Photoproduction of Hydroxyl Radicals in Aqueous Solution with Algae under High-Pressure Mercury Lamp

2004 ◽  
Vol 38 (1) ◽  
pp. 296-299 ◽  
Author(s):  
Xianli Liu ◽  
Feng Wu ◽  
Nansheng Deng
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Hydroxyl Radicals ◽  
Mercury Lamp

Ultraviolet irradiation combined with manganese ore catalyzed ozonation of 4-chlorophenol in aqueous solution

2010 ◽  
Vol 10 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Jie Fu ◽  
Guo Chen ◽  
Ying Yang ◽  
Zhi-Ming Zhang ◽  
Qing-Fu Zeng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Uv Irradiation ◽  
Catalytic Effect ◽  
Ph Value ◽  
Manganese Ore ◽  
Mercury Lamp ◽  
Acid Condition ◽  
Important Species ◽  
Uv Lamp

We have investigated ultraviolet (UV) irradiation combined with manganese ore (MO) catalyzed ozonation of 4-cholorophenol (4-CP) in aqueous solution. The preliminary results showed UV irradiation and MO had a strong synergetic catalytic effect on ozonation. We also studied the effect of UV lamp power, MO dosage, O3 dosage, initial 4-CP concentration, pH value and temperature. The results showed that high pressure mercury lamp (HPML) was more favorable for the degradation of 4-CP than low pressure mercury lamp (LPML). The optimal MO and O3 dosages were 2 g/L and 2 g/h respectively. When the 4-CP concentration was over 15 mg/L, the decrease of degradation efficiency accelerated. The acid condition was favorable for the degradation of 4-CP by UV/MO/O3. The reaction temperature could not be over 50°C. Through the mechanism discussion, we found that Mn2 +  was the most important species to catalyze the ozonation. In addition, UV irradiation could also accelerate the degradation by promoting the production of ∙OH.

An ESR study of irradiated mixtures of hydrogen peroxide and Cu(II) complexes at 77 K

1988 ◽  
Vol 53 (12) ◽  
pp. 3080-3088 ◽  
Author(s):  
Pavel Stopka
Keyword(s):  
Hydrogen Peroxide ◽  
High Pressure ◽  
Catalytic Activity ◽  
Oxalic Acid ◽  
Hydroxyl Radicals ◽  
Room Temperature ◽  
Active Species ◽  
Mercury Lamp ◽  
Catalytically Active ◽  
High Concentrations

When aqueous solutions containing hydrogen peroxide and CuSO4 are irradiated by a high-pressure mercury lamp at room temperature and at 77 K, hydrogen peroxide decomposes and hydroxyl radicals generated in high concentrations coordinate to CuSO4. The catalytic activity of Cu(II), which depends on the choice of the ligand (triene, diene, ethylenediamine, ammonia, EDTA, oxalic acid and glycerine) and the proportion between the monomeric and dimeric forms of the Cu(II) complex, shows a maximum at a concentration of 10-4 mol dm-3. The catalytically active species is the monomeric Cu(II) complex, the dimer being inactive.

Degradation of two fluoroquinolone antibiotics photoinduced by Fe(iii)-microalgae suspension in an aqueous solution

2015 ◽  
Vol 14 (4) ◽  
pp. 693-699 ◽  
Author(s):  
Liyun Ge ◽  
Huanhuan Deng
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Isochrysis Galbana ◽  
Marine Microalgae ◽  
Laboratory Scale ◽  
Mercury Lamp ◽  
Platymonas Subcordiformis ◽  
Ciprofloxacin Hydrochloride ◽  
Fluoroquinolone Antibiotics ◽  
Scale Experiment

Two fluoroquinolone (FQ) antibiotics, enrofloxacin (ENR) and ciprofloxacin hydrochloride (CIP), and two marine microalgae, Platymonas subcordiformis and Isochrysis galbana, were investigated under irradiation with a high-pressure mercury lamp (HPML) in a laboratory-scale experiment.

A photoelectron microscope study of surfaces

1989 ◽  
Vol 47 ◽  
pp. 10-11
Author(s):  
W. Engel ◽  
M. Kordesch ◽  
A. M. Bradshaw ◽  
E. Zeitler
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Field Strength ◽  
Uv Light ◽  
Physical Property ◽  
Photon Flux ◽  
Mercury Lamp ◽  
Object Surface ◽  
The Sixties ◽  
Physical Features

Photoelectron microscopy is as old as electron microscopy itself. Electrons liberated from the object surface by photons are utilized to form an image that is a map of the object's emissivity. This physical property is a function of many parameters, some depending on the physical features of the objects and others on the conditions of the instrument rendering the image.The electron-optical situation is tricky, since the lateral resolution increases with the electric field strength at the object's surface. This, in turn, leads to small distances between the electrodes, restricting the photon flux that should be high for the sake of resolution.The electron-optical development came to fruition in the sixties. Figure 1a shows a typical photoelectron image of a polycrystalline tantalum sample irradiated by the UV light of a high-pressure mercury lamp.

scholarly journals Antioxidant activity of Induna apple pomace extract

2005 ◽  
pp. 239-246 ◽  
Author(s):  
Sladjana Savatovic ◽  
Sonja Djilas ◽  
Vesna Tumbas ◽  
Jasna Canadanovic-Brunet ◽  
Gordana Cetkovic
Keyword(s):  
Aqueous Solution ◽  
Antioxidant Activity ◽  
Acetic Acid ◽  
Electron Spin Resonance ◽  
Hydroxyl Radicals ◽  
Electron Spin ◽  
Esr Spectroscopy ◽  
Methanol Extract ◽  
Apple Pomace ◽  
Spin Resonance

Different concentrations ofmethanol aqueous solution with or without 0.5% acetic acid and 80% acetone were used to achieve the highest yield of extraction of phenolics from Induna apple pomace. The highest content of phenolics (6.38 mg/g) was detected in the 80% methanol extract. The influence of 80% methanol extract of Induna apple pomace on stable l,l-diphenyl-2-picrylhydrazyl (DPPH) and reactive hydroxyl radicals has been investigated by electron spin resonance (ESR) spectroscopy. Based on the obtained results it can be concluded that the investigated extract is more effective in the DPPH test than on the DMPO-OH scavenging. In both cases antioxidant activity increased with increasing concentration of the investigated extract. The high contents ofphenolics (6.38 mg/g), flavonoids (1.01 mg/g) and flavan-3-ols (0.70 mg/g) in 80% methanol extract indicated that these compounds contributed to the antioxidant activity of Induna apple pomace.

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