Degradation of Recalcitrant Safranin T Through an Electrochemical Process and Three Photochemical Advanced Oxidation Technologies

Granda-Ramírez, Carlos F.; Hincapié-Mejía, Gina; Serna-Galvis, Efraím A.; Torres-Palma, Ricardo A.

doi:10.1007/s11270-017-3611-2

Cited by 7 publications

(3 citation statements)

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“…Although some comparative studies between different AOPs, or a combination of technologies have been reported, − to the best of our knowledge a comparative study specifically addressing the concentration dependent formation of chlorinated intermediates during ECD, PCD, and photoelectrochemical degradation (PECD), starting from a nonchlorinated parent compound in saline solutions, has not yet been performed.…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Brüninghoff

Duijne

Braakhuis

et al. 2019

Environ. Sci. Technol.

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We evaluated electrochemical degradation (ECD) and photocatalytic degradation (PCD) technologies for saline water purification, with a focus on rate comparison and formation and degradation of chlorinated aromatic intermediates using the same non-chlorinated parent compound, 4-ethylphenol (4EP). At 15 mA·cm –2 , and in the absence of chloride (0.6 mol·L –1 NaNO 3 was used as supporting electrolyte), ECD resulted in an apparent zero-order rate of 30 μmol L –1 ·h –1 , whereas rates of ∼300 μmol L –1 ·h –1 and ∼3750 μmol L –1 ·h –1 were computed for low (0.03 mol·L –1 ) and high (0.6 mol·L –1 ) NaCl concentration, respectively. For PCD, initial rates of ∼330 μmol L –1 ·h –1 and 205 μmol L –1 ·h –1 were found for low and high NaCl concentrations, at a photocatalyst (TiO 2 ) concentration of 0.5 g·L –1 , and illumination at λ max ≈ 375 nm, with an intensity ∼0.32 mW·cm –2 . In the chlorine mediated ECD approach, significant quantities of free chlorine (hypochlorite, Cl 2 ) and chlorinated hydrocarbons were formed in solution, while photocatalytic degradation did not show the formation of free chlorine, nor chlorine-containing intermediates, and resulted in better removal of non-purgeable hydrocarbons than ECD. The origin of the minimal formation of free chlorine and chlorinated compounds in photocatalytic degradation is discussed based on photoelectrochemical results and existing literature, and explained by a chloride-mediated surface-charge recombination mechanism.

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Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Brüninghoff

Duijne

Braakhuis

et al. 2019

Environ. Sci. Technol.

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“…These techniques can effectively degrade and mineralize persistent organic pollutants through generating highly active free radicals, such as •OH and •SO 4 2− . [19][20][21] In general, they have disadvantages of high cost, harsh reaction conditions and secondary pollution.…”

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confidence: 99%

Electrochemical Degradation of Tetracycline Antibiotics Using a Ti/SnO₂-Sb₂O₃/PbO₂Anode: Kinetics, Pathways, and Biotoxicity Change

Shuan

Liu

Jiang³

et al. 2019

J. Electrochem. Soc.

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The electrochemical degradation of tetracycline antibiotics (TCs), such as tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC), was investigated by using SnO 2 -Sb 2 O 3 and PbO 2 modified Ti electrode (Ti/SnO 2 -Sb 2 O 3 /PbO 2 anode). The modified electrode was prepared with a SnO 2 -Sb 2 O 3 interlayer and a PbO 2 active layer on the surface of Ti sheet, and characterized by scanning electron microscope, X-ray diffraction and cyclic voltammetry. The effects of supporting electrolyte, current density and the initial concentration of TCs on electrochemical degradation were also examined. For the degradation of 50 mg•L −1 TC, OTC and CTC at 5 mA cm −2 , the energy consumption were 39.9, 40.0 and 37.7 kWhmol −1 , and the removal efficiencies could reach 79.5%, 82.0% and 90.3% for 2 h, respectively. The degradation processes followed the first-order kinetic model, and the rate constants of TC, OTC and CTC were 0.78, 0.84 and 0.97 h −1 , respectively. The possible degradation pathways were proposed through monitoring the degradation products of TCs. The results from bioluminescence inhibition assays suggested the residual biotoxicity after complete TCs degradation, and extra reaction was necessary to reduce biotoxicity. Overall, the electrochemical degradation using Ti/SnO 2 -Sb 2 O 3 /PbO 2 anode has a great potential to remove TCs from wastewater.

