scholarly journals Removal of lead from aqueous solutions using Saudi activated bentonite

2010 ◽  
Author(s):  
S. Al-Shahrani
Keyword(s):  
Aqueous Solutions ◽  
Activated Bentonite

scholarly journals Application of activated bentonite for the removal of direct and reactive dye from aqueous solutions

2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic
Keyword(s):  
Aqueous Solutions ◽  
Dye Adsorption ◽  
Bentonite Clay ◽  
Reactive Dye ◽  
Second Order ◽  
Intra Particle Diffusion ◽  
Naoh Solution ◽  
Activated Bentonite ◽  
Endothermic Process ◽  
Pseudo Second Order

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.

scholarly journals Examination of the Effectiveness of Physical and Chemical Activation of Natural Bentonite for the Removal of Heavy Metal Ions from Aqueous Solutions

2002 ◽  
Vol 20 (2) ◽  
pp. 151-167 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Leena Abu-Aitah
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Chemical Activation ◽  
Sodium Dodecyl ◽  
Batch Adsorption ◽  
Initial Material ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Activated Bentonite

The ability of physically and chemically activated bentonite to adsorb copper and nickel ions from aqueous solutions was examined under various experimental conditions. Physically activated bentonite was obtained by thermal treatment of the initial material in an oven at 700°C (T-bentonite), while chemically activated bentonite was obtained in two ways, either by treatment of the initial material with sodium dodecyl sulphate (SDS) as an anionic surfactant to give SDS-bentonite or with aluminium hydroxypolycation as a pillaring agent to give Al-bentonite. Batch adsorption tests were undertaken to study the removal of Cu2+ and Ni2+ ions from aqueous solutions using the above-mentioned types of activated bentonite. The adsorption capacity of the bentonites towards both Cu2+ and Ni2+ ions followed the order: Al-bentonite > SDS-bentonite > T-bentonite > natural bentonite. The initial metal concentration, solution pH, temperature and salinity of the solution affected the adsorption capacity towards both metal ions. The uptake of Cu2+ ions increased with an increase in temperature (25–45°C) as well as with an increase in the initial pH of the solution (3–5). The uptake of Cu2+ and Ni2+ ions decreased significantly with an increase in the NaCl and KCl concentrations present in the aqueous solution. Sulphuric acid of 0.1 M concentration was found to be an effective desorbent for bentonite laden with heavy metals.

scholarly journals Sorption Study of a Basic Dye “Gentian Violet” from Aqueous Solutions Using Activated Bentonite

2012 ◽  
Vol 18 ◽  
pp. 924-933 ◽  
Author(s):  
K. Bellir ◽  
I. Sadok Bouziane ◽  
Z. Boutamine ◽  
M. Bencheikh Lehocine ◽  
A-H. Meniai
Keyword(s):  
Aqueous Solutions ◽  
Gentian Violet ◽  
Basic Dye ◽  
Activated Bentonite ◽  
Sorption Study

Adsorption of bisphenol A and 2,4,5-trichlorophenol onto organo-acid-activated bentonite from aqueous solutions in single and binary systems

2017 ◽  
Vol 66 ◽  
pp. 383-395 ◽  
Author(s):  
Nassima Djebri ◽  
Mokhtar Boutahala ◽  
Nacer-Eddine Chelali ◽  
Nadia Boukhalfa ◽  
Zerroual Larbi
Keyword(s):  
Bisphenol A ◽  
Aqueous Solutions ◽  
Binary Systems ◽  
Activated Bentonite ◽  
Single And Binary Systems

ADSORPTION OF AMMONIA BY BASE ACTIVATED BENTONITE CLAY KINETIC AND EQUILIBRIUM STUDIES

2018 ◽  
Vol 28 (4) ◽  
pp. 1251-1257
Author(s):  
Miodrag Šmelcerović ◽  
Miodrag Šmelcerović
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Waters ◽  
Bentonite Clay ◽  
Second Order ◽  
Ammonium Ions ◽  
Adsorbate Concentration ◽  
Activated Bentonite ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Nitrogen compounds are essential elements for living organisms. The increased concentration of ammonia in ionized (NH4+) and non-ionized form (NH3) in surface waters causes negative effects on aquatic organisms, since it enters into the nitrogen cycle, and thus contributes to the eutrophication of water. The presence of higher concentrations of ammonia in surface waters than natural ones is the result of faecal contamination through the sewage system or runoff from arable areas which were treated with fertilizer. Water contaminated with ammonia can be purified by various methods: biological (nitrification-denitrification method), oxidation with chlorine, chemical precipitation, membrane filtration, etc. One of the alternative methods is removal by adsorption with natural materials such as clay and zeolite. Bentonite clay was marked off as a suitable adsorbent of cationic pollutants due to the permanent negatively charged surface. Тhe textural properties (specific surface, porosity) and structural properties of bentonite clay (the distance between the layers, the type of ions in the space between the layers) and consequently its adsorption capacity for pollutants is changed with the activation by acid or base and intercalation. There is very little literature data on the application of bentonite clay for removal of ammonium ions. Therefore, the aim of this work is activating the raw bentonite clay with a base and its application as an adsorbent for removal of ammonium ions from aqueous solutions. The influence of the adsorption conditions (adsorbent dose, temperature, pH, adsorbate concentration and contact time) on the amount of removed ammonia from the aqueous solution was investigated. Equilibrium data were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The best agreement with experimental data was obtained by Langmuir isotherm (R2 = 0.987). The following kinetic models were applied: the pseudo-first order, pseudo-second order, and the intra-particle diffusion model. The pseudo-second order model is most suitable for describing the adsorption of ammonium ions onto the base activated bentonite from aqueous solutions (R2 = 0.997). Removal of ammonium ions by activated clay is a pH-dependent and endothermic process, the adsorption degree of pollutants is increased with rising temperature. The highest adsorption capacity of the base activated bentonite clay of 26.82 mg/g was obtained in a solution of pH 6 and a temperature of 40 °C, at an adsorbent dose of 2 g/dm3 and аt an adsorbate concentration of 100 mg/dm3. By activating the adsorbent in a 1 M NaOH solution, the adsorption ability of the bentonite clay towards ammonium ions is improved. The results of this study show that the base activated bentonite clay is a potential adsorbent material for ammonia, i.e. ammonium ions.

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