Adsorption of Methylene Blue onto Secondary Expanded Graphite

2010 ◽  
Vol 168-170 ◽  
pp. 2571-2574 ◽  
Author(s):  
Yan Hong Chang ◽  
Bin Wang ◽  
Hui Luo ◽  
Lin Jie Zhi

A secondary oxidation and expansion of graphite process resulted in a specific surface area enhanced material, which could be used in methylene blue (MB) adsorption in industry, due to the low running cost and mass production. The morphology of the samples was investigated using scanning electron microscopy, and the structures vary from the expansion level. It was found that with a pH value about 9, the sample exhibited better adsorption property toward MB after re-expansion. The adsorption capability of MB adsorbed on unit mass of the secondary expanded graphite turned out to be 120mg/g. The considerable adsorption capability could be further enhanced through a multiple expansion process.

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.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Fatima Zohra Boubekri ◽  
Amal Benkhaled ◽  
Zineb Elbahri

Abstract Novel bio-composite films based on Algerian earth chestnut i.e. Bunium incrassatum roots (Talghouda, TG) and cellulose derivatives (ethylcellulose; EC and cellulose acetate; AC) are prepared and tested for methylene blue (MB) adsorption from aqueous solutions. The biomaterial films are elaborated by dissolution solvent evaporation technique and are characterized by infrared spectroscopy, X-ray diffraction, SEM and optical microscopy. The pHpzc is also determined. For the adsorption tests, design of experiments based on 23 factorial design is built and followed. So, the effects of TG:EC:AC ratio, pH and MB initial concentration are discussed on the basis of mathematical modelling using Minitab software. Mathematical relations between equilibrium adsorption percentages and capacities versus selected variables were obtained and illustrated by surface plots. The interactive effects between variables have been also identified. The results showed that the MB adsorption percentage exceeded 83% and is mostly affected by pH value. Nevertheless the adsorption capacity is affected by MB initial concentration.


2011 ◽  
Vol 233-235 ◽  
pp. 604-607
Author(s):  
Ying Wu ◽  
Bo Zhang ◽  
Mei Liu ◽  
Ying Yun Lin ◽  
Yan Su ◽  
...  

A effective and cheap adsorbent, chitosan modified bentonite was prepared in this work. XRD, SEM and FTIR were used to characterize unmodified and chitosan modified bentonite materials. The adsorption property of bentonite and modified bentonite for mythlene blue in wastewater were investigated by spectrophotometry. The effects of initial pH value, sorbent dosage and contact time on the adsorption capacity have been investigated. The chitoan modified bentonite showed excellent removal capacities for methylene blue from waste water.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1279
Author(s):  
Wafa Mohammed Alghamdi ◽  
Ines El Mannoubi

Natural adsorbents as low-cost materials have been proved efficient for water remediation and have significant capacity for the removal of certain chemicals from wastewater. The present investigation aimed to use Citrullus colocynthis seeds (CCSs) and peels (CCPs) as an efficient natural adsorbent for methylene blue (MB) dye in an aqueous solution. The examined biosorbents were characterized using surface area analyzer (BET), scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and Fourier transform infra-red (FT-IR) spectroscopy. Batch adsorption experiments were conducted to optimize the main factors influencing the biosorption process. The equilibrium data for the adsorption of MB by CCSs were best described by the Langmuir isotherm followed by the Freundlich adsorption isotherms, while the equilibrium data for MB adsorption by CCPs were well fitted by the Langmuir isotherm followed by the Temkin isotherm. Under optimum conditions, the maximum biosorption capacity and removal efficiency were 18.832 mg g−1 and 98.00% for MB-CCSs and 4.480 mg g−1 and 91.43% for MB-CCPs. Kinetic studies revealed that MB adsorption onto CCSs obeys pseudo-first order kinetic model (K1 = 0.0274 min−1), while MB adsorption onto CCPs follows the pseudo-second order kinetic model (K2 = 0.0177 g mg−1 min−1). Thermodynamic studies revealed that the MB biosorption by CCSs was endothermic and a spontaneous process in nature associated with a rise in randomness, but the MB adsorption by CCPs was exothermic and a spontaneous process only at room temperature with a decline in disorder. Based on the obtained results, CCSs and CCPSs can be utilized as efficient, natural biosorbents, and CCSs is promising since it showed the highest removal percentage and adsorption capacity of MB dye.


