scholarly journals Removal of Fluoride and Arsenate from Aqueous Solutions by Aluminum-Modified Guava Seeds

2018 ◽  
Vol 8 (10) ◽  
pp. 1807 ◽  
Author(s):  
Sarai Ramos-Vargas ◽  
Ruth Alfaro-Cuevas-Villanueva ◽  
Rafael Huirache-Acuña ◽  
Raúl Cortés-Martínez
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Equilibrium ◽  
Order Model ◽  
Freundlich Model ◽  
Equilibrium Time ◽  
Fluoride Adsorption ◽  
Batch Type ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

The contamination of groundwater by arsenic and fluoride is a major problem worldwide, causing diseases in the population that uses these waters for their consumption. Therefore, the removal of these types of pollutants from groundwater is a very important issue. In this work, the removal of arsenate and fluoride from aqueous solutions by using aluminum-modified guava seeds (Al-GSs) was evaluated. Batch-type adsorption experiments were carried out with aqueous solutions of As(V) and F− and Al-GSs. The kinetic and equilibrium parameters of adsorption were determined, as well as the effects of adsorbent dose and pH. The adsorbent was characterized by scanning electron microscopy and infrared spectroscopy in order to determine its morphology and the functional groups present in the material. The results showed that hydroxyl and carboxyl are the main groups involved in the adsorption of As(V) and F−. The fluoride adsorption kinetics indicate that the equilibrium time was reached at 150 min and it can be described by the Lagergren model, while for As(V) the equilibrium time was lower (120 min) and the kinetic data were fitted well to the pseudo-second-order model. The Langmuir-Freundlich model can describe the adsorption equilibrium data in all cases. The fluoride adsorption capacity by Al-GS was 0.3445 mg/g, and for As(V) it was 4 mg/g. It can be established that the removal of arsenates and fluoride in Al-GSs is due to chemisorption on a heterogeneous surface.

Adsorption Equilibrium and Kinetics of Copper from Aqueous Solutions on Steel Slag

2011 ◽  
Vol 354-355 ◽  
pp. 33-36
Author(s):  
Jian Yun Li ◽  
Quan Xian Hua ◽  
Jun Ling Niu ◽  
Jian Wei Tang ◽  
Ke Xu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Equilibrium ◽  
Steel Slag ◽  
Adsorption Rate ◽  
Batch Adsorption ◽  
Equilibrium And Kinetics ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Kinetics Of

The adsorption of copper in aqueous solutions by steel slag was studied in batch adsorption experiments. The adsorption equilibrium data fitted best with Langmuir and Freundlich equations. The adsorption was preferential type. A comparison of the kinetics models on the apparent adsorption rate showed that the adsorption system was best described by the pseudo-second-order kinetics. The adsorption rate was controlled by both liquid film diffusion and intraparticle dispersion.

Synthesis of carboxylated chitosan and its adsorption properties for cadmium (II), lead (II) and copper (II) from aqueous solutions

2009 ◽  
Vol 60 (2) ◽  
pp. 467-474 ◽  
Author(s):  
K. L. Lv ◽  
Y. L. Du ◽  
C. M. Wang
Keyword(s):  
Aqueous Solutions ◽  
Ph Value ◽  
Order Model ◽  
Adsorption Capacities ◽  
Kinetic Rates ◽  
Experimental Parameters ◽  
Exothermic Process ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.

scholarly journals COMPARISON OF STINGING NETTLE ADSORPTION PERFORMANCE TOWARDS ANIONIC AND CATIONIC DYES

2021 ◽  
Vol 55 (9-10) ◽  
pp. 1131-1142
Author(s):  
BENGÜ ERTAN ◽  
Keyword(s):  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Stinging Nettle ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Cr Uptake

