A multi-site mechanism model for studying Pb and Cu retention from aqueous solutions by Fe-Mg-rich clays

Clay Minerals ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 175-192 ◽  
Author(s):  
Z. Kypritidou ◽  
A. Argyraki
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Methodological Approach ◽  
Synergetic Effect ◽  
Sorption Isotherms ◽  
Superior Performance ◽  
Isotherm Models ◽  
Sufficient Information ◽  
Retention Mechanisms ◽  
Clay Materials

ABSTRACTThe retention mechanisms of metal ions during interaction of clay with metal-rich aqueous solutions is usually investigated by sorption isotherms. Although classical isotherm models may provide sufficient information about the characteristics of the solid–liquid system, they do not distinguish among the various retention mechanisms. This study presents a methodological approach of combining batch experiment data and geochemical modelling for the characterization of the interaction of Mg-Fe-rich clay materials with monometallic solutions of Pb and Cu. For this purpose, a palygorskite clay (PCM), an Fe-smectite clay (SCM) and a natural palygorskite-Fe-smectite mixed clay (MCM) were assessed for their effectiveness as metal ion sorbents. The sorption capacity of the materials follows the order MCM > SCM > PCM and ranges between 27.6–52.1 mg g–1for Pb and 7.7–17.6 mg g–1for Cu. Based on the experimental results that allowed the speciation calculations, fitting of sorption isotherms and the investigation of relationships between protons, Mg and the metals studied we suggest that a combination of sorption mechanisms occurs during the interaction of clay materials with metal solutions. These involve surface complexation, ion exchange and precipitation of solid compounds onto the solid surface. A three-term isotherm model was employed to quantify the role of each of the above mechanisms in the overall retention process. The superior performance of mixed clay among the materials tested is attributed to the synergetic effect of exchange in the interlayer and specific sorption on the clay edges.

scholarly journals Studies on Removal of Cr (VI) from Aqueous Solutions Using Powder of Mosambi Fruit Peelings (PMFP) As a Low Cost Sorbent

2012 ◽  
Vol 9 (3) ◽  
pp. 1389-1399 ◽  
Author(s):  
R. Hema Krishna ◽  
A. V. V. S. Swamy
Keyword(s):  
Particle Size ◽  
Aqueous Solutions ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Batch Tests ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Data ◽  
Agitation Time

The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad(min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.

scholarly journals Effective Biosorption of Nickel(II) from Aqueous Solutions UsingTrichoderma viride

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
P. Sujatha ◽  
V. Kalarani ◽  
B. Naresh Kumar
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Low Cost ◽  
Trichoderma Viride ◽  
Toxic Metal ◽  
Freundlich Isotherm ◽  
Recovery Process ◽  
Primary Objective ◽  
Ion Concentration ◽  
Isotherm Models

The primary objective of the present study is to evaluate the optimization conditions such as kinetic and equilibrium isotherm models involved in the removal of Ni(II) from the aqueous solutions byTrichoderma viride. The biosorbent was characterized by FTIR and SEM. The optimum biosorption conditions were determined as a function of pH, biomass dosage, contact time, initial metal ion concentration, and temperature. The maximum Ni(II) biosorption was obtained at pH 4.5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The kinetic studies indicate that the biosorption process of the metal ion Ni(II) has followed well the pseudo-second-order model. The sum of the square errors (SSE) and chi-square (χ2) tests were also carried out to find the best fit kinetic model and adsorption isotherm. The maximum biosorption capacity (qm) ofT.viridebiomass was found to be 47.6 mg/g for Ni(II) ion. Therefore, it can be concluded thatT.viridebiomass was effective and low-cost potential adsorbent to remove the toxic metal Ni(II) from aqueous solutions. The recovery process of Ni(II) fromT.viridebiomass was found to be higher than 98% by using 0.25 M HNO3. Besides the application of removal of toxic metal Ni(II) from aqueous solutions, the biosorbentT.viridecan be reused for five consecutive sorption-desorption cycles was determined.

Removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone

2012 ◽  
Vol 66 (3) ◽  
pp. 564-572 ◽  
Author(s):  
Görkem Değirmen ◽  
Murat Kılıç ◽  
Özge Çepelioğullar ◽  
Ayşe E. Pütün
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Diffusion Kinetic ◽  
Biosorption Process ◽  
Biosorption Mechanism ◽  
Pine Cone ◽  
Pseudo Second Order

In this study, the removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone was studied. Variables that affect the biosorption process such as pH, biosorbent dosage, initial metal ion concentration, contact time and temperature of solution were optimized. Experimental data were fitted to Langmuir, Freundlich, Dubinin Radushkevich and Temkin isotherm models to investigate the equilibrium isotherms. Pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were used to determine the biosorption mechanism. The thermodynamics of biosorption were studied for predicting the nature of biosorption. Experimental results showed that pine cone could be evaluated as an alternative precursor for removal of heavy metal ions from aqueous solutions, due to its high biosorption capacity, availability, and low cost.

