Kinetics of Nitrogen Doped TiO2 for Degradation of Rhodamine B

2011 ◽  
Vol 183-185 ◽  
pp. 2037-2040
Author(s):  
Sheng Min Sun ◽  
Qian Nie
Keyword(s):  
Rhodamine B ◽  
Ph Value ◽  
Urea Solution ◽  
Tetrabutyl Titanate ◽  
Ultrasonic Dispersion ◽  
Doped Tio2 ◽  
Nitrogen Doped ◽  
Degradation Ratio ◽  
Effects Of Ph ◽  
Kinetics Of

Nitrogen doped TiO2 Photocatalysts was prepared by ultrasonic dispersion method based on the predominated materials as tetrabutyl titanate with the dopant of saturated Urea solution. The dynamic behavior of nitrogen doped TiO2 for the degradation of rhodamine B was researched on the catalyst volume and the effects of pH value on photocatalysis ratio. Results showed that the catalytic reaction was accord with the first class reaction dynamic model. When the catalyst was 0.1g and the pH value close to 7, the degradation ratio was the maximum.

Research on Photocatalytic Degradation Kinetics of S-Doped TiO2 to Phenol

2013 ◽  
Vol 676 ◽  
pp. 158-161 ◽  
Author(s):  
Jun Yu ◽  
Min Jie Shan ◽  
Ling Feng Qiu
Keyword(s):  
Ph Value ◽  
Degradation Kinetics ◽  
Synthesis Method ◽  
Phenol Concentration ◽  
Tetrabutyl Titanate ◽  
Solution Ph ◽  
Doped Tio2 ◽  
Optimal Value ◽  
Tio2 Nanomaterials ◽  
Kinetics Of

S-doped TiO2 nanomaterials were prepared via hydrothermal synthesis method using tetrabutyl titanate. Kinetics of S-doped TiO2 catalyzing phenol was researched by analysising the influence of initial phenol concentration, initial phenol pH value on photochemical catalysis speed. The results indicated that the value of K decreased with the rising of phenol concentration. The influence of initial solution pH was exsiting an optimal value. When pH value was 4, photocatalytic rate was maxium, corresponding K was 0.17983 min-1.

scholarly journals Modification to L-H Kinetics Model and Its Application in the Investigation on Photodegradation of Gaseous Benzene by Nitrogen-Doped TiO2

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 326 ◽  
Author(s):  
Peng Sun ◽  
Jun Zhang ◽  
Wenxiu Liu ◽  
Qi Wang ◽  
Wenbin Cao
Keyword(s):  
Adsorption Equilibrium ◽  
Illumination Intensity ◽  
Desorption Process ◽  
Doped Tio2 ◽  
Coverage Ratio ◽  
Nitrogen Doped ◽  
Desorption Equilibrium ◽  
Adsorption Desorption ◽  
Kinetics Of ◽  
Gaseous Benzene

In this paper, the Langmuir-Hinshelwood (L-H) model has been used to investigate the kinetics of photodegradation of gaseous benzene by nitrogen-doped TiO2 (N-TiO2) at 25 °C under visible light irradiation. Experimental results show that the photoreaction coefficient kpm increased from 3.992 × 10−6 mol·kg−1·s−1 to 11.55 × 10−6 mol·kg−1·s−1 along with increasing illumination intensity. However, the adsorption equilibrium constant KL decreased from 1139 to 597 m3·mol−1 when the illumination intensity increased from 36.7 × 104 lx to 75.1 × 104 lx, whereas it was 2761 m3·mol−1 in the absence of light. This is contrary to the fact that KL should be a constant if the temperature was fixed. This phenomenon can be attributed to the breaking of the adsorption-desorption equilibrium by photocatalytically decomposition. To compensate for the disequilibrium of the adsorption-desorption process, photoreaction coefficient kpm was introduced to the expression of KL and the compensation form was denoted as Km. KL is an indicator of the adsorption capacity of TiO2 while Km is only an indicator of the coverage ratio of TiO2 surface. The modified L-H model has been experimentally verified so it is expected to be used to predict the kinetics of the photocatalytic degradation of gaseous benzene.

Effects of pH value and temperature on the initiation, promotion, inhibition and direct reaction rate constants of natural organic matter in ozonation

RSC Advances ◽  
2016 ◽  
Vol 6 (22) ◽  
pp. 18587-18595 ◽  
Author(s):  
Ee Ling Yong ◽  
Yi-Pin Lin
Keyword(s):  
Natural Organic Matter ◽  
Organic Contaminants ◽  
Reaction Rate ◽  
Ph Value ◽  
Direct Reaction ◽  
Reaction Rate Constants ◽  
Effects Of Ph ◽  
Specific Reactions ◽  
Kinetics Of ◽  
Ozonation Process

pH and temperature affect the kinetics of specific reactions of NOM and influence organic contaminants removal in the ozonation process.

Oxidation kinetics of nitrogen doped TiO2−δ thin films

2012 ◽  
Vol 14 (37) ◽  
pp. 12930 ◽  
Author(s):  
Jianmin Shi ◽  
Doh-Kwon Lee ◽  
Han-Ill Yoo ◽  
Jürgen Janek ◽  
Klaus-Dieter Becker
Keyword(s):  
Thin Films ◽  
Oxidation Kinetics ◽  
Doped Tio2 ◽  
Nitrogen Doped ◽  
Kinetics Of

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

DIP quality influenced by process water quality

TAPPI Journal ◽  
2014 ◽  
Vol 13 (9) ◽  
pp. 51-60
Author(s):  
DENNIS VOSS ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL
Keyword(s):  
Water Quality ◽  
Surface Tension ◽  
Ph Value ◽  
Water Hardness ◽  
Process Water ◽  
Test Results ◽  
Negative Effects ◽  
Water Parameters ◽  
Effects Of Ph ◽  
Contamination Levels

The need for deinking mills to reduce their fresh water consumption has resulted in higher loads of various contaminants in the process water. Lower recovered paper quality also leads to higher contamination levels in the mills. This higher load has an influence on achievable target brightness. The objective of the work was to determine and explain the main reasons for relatively poor deinked pulp quality or poor deinking potential based on the influence of recovered paper composition and process water quality. The process water parameters significantly affect the deinking potential of recovered paper. The test results showed the negative effects of increased water hardness. For standard recovered paper mixtures, flotation selectivity is higher with increasing flotation pH-value. Good results were realized for standard recovered paper with low hardness, low surface tension, and high pH-value. The results for recovered paper containing flexo newsprint could be slightly improved with low hardness, low surface tension, and low pH-value. The results of the test program using design of experiments showed interacting effects of pH-value and surface tension on luminosity and flotation selectivity.

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