scholarly journals Photocatalytic Degradation of Humic Acids Using LaFeO3

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 630 ◽  
Author(s):  
Nazli Turkten ◽  
Isabella Natali Sora ◽  
Ayse Tomruk ◽  
Miray Bekbolet
Keyword(s):  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Size Fraction ◽  
Molecular Size ◽  
Combustion Method ◽  
Fulvic Acids ◽  
Bet Surface Area ◽  
Size Fractions ◽  
Simulated Solar Light ◽  
Auto Combustion

TiO2 photocatalytic degradation of dissolved organic matter (DOM), namely humic substances composed of humic (HA) and fulvic acids, has been investigated for decades. However, the application of non-TiO2 photocatalysis for this purpose has only received recent attention. Aiming to fill this gap, this study was performed to elucidate the photocatalytic degradation of HAs using the novel photocatalyst LaFeO3 (LF) under simulated solar light irradiation. HA was selectively fractionated by ultrafiltration to two different molecular size fractions representing high molecular fraction as 100 kDa and lower molecular size fraction comprised of humic components expressing size fractions smaller than 30 kDa. Photocatalyst LF was prepared by the citrate auto-combustion method and characterized by using various techniques and Brunauer–Emmett–Teller (BET) surface area. Ultraviolet (UV)-vis and excitation-emission matrix (EEM) fluorescence spectroscopic features were used to characterize the treated HA and photocatalytic mineralization extend was followed by dissolved organic carbon (DOC) contents. Photocatalytic performance of LF was compared to the metal modified version as Cu-doped LF. Highest mineralization was achieved upon the use of a photocatalyst dose of 0.25 mg/mL of LaFe0.90Cu0.10O3−δ (Cu-LF) for 30 kDaHA, whereas lowest mineralization was attained for 100 kDaHA upon the use of LF. Photocatalytic degradation kinetics indicated the possible use of LF and Cu-LF for the degradation of HA.

Photocatalytic Degradation of Direct Blue Dye by BiFeO3 Nanoparticles under Visible Light Irradiation

2017 ◽  
Vol 17 ◽  
pp. 194-201
Author(s):  
Caroline Ponraj ◽  
D. Prabhakaran ◽  
G. Vinitha ◽  
Joseph Daniel
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Combustion Method ◽  
Light Irradiation ◽  
Bet Surface Area ◽  
Blue Dye ◽  
Direct Blue ◽  
Auto Combustion ◽  
Uv Visible

Citric acid assisted auto combustion method was used in the synthesis of BiFeO3 nanoparticles. The synthesized nanoparticles were characterised using X-ray powder diffraction, Scanning electron Microscope, BET surface area analysis, UV-Visible Diffuse Reflectance Spectrometer and Vibratory Sample Magnetometer. The photocatalytic behaviour of the BFO nanoparticles has been studied by the degradation of the direct blue dye. It is observed that BFO shows a good photocatalytic degradation of dye in the visible light irradiation. The effect of pH, catalyst quantity has been studied. The optimum condition is identified as pH 2 and 150mg of the photocatalyst in 10ppm of the dye solution. The magnetic property of BiFeO3at room temperature helps in the efficient removal of them from the treated dye solution. The ability of BiFeO3 nanoparticles to absorb the solar energy and using it for the treatment of water gives it an upper hand over other photo catalysts like Titanium Oxide (TiO2) and Zinc Oxide (ZnO).

PHOTOCATALYTIC DEGRADATION OF PYRENE IN POROUS Pt/TiO2–SiO2 PHOTOCATALYST SUSPENSION UNDER UV IRRADIATION

NANO ◽  
2008 ◽  
Vol 03 (05) ◽  
pp. 317-322 ◽  
Author(s):  
ZHAOHUI LUO ◽  
KEIKO KATAYAMA-HIRAYAMA ◽  
KIMIAKI HIRAYAMA ◽  
TETSUYA AKITSU ◽  
HIDEHIRO KANEKO
Keyword(s):  
Molecular Weight ◽  
Photocatalytic Degradation ◽  
High Molecular Weight ◽  
Uv Irradiation ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Bet Surface Area ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
X Ray

