Treatment of anionic dye aqueous solution using Ti, HDTMA and Al/Fe pillared bentonite. Essay to regenerate the adsorbent (original) (raw)
Related papers
Thermal and chemical modification of bentonite for adsorption of an anionic dye
Advances in Environmental Technology (AET), 2018
Raw bentonite (RB), a known low-cost versatile clay was used as an adsorbent. RB was treated thermally and chemically to increase its adsorption capacity. For thermal treatment (TTB), the bentonite was heated at 400 °C for 60 min, and for the chemical modification, its surface was treated by cetyltrimethylammonium bromide (CTAB) to prepare organo-modified bentonite (CTAB-B). The removal of Congo red dye (CR) from aqueous solution was investigated in the batch mode. The prepared adsorbents were characterized by SEM, BET, and FTIR analyses. The effects of various experimental parameters such as contact time, pH, adsorbent dosage, dye concentration and temperature were investigated. The obtained results were in good agreement with the Langmuir isotherm model, and the maximum adsorption capacity of RB, TTB and CTAB-B was 43.1, 55.86 and 116.28 mg/g, respectively. The adsorption kinetic was better described by the pseudo-second order kinetic model. The results showed that thermally or chemically modified bentonite could be proposed as a low-cost adsorbent for the removal of CR from water.
2021
The present work focused on the preparation of hybrid-bentonite adsorbents by treating sodium bentonite (Na-B) with different amounts of hexadecyltrimethylammonium bromide (HDTMA+ Br-), corresponding to 50, 100 and 200% the value of the cation exchange capacity (CEC). The samples prepared, namely 50HDTMA-B, 100HDTMA and 200HDTMA-B, were characterized by different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA ). The removal efficiency of two anionic dyes, namely. Congo Red (CR) and Indigo Carmine (IC), from aqueous solutions, was studied as a function of the amount of HDTMA, contact time, hybrid adsorbent and initial dye concentration. In addition, a kinetic study was conducted to fit the experimental data in order to compare the adsorption rate constants and the equilibrium sorption capacities of anionic dyes on the prepared materials. The results obtained indicated that the adsorption kinetics of cla...
International Journal of Chemistry, 2013
The textile effluents have been considered as potential source of water contamination in the last few decades. Thus the effective methods were adopted for the removal of dyes and colorants from the textile effluents. In the present research, the removal of textile dye reactive red 223 (RR 223) was carried out by modified bentonite clay (MBC). The modification of bentonite clay was carried out by acid treatment method. The adsorption properties of MBC towards RR 223 were investigated using the batch method, at various temperatures 303-318 ±2 K under the optimized conditions. The adsorption equilibrium data were fitted in Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models and the values of the respective constants were evaluated by employing standard graphical method. From the correlation coefficient values (r 2), it was founded that Langmuir model is the best fitted isotherm. Feasibility of adsorption process (R L) and sorption energy (Es) was also determined. The pH PZC of adsorbent was estimated by pH drift method. Thermodynamic parameters such as free energy (ΔG⁰), enthalpy (ΔH⁰) and entropy (ΔS⁰) of the system were calculated. Kinetics of dye removal was investigated that it follows pseudo second order rate constant. The surface morphology of adsorbent was observed by the Scanning Electron Microscope (SEM). The interaction forces involved between the adsorbent and adsorbate was determined by Fourier Transform Infrared Spectroscopy (FTIR). In addition the recovery of dye and regeneration of adsorbent was carried out by desorption experiments. The sorption and desorption capacity of MBC was found to be 95.15% and 78%.
The effects of temperature, pH and ionic strength on the adsorption of crystal violet (CV þ ) by raw, Ni-saturated (Ni-), Co-saturated (Co-) and Zn-saturated (Zn-) bentonite samples were investigated. The amounts of CV þ adsorbed in equilibrium at 298.15 K were 0.27, 0.37, 0.49 and 0.54 mmol g À1 bentonite, which correspond to 108%, 148%, 196% and 216% of the cation exchange capacity (CEC) of the raw, Ni-, Zn-and Co-saturated bentonite samples, respectively. The adsorption of the dye on these samples is pH-independent within the range (2.5e 8.5), and it increases with ionic strength from 0 to 0.6 mol l À1 . Thermodynamic and Langmuir parameters showed that cation-saturated bentonite samples have relatively stronger ability than the raw bentonite towards the crystal violet (CV þ ) cation.
Surfactant Impregnated Bentonite Clay for the Adsorption of Anionic Dyes
7th International Conference on Latest Trends in Engineering and Technology (ICLTET'2015) Nov. 26-27, 2015 Irene, Pretoria (South Africa), 2015
Water scarcity is a reality in South Africa due to a number of factors including the presence of invasive foreign plant species and the effects of global warming. It is therefore necessary to develop efficient and cost effective water treatment techniques to protect our already limited water resources. In this study bentonite clay was impregnated with the surfactant hexadecyltrimethylammonium bromide (HDTM) and then used for the removal of anionic dyes from solutions. The clays were characterized using XRD, XRF and FT-IR spectroscopy. The firstand second order kinetic models as well as the Langmuir-and Freundlich isotherm models were used to determine the bentonite's adsorption affinity. The effects of adsorbent dosage, initial dye concentration and contact time were also tested in this study. The natural bentonite (NB) did not adsorb the tartrazine (TAR) or brilliant blue (BB). The HDTM impregnated bentonite performed very well in adsorbing both anionic dyes. The impregnated clay's affinity for BB (q e = 23.47 mg/g) and TAR (q e = 23.66 mg/g) are almost the same. HDTM-bentonite can therefore be considered to improve the adsorption capacity of bentonite clay applied for the treatment of water contaminated with anionic dyes.
