Modelling of Chlorophenol Treatment in Aqueous Solutions. 1. Ozonation and Ozonation Combined with UV Radiation under Acidic Conditions

1998 ◽  
Vol 20 (4) ◽  
pp. 259-282 ◽  
Author(s):  
Marjaana Hautaniemi ◽  
Juha Kallas ◽  
Rein Munter ◽  
Marina Trapido
Keyword(s):  
Aqueous Solutions ◽  
Uv Radiation ◽  
Acidic Conditions

Removal of Dyes from Aqueous Solutions by Adsorption on Chrome-Tanned Solid Wastes Generated in the Leather Industry

2003 ◽  
Vol 38 (2) ◽  
pp. 393-411 ◽  
Author(s):  
Soufiane Tahiri ◽  
Ali Messaoudi ◽  
Abderrahman Albizane ◽  
Mohamed Azzi ◽  
Mohamed Bouhria ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Operating Conditions ◽  
Solid Wastes ◽  
Cationic Dyes ◽  
Optimum Operating ◽  
Leather Industry ◽  
Anionic Dyes ◽  
Ph Values ◽  
Acidic Conditions ◽  
Dyes Adsorption

Abstract In this work, the ability of chrome shavings and of crust leather buffing dusts to remove dyes from aqueous solutions has been studied. Buffing dusts proved to be a much better adsorbent than chrome shavings for cationic dyes. The adsorption of anionic dyes is very important on two studied wastes. The pH has an obvious influence on the adsorption of dyes. Adsorption of cationic dyes is less favourable under acidic conditions (pH <3.5) and at high pH values (pH >10.5). The adsorption of anionic dyes on both adsorbents is more favourable under acidic conditions (pH <3). The adsorption on chrome shavings is improved by the use of finer particles. The kinetic adsorption was also studied. Adsorption isotherms, at the optimum operating conditions, were determined. Adsorption follows the Langmuir model. The isotherm parameters have been calculated. The column technique could be applied to treat significant volumes of solutions.

scholarly journals Photocatalytic degradation of alachlor by TiO2 nanoparticles from aqueous solutions under UV radiation

2019 ◽  
Vol 14 (1) ◽  
pp. 116-128
Author(s):  
Fatemeh Jamshidi ◽  
Mansooreh Dehghani ◽  
Saeed Yousefinejad ◽  
Aboolfazl Azhdarpoor
Keyword(s):  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Uv Radiation

Degradation of the Pesticide Chlorpyrifos in Aqueous Solutions with UV/H2O2: Optimization and Effect of Interfering Anions

2014 ◽  
Vol 17 (1) ◽  
Author(s):  
André Gadelha de Oliveira ◽  
Jefferson Pereira Ribeiro ◽  
Juliene Tome de Oliveira ◽  
Denis De Keukeleire ◽  
Maíra Saldanha Duarte ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Uv Radiation ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Inorganic Anions ◽  
Pesticide Concentration ◽  
Effects Of Temperature

AbstractThis study investigates the use of an advanced oxidation process (AOP) for removal of the pesticide chlorpyrifos in a recirculated system, especially considering the effects of temperature, hydrogen peroxide dosage, pH, pesticide concentration and added inorganic anions. The results indicate that a temperature of 45 °C gave the best performance using only UV-radiation, while for the UV/H

Chemical effects of UV radiation on aqueous solutions of heparin-Ca salt

1985 ◽  
Vol 6 (6) ◽  
pp. 465-474
Author(s):  
Khurshid A. Khan ◽  
Riaz Farooq ◽  
Mohammad N. Iqbal
Keyword(s):  
Aqueous Solutions ◽  
Uv Radiation ◽  
Chemical Effects

scholarly journals Iron sulfur clusters in protein nanocages for photocatalytic hydrogen generation in acidic aqueous solutions

2019 ◽  
Vol 10 (7) ◽  
pp. 2179-2185 ◽  
Author(s):  
Weijian Chen ◽  
Shuyi Li ◽  
Xiao Li ◽  
Chi Zhang ◽  
Xiantao Hu ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hydrogen Generation ◽  
Huge Amount ◽  
Iron Sulfur Clusters ◽  
Photocatalytic Hydrogen Generation ◽  
Iron Sulfur ◽  
Acidic Conditions

Apoferritin caged a huge amount of photocatalysts and enhanced H2 generation capability under homogeneous acidic conditions.

scholarly journals Evaluate the effectiveness of the UV/ persulfate process to remove catechol from solution aqueous

2021 ◽  
Keyword(s):  
Data Analysis ◽  
Aqueous Solutions ◽  
Uv Radiation ◽  
Removal Efficiency ◽  
Design Of Experiment ◽  
Contact Time ◽  
Batch Reactor ◽  
Acidic Ph ◽  
Optimum Conditions ◽  
Optimum Ph

