Total and Efficient Removal of Tribromoacetic Acid by Ultraviolet Irradiation

2012 ◽  
Vol 518-523 ◽  
pp. 2939-2943 ◽  
Author(s):  
Xu Chun Li ◽  
Jun Ma ◽  
Si Yang Yue
Keyword(s):  
Uv Irradiation ◽  
Disinfection Byproducts ◽  
Efficient Removal ◽  
Environment Friendly ◽  
Efficient Treatment ◽  
Chlorine Disinfection ◽  
First Order Kinetics ◽  
Photodegradation Mechanism ◽  
Tribromoacetic Acid ◽  
Almost All

Tribromoacetic acid (TBAA), one of the typically recalcitrant and toxic chlorine disinfection byproducts (DBPs), is widespread in the drinking water and threating human health. The environment-friendly technology, UV irradiation, could efficiently destruct TBAA. The present study investigated the removal efficiency, photodegradation kinetics, and photodegradation mechanism of TBAA under UV irradiation. It revealed that the photodegradaton process of TBAA agreed well with the pseudo-first order kinetics, with the rate constant of 1.084 min-1and half-time of 0.64 minutes. Further study on intermediate products formation and mass balance indicated that complete debromination and detoxification were obtained with almost all the bromine atoms released as bromide ions, and suggest that the cleavage of three C-Br bonds concurrently occurred during the photolysis of one TBAA molecule. It will provide some guidance for efficient treatment of brominated contaminants in water.

Efficient Destruction of Chlorophenols by Ultraviolet Irradiation

2012 ◽  
Vol 476-478 ◽  
pp. 1955-1959
Author(s):  
Xu Chun Li ◽  
Jun Ma ◽  
Si Yang Yue
Keyword(s):  
Human Health ◽  
Ultraviolet Irradiation ◽  
Chloride Ions ◽  
Solution Ph ◽  
Environment Friendly ◽  
Chlorine Atoms ◽  
Efficient Treatment ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order

Chlorophenols (CPs), a group of recalcitrant and toxic pollutants, are widespread in the environment and threating human health. The environment-friendly technology, UV irradiation, could efficiently destruct CPs. The study investigated the influence of solution pH and positions and number of substituted chlorine atoms on photodegradation process of CPs, and also studied the photodegradation pathway. It found that the photodegradaton process of CPs was highly dependent on solution pH, and higher pH favored the degradation. The photodegradation processes agreed well with the pseudo-first order kinetics, and para- and ortho- positions and lower chlorination degree were more favorable for photodegradation of CPs. Most of the chlorine atoms were released as chloride ions, and suggest that the cleavage of the C-Cl bond occurred during the photodegradation process. It will provide some guidance for efficient treatment of CPs in water.

scholarly journals Bleaching of chlorophylls by UV irradiation in vitro: The effects on chlorophyll organization in acetone and n-hexane

2008 ◽  
Vol 73 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Jelena Zvezdanovic ◽  
Dejan Markovic
Keyword(s):  
Uv Irradiation ◽  
Photosynthetic Pigments ◽  
Energy Input ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
The Stability ◽  
Major Factors

The stability of chlorophylls toward UV irradiation was studied by Vis spectrophotometry in extracts containing mixtures of photosynthetic pigments in acetone and n-hexane. The chlorophylls underwent destruction (bleaching) obeying first-order kinetics. The bleaching was governed by three major factors: the energy input of the UV photons, the concentration of the chlorophylls and the polarity of the solvent, implying different molecular organizations of the chlorophylls in the two solvents.

scholarly journals Degradation of Aqueous Polycyclic Musk Tonalide by Ultraviolet-Activated Free Chlorine

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 95 ◽  
Author(s):  
Lili Wang ◽  
Xiaowei Liu
Keyword(s):  
Disinfection Byproducts ◽  
Free Chlorine ◽  
Water Disinfection ◽  
Side Chain ◽  
Product Analysis ◽  
Direct Photolysis ◽  
Reaction Rate Constants ◽  
Water Matrix ◽  
First Order Kinetics ◽  
Drinking Water Disinfection

Chlorine-incorporating ultraviolet (UV) provides a multiple barrier for drinking water disinfection. Meanwhile, post-UV employment can promote the degradation of micropollutants by radical production from chlorine residual photolysis. This work studied the degradation of one such chemical, tonalide (AHTN), by low-pressure UV-activated free chlorine (FC) under typical UV disinfection dosage of <200 mJ·cm−2 and water matrix of filtered tank effluent. AHTN was rapidly degraded by UV/FC in accordance with pseudo-first-order kinetics. The reaction rate constants of AHTN with reactive chlorine species and hydroxyl radical (HO•) were estimated. Mechanistic exploration evidenced that under UV/FC, AHTN degradation was attributable to direct photolysis, ClO•, and HO•. The carbonyl side chain of AHTN served as an important attack site for radicals. Water matrices, such as natural organic matter (NOM), HCO3−, Cu2+, PO43−, and Fe2+, showed noticeable influence on the UV/FC process with an order of NOM > HCO3− >Cu2+ > PO43− > Fe2+. Reaction product analysis showed ignorable formation of chlorinated intermediates and disinfection byproducts.

scholarly journals Effects of continuous UV-irradiation on the antioxidant activities of quercetin and rutin in solution in the presence of lecithin as the protective target

