Free Radical Reactions Involving Cl•, Cl2-•, and SO4-•in the 248 nm Photolysis of Aqueous Solutions Containing S2O82-and Cl-

Yu, Xiao‐Ying; Bao, Zhen-Chuan; Barker, John R.

doi:10.1021/jp036211i

Cited by 318 publications

(98 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A3, Appendix A). The reported quantum yields of PS (Φ= 1,4 (Mark et al, 1990)) and Φ=2,0 (Yu et al, 2004) for deoxygenated and oxygenated solutions, respectively) are higher than the one of HP (Φ= 1,0 (Linden and Rosenfeldt, 2011)) confirming our results.…”

Section: Activation Of Oxidantssupporting

confidence: 89%

Comparison of UVC/S2O82− with UVC/H2O2 in terms of efficiency and cost for the removal of micropollutants from groundwater

Antoniou

Andersen

2015

Chemosphere

View full text Add to dashboard Cite

Highlights Cost comparison of UVC/HP and UVC/PS for groundwater treatment.  UVC/PS performed better for atrazine removal in Milli-Q water.  UVC/HP had a better overall performance for the removal of the mixture of contaminants.  Results from the collimated beam apparatus were comparable to the flow-through system.  UVC/PS is economically feasible for special matrices where selective oxidation is required. Graphical Abstract 2 AbstractThis study compared the UVC/S 2 O 8 2-system with the more commonly used AOP in water industry, UVC/H 2 O 2 , and examined whether the first one can be an economically feasible alternative technology. Atrazine and 4 volatile compounds (methyl tert-butyl ether, cisdichlorethen, 1,4-dioxane and 1,1,1-trichloroethane) were chosen as model contaminants because they exhibit different susceptibility to UVC photolysis and AOPs. A collimated beam apparatus was utilized for the majority of the experiments (controlled environment, without mass transfer phenomena), while selected experiments were performed in a flow-through reactor to simulate industrial applications. Initial experiments on the activation of oxidants with a LP lamp indicated that S 2 O 8 2-is photolysed about 2.3 times faster than H 2 O 2 and that the applied treatment times were not sufficient to utilize the majority of the oxidant. The effect of oxidants' concentrations were tested with atrazine alone and in the micropollutants' mixture and it was decided to use 11.8 mg/L S 2 O 8 2-and 14.9 mg/L H 2 O 2 for further testing since is closer to industrial applications and to minimize the residual oxidant concentration. Changes of the matrix composition of the treated water were investigated with the addition of chloride, bicarbonate and humic acids at concentrations relevant to a well-water-sample, the results showed that the system least affected was UVC/H 2 O 2 . Only when bicarbonate was used, UVC/S 2 O 8 2-performed better. Overall, testing these systems with the mixture of micropollutants gave better insights to their efficiency than atrazine alone and UVC/S 2 O 8 2-is recommended for selective oxidation of challenging matrices.

show abstract

Section: Activation Of Oxidantssupporting

confidence: 89%

Comparison of UVC/S2O82− with UVC/H2O2 in terms of efficiency and cost for the removal of micropollutants from groundwater

Antoniou

Andersen

2015

Chemosphere

View full text Add to dashboard Cite

show abstract

“…SO 4 À has an absorption maximum between 440 nm and 450 nm, which often allows a direct measurement of the radical concentration decay for the kinetic evaluation. The absorption spectrum of the sulphate radical anion has been discussed before, [89,90] which is also true for the effective quantum yields (F SO À 4 ) of the photolytic generation of SO 4 À from peroxodisulphate photolysis. [12] There are two recent quantum yield determinations to be discussed which are not included in ref.…”

Section: Overviewmentioning

confidence: 99%

“…[12]. Yu and Barker published in 2004 [90] a value of F SO À 4 = 2 at a photolysis wavelength of l = 248 nm in aqueous solution. This quantum yield is significantly higher than the latest reported value in Herrmann.…”

