Adsorptive removal of cobalt(II) from aqueous solutions using multi-walled carbon nanotubes and γ-alumina as novel adsorbents: Modelling and optimization based on response surface methodology and artificial neural network

2020 ◽  
Vol 299 ◽  
pp. 112154 ◽  
Author(s):  
Mohammad Hadi Dehghani ◽  
Kaan Yetilmezsoy ◽  
Mehdi Salari ◽  
Zoha Heidarinejad ◽  
Mahmood Yousefi ◽  
...  
2019 ◽  
Vol 21 (1) ◽  
pp. 64-69

<p>The aim of this study was to evaluate the mercury removal from aqueous solutions by using L-Cysteine functionalized Multi-walled Carbon Nanotubes. The effect of pH, adsorbent dose, contact time and mercury concentration in removal efficiency was evaluated. Multi -walled carbon nanotubes were functionalized with L-cysteine. The Response Surface Methodology (RSM) was used to find the optimum process parameters. The results showed that an increase in contact time, pH and adsorbent dosage resulted in an increase of the adsorption rate. However, removal efficiency decreases by increasing mercury concentration. The highest and lowest removal efficiencies of mercury were 89% and 17%, respectively. The maximum adsorption rate was occurring at 120 min. It is concluded that L-Cysteine functionalized multi-walled carbon nanotubes is an effective adsorbent for removal from aqueous solutions.</p>


2017 ◽  
Vol 76 (10) ◽  
pp. 2593-2602 ◽  
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Sedighi ◽  
Ehsan Jabbari

Abstract This paper reports a facile method for removal of sulfate from wastewater by magnetic multi-walled carbon nanotubes (MMWCNTs). Multi-walled carbon nanotubes and MMWCNTs were characterized by X-ray diffraction, Raman, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results of the analysis indicated that MMWCNTs were synthesized successfully. The MMWCNTs can be easily manipulated in a magnetic field for the desired separation, leading to the removal of sulfate from wastewater. Response surface methodology (RSM) coupled with central composite design was applied to evaluate the effects of D/C (adsorbent dosage per initial concentration of pollutant (mgadsorbent/(mg/l)initial)) and pH on sulfate removal (%). Using RSM methodology, a quadratic polynomial equation was obtained, for removal of sulfate, by multiple regression analysis. The optimum combination for maximum sulfate removal of 93.28% was pH = 5.96 and D/C = 24.35. The experimental data were evaluated by the Langmuir and Freundlich adsorption models. The adsorption capacity of sulfate in the studied concentration range was 56.94 (mg/g). It was found out that the MMWCNTs could be considered as a promising adsorbent for the removal of sulfate from wastewater.


2019 ◽  
Vol 43 (2) ◽  
pp. 593-600 ◽  
Author(s):  
Hossain-Ali Rafiee-Pour ◽  
Mahboubeh Nejadhosseinian ◽  
Masoumeh Firouzi ◽  
Saeed Masoum

In this study catalase (CAT) immobilization onto magnetic multi-walled carbon nanotubes (mMWCNTs) was undertaken and response surface methodology (RSM) employed to determine the optimum immobilization conditions.


2018 ◽  
Vol 57 ◽  
pp. 396-404 ◽  
Author(s):  
Jalil Jaafari ◽  
Mohammad Ghanbari Ghozikali ◽  
Ali Azari ◽  
Mohammad Bagher Delkhosh ◽  
Allah Bakhsh Javid ◽  
...  

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