Adsorption kinetics and isotherm of methylene blue and its removal from aqueous solution using bone charcoal

2010 ◽  
Vol 102 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Gh. Ghanizadeh ◽  
G. Asgari
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Nur Izzah Iwanina Zamri ◽  
Siti Lailatul N. Zulmajdi ◽  
Nur Zafirah A. Daud ◽  
Abdul Hanif Mahadi ◽  
Eny Kusrini ◽  
...  

Abstract In the present study, pectin-alginate-titania (PAT) composites were synthesized and the adsorptive removal behavior of methylene blue (MB) from aqueous solution, as a model of synthetic organic effluents, onto the prepared PAT composites were investigated by monitoring the effect of contact time, initial MB concentration, and temperature. The adsorption isotherm data were fitted well with the Freundlich isotherm model, suggesting the surface heterogeneity of the PAT composites and that the MB adsorption occurred on the active sites on multilayer surface of the composites. The adsorption kinetics of MB was demonstrated to be pseudo-second order, governed by two intraparticle diffusion rates, and the adsorption process was exothermic, spontaneous, and more disorder. The Langmuir isotherm model suggested that the maximum adsorption capacity of MB on the PAT composites was in the range of 435–637 mg g–1. In general, it increased with the TiO2 NPs content in the PAT composites, due most likely to the increase in surface area exposing more functional groups of the pectin and alginate to interact with the synthetic dye. The adsorptive removal of MB by the PAT composites was found to be more efficient compared with many other reported adsorbents, such as graphene oxide hybrids, pectin microspheres, magnetite-silica-pectin composites, clay-based materials, chemically treated minerals, and agricultural waste. The present study therefore demonstrated for the first time that PAT composites are not only promising to be utilized as an adsorbent in wastewater treatment, but also provide an insight into the adsorption mechanism of the synthetic dyes onto the biopolymers-titania composites. Graphic abstract Insight into the adsorption kinetics, mechanism, and thermodynamics of methylene blue from aqueous solution onto pectin-alginate-titania composite microparticles.


Author(s):  
Dan Wu ◽  
Yaxiu Zhao ◽  
Qiang Liu ◽  
Chein-Chi Chang ◽  
Wei Hou

Abstract A graphene film deposited on titanium substrate was successfully prepared by a facile solution evaporation method, as electrode exhibiting superior electrosorption property toward methylene blue (MB) from aqueous solution. The fabricated graphene film on titanium substrate was characterized in detail by scanning electron microscopy (SEM) and FTIR techniques. As electrode (GTE) for electrosorption of MB, some experimental parameters, such as applied potential, concentration of electrolyte, solution initial pH and temperature, were systematically investigated and discussed. The experimental results demonstrated that the maximum adsorption capacity using GTE can reach 86.06 mg· g−1 under the optimized conditions of −600 mV of applied potential, pH of 7.5, 293 K and 0.01 mg· L−1 Na2SO4 solution, which is 1.40 times of that obtained under open circuit condition in 10 mg· L−1 MB solution. The adsorption isotherm of MB on GTE was analyzed with Langmuir and Freundlich isotherm equations, Pseudo-first-order model, pseudo-second-order model, and intra-particle diffusion model were applied to depict the adsorption kinetics process. The electrosorption of MB preferably fitted Langmuir isotherm, indicating a single-layer adsorption of MB molecules on graphene film followed pseudo-second-order model. Moreover the electrosorption of MB on GTE was found to be spontaneous and endothermic process. This work would be helpful to design and fabricate high performance carbon-based electrodes for high efficiency electrosorption treatment of dye wastewaters.


Author(s):  
Bintou Coulibaly ◽  
Lemeyonouin Aliou Guillaume Pohan ◽  
Ollo Kambiré ◽  
Lébé Prisca Sandrine Kouakou ◽  
Hervé Goure-Doubi ◽  
...  

The objective of this work was to valorize the clays of Côte d'Ivoire in the treatment of wastewater. The study focused on the ability of raw clays from Bouaflé city to adsorb methylene blue and cadmium ions, in aqueous solution. The physicochemical characteristics of the clay were determined using the measurement of its specific surface area, chemical analysis and mineralogical analysis. It emerges from these characterizations that clay is essentially composed of type 2/1 minerals such as illite (32.94%), type 1/1 kaolinite (8.47%), quartz (40.23 %) and approximately iron oxy-hydroxides (18.36%). Its specific surface is 37.58 m2 / g. The kinetics, thermodynamics and isotherms of adsorption have been used to understand the mechanism of adsorption. The results obtained show that the organic pollutant alone in solution (methylene blue (MB)) is adsorbed quite quickly. We obtained a decoloration yield greater than 90% after 40 min of adsorbate-adsorbent contact. The elimination of methylene blue is greater in a basic medium. The BM adsorption kinetics were modeled. The comparison of the correlation factors of the different kinetic models used has shown that the adsorption kinetics of the organic pollutant (MB) better match the pseudo second order kinetic model. Thermodynamics predicted a spontaneous endothermic surface reaction, due to the positive sign of  and the negative sign of , obtained (  = 31.398;  = -12.635). Analysis of adsorption isotherms allowed us to show that the adsorption of methylene blue on clay is physisorption type and in monolayer. The experiments were also performed with an aqueous solution containing both methylene blue and cadmium ions. After a contact time of 120 min, 60% of the cadmium ions are adsorbed on the clay against only 20% of methylene blue. Thus, clay preferentially eliminates trace metal elements (Cd2+) compared to organic pollutants (methylene blue).


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4161
Author(s):  
Yuhong An ◽  
Wanqi Zhang ◽  
Hui Liu ◽  
Yuan Zhong ◽  
Zichu Hu ◽  
...  

Lignocellulose (LCE) was ultrasonically treated and intercalated into magnesium aluminum silicate (MOT) clay to prepare a nano-lignocellulose magnesium aluminum silicate polymer gel (nano-LCE-MOT) for the removal of Zn (II) from aqueous solution. The product was characterised using nitrogen adsorption/desorption isotherm measurements, Fourier-transform infrared spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The conditions for the adsorption of Zn (II) on nano-LCE-MOT were screened, and adsorption kinetics and isotherm model analysis were carried out to explore the adsorption mechanism and achieve the optimal adsorption of Zn (II). Optimal adsorption was achieved at an initial Zn (II) concentration of 800 mg/L at 60 °C in 160 min at a pH of 4.52. The adsorption kinetics were explored using a pseudo-second-order model, with the isotherm adsorption equilibrium found to conform to the Langmuir model. The maximum adsorption capacity of the nano-LCE-MOT polymer gel toward Zn (II) is 513.48 mg/g. The materials with adsorbed Zn (II) were desorbed using different media, with HCl found to be the most ideal medium to desorb Zn (II). The optimal desorption of Zn (II) was achieved in 0.08 mol/L HCl solution at 65 °C in 60 min. Under these conditions, Zn (II) was almost completely desorbed from the adsorbents, with the adsorption effect after cycling being slightly different from that of the initial adsorption.


Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.


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