Transformation of phenol, catechol, guaiacol and syringol exposed to sodium hypochlorite

Michałowicz, Jaromir; Duda, Wirgiliusz; Stufka-Olczyk, J.

doi:10.1016/j.chemosphere.2006.07.083

Cited by 41 publications

(18 citation statements)

References 12 publications

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“…Chlorine substitution onto catechol yields 4-chlorocatechol, 3,4-dichlorocatechol and 3,4,5-trichlorocatechol in only minor amounts relative to the chlorophenols, which are the product of OH replacement [24]. Syringol and guaiacol also yield chlorophenols via similar aqueous oxychlorination in addition to Cl substituted methoxyphenols.…”

Section: Resultsmentioning

confidence: 93%

PCDD/F Formation from Heterogeneous Oxidation of Wood Pyrolysates

Tame¹,

Dlugogorski²,

Kennedy³

2008

Fire Saf. Sci.

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This paper examines the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) during oxidative pyrolysis of wood. Model lignocellulosic compounds and fractions isolated from wood serve to generate volatiles which then interact with copper-loaded surrogate ash to produce PCDD/F. The measurements indicate a preference for the formation of PCDF over PCDD in all experiments. Lignin yields considerably more PCDD/F than the carbohydrates, in agreement with the previous measurement in experiments performed under inert conditions [Tame, Dlugogorski, Kennedy, Conversion of Wood Pyrolysates to PCDD/F, Proc. Combust. Inst. 32, submitted]. The ratio of PCDD to PCDF varies according to the chemical structure of the feed; with carbohydrates demonstrating greater relative propensity for PCDF than lignin. The lignin monomers with methyl ether subsitituents (i.e., vanillin and syringol) produce less PCDD/F than those without (i.e., catechol and p-hydroxybenzaldehyde). Ensuing experiments, to examine yield of PCDD/F as a function of temperature and mass loading of vanillin, reveal the mechanism of heterogeneous condensation of chlorophenols with subsequent chlorination/dechlorination.

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Section: Resultsmentioning

confidence: 93%

PCDD/F Formation from Heterogeneous Oxidation of Wood Pyrolysates

Tame¹,

Dlugogorski²,

Kennedy³

2008

Fire Saf. Sci.

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“…As pH increased, the concentration of CHCl 3 increased correspondingly, especially when pH is beyond 8. As is known, ClO − exhibited relatively low oxidation ability under alkaline conditions [15] , causing the reaction shown in equation (3) unable to proceed. Therefore, the bromine incorporation in DBPs was low under alkaline conditions.…”

Section: Effect Of Ph On the Proportion Of Bromo-dbps In Total Dbpsmentioning

confidence: 99%

Proportion of bromo-DBPs in total DBPs during reclaimed-water chlorination and its related influencing factors

Zhang

Liu

et al. 2008

Sci. China Ser. B-Chem.

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During the chlorine disinfection of reclaimed-water, the proportion of bromo-disinfection by-products (bromo-DBPs) in total DBPs is affected by chlorine dosage, reaction time, pH, ammonia nitrogen (NH 3 -N) and preozonation. Results show that bromo-trihalomethanes (bromo-THMs) form more easily than bromo-haloacetic acids (bromo-HAAs) and bromine incorporation in DBPs decreases with the increase of chlorine dosage. Within 5 h, bromine incorporation in THMs (n(Br)) increases but bromine incorporation in HAAs (n′(Br)) decreases with the extension of reaction time; however, n(Br) decreases and n′(Br) keeps relatively constant at a longer reaction time. Furthermore, bromine incorporation in DBPs is low under acidic and alkaline conditions. The increase of NH 3 -N concentration inhibits the formation of chloro-DBPs, resulting in the increase of n(Br) and n′(Br) to some extent. Preozonation enhances the formation of HOBr and the increase of bromine incorporation in DBPs; however, ozone of a high concentration oxidizes HOBr to its salt form, leading to the decrease of bromine incorporation in DBPs.bromine, chlorine disinfection, bromo-DBP Most sewage treatment plants (STPs) receive complex mixtures of urban and industrialized discharges. Even after secondary treatment, they still contain a large amount of dissolved organic matter (DOM), which serves as a precursor in the chlorination process to the formation of potentially harmful disinfection by-products (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs) [1,2] . There is also bromide ion (Br − ) in the effluent which cannot be easily removed via bio-treatment. During chlorine disinfection, Br − can be oxidized to hypobromous acid (HOBr) or hypobromite by hypochlorous acid (HClO) [3] . In both halogen substitution for THMs and dihalogenated HAA formation, HOBr shows an activity 20 times stronger than that of HOCl [4][5][6] . Furthermore, bromo-DBPs are reported to be more carcinogenic than chloro-DBPs [7][8][9][10] . Thus, more and more researches have focused on the control of bromo-DBPs.It is reported that as the Cl 2 /Br − molar ratio increases, the concentrations of chloroform (CHCl 3 ), bromodichloromethane (CHCl 2 Br) and dibromochloromethane (CHClBr 2 ) increase except for that of bromoform (CHBr 3 ) [5] . Increasing bromide concentration gradually shifts THMs and HAAs speciation from chlorinated species to the mixed bromochloro species during chlorination [6] . Furthermore, the Br − /DOC molar ratio was reported to influence the distribution of DBPs species. As the Br − /DOC molar ratio increases, dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) decrease rapidly, whereas dibromoacetic acid (DBAA) and

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“…Onodera and some other researchers have suspected that chlorinated acetic acid and maleic acids are formed from the destruction of the aromatic ring by chlorine in water (Onodera et al, 1984;Norwood et al, 1980). Michalowicz and coworkers detected carboxylic acids such as acetic and formic acid from the cleavage of phenolic aromatic rings, and the formation of non-toxic carboxylic acids decreased water toxicity (Michalowicz et al, 2007). In order to disclose the toxicity of these related compounds, benzophenone, phenyl benzoate ester, benzoic acid, and phenol were selected for more study.…”

Section: Toxicity With Significant Decreasementioning

confidence: 99%

“…Judging from the molecular structure of BP4, the hydroxyl group on the 4-position would increase its reactivity, and electrophilic chlorination readily occurred on the 3-and 5-positions. Generally, introducing chlorine atom into a molecule would increase its acute toxicity (Li et al, 2011), while the unchanged toxicity of BP4 after chlorination treatment might be due to formation of some non-toxic small molecular products (Michalowicz et al, 2007). The transformation products and their toxicity should be studied in more detail.…”

Section: Toxicity Without Significant Changesmentioning

confidence: 99%

Acute toxicity formation potential of benzophenone-type UV filters in chlorination disinfection process

Liu

Chen

Wei

et al. 2014

Journal of Environmental Sciences

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a b s t r a c tBenzophenones (BPs) are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.

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Transformation of phenol, catechol, guaiacol and syringol exposed to sodium hypochlorite

Cited by 41 publications

References 12 publications

PCDD/F Formation from Heterogeneous Oxidation of Wood Pyrolysates

PCDD/F Formation from Heterogeneous Oxidation of Wood Pyrolysates

Proportion of bromo-DBPs in total DBPs during reclaimed-water chlorination and its related influencing factors

Acute toxicity formation potential of benzophenone-type UV filters in chlorination disinfection process

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