Deposition Kinetics of Colloidal Manganese Dioxide onto Representative Surfaces in Aquatic Environments: The Role of Humic Acid and Biomacromolecules

2018 ◽  
Vol 53 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Xiaoliu Huangfu ◽  
Chengxue Ma ◽  
Ruixing Huang ◽  
Qiang He ◽  
Caihong Liu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Aquatic Environments ◽  
Deposition Kinetics ◽  
Kinetics Of

Effects of humic acid and surfactants on the aggregation kinetics of manganese dioxide colloids

2015 ◽  
Vol 9 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Xiaoliu Huangfu ◽  
Yaan Wang ◽  
Yongze Liu ◽  
Xixin Lu ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Aggregation Kinetics ◽  
Kinetics Of

scholarly journals PHOTO-REDUCTION KINETICS OF MnO2 IN AQUATIC ENVIRONMENTS CONTAINING HUMIC ACIDS

2010 ◽  
Vol 8 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Narsito Narsito ◽  
Sri Juari Santosa ◽  
Setya Lastuti
Keyword(s):  
Humic Acid ◽  
Aqueous Medium ◽  
Humic Acids ◽  
Radical Scavenger ◽  
Aquatic Environments ◽  
Oh Radicals ◽  
Anion Complex ◽  
Reduction Efficiency ◽  
Internal Electron ◽  
Kinetics Of

The kinetics of photo-reduction of manganese(IV) oxide, MnO2 in aqueous medium, in the presence of humic acid has been investigated, including the possibility for the involvement of such radicals in the reduction. Results showed that in aqueous medium, the efficiency of the photo-reduction of MnO2 producing a soluble ionic Mn(II) was governed strongly by an internal electron transfer within an intermediate of HA-MnO2 anion complex, resulted in the chemical adsorption of humic acid on MnO2 surface. It was observed that under solar radiation and atmosphere containing oxygen, the rate of MnO2 reduction increased considerably, by factors of about 46 and 2 respectively. Moreover, there was evidence that some radicals certainly played a role in the photo-reduction of MnO2, since radical scavenger addition significantly decreased the reduction efficiency of MnO2. In the present of an excess of propanol-2, however, which was expected to remove all OH radicals present, only about 60 % decrease in reduction efficiency were observed, suggesting that radicals other than OH radical are involved in the reduction of MnO2. It was observed further that the presence of iron(III) in MnO2 up to 1 % (w/w) did not alter the reduction efficiency of MnO2.   Keywords: MnO2 kinetics, photo-reduction, aquatic, humic acids

Influence of Electrolytes and Humic Acid on Aggregation Behavior of C60 Nanoparticles in Aquatic System

2013 ◽  
Vol 448-453 ◽  
pp. 48-51
Author(s):  
Hua Fang ◽  
Bing Bing Shen ◽  
Yu Xin Sun ◽  
Yuan Wang ◽  
Ji Lai Lu
Keyword(s):  
Humic Acid ◽  
Colloidal Stability ◽  
Dlvo Theory ◽  
Aquatic Environments ◽  
Aggregation Kinetics ◽  
Time Resolved ◽  
Diffusion Limited ◽  
Wide Range ◽  
Kinetics Of ◽  
And Diffusion

The aggregation kinetics of C60 nanoparticles have been investigated over a wide range of monovalent and divalent electrolyte concentrations by employing time-resolved dynamic light scattering (DLS). The results showed that the presence of electrolyte made a dramatic decrease in the surface zeta potential and increase in the particle size. The aggregation kinetics of C60 nanoparticles exhibited reaction-limited and diffusion-limited regimes, which was found to be consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. The critical coagulation concentration (CCC) values of C60 nanoparticles were estimated as 321mM Na+, 295mM K+, 9.6mM Ca2+and 6.7mM Mg2+, which were far higher than the electrolyte concentrations in natural water. The enhanced C60 stability in the presence of humic acid was attributable to steric repulsion. Therefore C60 nanoparticles can be relatively stable in typical aquatic environments.

The role of humic acid aggregation on the kinetics of photosensitized singlet oxygen production and decay

2011 ◽  
Vol 10 (6) ◽  
pp. 1080 ◽  
Author(s):  
Luciano Carlos ◽  
Brian W. Pedersen ◽  
Peter R. Ogilby ◽  
Daniel O. Mártire
Keyword(s):  
Humic Acid ◽  
Singlet Oxygen ◽  
Oxygen Production ◽  
Kinetics Of
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