Effect of chloride and sulfate ions on the advanced photo Fenton and modified photo Fenton degradation process of Alizarin Red S

Devi, L. Gomathi; Munikrishnappa, C.; Nagaraj, B.; Rajashekhar, K. Eraiah

doi:10.1016/j.molcata.2013.03.023

Cited by 94 publications

(34 citation statements)

References 29 publications

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“…Furthermore, the inorganic anions generated in the system may also contribute to HO • scavenging [31–33]. To investigate the effect of reducing agent concentration on PCE degradation, batch experiments were conducted in the presence of 1.0, 2.0, and 5.0 mM of reducing agents and 0.5 mM of Fe(III) and SPC each (Fig.…”

Section: Resultsmentioning

confidence: 99%

Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system

Miao

et al. 2015

Journal of Hazardous Materials

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In this study, the effects of reducing agents on the degradation of tetrachloroethene (PCE) were investigated in the Fe(II)/Fe(III) catalyzed sodium percarbonate (SPC) system. The addition of reducing agents, including hydroxylamine hydrochloride, sodium sulfite, ascorbic acid and sodium ascorbate, accelerated the Fe(III)/Fe(II) redox cycle, leading to a relatively steady Fe(II) concentration and higher production of free radicals. This, in turn, resulted in enhanced PCE oxidation by SPC, with almost complete PCE removal obtained for appropriate Fe and SPC concentrations. The chemical probe tests, using nitrobenzene and carbon tetrachloride, demonstrated that HO• was the predominant radical in the system and that O2•− played a minor role, which was further confirmed by the results of electron spin resonance measurements. PCE degradation decreased significantly with the addition of isopropanol, a HO• scavenger, supporting the hypothesis that HO• was primarily responsible for PCE degradation. It is noteworthy that Cl− release was slightly delayed in the first 20 mins, indicating that intermediate products were produced. However, these intermediates were further degraded, resulting in the complete conversion of PCE to CO2. In conclusion, the use of reducing agents to enhance Fe(II)/Fe(III) catalyzed SPC oxidation appears to be a promising approach for the rapid degradation of organic contaminants in groundwater.

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Section: Resultsmentioning

confidence: 99%

Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system

Miao

et al. 2015

Journal of Hazardous Materials

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“…Additionally, oxidation reactions involving these inorganic radicals (Eqs. (13) and (14)) should be expected (Kiwi et al 2000;Truong et al 2004;Elmorsi et al 2010;Deng et al 2012;Devi et al 2013;Silva et al 2015).…”

Section: •-mentioning

confidence: 92%

“…(15)-(22)), hindering the Fenton reactions and consequently decreasing the decolorization efficiency De Laat and Le 2006;Elmorsi et al 2010;Deng et al 2012;Devi et al 2013).…”

Section: •-mentioning

confidence: 99%

“…The presence of surfactants, suspended solids, certain inorganic ions (chloride, sulfate, phosphate, for example), and other organic compounds can significantly affect the efficiency of the Fenton reactions Babuponnusami and Muthukumar 2014), compromising the treatment, being important to evaluate the influence of these species on the degradation process (De Laat and Le 2006;Pignatello et al 2006;Devi et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Degradation of Direct Red 81 mediated by Fenton reactions: multivariate optimization, effect of chloride and sulfate, and acute ecotoxicity assessment

Marson

Paiva

Gonçalves

et al. 2016

Environ Sci Pollut Res

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The role of different operational parameters related to Fenton reactions (pH, concentration of Fe and HO, and reaction time) and of Cl and SO was investigated in the degradation of the azo dye Direct Red 81, expressed in terms of its decolorization. The factorial design and Pareto's charts showed that only Fe concentration and pH influence the decolorization under the conditions evaluated. So, only these parameters were optimized using the response surface model. Under the best experimental conditions (initial pH 2.5, 11 mg L Fe, 78 mg L HO, and 20 min of reaction), 94 % of decolorization was achieved. However, even under the these conditions, but in the presence of Cl and SO , a striking loss of efficiency was observed as the concentration of these ions was increased, due the formation of chloride- and sulfate-iron complexes and less reactive inorganic radicals (Cl and SO). The results show that the presence of Cl is more deleterious, since sulfate-iron complexes are more reactive towards HO, and the SO turns out to favor the degradation. On the other hand, the negative effect of Cl can be compensated by increasing the chloride concentration up to 300 mmol L. In addition, although a high degradation level has been obtained by monitoring the dye absorbance and by HPLC-UV, a low mineralization occurred, being generated degradation products of higher ecotoxicity to Vibrio fischeri, showing the need of subsequent studies to identify these compounds as well as the application of additional treatments aiming the complete mineralization of the dye.

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“…Similarly, sulphate ions can form complexes with ferrous and ferric ions, such as FeSO þ 4 . At pH 3.0, FeSO þ 4 and FeðOHÞ þ 2 are the predominant ferric species [36].…”

Section: Fenton-based Treatments Of Imazalil In Swmentioning

confidence: 99%

Treatment of wastewater containing imazalil by means of Fenton-based processes

Santiago

Araña

Díaz

et al. 2016

Desalination and Water Treatment

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A B S T R A C TThis work studies the elimination, mineralization and detoxification through Fenton-based processes of wastewaters contaminated with the fungicide imazalil as a result of the postharvest treatment of bananas. Fe(II) and H 2 O 2 concentrations were optimized for degradation of the corresponding imazalil concentrations. The activity of the imazalil degradation process was studied in deionized water and in simulated and real agroindustrial wastewaters. Results show that the water matrix had no detrimental effect on wastewater treatment when using the Fenton technique, but optimal iron content had to be increased when applying the photo-Fenton process. Even so, the optimal iron and H 2 O 2 contents required for the photo-Fenton reaction were 6 times and 50% lower, respectively, than for the Fenton procedure. Solar pilot plant tests confirmed the detoxification of two agro-industrial wastewater effluents containing imazalil.

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Effect of chloride and sulfate ions on the advanced photo Fenton and modified photo Fenton degradation process of Alizarin Red S

Cited by 94 publications

References 29 publications

Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system

Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system

Degradation of Direct Red 81 mediated by Fenton reactions: multivariate optimization, effect of chloride and sulfate, and acute ecotoxicity assessment

Treatment of wastewater containing imazalil by means of Fenton-based processes

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