilibrium sorption data in single metal systems and the maximum sorption capacities Qmax of the activated sludge (d.w.), calculated from Langmuir model were 540 ± 16 μmol/g for Zn2+ and 510 ± 17 μmol/g for Cd2+ ions. The Response surface methodology (RSM) was used for investigation of interaction and competitive effects in binary metal system. It was found that dried activated sludge in binary system Cd-Zn has slightly higher affinity for Cd2+ comparing with Zn2+ ions. Competitive effect of Cd on Zn uptake increased with increasing solution pH and Cd initial concentration. Maximum sorption capacities of the activated sludge were 321 μmol Cd2+/g and 312 μmol Zn2+/g. RSM appears to be a better tool for the evaluation of interaction and competitive effects in binary systems than both the simple extrapolation from single-component systems and experimentally difficult study of multi-component systems.

scholarly journals Sorption of phosphates and thiocyanates on isomorphic substituted Mg/Zn-Al-type hydrotalcites

2008 ◽  
Vol 73 (8-9) ◽  
pp. 835-843 ◽  
Author(s):  
Rodica Pode ◽  
Eveline Popovici ◽  
Laura Cocheci ◽  
Erika Reisz ◽  
Mihaela Seftel ◽  
...  
Keyword(s):  
Gibbs Energy ◽  
Standard Gibbs Energy ◽  
Physical Adsorption ◽  
Freundlich Isotherm ◽  
Sorption Data ◽  
Freundlich Isotherms ◽  
Data Standard ◽  
Langmuir And Freundlich Isotherms ◽  
Maximum Sorption ◽  
Equilibrium Data

The sorption equilibriums of phosphate and thiocyanate anions on isomorphic substituted Mg/Zn-Al-type hydrotalcites were investigated in this study. Langmuir and Freundlich isotherms were used to interpret the equilibrium data for phosphate. The sorption equilibriums of phosphate on Mg3Al, Mg2ZnAl and Mg1.5Zn1.5Al hydrotalcites were well described by the Langmuir isotherm. The highest maximum sorption capacities for these adsorbents were as follows: 111, 101 and 95 mg g-1. The equilibrium constant and standard Gibbs energy changes were also calculated from the sorption data. Standard Gibbs energy changes of about -20 kJ mol-1 indicated that the process might be considered as physical adsorption. The sorption equilibriums of phosphate on isomorphic substituted samples of MgZn2Al and Zn3Al were well described by the Freundlich isotherm. Thiocyanate showed a relative low affinity for the studied materials, as indicated by both the 'S'-shaped isotherms and low sorption capacities. The sorption of phosphate and thiocyanate on the investigated hydrotalcites showed a continuous decrease of the sorption capacity in the following order: Mg3Al > Mg2ZnAl > Mg1.5Zn1.5Al > MgZn2Al > Zn3Al.

Sorption Profile and Thermodynamic Characteristics of Nitrosonaphthol Functionalized Sorbent for Metal Ion Enrichment

2005 ◽  
Vol 70 (9) ◽  
pp. 1341-1356 ◽  
Author(s):  
Saima Q. Memon ◽  
Muhammad I. Bhanger ◽  
Muhammad Y. Khuhawar
Keyword(s):  
Metal Ion ◽  
Tap Water ◽  
Thermodynamic Characteristics ◽  
Chelating Agent ◽  
Standard Addition ◽  
Absorption Spectrometry ◽  
Sorption Data ◽  
Maximum Sorption ◽  
Styrene Divinylbenzene ◽  
Two Phases

A simple and reliable method has been developed using styrene-divinylbenzene-based polymeric material containing 1-nitroso-2-naphthol as chelating agent, to concentrate ultratrace amounts of Ni(II) and Cu(II) ions in aqueous samples. Sorption of both the ions on the new synthetic resin under static and dynamic conditions has been investigated. The sorption has been optimized with respect to pH, shaking and contact time of two phases. Maximum sorption has been achieved from solution of pH 5-8 after 8 min of agitation. Total saturation capacities were 516 ± 2 and 316 ± 2.5 μmol g-1 for Ni(II) and Cu(II) ions, respectively. The lowest concentration for quantitative recovery (98 ± 1%) is 1.33 and 5 ppb with the preconcentration factor of 750 and 200 for Ni(II) and Cu(II), respectively. Monitoring of the influence of diverse ions on the sorption of metal ions has revealed that phosphate, hydrogencarbonate and citrate reduce the sorption to some extent. Under optimum conditions the sorption data followed Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The kinetics and thermodynamics of sorption are studied in detail. The sorption procedure is utilized to preconcentrate these ions prior to their determination in tea, human hair, and tap water samples by atomic absorption spectrometry using direct and standard addition methods.

