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.

Comments on a Method to Measure Sucralose Using UV Photodegradation Followed by UV Spectrophotometry

2017 ◽  
Vol 100 (3) ◽  
pp. 810-813
Author(s):  
Te Fang ◽  
Susan A Andrews ◽  
Ron Hofmann
Keyword(s):  
Aqueous Solution ◽  
Uv Irradiation ◽  
Low Pressure ◽  
Linear Range ◽  
Uv Spectrophotometry ◽  
Fluence Rate ◽  
Photolysis Product ◽  
Quick Method ◽  
Uv Photodegradation ◽  
Uv Lamp

Abstract A simple and quick method to measure sucralose in aqueous solution at concentrations in the order of 0.1–1.2 g·L−1 proposed by Idris et al. uses UV irradiation prior to UV spectrophotometry. The photolysis of sucralose forms a photoactive compound characterized by maximum absorbance at approximately 270 nm. The conditions required for sucralose photolysis, however, had not been completely reported. In this work, the procedure described by Idris et al. was replicated using a low-pressure UV lamp to irradiate sucralose samples with a wider range of initial concentrations(0.04–10 g·L−1) with known fluences. It was determined that care must be taken to ensure that the same fluence is applied for both calibration and measurement steps because the absorbance of the sucralose photolysis product is a function of the applied fluence. The way thesamples are irradiated also has an impact on the results in that the method exhibits a greater linear range if an apparatus is used that maximizes the fluence rate (e.g., by placing samples closer to the UV source or using a higher-intensity lamp).

scholarly journals Enhancement of Solvent Resistance of Polyimide Electrospun Mat via the UV-Assisted Electrospinning and Photosensitive Varnish

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2055 ◽  
Author(s):  
Lin Qi ◽  
Chen-Yu Guo ◽  
Meng-Ge Huang Fu ◽  
Yan Zhang ◽  
Lu-meng Yin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Uv Irradiation ◽  
Starting Material ◽  
Current Work ◽  
Mercury Lamp ◽  
Solvent Resistance ◽  
One Step ◽  
The One

A new methodology for enhancing the solvent resistance of electrospun polyimide (PI) ultrafine fibrous mat (UFM) was investigated in the current work. For this purpose, a negative intrinsically photosensitive polyimide (PSPI) resin was prepared by the one-step high- temperature polycondensation procedure from 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and α,α-bis(4-amino-3,5-dimethylphenyl)phenylmethane (PTMDA). The PI varnish, by dissolving the derived PI (BTDA-PTMDA) resin in N,N-dimethylacetamide (DMAc) at a solid of 20 wt %, was used as the starting material for the standard electrospinning (ES) and ultraviolet-assisted ES (UVAES) fabrications, respectively. The 365 nm wavelength of the high-pressure mercury lamp ultraviolet (UV) irradiation induced the photocrosslinking reaction in the PSPI mat. Solubility tests indicated that the PI UFM fabricated by standard ES procedure showed poor DMAc resistance, while the one by UVAES (PI-UV) exhibited excellent resistance to DMAc.

UV degradation of carbofuran insecticide in aqueous solution: identification and toxicity evolution of by-products

2004 ◽  
Vol 4 (5-6) ◽  
pp. 313-319
Author(s):  
G. Mascolo ◽  
A. Lopez ◽  
A. Detomaso ◽  
L. Guzzella
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
High Pressure ◽  
Liquid Chromatography Mass Spectrometry ◽  
Uv Degradation ◽  
Radical Coupling ◽  
Carbamate Group ◽  
Uv Lamp ◽  
Hydrolysis Of ◽  
By Products

The paper reports the results of an investigation about the UV degradation of carbofuran, a widely used insecticide in Europe. Specific objectives were the identification of the by-products formed and the evaluation of the toxicity of the irradiated solution compared to that of carbofuran. The experimental results, obtained treating an aqueous carbofuran solution (50 mg/L) by high pressure UV lamp (125 W), show that the insecticide is completely removed within 120 min. Several intermediate by-products have been identified by liquid chromatography-mass spectrometry (LC-MS) as a result of hydroxylation process of the 2,3-dihydro benzofurane ring and other reactions such as the cleavage of the carbamate group, the hydrolysis of ethereal moiety, radical coupling and decarboxylation processes. After 270 min of reaction the identified by-products were completely degraded and COD and TOC removals of 35 and 20% were measured, respectively. Toxicological analyses performed using the comparison procedure of the MicrotoxTM assay provided interesting clues concerning toxic effects of the photodegradation by-products. The results revealed a substantial increase of the toxicity during the first 15 min proving that photodegradation of organic contaminant could even lead to an increase of the toxicity of treated solution.

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.

Heteropolyacid Photocatalytical Degradation of Atrazine in Aqueous Solution under UV-Irradiation

2013 ◽  
Vol 652-654 ◽  
pp. 1680-1683
Author(s):  
Wei Yang Shen ◽  
Fei Ye Liu ◽  
Jian Qiu Chen ◽  
Rui Xin Guo
Keyword(s):  
Aqueous Solution ◽  
Organic Compounds ◽  
Uv Irradiation ◽  
Degradation Rate ◽  
Ph Value ◽  
Degradation Products ◽  
Affecting Factors ◽  
Obvious Effect ◽  
Initial Concentration ◽  
Temperature Exposure

The photodegradation of atrazine induced by UV-irradiation in aqueous solution was investigated initially. The affecting factors on the photodetradation were studied and described in details such as atrazine initial concentration, temperature, pH value, exposure intensity, oxidant and co-existing substances. It was found that the atrazine initial concentration had no obvious effect on the photodegradation. With the pH value increasing, photodegradation rates decreased. However, we also observed a positive correlation between the degradation rate of atrazine and temperature, exposure intensity and oxidant while the coexisting organic compounds may decelerate photodegradation of the atrazine in water. In this paper, the degradation products had also been confirmed by using LC-MS.

scholarly journals Oxidation of Sulfonamides in Aqueous Solution by UV-TiO2-Fe(VI)

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yan Ma ◽  
Kejia Zhang ◽  
Cong Li ◽  
Tuqiao Zhang ◽  
Naiyun Gao
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Conduction Band ◽  
Uv Irradiation ◽  
Photocatalytic Oxidation ◽  
Ph Value ◽  
Electron Acceptors ◽  
Potassium Ferrate ◽  
The Stability ◽  
Complete Mineralization

The photocatalytic degradation of sulfonamides in aqueous TiO2suspension under UV irradiation has been investigated using potassium ferrate as electron acceptors. The results showed that the stability of Fe(VI) is dependent on pH significantly, and the stability reduces obviously in the presence of UV-TiO2. The experiments indicated that Fe(VI) could effectively scavenge the conduction band electrons from the surface of TiO2. The photocatalytic oxidation of sulfonamides with Fe(VI) was found to be much faster than that without Fe(VI). The SD, SM, and SMX concentration was greatly reduced by 89.2%, 83.4%, and 82.0%, respectively, after 10 min with UV-TiO2-Fe(VI), comparing to 65.2%, 66.0%, and 71.9%, respectively, with Fe(VI) only in the dark and 71.3%, 72.7%, and 76.0%, respectively, with UV-TiO2. The pH value of solution significantly influenced the sulfonamides degradation in UV-TiO2-Fe(VI) system. The degradation amount of sulfonamides after 10 min was a maximum at pH 7. The intermediate products of sulfonamides oxidation by UV-TiO2-Fe(VI) were analysed by LC-HESI-MS-MS and the results suggested that a majority of sulfonamides turned into large-molecule products without complete mineralization.

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