<p>Catechol is used as an antioxidant, fungicide, and polymerization inhibitors in a variety of industries such as petrochemical. Catechol must be removed from effluents before it enters to environment. This study aimed to investigate combined UV radiation and persulfate process in removal of catechol from aqueous solutions. All experiments were performed in a batch reactor. Data analysis were done with Design of Experiment (DoE) software. The effects of various variables such as pH, initial persulfate concentration, and initial Catechol concentration were investigated. The findings indicated with increases in persulfate concentration and decrease in catechol concentrations, the removal efficiency increased. Acidic pH and UV radiation were the leading factors in removal of catechol. The optimum pH, persulfate concentration, and catechol concentration were obtained 7, 0.04 M, and 100 mg l-1, respectively. More removes of catechol was achieved in optimum conditions within contact time of 60 min. The synergic effects of UV and persulfate radical were about 88%. Approximately 60% of catechol was mineralized within contact time of 60 min. Persulfate radicals resulting from UV/S2O82- were the main effective oxidants in removal and mineralization of catechol. Owing to high removal efficiency of persulfate compounds which are, also, abundant and inexpensive, these can be applied in removal of persistent organic pollutants from aqueous solutions.</p>

UV Protection of Bacteria Under Simulated Martian Conditions

2020 ◽  
Author(s):  
Paul Godin ◽  
Andrew Schuerger ◽  
Casey Moore ◽  
John Moores
Keyword(s):  
Uv Radiation ◽  
Light Transmission ◽  
Uv Protection ◽  
Genus Bacillus ◽  
Short Term ◽  
Planetary Protection ◽  
Microbial Life ◽  
Acidic Conditions ◽  
Acidic Environments ◽  
Martian Regolith

&lt;p&gt;Ultraviolet (UV) irradiation on the surface of Mars is an important factor a&amp;#64256;ecting the survivability of microorganisms on Mars. The possibility of Martian brines made from Fe&lt;sub&gt;2&lt;/sub&gt;(SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;, MnSO&lt;sub&gt;4&lt;/sub&gt;, and MgSO&lt;sub&gt;4&lt;/sub&gt; salts providing a habitable niche on Mars via attenuation of UV radiation was investigated on the bacteria Bacillus subtilis and Enterococcus faecalis. Results demonstrated that it is possible for brines containing Fe&lt;sub&gt;2&lt;/sub&gt;(SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3 &lt;/sub&gt;on Mars to provide protection from harmful UV radiation, even at concentrations as low as 0.5%. Brines made from MnSO&lt;sub&gt;4&lt;/sub&gt; and MgSO&lt;sub&gt;4&lt;/sub&gt;, did not provide significant UV protection and most spores/cells died over the course of short-term experiments.&lt;/p&gt; &lt;p&gt;However, Fe&lt;sub&gt;2&lt;/sub&gt;(SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3 &lt;/sub&gt;brines are strongly acidic, and thus, were lethal to E. faecalis. In contrast, B. subtilis, as a spore-forming bacterium resistant to pH extremes, was una&amp;#64256;ected by the acidic conditions of the brines and did not experience any significant lethal e&amp;#64256;ects. Any extant microbial life in Martian Fe&lt;sub&gt;2&lt;/sub&gt;(SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3 &lt;/sub&gt;brines (if present) would need to be capable of surviving acidic environments, if these brines are to be considered a possible habitable niche.&lt;/p&gt; &lt;p&gt;The results from this work are important to both the search for life on planets with an atmosphere unable to significantly attenuate UV radiation (i.e., like Mars); and for planetary protection, since it is possible that terrestrial bacteria in the genus Bacillus are likely to survive in Fe-sulfate brines on Mars.&lt;/p&gt; &lt;p&gt;Furthermore, preliminary work on UV and photosynthetically active radiation (PAR) light transmission and scattering through simulated Martian regolith and rock samples are also presented. Regoliths that block UV but allow for PAR would be likely candidates for supporting bacterial life.&lt;/p&gt;

Photocatalytic Degradation of Reactive Green KE-4BD in Aqueous Solutions over N-Doped Titania

2011 ◽  
Vol 183-185 ◽  
pp. 1767-1771
Author(s):  
Gang Xin ◽  
Ju Shen ◽  
Ya Li Meng
Keyword(s):  
Aqueous Solutions ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
Inorganic Substances ◽  
Acidic Conditions ◽  
Uv Visible ◽  
Doped Titania

The photodegradation of reactive green KE-4BD solution is investigated using N-doped titania (N-TiO2) under visible light irradiation. N-TiO2 is prepared using ammonia or urea as a nitrogen source and characterized by X-ray diffraction, Brunauer-Emmett-Teller methods, and UV-visible diffuse reflectance spectra. The effects of the initial dye concentration and pH on photocatalytic degradation are studied, and the direct correlation between pH, dye concentration, and the rate of degradation are determined. Experimental results show that aqueous solutions of KE-4BD degrade easily in weakly acidic conditions in the presence of N-doped TiO2 (1 g/L) as a photocatalyst. The optimized dye concentration for photolysis is 150 mg/L. The complete degradation of KE-4BD could be achieved under visible light irradiation, and the dye molecules could be partly decomposed into inorganic substances.

Chemical effects of UV radiation on aqueous solutions of chondroitin-6-sulphate

1984 ◽  
Vol 4 (5) ◽  
pp. 385-392 ◽  
Author(s):  
Khurshid A. Khan ◽  
Mohammad N. Iqbal
Keyword(s):  
Aqueous Solutions ◽  
Uv Radiation ◽  
Chemical Effects
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