Pyrene is a high molecular weight polycyclic aromatic hydrocarbon (PAH) that is found in water systems worldwide. It is harmful to living organisms, even when taken in very small amounts. The photocatalytic degradation of pyrene in porous Pt / TiO 2– SiO 2 photocatalyst (PPtPC) suspension under UV irradiation was investigated in this study. PPtPC was prepared by a simple heat treatment of the compacted powder mixtures of anatase TiO 2 and amorphous SiO 2 with camphor as a pore directing template, followed by coating platinum by the dip-coating method. X-ray diffraction (XRD), scanning electron microscopy (SEM) with an integrated energy-dispersive analysis of the X-ray (EDX) system, and Brunauer–Emmett–Teller (BET) were used to characterize PPtPC. The degradation kinetics of pyrene in different experimental conditions, such as initial concentration of pyrene, oxygen concentrations, pH, and temperature, were investigated. The durability of PPtPC was also tested. The results indicate that the structure of TiO 2 in PPtPC is anatase. The aggregated size of PPtPC is in the range of 10–100 μm, the mean pore diameter is 3 nm, and the BET surface area is 109 m2 g-1. The photocatalytic degradation process of pyrene follows pseudo-first-order kinetics. The rate constants increase as the initial concentration of pyrene and pH decrease. Higher temperature slightly enhances the rate constant. The dissolved oxygen in the photocatalytic degradation process is not as important as in the photolysis process. The recovered PPtPC still shows high photoactivity. This work suggests that PPtPC offers a promising method for high molecular weight PAH removal.

Evaluation of photocatalytic degradation of a commercial humic acid in water using a simulated solar UV irradiation and monitoring the changes by size exclusion chromatography

2011 ◽  
Vol 11 (6) ◽  
pp. 692-698 ◽  
Author(s):  
S. Valencia ◽  
J. Marín ◽  
G. Restrepo ◽  
F. H. Frimmel
Keyword(s):  
Humic Acid ◽  
Photocatalytic Degradation ◽  
Size Exclusion Chromatography ◽  
Uv Irradiation ◽  
Molecular Size ◽  
Size Exclusion ◽  
Size Fractions ◽  
Preferential Adsorption ◽  
Exclusion Chromatography ◽  
Solar Uv

Much research has been undertaken on the photocatalytic degradation of humic substances with titanium dioxide using commercial humic acids (HA), which are extracts from either peat or coal. Most of the research has been focused on the changes in dissolved organic carbon (DOC) and UV254 absorption. These parameters only give a general assessment. This work studies the changes in the physical and structural properties of a commercial humic acid by size exclusion chromatography with DOC and UV254 absorption detection (SEC-DOC, SEC-UV254), and the evolution of halogenated organic compounds (AOX) and trihalomethanes (THMs) during the photocatalytic degradation with simulated solar UV irradiation and Degussa P-25 TiO2. These changes are compared with those reported for natural organic matter (NOM). The photodegradation of commercial HA and NOM proceeds in a similar and sequential manner, initially with the preferential adsorption of larger molecules, then the degradation of these larger molecular size fractions and proceeding towards smaller molecular size fractions, while decreasing THMs and AOX formation potential.

TiO2-assisted photocatalytic degradation of humic acids: effect of copper ions

2010 ◽  
Vol 61 (10) ◽  
pp. 2581-2590 ◽  
Author(s):  
C. S. Uyguner ◽  
M. Bekbolet
Keyword(s):  
Humic Acid ◽  
Photocatalytic Degradation ◽  
Humic Acids ◽  
Rate Constants ◽  
Copper Ions ◽  
Degradation Kinetics ◽  
Spectral Characteristics ◽  
Molecular Size ◽  
Spectroscopic Techniques ◽  
Concentration Effects