Oriental Journal of Chemistry, 2016
The synthesis of acid activated titanium dioxide-pillared bentonite (TiO 2-pillared bentonite) and its adsorption properties on napthol blue black (NBB) dye has been studied. Natural bentonite was activated by using hydrochloric acid solutions and was intercalated with tetraisopropyl orthotitanate as titanium dioxide precursor. The as-prepared materials were characterized by X-ray Diffraction (XRD), nitrogen adsorption-desorption isotherms and Scanning Electron Microscopy Energy Dispersive X-ray Analysis (SEM-EDX). Napthol blue black dye removal was seen to increase with increasing contact time and the adsorption capacity of acid activated TiO 2-pillarred bentonite was depending on the pH, initial dye concentration and the amount of adsorbent. The optimum condition of NBB dye adsorption was found at a pH of 3.0, adsorbent amount of 0.2 g, initial dye concentration 25 mg/L for 120 minutes adsorption time. The adsorption capacity for the dye was found to be 1.496 mg/g. Adsorption of NBB onto TiO 2-pillarred bentonite at these conditions followed the Langmuir and Freundlich isotherm but the value of the correlation coefficient of Langmuir isotherm (0.998) is higher than Freundlich isotherm value (0.952).
2019
Natural bentonite (B) mineral clay was modified by anionic surfactant sodium dodecyl sulfate (SDS) and characterized using different techniques such as: FTIR spectroscopy, scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The bentonite and modified bentonite were used as adsorbents for the adsorption of methyl violet (MV) from aqueous solutions. The adsorption study was carried out at different conditions such as: contact time, pH value and adsorbent weight. The adsorption kinetic described by pseudo– first order and pseudo – second order equilibrium experimental data described by Langmuir, Freundlich and Temkin isotherm models. The thermodynamic parameters standard free energy ( ), standard entropy ( ) standard enthalpy ( ) were investigated and determined.
Investigation of a basic dye removal from aqueous solution onto chemically modified Unye bentonite
Journal of Hazardous Materials, 2009
The adsorption behavior of crystal violet (CV + ) from aqueous solution onto magnesium-oxide coated bentonite (MCB) sample was investigated as a function of parameters such as initial CV + concentration, contact time and temperature. The Langmuir, and Freundlich adsorption models were applied to describe the equilibrium isotherms. The Langmuir monolayer adsorption capacity of MCB were estimated as 496 mg/g. The pseudo-first-order, pseudo-second-order kinetic and the intra-particle diffusion models were used to describe the kinetic data and rate constants were evaluated. The values of the energy (E a ), enthalpy ( H / = ) and entropy of activation ( S / = ) were 56.45 kJ/mol, 53.90 kJ/mol and −117.26 J/mol K, respectively, at pH 6.5.
Ibn AL-Haitham Journal For Pure and Applied Sciences
Natural bentonite (B) mineral clay was modified by anionic surfactant sodium dodecyl sulfate (SDS) and characterized using different techniques such as: FTIR spectroscopy, scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The bentonite and modified bentonite were used as adsorbents for the adsorption of methyl violet (MV) from aqueous solutions. The adsorption study was carried out at different conditions such as: contact time, pH value and adsorbent weight. The adsorption kinetic described by pseudo– first order and pseudo – second order equilibrium experimental data described by Langmuir, Freundlich and Temkin isotherm models. The thermodynamic parameters standard free energy ( ), standard entropy ( ) standard enthalpy ( ) were investigated and determined.
Adsorption of Orange G Dye on Hydrophobic Activated Bentonite from Aqueous Solution
Crystals
This report focusses on the modification of physical structure and chemical properties of a bentonite clay from the Hammam Boughrara region of the Maghnia district in western Algeria to maximize its adsorption capacity. The purified bentonite clay (called B) was modified, either by acid activation with 1M sulfuric acid (B-Act), or by intercalation with the cationic surfactant cetytrimethyl ammonium bromide (CTAB), applying a cation exchange capacity (CEC) of 100% (called B-CTAB). Modification of B was also introduced by combining these two steps consecutively, i.e., at first acid activation of B, followed by intercalation with CTAB (B-Act-CTAB). The B-Act-CTAB was obtained by H2SO4 (1M) acid activation, followed by co-adsorption of CTAB with 100% and 300% of the CEC of B-Act as precursor. In particular, a strong increase of surface area and pore volume of the modified bentonites was observed for B-Act (469.83 m²/g and 0.401 cm3g−1), B-Act-CTAB100 (267.72 m²/g and 0.316 cm3 g−1) and ...