Adsorption of methylene blue and methyl red dyes from aqueous solutions onto modified zeolites

2013 ◽  
Vol 67 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
Z. Ioannou ◽  
Ch. Karasavvidis ◽  
A. Dimirkou ◽  
V. Antoniadis

Zeolite, hematite, modified zeolite and commercial activated charcoal were examined for their ability to remove methylene blue (MB) and methyl red (MR) from their aqueous solutions. Modified zeolite and hematite were produced according to the Schwertmann and Cornell method while zeolite and commercial activated charcoal were obtained from S&B and Fluka AG companies, respectively. Adsorption experiments were conducted at three different adsorbent-to-solution ratios, namely 8, 16 and 24 g/L under environmental conditions and continuous stirring. Equilibrium isotherms of MB and MR were studied at different initial concentrations (from 5 × 10−4 to 5 × 10−3 g/L). MB adsorption kinetics were also studied. The maximum adsorption of MB and MR from their aqueous solutions was achieved at 24 g/L (adsorbent-to-dye solution ratio) after 1 h and was equal to 100% (MB) on modified zeolite and 99% (MR) on commercial activated charcoal, respectively. All the other materials achieved intermediate values of dye adsorption. From the applied kinetic models, the pseudo-second-order equation best described the adsorption of MB and MR. Consequently, modified zeolite showed the highest adsorption capacity for MB, while commercial activated charcoal showed the highest adsorption capacity of MR. The studied adsorbents can be used as filters to remove dyes from wastewaters.

2012 ◽  
Vol 550-553 ◽  
pp. 2259-2262
Author(s):  
Song Bo Cui ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang

The adsorption behavior of methylene blue (MB) dye from aqueous solutions onto honeycomb-cinder (HC) and its acid-activated product was investigated in a batch system. The results showed the adsorption capacity was decreased for raw HC samples with the increase of pH value, while it was increased for activated samples. The adsorption data were fit with Langmuir isotherm model for MB adsorption by all samples. The MB adsorption capacity on samples was increased from 2.62 mg/g to 7.81 mg/g and 7.00 mg/g after acid-activated by HCl and H2SO4, respectively. The adsorption processes of MB followed pseudo-second-order kinetics with a coefficient of correlation≥0.99. This study demonstrated that acid-activated HC has superior adsorbing ability for MB than raw HC and can be used as alternative adsorbents in dye wastewater treatment.


2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.


2015 ◽  
Vol 1125 ◽  
pp. 281-285
Author(s):  
Siti Aishah Muhmed ◽  
Mohd Ghazali Mohd Nawawi

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.


2021 ◽  

<p>In this paper, the low-cost and practical adsorption for removing methylene blue (MB) dye has been developed by using recoverable natural zeolite that was magnetized with Fe3O4. The magnetization was conducted by co-precipitation technique. The adsorbents obtained from the magnetization were characterized by XRD, FTIR, surface area analyzer and turbidity meter machines. The MB adsorption on the recoverable adsorbent was performed by batch experiment. The effect of Fe3O4 fraction on adsorbent characters, recoverability, and adsorption ability was evaluated. The adsorption kinetic and isotherm were also determined. The research results attributed that recoverable zeolite/Fe3O4 adsorbent has been successfully produced. It was found that the increase of Fe3O4 fraction in the adsorbent, has improved the recoverability, but in the same time, it caused the adsorption decreased. The fraction of Fe3O4 as much 33.30%w displayed compromisingly good capacity and recoverability. The maximum MB dye adsorption was reached by a condition of 0.25 g L-1 of the adsorbent dose, pH 8, and in 60 mins of the contact time The adsorption kinetic well fitted with pseudo second-order with the adsorption rate of 0.0238 mg g-1 min-1. The adsorption strongly agreed with the Langmuir isotherm with adsorption capacity of 32.258 mg g-1 .</p>


2021 ◽  
Author(s):  
Zohra Draoua ◽  
Amine Harrane ◽  
Mehdi Adjdir

Abstract This study focuses on the synthesis, characterization, and application of amphiphilic PCL-PEG-PCL/Bentonite-TBHSA (A2). The prepared of A2 nanocomposite was prepared from Algerian Bentonite modified by the intercalation of tetrabutylammonium hydrogen sulfate (TBHSA) (A1), were characterized by different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD), (TEM),(DSC) and thermogravimetric analysis (TGA ). The removal efficiency of of methylene blue, from aqueous solutions. The effects of the initial pH of a solution, contact time, and nanocomposite mass on the adsorption efficiency were investigated. Pseudo-first/second-order isotherms were applied to determine the efficiency of nanocomposite solid. The experimental data fitted well with the pseudo-second-order model for MB dye adsorption. The mass of nanocomposite increased, the adsorption capacity of dye increases to reach an optimal value at 0.13 g of adsorbent in pH = 6.8. The Langmuir isotherm exhibited the best fit, with an adsorption capacity equal to 600 mg/g .


2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.


2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic

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.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6138
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Bayan Al-Shaikh Al-Shaikh Yousef

Adsorptive removal of methylene blue (MB) from contaminated water samples was achieved using green tea waste (GTW). Adsorption of MB onto raw (RGTW) and thermally treated waste (TTGTW250–TTGTW500) was explored. The performance of the tested adsorbents was assessed in terms of percentage removal of MB (%R) and adsorption capacity (qe, mg/g). A full factorial design (FFD) was employed to optimize the adsorption of MB onto both RGTW and TTGTW500. Four factors were studied: pH, adsorbent dose (AD), dye concentration (DC), and contact time (CT). Value for %R of 96.58% and 98.07% were obtained using RGTW and TTGTW500, respectively. FT-IR and Raman analyses were used to study the surfaces of the prepared adsorbents, and the IR spectrum showed the existence of a variety of functionalities on the surfaces of both the RGTW and thermally treated samples. BET analysis showed the presence of mesopores and macropores in the case of RGTW and micropores in the case of thermally processed adsorbents. Equilibrium studies indicated that the Freundlich isotherm best described the adsorption of MB onto both adsorbents. The maximum adsorption capacity (qmax) was found to be 68.28 and 69.01 mg/g for RGTW and TTGTW500, respectively, implying the superior capacity of TTGTW500 in removing MB. Adsorption of MB was found to proceed via chemisorption (RGTW) and physisorption (TTGTW500), as indicated by the Dubinin–Radushkevich (D-R) isotherm. A pseudo-second order (PSO) model best demonstrated the kinetics of the MB adsorption onto both adsorbents.


2020 ◽  
Vol 9 (3) ◽  
pp. 9-14
Author(s):  
Hao Pham Van ◽  
Linh Ha Xuan ◽  
Oanh Phung Thi ◽  
Hong Phan Ngoc ◽  
Huy Nguyen Nhat ◽  
...  

This report presents the effect of synthesis conditions on the synthesis of graphene nanosheets via electrochemical exfoliation method for adsorbing methylene blue from aqueous solution. Oxygen-containing functional groups and defects in the material were characterized by Raman and X-ray photoelectron spectroscopy (XPS). As a result, by using voltage of 15 V, (NH4)2SO4 (5%, 250 mL) and KOH (7.5%, 250 mL), the obtained material showed the highest MB adsorption capacity due to the high densities of oxygen-containing groups and defects comparison to other conditions.


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