scholarly journals Adsorption of Toluene and Paraxylene from Aqueous Solution Using Pure and Iron Oxide Impregnated Carbon Nanotubes: Kinetics and Isotherms Study

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Aamir Abbas ◽  
Basim Ahmed Abussaud ◽  
Ihsanullah ◽  
Nadhir A. H. Al-Baghli ◽  
Halim Hamid Redhwi

Multiwall carbon nanotubes (CNTs) and iron oxide impregnated carbon nanotubes (CNTs-iron oxide) were investigated for the adsorption of hazardous toluene and paraxylene (p-xylene) from aqueous solution. Pure CNTs were impregnated with iron oxides nanoparticles using wet impregnation technique. Various characterization techniques including thermogravimetric analysis, scanning electron microscopy, elemental dispersion spectroscopy, X-ray diffraction, and nitrogen adsorption analysis were used to study the thermal degradation, surface morphology, purity, and surface area of the materials. Batch adsorption experiments show that iron oxide impregnated CNTs have higher degree of removal of p-xylene (i.e., 90%) compared with toluene (i.e., 70%), for soaking time 2 h, with pollutant initial concentration 100 ppm, at pH 6 and shaking speed of 200 rpm at 25°C. Pseudo-second-order model provides better fitting for the toluene and p-xylene adsorption. Langmuir and Freundlich isotherm models demonstrate good fitting for the adsorption data of toluene and p-xylene.

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Muhammad I. Qureshi ◽  
Faheemuddin Patel ◽  
Nadhir Al-Baghli ◽  
Basim Abussaud ◽  
Bassam S. Tawabini ◽  
...  

The present study reports the use of raw, iron oxide, and aluminum oxide impregnated carbon nanotubes (CNTs) for the adsorption of hexavalent chromium (Cr(VI)) ions from aqueous solution. The raw CNTs were impregnated with 1% and 10% loadings (weight %) of iron oxide and aluminum oxide nanoparticles using wet impregnation technique. The synthesized materials were characterized using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Batch adsorption experiments were performed to assess the removal efficiency of Cr(VI) ions from water and the effects of pH, contact time, adsorbent dosage, and initial concentration of the Cr(VI) ions were investigated. Results of the study revealed that impregnated CNTs achieved significant increase in the removal efficiency of Cr(VI) ions compared to raw CNTs. In fact, both CNTs impregnated with 10% loading of iron and aluminum oxides were able to remove up to 100% of Cr(VI) ions from aqueous solution. Isotherm studies were carried out using Langmuir and Freundlich isotherm models. Adsorption kinetics of Cr(VI) ions from water was found to be well described by the pseudo-second-order model. The results suggest that metallic oxide impregnated CNTs have very good potential application in the removal of Cr(VI) ions from water resulting in better environmental protection.


2020 ◽  
Vol 10 (1) ◽  
pp. 22-32
Author(s):  
Abdoulaye Demba N'diaye ◽  
Youcef Aoulad El Hadj Ali ◽  
Mohamed Abdallahi Bollahi ◽  
Mostafa Stitou ◽  
Mohamed Kankou ◽  
...  

In this work, batch adsorption experiments were carried out for the removal of Methylene Blue (MB) from aqueous solutions using Typha australis leaf as a low cost adsorbent. The effects of some variables governing the efficiency of the process such as adsorbent mass, pH, ionic strength, contact time and temperature were investigated. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. The experimental equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The results show that the PSO model is the best for describing the adsorption of MB by Typha australis for all initial MB concentrations. The equilibrium data fitted well with the Langmuir model with the monolayer adsorption capacity for MB-Typha australis leaf system was of 103.12 mg g-1. The values of activation parameters such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were also determined as - 4.44 kJ mol−1, 55.13 kJ mol−1 and 203.21 J mol−1 K−1, respectively. The thermodynamics parameters of MB-Typha australis system indicate spontaneous and endothermic process. These results indicate that the Typha australis leaf can be feasibly employed for the eradication of MB from aqueous solution.


2018 ◽  
Vol 73 (2) ◽  
pp. 113-120 ◽  
Author(s):  
M. R. Elamin ◽  
Babiker Y. Abdulkhair ◽  
Kamal K. Taha

AbstractCoiled multiwall carbon nanotubes (MWCNTs) were prepared on Fe, Co, and Ni metal oxides supported on α-Al2O3 using urea as fuel and catalyst surface modifying agent by catalytic chemical vapour deposition (CCVD). The shape of the nanotubes was influenced by the addition of urea, where coiled and uncoiled tubes were obtained in the presence and absence of urea, respectively. The MWCNTs were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nitrogen adsorption analysis. The coiling/uncoiling of the nanotubes was visualized from the SEM and TEM images of the prepared specimens. The XRD data showed the characteristic peaks of the nanotubes. BET analysis of the coiled tubes revealed 85.57 m2 g−1 surface area with a pore diameter 102.2–110.8 Å. A mechanism for the nanotubes coiling is suggested.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Gamal Owes El-Sayed ◽  
Talaat Younis Mohammed ◽  
Ashraf Abd-Allah Salama

Sugarcane stalks powder was tested for its efficiency of removing a textile dye Maxilon Red GRL from aqueous solution. Different parameters affecting dye removal efficiency were studied. These parameters include contact time, initial dye concentration, adsorbent dose, ionic strength, pH, and temperature. Langmuir and Freundlich isotherm models were applied to the equilibrium data. The data fitted well with the Langmuir isotherm (). The maximum monolayer adsorption capacity () was found to be 20.96 mg/g at an initial pH of 7.2. The temperature variation study showed that dye adsorption is exothermic and spontaneous with increased randomness at the solid solution interface. The results indicated that sugarcane stalks could be an alternative for more costly adsorbents used for dye removal. The kinetic of the adsorption process followed the pseudo second-order kinetics model.