Stinging nettle was used as lignocellulosic adsorbent for the removal of cationic dye – malachite green (MG), and anionic dye – Congo red (CR), from aqueous solution, without any chemical pretreatment. The adsorption equilibrium data fitted well with the Langmuir model for the adsorption of both dyes, with the calculated maximum adsorption capacity of 270.27 mgg-1 and 172.14 mgg-1 for MG and CR, respectively. The adsorption process was controlled by the pseudo-second-order model in the adsorption of MG and by the pseudo-first-order model in the adsorption of CR. The thermodynamics modelling displayed that the process was spontaneous and endothermic. The π–π electron–donor interaction, hydrogen bonds and pore diffusion may also be effective, besides electrostatic interaction between the adsorbate and the adsorbent in the mechanism of MG and CR uptake.

scholarly journals Adsorption isotherm and thermodynamic studies of As(III) removal from aqueous solutions using used cigarette filter ash

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Pezhman Zein Al-Salehin ◽  
Farid Moeinpour ◽  
Fatemeh S. Mohseni-Shahri
Keyword(s):  
Aqueous Solutions ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Cigarette Filter ◽  
Electron Microscopy Analysis ◽  
Equilibrium Data ◽  
Thermodynamic Variables ◽  
Adsorption Equilibrium Data

Abstract In the present paper, used cigarette filter ash was prepared and used as an active adsorbent to remove As(III) ions from aqueous solutions. The prepared adsorbent structure was identified by scanning electron microscopy analysis, Brunauer–Emmett–Teller method and energy-dispersive X-ray spectroscopy analysis. The influence of contact time, pH, adsorbent dose and initial concentration of As(III) on the removal of As(III) was assessed. Several isotherm models were checked to illustrate the adsorption equilibrium. The adsorption equilibrium data adapted well with the Langmuir isotherm model. The maximum adsorption capacity of 33.33 mg/g was acquired from the Langmuir isotherm. The calculated thermodynamic variables verified that the adsorption process is spontaneous and endothermic.

Adsorption of Methylene Blue on Modified Bentonite

2013 ◽  
Vol 726-731 ◽  
pp. 2380-2383
Author(s):  
Li Xia Li ◽  
Xin Dong Zhai
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Freundlich Isotherm ◽  
Batch Process ◽  
Experimental Results ◽  
Order Model ◽  
Modified Bentonite ◽  
Equilibrium Data ◽  
Pseudo Second Order

Modified bentonite was used as adsorbent for the methylene blue adsorption in a batch process. Experimental results show that the adsorption kinetics is well described by pseudo-second-order model and the equilibrium data was better represented by the Freundlich isotherm model. The results revealed that the modified bentonite has the potential to be used as a good adsorbent for the removal of methylene blue from aqueous solutions.

Graphene-Based Nanocomposites for Enhanced Pb2+ Adsorption

2017 ◽  
Vol 13 ◽  
pp. 323-329 ◽  
Author(s):  
Anastasiya E. Kucherova ◽  
Irina V. Romantsova ◽  
Alexandr E. Burakov ◽  
Nariman R. Memetov ◽  
Mikhail N. Krasnyansky
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Kinetic Data ◽  
Adsorption Equilibrium ◽  
Intercalation Compound ◽  
Expanded Graphite ◽  
Graphite Intercalation Compound ◽  
Order Model ◽  
Graphite Intercalation ◽  
Pseudo Second Order

The present paper describes an investigation of the adsorption of lead ions (Pb2+) on graphene-based nanocomposites obtained via exfoliation of hydrolyzed expanded graphite intercalation compound. Three types of these nanocomposites - suspension of graphene nanoplatelets (SGN), paste of multi-layered oxidized graphene (PMOG), and paste of few-layered oxidized graphene (PFOG) - were used to extract Pb2+ from 1,040 mg L-1 aqueous solutions of Pb (NO3)2, and the kinetic of the Pb2+ adsorption was studied. It was found that the kinetic data are best fitted by the pseudo-second-order model. The adsorption equilibrium was achieved within 30 min under normal conditions. The maximum Pb2+ adsorption capacity of SGN, PMOG and PFOG was found to be 457, 103 and 38 mg g-1, respectively. Considering the obtained results, it can be assumed that the phenolic and hydroxyl oxygen-containing functional groups located at the surface of the adsorption materials under study play an important role in the Pb2+ removal process.

