scholarly journals Effect of Oxidation Agents on Photo-Decolorization of Vitamin B12 in the Presence of ZnO/UV-A System

2018 ◽  
Vol 18 (2) ◽  
pp. 272 ◽  
Author(s):  
Luma Majeed Ahmed ◽  
Shaymaa Ibrahim Saaed ◽  
Ashraff Aziz Marhoon
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Vitamin B12 ◽  
Fenton Reaction ◽  
Maximum Efficiency ◽  
Vitamin B ◽  
Activity Sequence ◽  
The Many ◽  
Oxidation Agent

The aim of this work was to apply the many various oxidation agents namely H2O2, K2S2O8 and Fe2+ on the aqueous solution of vitamin B12 with the presence of ZnO. The results indicated that the use of the mixture of H2O2 and K2S2O8 in suspension of vitamin B12 and ZnO gave a maximum efficiency percentage about 95.85% in 12 min; it was higher than that without the addition of oxidation reagent 79.33% in the same time. The obtained results demonstrated that the activation energy for this photoreaction without the addition of oxidation agent was more than that the apparent activation energy value with the used mixture of H2O2 and K2S2O8. The thermodynamic study showed that both reactions were endothermic, less-random and non-spontaneous. The ΔH# with the oxidant agents (31.43 kJ mol-1) is less than that without using oxidant agents (35.81 kJ mol-1). Moreover, the addition of series of oxidant agent solution to vitamin B12 solution led to change the photocatalytic activity for decolorization of vitamin B12 in suspension solution of ZnO, and was found the activity sequence as follows: (H2O2 + K2S2O8) > (H2O2 + Fe(II)) (Fenton reaction) > (H2O2) > (K2S2O8) > (without the oxidation agents) > (K2S2O8 + Fe(II)) > Fe(II).

Decolorization of Reactive Blue 220 aqueous solution using fungal synthesized Co3O4 nanoparticles

2019 ◽  
Vol 68 (8) ◽  
pp. 675-686 ◽  
Author(s):  
Riya Sidhikku Kandath Valappil ◽  
Ajuy Sundar Vijayanandan ◽  
Raj Mohan Balakrishnan
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Reaction Kinetics ◽  
Uv Light ◽  
Textile Dye ◽  
Co3o4 Nanoparticles ◽  
Alkaline Ph ◽  
Uv Light Irradiation

Abstract In this work, the photocatalytic activity of the biosynthesized cobalt oxide (Co3O4) nanoparticle (NP) is investigated using a textile dye Reactive Blue 220 (RB220) and decolorization % was monitored using UV–Vis spectrophotometer. The photocatalytic activity has been observed maximum at alkaline pH of 9, NP dosage of 250 mg/L, and reaction time of 270 min. In the presence of UV light irradiation, a maximum dye concentration of 10 mg/L was treated effectively using 150 mg/L NP, and 67% decolorization was achieved. Reaction kinetics has been analyzed, and the reaction followed the pseudo kinetics model with an activation energy of −484 kJ mol−1.

Use of Nanopillars-TiO2 Thin Films in the Photocatalytic Degradation of Bromophenol Blue from Aqueous Solution

2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia
Keyword(s):  
Thin Films ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Bromophenol Blue ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.

scholarly journals Molecularly imprinted membrane for transport of urea, creatinine, and vitamin B12 as a hemodialysis candidate membrane

2021 ◽  
Vol 19 (1) ◽  
pp. 806-817
Author(s):  
Muhammad Cholid Djunaidi ◽  
Nabilah Anindita Febriola ◽  
Abdul Haris
Keyword(s):  
Polyethylene Glycol ◽  
Vitamin B12 ◽  
Kidney Function ◽  
Cross Linking ◽  
Vitamin B ◽  
Molecularly Imprinted ◽  
Selective Transport ◽  
Molecularly Imprinted Membrane ◽  
Better Than ◽  
Imprinted Membrane

Abstract High levels of urea and creatinine in the blood are a sign of decreased kidney function. To remove these substances from the blood, hemodialysis which utilizes membranes could be used. In this study, a molecularly imprinted membrane (MIM) was synthesized for the selective transport of urea. The synthesis is initiated with the polymerization of eugenol into polyeugenol and then into polyeugenoxy acetate (PA). The PA is then contacted with urea and then used as the functional polymer in the synthesis of MIM with polysulfone as the membrane base, and polyethylene glycol as the cross-linking agent. The result was later analyzed with FTIR and SEM-EDX. The membrane is then used in the transport of urea, creatinine, and vitamin B12 and then compared with the non-imprinted membrane (NIM) performance. By using UV-Vis spectrophotometry, the results showed that the membrane with 10 h heating variation is able to transport more urea and is more selective than NIM; this proves that the urea template on the MIM enables it to recognize urea molecules better than creatinine and vitamin B12. The order of transport from the best results is urea > creatinine > vitamin B12.