2019 ◽  
Vol 79 (11) ◽  
pp. 2175-2184 ◽  
Author(s):  
Dan Liu ◽  
Zhanbin Huang ◽  
Shuhui Men ◽  
Zhen Huang ◽  
Chunrong Wang

Abstract The aim of this study was to reveal the mechanism of nitrogen and phosphorus adsorption by humic acids (HAs). HAs were extracted from weathered coal and used as adsorbents of urea-N and phosphate-P in water. The effect of different factors was considered, such as the initial concentration of urea-N and phosphate-P, temperature, and pH. The surface characteristics of the HAs were analyzed by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectrometry. The results of batch adsorption experiments showed high effectiveness for nitrogen adsorption, the kinetics fitted with the pseudo-second-order model, and the isotherm followed the Langmuir model. For phosphorus adsorption, the data fitted well with the Weber and Morris model and the adsorption isotherms followed both the Langmuir and Freundlich isotherm models. The experimental results indicated that the adsorption behavior of HAs was both an endothermic and spontaneous process. These findings can be used as a reference for the mitigation of non-point source pollution and the application of fertilizer in agriculture.


2017 ◽  
Vol 889 ◽  
pp. 221-225
Author(s):  
Nur Aqilah Zainal ◽  
Shariff Ibrahim ◽  
Borhannuddin Arifin

Cocoa pod husk, an agricultural waste was chemically modified using Zinc Chloride (ZnCl2) and used as an adsorbent for removal of acid dyes; (i) Acid Violet 17 (AV17) and (ii) Acid Yellow 36 (AY36) from aqueous solution. The raw (CPHC) and chemically modified cocoa pod husk carbon (ZCPHC) were characterized by Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (EDX). The adsorption was performed on removing AV17 and AY36 from aqueous solution in batch adsorption system. The experimental data was simulated using Langmuir and Freundlich isotherm models. The isotherm study revealed that the AV17 adsorption on ZCPHC matched well with the Langmuir model, whereas AY36 adsorption on ZCPHC fitted well with Freundlich model. The maximum adsorption capacity determined from the Langmuir isotherm was 11.02 mg/g and 11.37 mg/g for AV17 and AY36 respectively at room temperature.


2011 ◽  
Vol 8 (2) ◽  
pp. 649-656 ◽  
Author(s):  
R. Jayaraj ◽  
M. Chandra Mohan ◽  
P. Martin Deva Prasath ◽  
T. Hidhayathullah Khan

Malachite green adsorption from an aqueous solution onto activatedEnteromorphacarbon has been studied experimentally using batch adsorption method. Adsorption kinetics and equilibrium were investigated as a function of initial dye concentration, pH, contact time and adsorbent dosage. Kinetics studies indicated that the adsorption followed pseudo second order reaction. Equilibrium data was analyzed using Langmuir and Freundlich isotherm models. The adsorption capacity ofEnteromorphawas found to be 94.74%. On the basis of experimental results and the model parameters, it can be inferred that the carbonaceousEnteromorphais effective for the removal of malachite green from aqueous solution.


Author(s):  
L. Salami ◽  
D. O. Olumuyiwa ◽  
E. A. Alfred ◽  
O. S. Olakanmi

Dumpsite leachate has the potential to pollute ground and surface water as well as vegetation within the vicinity of the dumpsite.  Its treatment therefore needs adequate attention. The aim of this work is to study the adsorption of Soluos dumpsite leachate treatment using Musa sapientum peel as biosorbent with a view of establishing the adsorption isotherm model. Musa sapientum peels sourced from Ayetoro market in Epe area of Lagos State, Nigeria were used to prepare the adsorbent. Batch adsorption was carried out with various dosage of the prepared absorbent in leachate collected from Soluos dumpsite in Lagos. The adsorption data obtained were fitted into Linear, Freundlich, Langmuir, Temkin and Hasley isotherm models. The results showed that the concentration of total dissolved solids (TDS) in the dumpsite leachate decreased as the adsorbent dosage increased. At adsorbent dosage of 10 g/L, the concentration of TDS in the leachate was 485.7 mg/L which was less than the 500 mg/L stipulated by National Environmental Standard and Regulatory Agency (NAESRA) for the discharge of wastewater. The coefficient of determination (R2) values for Linear, Freundlich and Hasley, Langmuir and Temkin isotherm models were 0.9944, 0.9936, 0.8562 and 0.9723 respectively. Linear isotherm model was jettisoned because the plot did not pass through the origin and Freundlich isotherm model was ignored as a result of N value which was less than unity hence Hasley isotherm model was adopted in this work. A good correlation existed between the experimental and predicted values, having a R2 value of 0.9965 which further validated the Hasley isotherm model as the best adsorption model for the treatment of Soluos dumpsite leachate using Musa sapientum peel as biosorbent. It was concluded that Musa sapientum peel as biosorbent can be used for treatment of Soluos dumpsite leachate.


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