Section: Overviewmentioning

confidence: 99%

Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

et al. 2010

View full text Add to dashboard Cite

The most important radicals which need to be considered for the description of chemical conversion processes in tropospheric aqueous systems are the hydroxyl radical (OH), the nitrate radical (NO(3)) and sulphur-containing radicals such as the sulphate radical (SO(4)(-)). For each of the three radicals their generation and their properties are discussed first in the corresponding sections. The main focus herein is to summarize newly published aqueous-phase kinetic data on OH, NO(3) and SO(4)(-) radical reactions relevant for the description of multiphase tropospheric chemistry. The data compilation builds up on earlier datasets published in the literature. Since the last review in 2003 (H. Herrmann, Chem. Rev. 2003, 103, 4691-4716) more than hundred new rate constants are available from literature. In case of larger discrepancies between novel and already published rate constants the available kinetic data for these reactions are discussed and recommendations are provided when possible. As many OH kinetic data are obtained by means of the thiocyanate (SCN(-)) system in competition kinetic measurements of OH radical reactions this system is reviewed in a subchapter of this review. Available rate constants for the reaction sequence following the reaction of OH+SCN(-) are summarized. Newly published data since 2003 have been considered and averaged rate constants are calculated. Applying competition kinetics measurements usually the formation of the radical anion (SCN)(2)(-) is monitored directly by absorption measurements. Within this subchapter available absorption spectra of the (SCN)(2)(-) radical anion from the last five decades are presented. Based on these spectra an averaged (SCN)(2)(-) spectrum was calculated. In the last years different estimation methods for aqueous phase kinetic data of radical reactions have been developed and published. Such methods are often essential to estimate kinetic data which are not accessible from the literature. Approaches for rate constant prediction include empirical correlations as well as structure activity relationships (SAR) either with or without the usage of quantum chemical descriptors. Recently published estimation methods for OH, NO(3) and SO(4)(-) radical reactions in aqueous solution are finally summarized, compared and discussed.

show abstract

“…However, as the photo-Fenton process proceeds, partial degradation of the organic material causes the pH of the medium to fall to ca. pH 2.0, where photolysis of FeCl 2+ dominates over photolysis of Fe(OH) 2+ and where the chloride ion efficiently converts any HO • formed in the system into the intrinsically much less reactive Cl 2 • -radical anion (Bacardit et al, 2007;Buxton et al, 1999;De Laat et al, 2004;George & Chovelon, 2002;Kiwi et al, 2000;McElroy, 1990;Moraes, et al, 2004a;Nadtochenko & Kiwi, 1998;Pignatello, 1992;Soler et al, 2009;Truong et al, 2004;Yu, 2004;Yu et al, 2004;Yu & Barker, 2003a, 2003bZapata et al, 2009). As a result, virtually complete inhibition of the photoFenton degradation of typical organic substrates (Kiwi & Nadtochenko, 2000; www.intechopen.com Moraes et al, 2004aMoraes et al, , 2004bPignatello, 1992) will occur at moderate chloride ion concentrations [>0.03 M NaCl for aliphatic hydrocarbons (Moraes et al, 2004a); >0.2 M NaCl for phenols] when the pH of the medium reaches pH 2.0 or below.…”

Section: Wwwintechopencom Organic Pollutants Ten Years After the Stmentioning

confidence: 99%

Fundamental Mechanistic Studies of the Photo-Fenton Reaction for the Degradation of Organic Pollutants

Machulek¹,

Quina²,

Gozzi³

et al. 2012

Organic Pollutants Ten Years After the Stockholm Convention - Environmental and Analytical Update

View full text Add to dashboard Cite

Free Radical Reactions Involving Cl^•, Cl₂^-•, and SO₄^-•in the 248 nm Photolysis of Aqueous Solutions Containing S₂O₈^2-and Cl^-

Abstract: For Abstract see ChemInform Abstract in Full Text.

Cited by 318 publications

References 104 publications

Comparison of UVC/S2O82− with UVC/H2O2 in terms of efficiency and cost for the removal of micropollutants from groundwater

Comparison of UVC/S2O82− with UVC/H2O2 in terms of efficiency and cost for the removal of micropollutants from groundwater

Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

Fundamental Mechanistic Studies of the Photo-Fenton Reaction for the Degradation of Organic Pollutants

Contact Info

Product

Resources

About