scholarly journals Removal of Methylene Blue from Aqueous Solution by Activated Carbon Prepared from Pea Shells (Pisum sativum)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ünal Geçgel ◽  
Gülce Özcan ◽  
Gizem Çağla Gürpınar

An activated carbon was prepared from pea shells and used for the removal of methylene blue (MB) from aqueous solutions. The influence of various factors such as adsorbent concentration, initial dye concentration, temperature, contact time, pH, and surfactant was studied. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. The adsorption isotherm was found to follow the Langmuir model. The monolayer sorption capacity of activated carbon prepared from pea shell for MB was found to be 246.91 mg g−1at 25∘C. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second-order kinetic model. Various thermodynamic parameters such as , , and were evaluated. The results in this study indicated that activated carbon prepared from pea shell could be employed as an adsorbent for the removal of MB from aqueous solutions.

2021 ◽  
Vol 68 (2) ◽  
pp. 363-373
Author(s):  
Roya Salahshour ◽  
Mehdi Shanbedi ◽  
Hossein Esmaeili

In the present work, methylene blue was eliminated from aqueous solution using activated carbon prepared by lotus leaves. To perform the experiments, batch method was applied. Also, several analyses such as SEM, FTIR, EDAX and BET were done to determine the surface properties of the activated carbon. The results showed that the maximum sorption efficiency of 97.59% was obtained in initial dye concentration of 10 mg/L, pH of 9, adsorbent dosage of 4 g/L, temperature of 25 °C, contact time of 60 min and mixture speed of 400 rpm. Furthermore, the maximum adsorption capacity was determined 80 mg/g, which was a significant value. The experimental data was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, which the results showed that the pseudo-second order kinetic model could better describe the kinetic behavior of the sorption process. Also, the constant rate of the pseudo-second order kinetic model was obtained in the range of 0.0218–0.0345 g/mg.min. Moreover, the adsorption equilibrium was well described using Freundlich isotherm model. Furthermore, the thermodynamic studies indicated that the sorption process of methylene blue dye using the activated carbon was spontaneous and exothermic.


2018 ◽  
Vol 78 (10) ◽  
pp. 2055-2063
Author(s):  
Asmaa Msaad ◽  
Mounir Belbahloul ◽  
Samir El Hajjaji ◽  
Abdeljalil Zouhri

Abstract In this work, the use of a novel low-cost adsorbent derived from Ziziphus lotus (ZL) and industrial carbon (IC) has been successfully applied to the removal of methylene blue (MB) from aqueous solutions. The efficiency of this material was studied through Lagergren pseudo-first-order and pseudo-second-order kinetic models. The process for the novel activated carbon and the IC were best represented by the pseudo-second-order rate model. Langmuir and Freundlich isotherms were used to describe the sorption equilibrium data. The Langmuir model turned out to be the most adequate and maximum capacities were measured to be 833.33 and 142.85 mg.g−1 for ZL activated carbon and IC from Sigma Aldrich, respectively. The thermodynamic study revealed that the sorption process is spontaneous and endothermic for the two adsorbents. To explain the effectiveness of MB removal, ZL activated carbon was characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area, X-ray diffraction and Fourier transform infrared spectroscopy.


Author(s):  
Mohamed Nasser Sahmoune ◽  
Krim Louhab ◽  
Aissa Boukhiar

Dead streptomyces rimosus was found to be an effective biosorbent for the removal of chromium from industrial tanning effluents. A sorption level of 65 mg/g was observed at pH 4.8 while the precipitation effect augmented this value at a higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. The biosorption data of trivalent chromium by streptomyces rimosus has been used for kinetic studies based on fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The time-dependent Cr (III) biosorption data were well-described by a pseudo-second-order kinetic model. The intraparticle diffusion is not the rate-limiting step for the whole reaction. It was found that the biosorption equilibrium data fit well with the Langmuir model.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.


2020 ◽  
pp. 13-22

Hexavalent chromium (Cr(VI)) has the characteristic of forming anionic species, which are very toxic, very soluble in water and difficult to be removed. In this study, dichromate removal from aqueous solutions by chitosan and chitosan modified by sodium dodecyl sulfate (SDS) was addressed. The effect of various experimental parameters, such as pH (1-9), initial concentration (10-100 mg L-1), adsorbent dose (0.005-0.350 g) and contact time (5-60 min) was investigated. All experiments were conducted in batch mode at room temperature (~21 oC). The obtained equilibrium adsorption isotherms were analyzed using the Langmuir and Freundlich models. Furthermore, the kinetics of dichromate removal was analyzed by pseudo-first order, pseudo-second order and the Elovich models. Optimum conditions for obtaining high removal (~97%) within a relatively short time (60 min) are: 5.0 pH, 0.100 g SDS-chitosan dosage and an initial Cr2O72- concentration of 10 mg L-1. The dichromate adsorption capacity of chitosan is 8.3 mg L-1, while that of SDS-chitosan is 9.7 mg L-1. In addition, the adsorption of dichromate by chitosan and SDS-chitosan is well-fitted by the Langmuir and Freundlich models while the adsorption kinetics is best fitted by the pseudo-second-order kinetic model.


