Kinetic studies on visible light-assisted degradation of acid red 88 in presence of metal-ion coupled oxone reagent

2008 ◽  
Vol 83 (1-2) ◽  
pp. 8-14 ◽  
Author(s):  
J. Madhavan ◽  
P. Maruthamuthu ◽  
S. Murugesan ◽  
S. Anandan
Keyword(s):  
Visible Light ◽  
Metal Ion ◽  
Kinetic Studies

Efficient Preconcentration of Cu2+, Zn2+ and Fe3+ with an Agarose-Schiff Base Sorbent

2007 ◽  
Vol 72 (7) ◽  
pp. 908-916 ◽  
Author(s):  
Payman Hashemi ◽  
Hatam Hassanvand ◽  
Hossain Naeimi
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Metal Ion ◽  
Good Accuracy ◽  
Kinetic Studies ◽  
Sample Volume ◽  
Effects Of Ph ◽  
Glass Column ◽  
High Concentrations ◽  
Ph Range

Sorption and preconcentration of Cu2+, Zn2+ and Fe3+ on a salen-type Schiff base, 2,2'- [ethane-1,2-diylbis(nitrilomethylidyne)]bis(2-methylphenol), chemically immobilized on a highly crosslinked agarose support, were studied. Kinetic studies showed higher sorption rates of Cu2+ and Fe3+ in comparison with Zn2+. Half-times (t1/2) of 31, 106 and 58 s were obtained for sorption of Cu2+, Zn2+ and Fe3+ by the sorbent, respectively. Effects of pH, eluent concentration and volume, ionic strength, buffer concentration, sample volume and interferences on the recovery of the metal ions were investigated. A 5-ml portion of 0.4 M HCl solution was sufficient for quantitative elution of the metal ions from 0.5 ml of the sorbent packed in a 6.5 mm i.d. glass column. Quantitative recoveries were obtained in a pH range 5.5-6.5 for all the analytes. The volumes to be concentrated exceeding 500 ml, ionic strengths as high as 0.5 mol l-1, and acetate buffer concentrations up to 0.3 mol l-1 for Zn2+ and 0.4 mol l-1 for Cu2+ and Fe3+ did not have any significant effect on the recoveries. The system tolerated relatively high concentrations of diverse ions. Preconcentration factors up to 100 and detection limits of 0.31, 0.16 and 1.73 μg l-1 were obtained for Cu2+, Zn2+ and Fe3+, respectively, for their determination by a flame AAS instrument. The method was successfully applied to the metal ion determinations in several river water samples with good accuracy.

scholarly journals A Study on the Photocatalytic Reduction of Some Metal Ions in Aqueous Solution Using UV- Titanium Dioxide System

2019 ◽  
pp. 1-7
Author(s):  
I. O. Ekwere ◽  
M. Horsfall ◽  
J. O. E. Otaigbe
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Metal Ions ◽  
Metal Ion ◽  
Uv Light ◽  
Kinetic Studies ◽  
Photocatalytic Reduction ◽  
Alkaline Ph ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Therefore, the results of this study will be useful in metal ion removal from industrial waste water using photocatalytic process.

scholarly journals Effective removal of heavy metal ions from aqueous solutions using a new chelating resin poly [2,5-(1,3,4-thiadiazole)-benzalimine]: kinetic and thermodynamic study

2015 ◽  
Vol 6 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Selvaraj Dinesh Kirupha ◽  
Selvaraj Kalaivani ◽  
Thangaraj Vidhyadevi ◽  
Periyaraman Premkumar ◽  
Palanithamy Baskaralingam ◽  
...  
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Ph Value ◽  
Thermo Gravimetric Analysis ◽  
Kinetic Studies ◽  
Ion Concentration ◽  
Chelating Resin ◽  
Gravimetric Analysis ◽  
Equilibrium Data ◽  
Experimental Values

A novel poly [2,5-(1,3,4-thiadiazole)-benzalimine] abbreviated as TDPI adsorbent was synthesized using simple polycondensation technique. The synthetic route involves the preparation of 2,5-diamino-1,3,4-thiadiazole from 2,5-dithiourea and subsequent condensation with terephthalaldehyde. The resin was chemically characterized using Fourier transform infrared (FT-IR), 1H-NMR, and 13C-NMR spectroscopic analysis. Surface morphology and thermal stability were analyzed using scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The effect of the pH value of solution, contact time, adsorbent dose, and initial metal ion concentration were investigated by batch equilibrium adsorption experiments. Kinetic studies show that the adsorption of metal ions onto the resin proceeds according to the pseudo-second-order model and the equilibrium data were best interpreted by the Redlich–Peterson isotherm. The experimental values of the adsorption capacities of Pb2+, Cu2+, Ni2+, and Cd2+ on to TDPI could reach up to 437.2, 491.6, 493.7, and 481.9 mg.g−1 respectively. The exothermic nature of the process, the affinity of the adsorbent towards the metal ions and the feasibility of the process are explained in the thermodynamic parameters. The resin stability and re-usability studies suggest that the resin is chemically stable (0.3 N HCl and H2SO4) and could be regenerated without any serious decline in performance.