2011 ◽  
Vol 76 (7) ◽  
pp. 973-985 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic ◽  
Dragana Cvetkovic ◽  
Blaga Radovanovic
Keyword(s):  
Lipid Peroxidation ◽  
Uv Irradiation ◽  
Energy Input ◽  
Antioxidant Activities ◽  
Antioxidant Action ◽  
First Order ◽  
First Order Kinetics ◽  
Uv Photons ◽  
Uv C

The stabilities and antioxidant action of two selected flavonoids, quercetin and rutin, dissolved in methanol and water, toward continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C) were studied. The flavonoids underwent degradation (bleaching) following first-order kinetics. The bleaching rates were highly dependent on the energy input of the involved UV-photons. The antioxidant activities of the two flavonoids on UV-induced lecithin lipid peroxidation were studied by the TBA-MDA test, and appeared to be also affected by the continuous UV irradiation. The energy input of the incident UV-photons again played a major governing role, but an impact of the flavonoids structures cannot be neglected.

scholarly journals Degradation of clofibric acid in UV/chlorine disinfection process: kinetics, reactive species contribution and pathways

2018 ◽  
Vol 5 (2) ◽  
pp. 171372 ◽  
Author(s):  
Yuqing Tang ◽  
Xueting Shi ◽  
Yongze Liu ◽  
Li Feng ◽  
Liqiu Zhang
Keyword(s):  
Degradation Kinetics ◽  
Clofibric Acid ◽  
Basic Solution ◽  
Uv Photolysis ◽  
Chlorination Process ◽  
Chlorine Disinfection ◽  
First Order Kinetics ◽  
Disinfection Process ◽  
Acidic Conditions ◽  
Degradation Intermediates

As a potential endocrine disruptor, clofibric acid (CA) was investigated in this study for its degradation kinetics and pathways in UV/chlorine process. The results showed that CA in both UV photolysis and UV/chlorine processes could be degraded via pseudo-first-order kinetics, while it almost could not be degraded in the dark chlorination process. The observed rate constant ( k obs ) in UV photolysis was 0.0078 min −1, and increased to 0.0107 min −1 combining with 0.1 mM chlorine. The k obs increased to 0.0447 min −1 with further increasing the chlorine dosage from 0.1 to 1.0 mM, and reached a plateau at higher dosage (greater than 1.0 mM). The higher k obs was obtained at acid solution rather than basic solution. Moreover, the calculated contributions of radical species to k obs indicated that the HO• contributed significantly to CA degradation in acidic conditions, while the reactive chlorine species and UV direct photolysis dominated in neutral and basic solution. The degradation of CA was slightly inhibited in the presence of HC O 3 − (1 ∼ 50 mM), barely affected by the presence of Cl − (1 ∼ 200 mM) and greatly suppressed by humic acid (0 ∼ 5 mg l −1 ). Thirteen main degradation intermediates and three degradation pathways of CA were identified during UV/chlorine process.

A novel environment-friendly hybrid material based on a modified silica gel with a bispyrazole derivative for the removal of ZnII, PbII, CdIIand CuIItraces from aqueous solutions

2017 ◽  
Vol 4 (11) ◽  
pp. 1821-1831 ◽  
Author(s):  
Smaail Radi ◽  
Mohamed El Massaoudi ◽  
Maryse Bacquet ◽  
Stéphanie Degoutin ◽  
N. N. Adarsh ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Silica Gel ◽  
Hybrid Material ◽  
Efficient Removal ◽  
Modified Silica ◽  
Modified Silica Gel ◽  
Environment Friendly ◽  
Novel Environment ◽  
Removal Of Heavy Metals

New surface-functionalized with bispyrazole receptor was designed for efficient removal of heavy metals. The architecture of host–guest on the surface was identified.

Emerging nitrogenous disinfection byproducts: Transformation of the antidiabetic drug metformin during chlorine disinfection of water

2015 ◽  
Vol 79 ◽  
pp. 104-118 ◽  
Author(s):  
Dominic Armbruster ◽  
Oliver Happel ◽  
Marco Scheurer ◽  
Klaus Harms ◽  
Torsten C. Schmidt ◽  
...  
Keyword(s):  
Disinfection Byproducts ◽  
Antidiabetic Drug ◽  
Chlorine Disinfection

Impact of industrial discharge on the performance of a biological POTW - model development

1997 ◽  
Vol 36 (2-3) ◽  
pp. 35-43
Author(s):  
Y. Argaman ◽  
W. W. Eckenfelder ◽  
A. J. O'Reilly
Keyword(s):  
Industrial Wastewater ◽  
Combined Treatment ◽  
Model Development ◽  
Experimental Studies ◽  
Weighted Average ◽  
Monod Kinetics ◽  
Efficient Treatment ◽  
First Order Kinetics ◽  
Efficient Alternative ◽  
Alternative Solutions

This paper describes the development of a mathematical model and its application for predicting the dimensions of an industrial wastewater pretreatment system, and its comparison with alternative solutions. The model is based on pseudo first order kinetics for both the municipal and the industrial wastewater, and also on the Monod kinetics for the industrial wastewater. In the combined treatment process the biomass is taken as a mixture of specialist microorganisms capable of degrading target compounds. The kinetic rate of the combined stream is taken as the weighted average of the reciprocal K values. The model was used to compare the alternative treatment schemes and the main conclusions were: (1) pretreatment of industrial wastewater is always the most efficient alternative, and (2) an optimal VSS concentration exists in the pretreated effluent, leading to the most efficient treatment system. Experimental studies aimed at validation of this model are strongly recommended.

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