Kinetics and mechanism for omethoate degradation by catalytic ozonation with Fe(III)-loaded activated carbon in water

Qiang, Zhimin; Ling, Wencui; Tian, Fang

doi:10.1016/j.chemosphere.2012.10.059

Cited by 32 publications

(14 citation statements)

References 22 publications

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“…The active component in Fe promoted the aqueous ozone decomposition into ·OH, which agreed with previous studies (Qiang et al 2013). The enhanced COD removal rate in the AC/O3 process also indicated that AC positively contributed to ozone degradation into oxygen-containing radical species in the aqueous phase, also in accordance with previous reports (Li et al 2006;Faria et al 2009;Li et al 2009;Ling et al 2011).…”

Section: Enhanced Cod and Color Removalsupporting

confidence: 81%

“…In previous research on catalytic ozonation (Ling et al 2011;Qiang et al 2013), the iron-loaded activated carbon has acted as a highly effective catalyst in the degradation of the non-biodegradable pollutant omethoate. Additionally, enhanced hydroxyl radical (HO·) generation in the process of oxidation was demonstrated by experiments conducted in the presence of tert-butanol, a commonly used hydroxyl radical scavenger.…”

Section: Introductionmentioning

confidence: 99%

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Enhanced Removal of COD and Color in Paper-making Wastewater by Ozonation Catalyzed by Fe Supported on Activated Carbon

et al. 2016

BioResources

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After biological treatment, pulp and paper mill effluent still may contain large amounts of recalcitrant organic pollutants that need to be further treated. In this study, Fe supported on activated carbon (Fe@AC) was prepared and used as a catalyst in the catalytic ozonation of pulp and paper mill effluent. The activity of this catalyst was studied in terms of color and chemical oxygen demand (COD) removal efficiencies. Results showed that the COD removal rate was increased by 21% in the presence of the Fe@AC catalyst. After 60 min of ozonation (3g/h ozone flow rate) of the pulp and paper mill effluent (initial COD 360 mg/L), COD removal rates reached 56% in the presence of Fe@AC, 43% using AC as catalyst, and only 35% with ozonation alone. Ozone alone can achieve satisfactory color removal results. Owing to the scavenging effect of carbonate and bicarbonate ions towards hydroxyl radicals, the COD removal rate in Fe/AC catalytic ozonation of the effluent was strongly inhibited in the presence of these two ions. The COD removal rate followed the pseudosecond-order kinetics model well. The COD removal rate constant in the Fe@AC/O3 process was about 1.6 times higher than that of the AC/O3 process, and approximately 2.1 times higher than that of ozone alone.

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Section: Enhanced Cod and Color Removalsupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Enhanced Removal of COD and Color in Paper-making Wastewater by Ozonation Catalyzed by Fe Supported on Activated Carbon

et al. 2016

BioResources

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“…Compound 2 (C2), with a molecular ion of m/z 119, could correspond to N-methyl-2-(methylthio) acetamide by comparing its mass spectrum with that reported in the literature (Evgenidou et al, 2006;Qiang et al, 2013), which was also detected during DMT degradation by photocatalysis and OMT degradation by catalytic ozonation (Evgenidou et al, 2006;Qiang et al, 2013).…”

Section: Byproducts Formationmentioning

confidence: 99%

“…The fragment ions at m/z 141 and 125 could arise from its molecular ion (m/z 156) by the loss of CH 3 À and CH 3 OÀ, respectively. Phosphorothioic acid was reported as a byproduct in the photodegradation of DMT catalyzed by TiO 2 and in the catalytic ozonation of OMT with Fe(III)-loaded activated carbon (Evgenidou et al, 2006;Qiang et al, 2013).…”

