Photodegradation of three benzotriazoles induced by four FeIII–carboxylate complexes in water under ultraviolet irradiation

2013 ◽  
Vol 10 (2) ◽  
pp. 135 ◽  
Author(s):  
You-Sheng Liu ◽  
Guang-Guo Ying ◽  
Ali Shareef ◽  
Rai S. Kookana
Keyword(s):  
Aqueous Solutions ◽  
Uv Irradiation ◽  
Carboxylate Complexes ◽  
Photodegradation Rate ◽  
Photolytic Degradation ◽  
Household Products ◽  
Uv Photodegradation ◽  
Degradation Rates ◽  
Exposure Risks ◽  
Iron Carboxylate

Environmental context Benzotriazoles are chemicals widely used to inhibit corrosion in various industrial processes and in household products. They persist in aquatic environments, even under UV irradiation, and thus there is a need to improve their photolytic degradation to minimise the environmental exposure risks. We investigated the effects of four iron–carboxylate complexes on the UV photodegradation of three benzotriazoles in aqueous solutions and show that they significantly increase the degradation rates of benzotriazoles. Abstract The effects of FeIII–carboxylate complexes on the photodegradation of three benzotriazoles (BTs), i.e. benzotriazole (BT), 5-methylbenzotriazole (5-TTri) and 5-chlorobenzotriazole (CBT) in aqueous solutions were investigated under exposure to UV irradiation at 254nm in the presence of FeIII and four carboxylate ions (oxalate, tartrate, succinate and citrate). The results showed that the presence of FeIII–carboxylate complexes significantly enhanced the photodegradation rates of all three selected BTs. The photodegradation of BT, 5-TTri and CBT followed first-order reaction kinetics with half-lives ranging from 0.57 to 3.98h for BT, 6.08 to 8.25h for 5-TTri and 2.63 to 5.50h for CBT in the four systems of the FeIII–carboxylate complexes. In comparison, the half-lives ranged between 3.40 and 4.81h for BT, 6.42 and 11.55h for 5-TTri and 4.13 and 6.79h for CBT in pure aqueous solution and in the presence of FeIII or carboxylate. The degradation rates of these BTs were dependent on the pH values, type of carboxylate and FeIII/carboxylate ratios. Both BT and CBT showed the highest photodegradation rates with the shortest respective half-lives of 0.57 and 2.63h at the initial FeIII/oxalate ratio of 10/200µmolL–1 in aqueous solutions at pH 3, whereas 5-TTri had the highest photodegradation rate with the shortest half life of 6.08h at the initial FeIII/succinate ratio of 10/10µmolL–1.

Preparation and structure of ordered films of iron carboxylate complexes

1996 ◽  
Vol 274 (1-2) ◽  
pp. 143-146 ◽  
Author(s):  
M. Popescu ◽  
C. Turta ◽  
V. Meriacre ◽  
V. Zubareva ◽  
T. Gutberlet ◽  
...  
Keyword(s):  
Carboxylate Complexes ◽  
Iron Carboxylate ◽  
Ordered Films

scholarly journals Evaluation of Malathion Pesticide Removal Efficiency by g-C3N4/ Fe3O4/Ag Nanocomposites from Aqueous Solutions in the Presence of UV Irradiation

2020 ◽  
Vol 7 (3) ◽  
pp. 261-279
Author(s):  
Ali Esrafili ◽  
Soudabeh Ghodsi ◽  
Roshanak Rezaei Kalantary ◽  
Mitra Gholami ◽  
◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Uv Irradiation ◽  
Pesticide Removal

scholarly journals Photo-transformation of aqueous nitroguanidine and 3-nitro-1,2,4-triazol-5-one : emerging munitions compounds

2021 ◽  
Author(s):  
Julie Becher ◽  
Samuel Beal ◽  
Susan Taylor ◽  
Katerina Dontsova ◽  
Dean Wilcox
Keyword(s):  
Aqueous Solutions ◽  
Degradation Products ◽  
Pure Water ◽  
Transformation Products ◽  
Water Soluble ◽  
Uv Exposure ◽  
Degradation Pathways ◽  
Solution Ph ◽  
Photo Degradation ◽  
Degradation Rates