Use of sesame stalk biomass for the removal of Ni(II) and Zn(II) from aqueous solutions

2012 ◽  
Vol 66 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Çisem Kırbıyık ◽  
Murat Kılıç ◽  
Özge Çepelioğullar ◽  
Ayşe E. Pütün
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Metal Ion ◽  
Low Cost ◽  
Second Order ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study an agricultural residue, sesame stalk, was evaluated for the removal of Ni(II) and Zn(II) metal ions from aqueous solutions. Biosorption studies were carried out at different pH, biosorbent dosage, initial metal ion concentrations, contact time, and solution temperature to determine the optimum conditions. The experimental data were modeled by Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Langmuir model resulted in the best fit of the biosorption data. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data and to evaluate rate constants. The best correlation was provided by the second-order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The experimental results showed that sesame stalk can be used as an effective and low-cost biosorbent precursor for the removal of heavy metal ions from aqueous solutions.

Moringa oleifera seeds for single and simultaneous removal of Pb2+ and Cd2+ from aqueous solutions

2020 ◽  
Author(s):  
Mohamed Abatal ◽  
Yaneth Stephanie Durán Avendaño ◽  
M. Teresa Olguin ◽  
Joel Vargas
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Moringa Oleifera ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Sorption Data ◽  
Batch Tests ◽  
Pseudo Second Order

<p>In this study, we report the effectiveness of natural and NaOH treated Moringa oleifera seeds for single and simultaneous Pb<sup>2+ </sup>and Cd<sup>2+</sup> from aqueous solutions. The biosorbent was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. The pH of point zero charge (pH<sub>pzc</sub>) was determined. Effects of contact time (15-1440 min), pH of solutions (2-10), mass of biosorbent (0.1-0.5 g) and initial metal ion concentration (10-1000 mg/L) were investigated using batch tests. The results show the pretreatment of biosorbent by NaOH improve significantly uptake capacity (mg/g) of the metal ions (q (Pb<sup>2+</sup>) = 38.45 and q (Cd<sup>2+</sup>) = 17.32 ˃ q (Pb<sup>2+</sup>) = 31.45 and q (Cd<sup>2+</sup>)= 14.67). Kinetic studies shown that the more than 90 % uptake of ion metals occurring within 120-180 min and the experimental data were better describe by a pseudo-second-order model. The sorption data for non-treated and NaOH treated Moringa oleifera seeds were evaluated by the Freundlich isotherm models to describe the adsorption equilibrium.</p>

scholarly journals Studies on chromium(III) removal from aqueous solutions by sorption on Sphagnum moss peat

2009 ◽  
Vol 74 (8-9) ◽  
pp. 953-964 ◽  
Author(s):  
Catalin Balan ◽  
Doina Bilba ◽  
Matei Macoveanu
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Sorption Isotherms ◽  
Second Order ◽  
Ion Concentration ◽  
Sphagnum Moss ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

Batch sorption experiments were performed for the removal of chromium(III) ions from aqueous solutions using Romanian Sphagnum moss peat (untreated and treated with NaCl solution) as sorbent. In order to establish the best conditions for the sorption of chromium(III), the influence of initial pH, contact time, peat dose and metal ion concentration was investigated. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to describe the sorption isotherms and to calculate its constants. The experimental data fitted well to the Langmuir model with a maximum sorption capacity of 18.6 mg Cr(III)/g of peat. The mean free energy of sorption suggests that the binding of Cr(III) on peat occurred through an ion exchange mechanism. The kinetic data evaluated by pseudo-first order and pseudo-second order kinetic models showed that the sorption of chromium onto the peat followed a pseudo-second order rate equation. The chromium(III) could be easily eluted from the loaded peat using 0.10 M HCl and the peat may be reused in several sorption/ desorption cycles. The experimental results indicated the potential of Sphagnum moss peat for removal of Cr(III) from wastewaters.

scholarly journals Nano sized carbonized waste biomass for heavy metal ion remediation

2014 ◽  
Vol 16 (4) ◽  
pp. 6-13 ◽  
Author(s):  
Garima Mahajan ◽  
Dhiraj Sud
Keyword(s):  
Heavy Metal ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Agricultural Waste ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Waste Biomass