scholarly journals Sulfur-doped CoFe2O4 nanopowders for enhanced visible-light photocatalytic activity and magnetic properties

RSC Advances ◽  
2017 ◽  
Vol 7 (80) ◽  
pp. 50546-50554 ◽  
Author(s):  
Rong Li ◽  
Chencen Sun ◽  
Jia Liu ◽  
Qiang Zhen
Keyword(s):  
Aqueous Solution ◽  
Magnetic Properties ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Photocatalytic Activity ◽  
Magnetic Recovery ◽  
Visible Light Photocatalytic

Magnetic recovery S-CoFe2O4 nanopowders showed excellent visible photocatalytic degradation of oxytetracycline and recycling performances in aqueous solution.

scholarly journals Fabrication of TiO2/Fe2O3/CdS systems: effects of Fe2O3 and CdS content on superior photocatalytic activity

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10300-10308
Author(s):  
Hui Feng ◽  
Siqi Feng ◽  
Niu Tang ◽  
Songbai Zhang ◽  
Xiangyang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Organic Pollutants ◽  
High Performance ◽  
Low Cost

New idea for the low cost synthesis of high performance photocatalysts for the photodegradation of organic pollutants in aqueous solution.

Röntgenspektroskopische Bestimmung der Wertigkeit des Kobalts im Vitamin B12

1954 ◽  
Vol 9 (8) ◽  
pp. 509-513 ◽  
Author(s):  
G. Boehm ◽  
A. Faessler ◽  
G. Rittmayer
Keyword(s):  
Vitamin B12 ◽  
Vitamin B

Mit einem fokussierenden Spektrographen großer Dispersion wird die Lage der K-Röntgen-absorptionskante des Kobalts in verschiedenen Verbindungen untersucht. Die Ergebnisse zeigen, daß es möglich ist, durch Bestimmung der Kantenlage die Wertigkeit des Kobalts in einer Verbindung zu bestimmen. Die Methode gestattet den eindeutigen Nachweis, daß das Kobalt im Vitamin B12 dreiwertig ist.

scholarly journals Exfoliation of graphite into graphene in aqueous solution: an application as graphene/TiO2 nanocomposite to improve visible light photocatalytic activity

RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 93048-93055 ◽  
Author(s):  
R. Giovannetti ◽  
E. Rommozzi ◽  
M. Zannotti ◽  
C. A. D'Amato ◽  
S. Ferraro ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Liquid Phase ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Visible Light Photocatalytic Activity ◽  
Positive Effects ◽  
Graphene Dispersion ◽  
Visible Light Photocatalytic

Graphene dispersion (GR) was prepared by liquid-phase sonication of graphite and evaluated by XRD, DLS and UV-Vis analysis. It was used to prepare PP@mgGR–TiO2, showing positive effects on ARS photodegradation under visible light irradiation.

Facile Preparation of Nanoporous SnO2 for Application in Photodegradation of Methylene Blue

2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
High Photocatalytic Activity ◽  
N2 Adsorption ◽  
Photochemical Method ◽  
Degussa P25 ◽  
Adsorption Desorption

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.

scholarly journals Removal of Chromium from Aqueous Solution Using Modified Pomegranate Peel:Mechanistic and Thermodynamic Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Batch Process ◽  
The Other ◽  
Water Molecules ◽  
Pomegranate Peel ◽  
Solution Interface ◽  
Adsorbent Surface

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .

THE OXIDATION OF NITRITE AND IODATE IONS BY HYPOCHLORITE IONS

1961 ◽  
Vol 39 (8) ◽  
pp. 1645-1651 ◽  
Author(s):  
M. W. Lister ◽  
P. Rosenblum
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Rate Constant ◽  
Hypochlorous Acid ◽  
Slow Stage ◽  
Iodate Ions

The oxidation of nitrite ions and of iodate ions by hypochlorite ions in aqueous solution has been examined. The oxidation of nitrite is really a reaction of hypochlorous acid, with the slow stage HOCl + NO2− + H2O → H3O+ + Cl− + NO3−. The rate constant is given by log k = 7.36−6450/RT (time in minutes, and the activation energy in calories). The oxidation of iodate is chiefly a reaction of hypochlorite ions, probably ClO− + IO3− → Cl− + IO4−, although the rate is somewhat increased by a higher concentration of hydroxide ions. The rate constant is given by log k = 16.15−26,100/RT. These results are compared with other oxidations by hypochlorite ions, to see if any general trends are apparent.

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