scholarly journals Magnetic bentonite nanocomposite for removal of amoxicillin from wastewater samples using response surface methodology before determination by high performance liquid chromatography

2020 ◽  
Vol 3 (03) ◽  
pp. 25-31
Author(s):  
Mohammad Reza Rezaei Kahkha ◽  
Ali Faghihi Zarandi ◽  
Nahid Shafighi ◽  
Saeedeh Kosari ◽  
Batool Rezaei Kahkha

Antibiotics and pharmaceutical products cannot remove by conventional sewage treatment. In this work, an effective adsorbent Magnetic Multiwalled Carbon nanotube (MMWCNTs) was synthesized by co-precipitation of MWCNTs with Fe3O4 and used for removal of Amoxicillin from aqueous solutions. Response surface methodology on Central Composition Design (CCD) was applied for designing of experiments and building of models. Four factors including pH, adsorbent dose, time, and temperature were studied and used for the quadratic equation model to the prediction of optimal points.  By solvent the equation and considering the regression coefficient (R2 =0.99) the optimal points obtained as follows: pH =2.98; adsorbent dosage =2.16 g; time =22 min and temperature = 37.88 o C. Isotherm study of adsorption showed that the adsorption of amoxicillin onto MMWCNTs follows the Langmuir model. The maximum adsorption capacity is 215 mg g-1 obtained from Langmuir isotherm. 

2020 ◽  
Vol 3 (03) ◽  
pp. 44-53
Author(s):  
Mohammad Reza Rezaei Kahkha ◽  
Gholamreza Ebrahimzadeh ◽  
Ahmad Salarifar

Antibiotics and pharmaceutical products cannot remove by conventional sewage treatment. In this work, an effective adsorbent magnetic multiwalled carbon nanotube (Fe3O4@MWCNTs) was synthesized by co-precipitation of MWCNTs with Fe3O4 and used for removal of Metronidazole from aqueous solutions. Response surface methodology on central composition design (CCD) was applied for designing of experiments and building of models for Metronidazole removal before a determination by HPLC. Four factors including pH, the adsorbent dose, time, and temperature were studied and used for the quadratic equation model to the prediction of optimal points.  By solvent the equation and considering the regression coefficient (R2 =0.9997), the optimal points obtained as follows: pH =2.98; adsorbent dosage =2.16 g; time =22 min and temperature = 37.9 o C. The isotherm study of adsorption showed that the metronidazole adsorption on Fe3O4@MWCNTs follows the Langmuir model. The maximum adsorption capacity (AC) is 215 mg g-1 obtained from Langmuir isotherm.


2014 ◽  
Vol 33 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Yuxiang Chen ◽  
Bin Zhang ◽  
Shenghui Guo ◽  
Jinhui Peng ◽  
Lei Guo ◽  
...  

AbstractIn order to obtain the vanadium pentoxide, the process of vanadium pentoxide preparation by calcination from industrial ammonium metavanadate was further investigated. The effects of calcination temperature and calcination time were studied. The conditions of technique to prepare vanadium pentoxide in flakes by calcination from industrial ammonium metavanadate were optimized using a central composite design of response surface methodology. A quadratic equation model for field was built and effects of main factors and their corresponding relationships were obtained. The statistical analysis of the results showed that in the range studied, the rate of weight loss of the industrial ammonium metavanadate was significantly affected by the calcination temperature and calcination time. The results showed that the optimum conditions of ammonium metavanadate calcination were as follows: sample mass 15 g, calcination temperature 900 °C, calcination time 2.4 h, the rate of weight loss 85.1%. In addition, the sample was characterized by XRD and SEM. The SEM analysis and XRD showed the product was layer structure. According to results from analysis of variance, the value of the determination coefficient (R2 = 0.9417) indicates that the model was a good fit that 94.17% of the variation could be explained well by the model.


Author(s):  
Negar Jafari ◽  
Afshin Ebrahimi ◽  
Karim Ebrahimpour ◽  
Ali Abdolahnejad

Introduction: Microcystin-leucine arginine (MC-LR) is a toxin with harmful effects on the liver, kidney, heart, and gastrointestinal tract. So, effective removal of MC-LR from water resources is of great importance. The aim of this study was to remove microcystin-LR (MC-LR) from aqueous solution by Titanium Dioxide (TiO2). Materials and Methods: In the present study, TiO2, as a semiconductor, was used for photodegradation of MC-LR under ultraviolet light (UV). The Response Surface Methodology was applied to investigate the effects of operating variables such as pH (A), contact time (B), and catalyst dose (B) on the removal of MC-LR. The MC-LR concentration was measured by high-performance liquid chromatography (HPLC). Results: The results showed that single variables such as A, B, and C had significant effects on MC-LR removal (pvalue < 0.05). In other words, increase of the contact time and catalyst dose had a positive effect on enhancing the removal efficiency of MC-LR, but the effect of pH was negative. The analysis of variance showed that BC, A2, and C2 variables had a significant effect on the MC-LR removal (pvalue < 0.05). Finally, the maximum removal efficiency of MC-LR was 95.1%, which occurred at pH = 5, contact time = 30 minutes, and catalyst dose = 1 g/l. Conclusion: According to the findings, TiO2, as a photocatalyst, had an appropriate effect on degradation of the MC-LR.


2019 ◽  
Vol 80 (4) ◽  
pp. 685-694 ◽  
Author(s):  
Maryam Dolatabadi ◽  
Saeid Ahmadzadeh

Abstract Presence of emerging contaminants such as pharmaceutical products in aquatic environments has received high concern due to their undesirable effect on wildlife and human health. Current work deals with developing a treatment model based on the electro- Fenton (EF) process for efficient removal of metformin (MET) from an aqueous medium. The obtained experimental results revealed that over the reaction time of 10 min and solution pH of 3, the maximum removal efficiency of 98.57% is achieved where the value of MET initial concentration, current density, and H2O2 dosage is set at 10 mg.L−1, 6 mA.cm−2, and 250 μL.L−1, respectively, which is in satisfactory agreement with the predicted removal efficiency of 98.6% with the desirability of 0.99. The presence of radical scavengers throughout the mineralization of MET under the EF process revealed that the generation of •OH radicals, as the main oxidative species, controlled the degradation mechanism. The obtained kinetics data best fitted to the first order kinetic model with the rate constant of 0.4224 min−1 (R2 = 0.9940). The developed treatment process under response surface methodology (RSM) was employed for modeling the obtained experimental data and successfully applied for efficient removal of the MET contaminant from pharmaceutical wastewater as an adequate and cost-effective approach.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Norazlina Mohamad Yatim ◽  
Azizah Shaaban ◽  
Mohd Fairuz Dimin ◽  
Faridah Yusof ◽  
Jeefferie Abd Razak

Efficient use of urea fertilizer (UF) as important nitrogen (N) source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs) grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and use efficiency (NUE). The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt%) and functionalization reflux time (12–24 hrs) with the corresponding responses (NUE, NU) were structured via the Response Surface Methodology (RSM) based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (pvalue < 0.05) for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.


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