Adsorption mechanism of As(V) and As(III) on Fe–Mn binary oxides in synthetic and real water matrices

2016 ◽  
Vol 16 (4) ◽  
pp. 992-1001 ◽  
Author(s):  
Jasmina Nikić ◽  
Jasmina Agbaba ◽  
Malcolm Watson ◽  
Snežana Maletić ◽  
Jelena Molnar Jazić ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Binary Oxides ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
The Eu

A series of Fe–Mn binary oxides with different Fe:Mn ratios (1:1, 3:1, 6:1, 9:1) were synthesized to investigate the optimal Fe:Mn ratio for the removal of As(III) and As(V). Batch experiments were performed to determine the rate of adsorption and equilibrium isotherms. Adsorption kinetics were well described by the pseudo-second-order kinetic model for both As(III) and As(V). The adsorption equilibrium data fitted well to Langmuir and Freundlich isotherms. The maximum As(V) sorption capacity was observed at an Fe:Mn ratio of 6:1 (65.0 mg/g), whereas maximum As(III) uptake was at Fe:Mn ratio 3:1 (46.9 mg/g). Arsenic levels in real water samples were reduced from 37 μg/l to below the EU Water Framework Directive limit (10 μg/L) after treatment with Fe–Mn adsorbents.

scholarly journals SYNTHESIS AND APPLICATION OF CHITOSAN/GRAPHENE OXIDE/MAGNETITE NANOSTRUCTURED COMPOSITE FOR Fe(III) REMOVAL FROM AQUEOUS SOLUTION

2018 ◽  
Vol 56 (2) ◽  
pp. 158
Author(s):  
Truong Dang Le ◽  
Hoang Vinh Tran ◽  
Le Dieu Thu ◽  
Tran Ngoc Quang ◽  
Nguyen Thi Minh Hang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Adsorption Equilibrium ◽  
Efficient Removal ◽  
Nanostructured Composite ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data ◽  
Efficient Adsorbent

In this research, the potential of chitosan/Fe3O4/graphene oxide (CS/Fe3O4/GO) nanocomposite for efficient removal of Fe(III) a cationic metal ion from aqueous solutions was investigated. The synthesized CS/Fe3O4/GO was characterized by XRD, VSM and SEM techniques. Also, the various parameters affecting Fe3+ removal were investigated. Fe(III) adsorption equilibrium data were fitted well to the Langmuir isotherm and the maximum monolayer capacity (qmax), was calculated from the Langmuir as 6.5 mg.g-1. The results show that, CS/Fe3O4/GO nanocomposite, can be used as a cheap and efficient adsorbent for removal of heavy metal ions from aqueous solutions.

Caffeine Removal by Adsorption: Kinetics, Equilibrium Thermodynamic and Regeneration Studies

2021 ◽  
Vol 47 (1) ◽  
pp. 95-103
Author(s):  
Ivone Vanessa Jurado Dávila ◽  
Júlia Viola Matzenbacher Hübner ◽  
Keila Guerra Pacheco Nunes ◽  
Liliana Amaral Féris
Keyword(s):  
Adsorption Equilibrium ◽  
Isotherm Models ◽  
Equilibrium Thermodynamic ◽  
Reversible Process ◽  
Experimental Conditions ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Influence Of Ph

In this work, it was studied the caffeine removal through the adsorption on granular activated carbon (CAG). The influence of pH, contact time and CAG dosage were analyzed by batch experiments. Adsorption Kinetic was studied using the models of pseudo-first-order and pseudo-second-order. The adsorption equilibrium data was studied with Langmuir, Freundlich, and Redlich-Peterson isotherm models. The process thermodynamic also was studied. It was obtained 88 % of removal under the experimental conditions of natural pH, 60 min of adsorption and 8 g.L-1 of CAG. The kinetic model that showed the best results was the pseudo-secondorder and Langmuir was the isotherm model that best described the adsorption behavior. The thermodynamic parameters obtained showed a spontaneous, endothermic and reversible process. The desorption efficiency also was studied by regenerant solvents. The best results were obtained using a solvent combination of ethyl acetate, ethanol, and water (50:25:25), and it was obtained a caffeine removal of 57 %, achieving 70 % when a new solution is used in each regeneration step.

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