Photocatalytic Activities of Noble Metal Ion Doped SrTiO3under Visible Light Irradiation

2004 ◽  
Vol 108 (26) ◽  
pp. 8992-8995 ◽  
Author(s):  
Ryoko Konta ◽  
Tatsuya Ishii ◽  
Hideki Kato ◽  
Akihiko Kudo
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Visible Light Irradiation ◽  
Metal Ion ◽  
Light Irradiation ◽  
Photocatalytic Activities

scholarly journals Perovskite-type LaFeO3: Photoelectrochemical Properties and Photocatalytic Degradation of Organic Pollutants Under Visible Light Irradiation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 342 ◽  
Author(s):  
Mohammed Ismael ◽  
Michael Wark
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Irradiation ◽  
Complexing Agent ◽  
X Ray ◽  
Perovskite Type

Perovskite-type oxides lanthanum ferrite (LaFeO3) photocatalysts were successfully prepared by a facile and cost-effective sol-gel method using La(NO)3 and Fe(NO)3 as metal ion precursors and citric acid as a complexing agent at different calcination temperatures. The properties of the resulting LaFeO3 samples were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDXS), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (IR), transmission electron microscopy (TEM), N2 adsorption/desorption and photoelectrochemical tests. The photoactivity of the LaFeO3 samples was tested by monitoring the photocatalytic degradation of Rhodamine B (RhB) and 4-chlorophenol (4-CP) under visible light irradiation, the highest photocatalytic activity was found for LaFeO3 calcined at 700 °C, which attributed to the relatively highest surface area (10.6 m2/g). In addition, it was found from trapping experiments that the reactive species for degradation were superoxide radical ions (O2−) and holes (h+). Photocurrent measurements and electrochemical impedance spectroscopy (EIS) proved the higher photo-induced charge carrier transfer and separation efficiency of the LaFeO3 sample calcined at 700 °C compared to that that calcined at 900 °C. Band positions of LaFeO3 were estimated using the Mott-Schottky plots, which showed that H2 evolution was not likely.

scholarly journals A modified ionic liquid clay to remove heavy metals from water: investigating its catalytic activity

2019 ◽  
Vol 17 (4) ◽  
pp. 2043-2058
Author(s):  
S. Kakaei ◽  
E. S. Khameneh ◽  
M. H. Hosseini ◽  
M. M. Moharreri
Keyword(s):  
Heavy Metal ◽  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Kinetic Studies ◽  
Heavy Metal Ion ◽  
Ambient Conditions ◽  
X Ray ◽  
Metal Ion Adsorption ◽  
Map Analysis

Abstract The new clay modified with triazole and triazolium ligands was prepared in this research. These materials were applied as abundant and eco-friendly adsorbents for removal of heavy metal ions such as Pb(II), Co(II) and Zn(II) ions. The adsorption efficiency of these materials was calculated by relevant equations such as Langmuir and Freundlich as well as kinetic studies with pseudo-first-order and pseudo-second-order models. These adsorbents proved to be very active on heavy metal ion adsorption. The characterization of these new materials was carried out by various techniques such as X-ray diffraction, thermogravimetric analysis, scanning electron microscope (SEM), X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy as well as SEM-map analysis. Eventually, the catalytic activity of the adsorbents which treated with heavy metal ion solutions was studied in the reduction of nitroarenes to its corresponding amines. The prepared adsorbent–catalyst materials indicated efficient catalytic activity in the reduction of nitroarenes to amines in ambient conditions. Graphic abstract

Kinetic studies on visible-light-switchable photochromic fluorophores based on diarylethenes

2011 ◽  
Vol 10 (9) ◽  
pp. 1488 ◽  
Author(s):  
Britta Seefeldt ◽  
Kai Altenhöner ◽  
Oliver Tosic ◽  
Thomas Geisler ◽  
Markus Sauer ◽  
...  
Keyword(s):  
Visible Light ◽  
Kinetic Studies
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