A novel catalytic process for degradation of bisphenol A from aqueous solutions: A synergistic effect of nano-Fe 3 O 4 @Alg-Fe on O 3 /H 2 O 2

2016 ◽  
Vol 104 ◽  
pp. 413-421 ◽  
Author(s):  
Mehdi Ahmadi ◽  
Hasan Rahmani ◽  
Afshin Takdastan ◽  
Neemat Jaafarzadeh ◽  
Azar Mostoufi
Author(s):  
Svetlana A. Popova ◽  
Galina G. Matafonova ◽  
Valeriy B. Batoev

In present work, we have studied the kinetic fundamentals of sonophotochemical oxidation of emerging organic contaminants, atrazine and bisphenol A, in model aqueous solutions, simultaneously exposed to high-frequency ultrasound (US, 1.7 MHz) and ultraviolet light-emitting diodes (UV LEDs, 365 nm) in the absence and presence of persulfate (S2O82-) oxidant. Synergistic indices were calculated to assess a synergistic effect in the hybrid oxidation systems. It was found that the hybrid system {UV/US/S2O82-} exhibited the synergistic effect and was the most efficient for degrading bisphenol A in a raw: UV/US/S2O82- > UV/S2O82- > US/UV > US/S2O82- >> UV > US. In case of atrazine, no ultrasound effect was observed and the efficiencies of {UV/US/S2O82-} and {UV S2O82-} systems in terms of degradation rates were similar. In these oxidation systems, more than 90% of a contaminant was removed after 30 min treatment. Meanwhile, degradation rates for atrazine were higher than those wich were found for bisphenol A. This indicates a predomination of sulfate anion radicals, which react with bisphenol A rather slowly compared to atrazine. A synergism was also found under sonophotolysis of both contaminants without persulfate; however, this process requires a more prolonged irradiation time (~20% degraded in 40 min), hence, it is less energy-effective. The obtained results are promising for application of UV LEDs and high-frequency ultrasound in persulfate-based advanced oxidation processes to degrade organic contaminants in natural water and wastewater.


2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1136 ◽  
Author(s):  
Qiang Li ◽  
Fei Pan ◽  
Wentao Li ◽  
Dongya Li ◽  
Haiming Xu ◽  
...  

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.


2014 ◽  
Vol 54 (1) ◽  
pp. (iii)-(iii)
Author(s):  
Mohammad Hadi Dehghani ◽  
Amir Hossein Mahvi ◽  
Noushin Rastkari ◽  
Reza Saeedi ◽  
Shahrokh Nazmara ◽  
...  

1978 ◽  
Vol 56 (23) ◽  
pp. 2922-2926 ◽  
Author(s):  
J. M. Singh ◽  
S. N. Tandon

Cd(HSal)2 is extracted from aqueous solutions into n-butanol, but not into non-hydroxylic solvents (such as benzene and chloroform) at pH 4.5 to 6.0. Addition of N bases, which have no effect alone, causes extraction into the latter solvents, apparently by displacement of coordinated water, giving Cd(HSal)2•2B. This synergistic effect varies with B (β-picoline > pyridine > quinoline). Formation and distribution constants are given for the experimental conditions.


2014 ◽  
Vol 54 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Mohammad Hadi Dehghani ◽  
Amir Hossein Mahvi ◽  
Noushin Rastkari ◽  
Reza Saeedi ◽  
Shahrokh Nazmara ◽  
...  

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