Abstract Utilization of agricultural waste material with approach to enhance the heavy metal remediation properties by carbonizing the biomass at nano size particles has been explored in present investigation from aqueous solutions. In this study the lignocellulosic, nitrogenous agricultural waste biomass Delbergia sissoo pods (DSP) has been tried for sequestering of Cd (II), Pb (II) and Ni (II) metal ions from aqueous solutions. Batch experiments were performed for removal of targeted metal ions keeping in consideration the preliminary affecting parameters such as effect of adsorption dose, pH, initial metal ion concentration, stirring speed and contact time. The sorption studies were analyzed by using, Freundlic isotherm and Langmuir isotherm models. The kinetics of the process was evaluated by pseudo pseudo-first order and pseudo second order kinetic models. Studies reveal that the equilibrium was achieved with in 30 min of the contact time at optimized parameters. Analytical studies of biosorbent were done by means of FT-IR, SEM and XRD. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

Identification of managerial competencies of the organizational leaders of the Passifloraceae production sector in the Huila Department

2020 ◽  
Vol 36 (67) ◽  
pp. 61-78
Author(s):  
Hernando Gil Tovar ◽  
Derly Cibelly Lara Figueroa
Keyword(s):  
Methodological Approach ◽  
Superior Performance ◽  
Organizational Leaders ◽  
Management Skills ◽  
Generational Change ◽  
Production Sector ◽  
Managerial Competencies ◽  
Conducting Research ◽  
Definition Of ◽  
Small Producers

Managerial competencies, defined as the “underlying characteristics of an individual that have a causal relationship with effective or superior performance in the job” (Boyatzis, 1982, p. 12), are key to achievement of productive purposes in the Huila department, in Colombia. The present article, as an investigative result, seeks to identify those managerial competencies, both current and required, of the organizational leaders in the Passifloraceae productive sector in the Huila department, in Colombia. The epistemological paradigm used in this article is that of interpretivism. The reasoning method is deductive, and the methodological approach is mixed. The unit of analysis for this study consists of the directors of the associative organizations of Passifloraceae producers in the productive chain, where two types of players are identified: thirteen (13) leaders of organizations producing passion fruit, and five (5) representatives of institutions in the Huila department that influence the sector. The study concludes with the definition of the map of current managerial competences of organizations in the passionfruit productive sector, and is then contrasted with the map of competences required from these. It also highlights the importance of associativity for small producers, the need to continue conducting research in the sector, and the need to intervene through social outreach projects, so as to generate appropriation and training processes for a set of managerial competencies identified herein, which will strengthen management skills and competitiveness in this type of organization, and ensure, over time, generational change within the sector.

Biosorption of Cadmium onto Pseudomonas fluorescens: Application of Isotherm and Kinetic Models

2010 ◽  
Vol 171-172 ◽  
pp. 49-52 ◽  
Author(s):  
Chang Li Yu ◽  
Zhi Peng Lu ◽  
Fa Zhi Ge ◽  
Er Li Zhao
Keyword(s):  
Pseudomonas Fluorescens ◽  
Functional Groups ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Industrial Effluents ◽  
Rate Equations ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Kinetics Of Adsorption ◽  
Isotherm And Kinetic Models

The present study was undertaken to evaluate the feasibility of Pseudomonas fluorescens biomass for the removal of cadmium ions from aqueous solutions. Batch experiments were performed to study the adsorption of cadmium on pH, Pseudomonas fluorescens biomass adsorbent with respect to initial Cd(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Cd(II) was 66.25 mg/g (pH 5.0 and 5 g/L biomass dose). Kinetics of adsorption followed second-order rate equations. The FTIR results of Pseudomonas fluorescens biomass showed that biomass has different functional groups and these functional groups are able to react with metal ion in aqueous solution. The results of the present study suggest that Pseudomonas fluorescens biomass can be used beneficially in treating industrial effluents containing heavy metal ions.

scholarly journals Comparison between Different Keratin-composed Biosorbents for the Removal of Heavy Metal Ions from Aqueous Solutions

2002 ◽  
Vol 20 (4) ◽  
pp. 393-416 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Dheaya‘ Al-Rousan
Keyword(s):  
Aqueous Solutions ◽  
Human Hair ◽  
Metal Ion ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Ion Uptake ◽  
Chicken Feathers ◽  
Initial Ph ◽  
Metal Ion Uptake

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.

Sign in / Sign up

Export Citation Format

Share Document