2012 ◽  
Vol 560-561 ◽  
pp. 1174-1177 ◽  
Author(s):  
Dimitar Petrov Georgiev ◽  
Bogdan Iliev Bogdanov ◽  
Yancho Hristov ◽  
Irena Markovska

In this study, the sorption of Cu(II) ions in aqueous solutions of Zeolite NaA by performing batch kinetic sorption experiments. The equilibrium kinetic data were analyzed using the pseudo-second-order kinetic model. A comparison was made of the linear least-squares method and nonlinear method of the widely used pseudo-second-order kinetic model for the sorption of Cu(II) ions of Zeolite . Four pseudo-second-order kinetic linear equations are discussed. Kinetic parameters obtained from the four kinetic linear equations using the linear method differed but they were the same when using the non-linear method. Kinetic parameters obtained from four kinetic linear equations using the linear method differed. Equation type 1 pseudo-second-order kinetic model very well represented the kinetic of the adsorption Cu(II) ions by Zeolite NaA. Equation type 4 exhibited the worst fit. Present investigation showed that the non-linear method may be a better way to determine the kinetic parameters.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.


2011 ◽  
Vol 8 (4) ◽  
pp. 1512-1521 ◽  
Author(s):  
A. Esmaeili ◽  
P. Beirami ◽  
S. Ghasemi

The batch removal of Ni2+from aqueous solution and wastewater using marine dried (MD) red algaeGracilariaand its activated carbon (AC) was studied. For these experiments, adsorption of Ni2+was used to form two biomasses of AC and MD. Both methods used different pH values, biomass and initial concentration of Ni2+. Subsequently adsorption models and kinetic studies were carried out. The maximum efficiencies of Ni2+removal were 83.55% and 99.04% for MD and AC respectively developed from it. The experimental adsorption data were fitted to the Langmuir adsorption model. The nickel(II) uptake by the biosorbents was best described by pseudo-second order rate model. The kinetic studies showed that the heavy metal uptake was observed more rapidly by the AC with compared to MD. AC method developed from MD biomass exhibited higher biosorption capacity. Adsorption capacity is related to the pH of solution, pH 5.0 is optimal for nickel. The maximum efficiencies of Ni2+removal were for AC method. The capacity is related to the pH of solution, pH 5.0 is optimal for nickel. The equilibrium adsorption data are correlated by Langmuir isotherm equation. The adsorption kinetic data can be described by the second order kinetic models


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 607 ◽  
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Guoqing Hu ◽  
...  

The magadiite–magnetite (MAG–Fe3O4) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe3O4 and the high adsorption capacity of pure magadiite (MAG). MAG–Fe3O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe3O4 nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe3O4 was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe3O4 were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe3O4 improved remarkably compared with MA and Fe3O4. The adsorption capacity of MAG–Fe3O4 and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe3O4 was better than that of MAG and Fe3O4. Moreover, the adsorption behavior of MB on MAG–Fe3O4 was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe3O4 nanocomposite was a monolayer adsorption.


2019 ◽  
Vol 800 ◽  
pp. 181-186 ◽  
Author(s):  
Nour El Houda Larbi ◽  
Djilali Redha Merouani ◽  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
Amine Khelifa

Heavy metals are very toxic water pollutant. Their presence not only affect human beings but also animals and vegetation because of their mobility in aqueous ecosystem, toxicity and non-biodegradability [1].in the aim of removing heavy metals from aqueous solutions, an eco-friendly biosorbent was prepared from lagoon sludge by a humification process. The biosorption of Cd2+ and Al3+ ions from aqueous solutions was investigated as a function of initial pH,contact time, initial metal ions concentration, and temperature. Langmuir and Freundlich models were used to determine the sorption isotherm. Optimum pH for the removal of cadmium and aluminum was found respectively to be around 6 and 4 [2] . The equilibrium was obtained in 60 min with the pseudo-second-order kinetic model. The Langmuir model was a better fit with the experimental data for both cadmium and aluminum adsorption with a regression coefficient up to 0.99 and Qmax of 100 and 142 mg.g-1 respectively for Cd2+and Al3+.


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