Section: Byproducts Formationmentioning

confidence: 99%

Kinetics and mechanism of dimethoate chlorination during drinking water treatment

et al. 2014

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h i g h l i g h t sThe reaction of DMT with chlorine was of first-order in each reactant. The observed rate constant of DMT degradation was strongly pH dependent. Both bromide and humic acid promoted but ammonium inhibited the degradation of DMT. Three organic byproducts were detected in DMT degradation by chlorine. The toxicity of DMT solution obviously increased after chlorination. a r t i c l e i n f o a b s t r a c t Dimethoate (DMT), a commonly used organophosphorus pesticide, is of great concern because of its toxicity and potentially harmful effects on water sources. The elimination of DMT as well as the toxicity and persistence of the byproducts formed during DMT degradation is most important for the safety of drinking water. This study first determined the reaction kinetics of DMT with free chlorine (FC) under typical water treatment conditions. The reaction between DMT and FC proceeded rapidly, exhibiting first-order with respect to each reactant. The degradation of DMT by FC was highly pH dependent, and the pseudofirst-order rate constant decreased obviously from 0.13 to 0.02 s À1 with an increase in pH from 7.0 to 8.3. Bromide ion accelerated the reaction by acting as a catalyst, and the accelerated reaction rate was linearly proportional to the bromide concentration. As a ubiquitous component in natural waters, humic acid also increased the reaction rate. However, the presence of ammonium inhibited the degradation of DMT due to its rapid converting FC to chloramines. Omethoate (OMT) was identified as an important byproduct of DMT chlorination, but only accounted for ca. 28% of the DMT degraded; and other two organic byproducts were also identified. The acute toxicity of DMT solution increased after treatment with FC due to the formation of more toxic byproducts (e.g. OMT).

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“…There are three main routes for OP degradation in the environment: physical degradation (Hao et al 2011;Golash and Gogate 2012;Rao et al 2012), chemical degradation (Bai et al 2010;Ling et al 2011;Qiang et al 2013), and microbial degradation (Cáceresa et al 2007;Ruoss et al 2011;Sasikala et al 2012), of which chemical degradation has received the greatest attention (Tang et al 1998). Chemical degradation includes hydrolysis and oxidation reactions; the former is considered to be the most important.…”

Section: Introductionmentioning

confidence: 99%

Degradation of four organophosphorous pesticides catalyzed by chitosan-metal coordination complexes

Zhang

Meng

et al. 2015

Environ Sci Pollut Res

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Three types of chitosan with high (3.40 × 10(6)), medium (2.11 × 10(5)), and low (5.89 × 10(4)) molecular weights were chosen as ligands to synthesize chitosan magnesium, calcium, iron(III), and zinc coordination complexes. Degradation of four organophosphorous pesticides (dichlorvos, omethoate, dimethoate, and chlorpyrifos) by the above complexes in a heterogeneous system was studied using solid-phase extraction (SPE) and gas chromatography (GC). The degradation effect is related to the different types of chitosan, metal, and organophosphorus pesticides (OPs). Complexes of transition metals and the low molecular weight chitosan showed high hydrolytic activity. The chitosan-iron(III) complex was further used to study its catalytic kinetics on the hydrolysis of OPs. At pH 7.0 and 20 °C, the half-life of dichlorvos hydrolyzed by chitosan iron(III) was 52 h, whereas that of spontaneous dichlorvos hydrolysis was 105 h. The degradation ratio of omethoate and dimethoate increased to 38 and 52 %, respectively, which were 34 and 48 % higher than the control after 6 days at pH 7.0 and 20 °C. For all tested conditions, an increase of pH and temperature resulted in a higher degradation rate.

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Kinetics and mechanism for omethoate degradation by catalytic ozonation with Fe(III)-loaded activated carbon in water

Cited by 32 publications

References 22 publications

Enhanced Removal of COD and Color in Paper-making Wastewater by Ozonation Catalyzed by Fe Supported on Activated Carbon

Enhanced Removal of COD and Color in Paper-making Wastewater by Ozonation Catalyzed by Fe Supported on Activated Carbon

Kinetics and mechanism of dimethoate chlorination during drinking water treatment

Degradation of four organophosphorous pesticides catalyzed by chitosan-metal coordination complexes

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