The present study investigated the removal efficiency of aqueous humic acid solutions by TiO2 photocatalytic degradation in the presence of Cu(II) species. The pseudo-first-order kinetics revealed rate constants as 9.87 × 10−3, 7.19 × 10−3, 3.81 × 10−3 min−1 for Color436, UV254 and TOC, respectively. Comparatively, lower rate constants were attained with respect to photocatalytic degradation of humic acid. Considering the source-dependent diverse chemical and spectral characteristics of NOM, a particular interaction would be expected for humic acid with Cu(II) species (0.1 mg L−1). The presence of copper ions significantly altered the photocatalytic degradation kinetics of humic acids in relation to the concentration effects of humic acid as expressed by spectroscopic parameters and TOC. Batch equilibrium adsorption experiments revealed a distinct Langmuirian-type adsorptive behavior of humic acid onto TiO2 both in terms of UV254 and Color436 and a C-type adsorption isotherm was attained for TOC. KF values displayed an inconsistent effect of Cu(II) species, while adsorption intensity factor 1/n<1 denoted a prevailing favorable type of adsorption for Color436 and UV254. Because of the role of intra- and intermolecular interactions between copper ions and humic molecular size fractions, spectroscopic techniques were also employed for the assessment of the adsorption as well as photocatalytic degradation efficiencies.

Study of Photocatalytic Dergradation, Kinetics and Microbial Activities of Copper (ii) Soya Urea Complex in Non Aqueous Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Staphylococcus Aureus ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Waste Water Treatment ◽  
Aqueous Media ◽  
Research Work ◽  
Solvent Polarity ◽  
Urea Complex ◽  
Pseudo First Order Reaction ◽  
Aqueous Solvent

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics and microbial activity of new surfactant Copper (II) soya urea complex(CSU). Background: Photocatalytic degradation has attracted the attention of scientific community throughout the world due to its multiple applications in environment, energy, waste water treatment, pollution control, green chemistry, etc. Copper (II) soya urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Present work deals with the study of photocatalytic degradation of Copper (II) soya urea complex by using ZnO as semiconductor. This study employs a semiconductor catalyst using non polar and non aqueous solvent in photocatalytic degradation. Reaction rate is chosen as the photocatalytic activity, which has been governed by several factors. Antibacterial activities of Copper (II) complex have also been studied against Staphylococcus aureus. Method: Optical density (O.D.) was measured after different time intervals spectrophotometrically to measure the degradation of complex. Mueller-Hinton agar medium was used for antimicrobial activity of synthesized compound at different concentrations by disk/ well diffusion susceptibility testing. Result: Plot of 2+log O.D. (absorbance) versus time was plotted and found linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics.The present study suggests that Copper (II) soya urea (CSU) complex shows antibacterial activity against Staphylococcus aureus at different concentrations. Conclusion: The results were used to determine the rate of photocatalytic degradation of CSU complex .It has been found that rate of degradation varies with different parameters like concentration of complex, amount of catalyst, light intensity, solvent polarity etc. CSU complex derived from soyabean oil has been shown an inhibitory effect on the growth of S. aureus which may causes skin disease.

Photocatalytic Degradation and Antibacterial Study of Copper(II) Mustard Thiourea Complex

2020 ◽  
Vol 10 (3) ◽  
pp. 229-242
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Photocatalytic Degradation ◽  
Skin Diseases ◽  
Polar Solvent ◽  
Degradation Kinetics ◽  
Research Work ◽  
Solvent Polarity ◽  
Inhibitory Effect ◽  
Mustard Oil ◽  
Urea Complex ◽  
Pseudo First Order Reaction

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics. Background: Copper(II) mustard thio urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Photocatalytic degradation of copper(II) mustard thio urea complex was studied in the presence of ZnO as a catalyst in the solution form, using a non polar solvent benzene and a polar solvent methanol with different compositions. Antibacterial activities of copper(II) complex have also been studied against Staphylococcus aureus. Method: O.D. was measured after different time intervals spectrophotometrically to measure the degradation of the complex. Result: Plot of 2+ log O.D. (absorbance) versus time was plotted and found to be linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics. The present study suggests that the CMT complex shows antibacterial activity at different concentrations. Conclusion: The rate of photocatalytic degradation of CMT complex was studied and analyzed. It has been found that the rate of degradation varies with different parameters like the concentration of complex, the amount of catalyst, light intensity, solvent polarity etc. The CMT complex derived from natural mustard oil has shown an inhibitory effect on the growth of S. aureus which may cause skin diseases.

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