2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.


2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.


2012 ◽  
Vol 512-515 ◽  
pp. 1980-1985
Author(s):  
Ya Jun Luo ◽  
Xue Li ◽  
Xiao Li Hu ◽  
Deng Liang He ◽  
Peng Lin

SiO2aerogel is prepared under normal conditions by taking tetraethyl orthosilicate (TEOS) as the silica source, N-hexane as the displacer, trimethylchlorosilane hexane as the modifier and hydrolysis environment provided by hydrochloric acid and ammonia water. The effect of pH value, time, temperature, initial concentration on the adsorption of nitrobenzene by aerogel has been studied. The results show that the best range of the pH value for adsorption is 10.72. When adsorption time is 100 min, adsorption equilibrium can be reached. The best temperature for adsorption is 40 °C. The adsorption capacity becomes larger with the concentration increasing of the nitrobenzene solution. When the concentration reaches 500 mg/L, the adsorption reaches 32.402 mg/g. The adsorption equation matches Langmuir model. Scanning Electron Microscopes (SEM), infrared absorption spectrum and specific surface area measurements have shown that the adsorption property of SiO2aerogel for the nitrobenzene is related to cellular structure of the aerogel and large specific surface area.


2011 ◽  
Vol 183-185 ◽  
pp. 873-876
Author(s):  
Jun Jie Yue ◽  
Xing Long Jin ◽  
Zhao Hui Jin

In this paper, the adsorption and decolorization capability of expanded graphite (EG) on the simulated wastewater containing Acid Orange Ⅱwere studied. The experimental results show that the initial concentration of wastewater, the dosage of EG, the pH value and the temperature all have greater effects on the decolorization ratio of simulated Acid Orange Ⅱ wastewater. The dye- wastewater containing lower concentration(<150 mg/L) of Acid Orange Ⅱ is more suitable to be treated by EG, and approximately 100 mg/L is the preferable concentration. The decolorization ratio increases with the increment of the dosage of EG and the temperature level, but the growth rate obviously decreases at the higher initial concentration. All the decolorization ratios under strong acidic (pH<5) and alkalic (pH>11) conditions are higher than that at the range of 5-11 pH values, the highest value even reaches over 94%, while the decolorization ratio under the latter conditions are only between 75% and 85%.


2019 ◽  
Vol 6 (7) ◽  
pp. 190351 ◽  
Author(s):  
Shuangxi Zhou ◽  
Zhiling Du ◽  
Xiuwen Li ◽  
Yunhai Zhang ◽  
Yide He ◽  
...  

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m 2 g −1 , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4–8) and initial concentration of MB (10–50 mg l −1 ), but positively with the dosage of MnO x (1–5 g l −1 ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.


Author(s):  
Nguyen The Manh ◽  
Duong Hong Quan ◽  
Vu Thi Ngoc Minh ◽  
Vuong Pham Hung

Micro/nano urchin-like VO2 particles were synthesized successfully by hydrothermal method. Vanadium pentoxide (V2O5), oxalic acid (C2H2O4) and sodium dodecyl sulfate (SDS) surfactant were used as reagents for the synthesis of VO2. In this article, we have reported the synthesis procedure of VO2 nanorods and micro/nano urchin-like VO2 structure and evaluating the methylene blue (MB) adsorption properties. Morphology and particle size of VO2 were observed by FE-SEM. The phase formation of VO2 was studied by XRD. Raman spectroscopy was also used for characterization of VO2. Micro/nano urchin-like VO2 structure was showed good MB adsorption properties that have potential applications in dye-contaminated water treatments.


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