Two major components of insensitive munition formulations, nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO), are highly water soluble and therefore likely to photo-transform while in solution in the environment. The ecotoxicities of NQ and NTO solutions are known to increase with UV exposure, but a detailed accounting of aqueous degradation rates, products, and pathways under different exposure wavelengths is currently lacking. We irradiated aqueous solutions of NQ and NTO over a 32-h period at three ultraviolet wavelengths and analyzed their degradation rates and transformation products. NQ was completely degraded by 30 min at 254 nm and by 4 h at 300 nm, but it was only 10% degraded after 32 h at 350 nm. Mass recoveries of NQ and its transformation products were >80% for all three wavelengths. NTO degradation was greatest at 300 nm with 3% remaining after 32 h, followed by 254 nm (7% remaining) and 350 nm (20% remaining). Mass recoveries of NTO and its transformation products were high for the first 8 h but decreased to 22–48% by 32 h. Environmental half-lives of NQ and NTO in pure water were estimated as 4 and 6 days, respectively. We propose photo-degradation pathways for NQ and NTO supported by observed and quantified degradation products and changes in solution pH.

2-Hydroxypyridine photolytic degradation by 254nm UV irradiation at different conditions

Chemosphere ◽  
2009 ◽  
Vol 77 (8) ◽  
pp. 1099-1105 ◽  
Author(s):  
David R. Stapleton ◽  
Ioannis K. Konstantinou ◽  
Anastasia Karakitsou ◽  
Dimitra G. Hela ◽  
Maria Papadaki
Keyword(s):  
Uv Irradiation ◽  
Photolytic Degradation

Efficiency of singlet oxygen generation by fulvic acids and its influence on UV photodegradation of herbicide Amitrole in aqueous solutions

2017 ◽  
Vol 27 (4) ◽  
pp. 399-401 ◽  
Author(s):  
Ivan P. Pozdnyakov ◽  
Victoria A. Salomatova ◽  
Marina V. Parkhats ◽  
Boris M. Dzhagarov ◽  
Nikolai M. Bazhin
Keyword(s):  
Aqueous Solutions ◽  
Singlet Oxygen ◽  
Fulvic Acids ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Uv Photodegradation

Oxidative degradation of EDTA in aqueous solutions under UV irradiation

2008 ◽  
Vol 50 (1) ◽  
pp. 70-74 ◽  
Author(s):  
A. F. Seliverstov ◽  
B. G. Ershov ◽  
Yu. O. Lagunova ◽  
P. A. Morozov ◽  
A. S. Kamrukov ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Uv Irradiation ◽  
Oxidative Degradation

scholarly journals Hydrothermal Enhanced Nanoscale Zero-Valent Iron Activated Peroxydisulfate Oxidation of Chloramphenicol in Aqueous Solutions: Fe-Speciation Analysis and Modeling Optimization

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 131 ◽  
Author(s):  
Lie Yang ◽  
Hong Li ◽  
Jianming Xue ◽  
Liuyang He ◽  
Yongfei Ma ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Speciation Analysis ◽  
Zero Valent Iron ◽  
Quadratic Model ◽  
X Ray ◽  
Condition Optimization ◽  
Degradation Rates ◽  
Nanoscale Zero Valent Iron ◽  
Initial Ph

The efficiencies of the nanoscale zero-valent iron (nZVI) and hydrothermal and nZVI-heat activation of peroxydisulfate (PS) were studied for the decomposition of chloramphenicol (CAP) in aqueous solutions. The nZVI heat combined with activation of PS provided a significant synergistic effect. A central composite design (CCD) with response surface methodology (RSM) was employed to explore the influences of single parameter and interactions of selected variables (initial pH, PS concentration, nZVI and temperature) on degradation rates with the purpose of condition optimization. A quadratic model was established based on the experimental results with excellent correlation coefficients of 0.9908 and 0.9823 for R2 and R2adj. The optimized experimental condition for 97.12% CAP removal was predicted with the quadratic model as 15 mg/L, 0.5 mmol/L, 7.08 and 70 °C for nZVI dosage, PS, initial pH, and temperature, respectively. This study demonstrated the effectiveness of RSM for the modeling and prediction of CAP removal processes. In the optimal condition, Fe2O3 and Fe3O4 were the predominant solid products after reactions based on X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis, which could also act as the activators along with the reaction. Overall, it could be concluded that hydrothermal enhanced nZVI activation of PS was a promising and efficient choice for CAP degradation.

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