scholarly journals Soil Organic Carbon Stocks in Terrestrial Ecosystems of China: Revised Estimation on Three-Dimensional Surfaces

2016 ◽  
Vol 8 (10) ◽  
pp. 1003 ◽  
Author(s):  
Rui Zhou ◽  
Xianzhang Pan ◽  
Hongxu Wei ◽  
Xianli Xie ◽  
Changkun Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Three Dimensional ◽  
Terrestrial Ecosystems ◽  
Carbon Stocks ◽  
Soil Organic Carbon Stocks

scholarly journals Phase Transition in Modified Newtonian Dynamics (MONDian) Self-Gravitating Systems

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1158
Author(s):  
Mohammad Hossein Zhoolideh Zhoolideh Haghighi ◽  
Sohrab Rahvar ◽  
Mohammad Reza Rahimi Rahimi Tabar
Keyword(s):  
Phase Transition ◽  
Binary Systems ◽  
Dimensional Space ◽  
Gravitational Interaction ◽  
Three Dimensional ◽  
Physical Parameters ◽  
Canonical Systems ◽  
Modified Newtonian Dynamics ◽  
Newtonian Dynamics ◽  
Gravitating Systems

We study the statistical mechanics of binary systems under the gravitational interaction of the Modified Newtonian Dynamics (MOND) in three-dimensional space. Considering the binary systems in the microcanonical and canonical ensembles, we show that in the microcanonical systems, unlike the Newtonian gravity, there is a sharp phase transition, with a high-temperature homogeneous phase and a low-temperature clumped binary one. Defining an order parameter in the canonical systems, we find a smoother phase transition and identify the corresponding critical temperature in terms of the physical parameters of the binary system.

scholarly journals Irradiation Effects in Compact Binaries

2002 ◽  
Vol 187 ◽  
pp. 253-258
Author(s):  
Martin E. Beer ◽  
Philipp Podsiadlowski
Keyword(s):  
Binary Systems ◽  
Three Dimensional ◽  
Close Binary ◽  
Close Binaries ◽  
External Irradiation ◽  
Black Hole Binaries ◽  
Compact Binaries ◽  
Critical Configurations ◽  
Main Effects

AbstractIrradiation of the secondaries in close binary systems affects their appearance and can drastically change their internal structure and hence long-term evolution. In this paper we review the main effects of external irradiation in close binaries with compact primaries, such as the distortion of the shape of the secondary and the conditions for the occurrence of outer critical configurations, and apply these to normal X-ray binaries, including systems such as HZ Her/Her X-l, Vela X-l and black-hole binaries during outburst (e.g. Nova Sco). Particular emphasis will be given to the role of circulation driven by the external heating and the radiative surface stress. We have developed a three-dimensional fluid dynamics code for modelling these effects. We present initial results of self-consistent calculations for the circulation in irradiated systems and show how the inclusion of these effects is vital to the understanding and interpretation of any system where external irradiation of the secondary is significant.

scholarly journals Eclipse mapping at X-ray wavelengths

1996 ◽  
Vol 176 ◽  
pp. 85-94 ◽  
Author(s):  
J.H.M.M. Schmitt
Keyword(s):  
Solar Corona ◽  
Binary Systems ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Similar Amount ◽  
Inversion Problem ◽  
X Ray ◽  
Three Dimensional Structure ◽  
Spatially Resolved ◽  
Rotational Modulation

Stellar coronae cannot be spatially resolved, and yet stellar coronae are likely to exhibit a similar amount of structure as the solar corona. Currently, the only way to infer structure from spatially unresolved data is to look for rotational modulation of the X-ray emission or eclipses in the case of binary systems. I will discuss some of the observations obtained and critically review the methods used to infer structure from these data. Particular emphasis will be placed on the ill-conditioned nature of the inversion problem, that makes it next to impossible to infer the possibly three-dimensional structure of stellar coronae.

scholarly journals Valorization of Uncharred Dry Leaves of Ficus benjamina towards Cr (VI) removal from Water: Efficacy Influencing Factors and mechanism

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Preeti S. Kulkarni ◽  
Varuna S. Watwe ◽  
Abubakar J. Hipparge ◽  
Sana I. Sayyad ◽  
Rutika A. Sonawane ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Maximum Adsorption Capacity ◽  
Equilibration Time ◽  
Aqueous Samples ◽  
Sorption Data ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Better Than ◽  
Work Treatment