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“…•− , H 2 O 2, and HO • degrade organic contaminants (Equation ( 6)) [9][10][11][12]. It should be indicated that the redox potential (E • ) for the h + in CdS corresponds to~1.7 V [13], which is lower than required to oxidize water (E • = 2.31 V at pH 7 [14]) or hydroxyl anion (E • = 1.9 V [15]).…”

Section: Introductionmentioning

confidence: 99%

Use of CdS from Teaching-Laboratory Wastes as a Photocatalyst for the Degradation of Fluoroquinolone Antibiotics in Water

Serna-Galvis

Ávila-Torres

Ibáñez

et al. 2021

Water

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Laboratory wastes containing Cd2+ and water polluted by pharmaceuticals represent an environmental concern. In this work, a proof concept, consisting of the use of teaching-laboratory wastes to synthesize CdS and its subsequent use as a photocatalyst to degrade fluoroquinolone antibiotics, was developed. The CdS was prepared by extraction with thioacetamide and calcination (at 450 °C) and characterized using several techniques. The photocatalytic activity of the CdS, to degrade levofloxacin and norfloxacin, was tested, and the routes involved in the process and the primary transformations of the fluoroquinolones were established. Moreover, the ability of CdS-photocatalysis to eliminate levofloxacin in simulated matrices of fresh urine and hospital wastewater was evaluated. The characterization analyses indicated that the CdS semiconductor was synthesized successfully. Effectively, the CdS acted as a photocatalyst toward degradation of levofloxacin, involving the action of superoxide anion radical, holes, and singlet oxygen mainly. The process induced transformations on the methyl-piperazyl moiety, plus hydroxylation of the fluoroquinolone nucleus on levofloxacin. Additionally, CdS-photocatalysis was highly selective for the elimination of the target pollutant in both tested matrices. Our research indicated the good potentiality of recycling teaching-laboratory wastes to generate photocatalysts to degrade organic pollutants. This work was presented at 4° Congreso Colombiano de Procesos Avanzados de Oxidación (4CCPAOx).

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Degradation of Recalcitrant Safranin T Through an Electrochemical Process and Three Photochemical Advanced Oxidation Technologies

Cited by 7 publications

References 46 publications

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Electrochemical Degradation of Tetracycline Antibiotics Using a Ti/SnO₂-Sb₂O₃/PbO₂Anode: Kinetics, Pathways, and Biotoxicity Change

Use of CdS from Teaching-Laboratory Wastes as a Photocatalyst for the Degradation of Fluoroquinolone Antibiotics in Water

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Degradation of Recalcitrant Safranin T Through an Electrochemical Process and Three Photochemical Advanced Oxidation Technologies

Cited by 7 publications

References 46 publications

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Comparative Analysis of Photocatalytic and Electrochemical Degradation of 4-Ethylphenol in Saline Conditions

Electrochemical Degradation of Tetracycline Antibiotics Using a Ti/SnO2-Sb2O3/PbO2Anode: Kinetics, Pathways, and Biotoxicity Change

Use of CdS from Teaching-Laboratory Wastes as a Photocatalyst for the Degradation of Fluoroquinolone Antibiotics in Water

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Electrochemical Degradation of Tetracycline Antibiotics Using a Ti/SnO₂-Sb₂O₃/PbO₂Anode: Kinetics, Pathways, and Biotoxicity Change