AbstractThe potential of uncharred biomaterial derived from dry leaves of Ficusbenjamina (Family: Moraceae,local name: Weeping Fig) plant to remove Cr(VI) from aqueous samples was investigated. In the present work, treatment of dilute acids was used for activating the adsorption centres on the biomass instead of cumbersome charring process. The plant material was characterized using FT-IR, FE-SEM and EDX. Various influencing factors such as pH of equilibrating solution, contact time, Cr (VI) concentrations, adsorbent dose and temperature were optimized to obtain maximum sorption efficacy. The interactions among the biomaterial and Cr (VI) in water were studied by fitting the sorption data in four different adsorption isotherms. The data fitting and experimental evidences indicated formation of monolayer of Cr(VI) over the biomass surface. The process followed pseudo-second order kinetics and was thermodynamically spontaneous under laboratory conditions and reached equilibrium in 24 hours. Maximum adsorption capacity of 56.82 mg/g was obtained at the pH 2 when the concentration before adsorption was 200 mg L−1 of Cr(VI) with 24 hours of equilibration time and 2.50 g L−1 of dose of biomaterial at room temperature. The sorption efficiency was found to be better than many charred bio-based materials.

scholarly journals Preparation of Nanochitosan as an Effective Adsorbent for Removal of Pb (II) From Aqueous Solution

2019 ◽  
Author(s):  
Camellia Zareie ◽  
Saeideh Kholghi Eshkalak ◽  
Ghasem Najafpour Darzi ◽  
Mazyar Sharifzadeh baei ◽  
Habibollah Younesi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Ph Value ◽  
Sorption Process ◽  
Sorption Data ◽  
Kinetics Of Adsorption ◽  
Force Microscopy ◽  
Freundlich Isotherms ◽  
Atomic Force ◽  
Pseudo Second Order ◽  
Sorption Parameters

In this work, nanochitosan (NC) was prepared through ionic gelation using low-molecular-weight chitosan and maleic acid (MA). The synthesized NC was charac¬terized by means of Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). In the course of preparation, the particle size of the material was strongly depended on the parameters such as chitosan concentration and pH of the solution. By controlling the above parameters, NC with the size of smaller than 100 nm was prepared. The chitosan and prepared NC were used for the adsorption of Pb (II) from aqueous solutions in a batch system. Among the sorption parameters, pH showed the strongest effect on the sorption process and maximum Pb (II) removal was obtained at pH value of 6. The pseudo-first-order and pseudo-second-order were used to track the kinetics of adsorption process. Langmuir and Freundlich isotherms were subjected to sorption data to estimate the sorption capacity. NC proved to be an excellent adsorbent with remarkable capacity to remove Pb (II) ions from the aqueous solutions at various concentrations. The NC also showed incredible performance with a comparatively easier preparation process than other reported work.

scholarly journals Wind accretion in Cygnus X-1

2020 ◽  
Vol 637 ◽  
pp. A66 ◽  
Author(s):  
E. Meyer-Hofmeister ◽  
B. F. Liu ◽  
E. Qiao ◽  
R. E. Taam
Keyword(s):  
Black Hole ◽  
Stellar Wind ◽  
Binary Systems ◽  
Three Dimensional ◽  
Stable States ◽  
X Ray ◽  
Hard State ◽  
Hard Spectrum ◽  
Low Mass ◽  
Hydrodynamical Simulations

Context. Cygnus X-1 is a black hole X-ray binary system in which the black hole captures and accretes gas from the strong stellar wind emitted by its supergiant O9.7 companion star. The irradiation of the supergiant star essentially determines the flow properties of the stellar wind and the X-ray luminosity from the system. The results of three-dimensional hydrodynamical simulations of wind-fed X-ray binary systems reported in recent work reveal that the ionizing feedback of the X-ray irradiation leads to the existence of two stable states with either a soft or a hard spectrum. Aims. We discuss the observed radiation of Cygnus X-1 in the soft and hard state in the context of mass flow in the corona and disk, as predicted by the recent application of a condensation model. Methods. The rates of gas condensation from the corona to the disk for Cygnus X-1 are determined, and the spectra of the hard and soft radiation are computed. The theoretical results are compared with the MAXI observations of Cygnus X-1 from 2009 to 2018. In particular, we evaluate the hardness-intensity diagrams (HIDs) for its ten episodes of soft and hard states which show that Cygnus X-1 is distinct in its spectral changes as compared to those found in the HIDs of low-mass X-ray binaries. Results. The theoretically derived values of photon counts and hardness are in approximate agreement with the observed data in the HID. However, the scatter in the diagram is not reproduced. Improved agreement could result from variations in the viscosity associated with clumping in the stellar wind and corresponding changes of the magnetic fields in the disk. The observed dipping events in the hard state may also contribute to the scatter and to a harder spectrum than predicted by the model.

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