Degradation of β-blockers in water by sulfate radical-based oxidation: kinetics, mechanism and ecotoxicity assessment

Tay, Kheng Soo; Ismail, Noor Azina

doi:10.1007/s13762-016-1083-3

Cited by 13 publications

(2 citation statements)

References 31 publications

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“…The rate constant of the sulfate radical anion reaction (k SO4•À ) determined by Liu et al (2013) for ATE, 1.3 Â 10 10 M À1 s À1 , is much higher than the value of Lian et al (2017), 5.11 + 0.26 Â 10 9 M À1 s À1 . The same is true for the values determined for MET 5.11 + 0.12 Â 10 9 and 1.0 + 0.1 Â 10 10 M À1 s À1 , respectively (Tay & Ismail 2016;Lian et al 2017). The value for PRO is 4.79 + 0.26 Â 10 9 M À1 s À1 (Lian et al 2017).…”

Section: Rate Constants Of Reactive Radicals In Reaction With β-Blockerssupporting

confidence: 59%

Evaluation of advanced oxidation processes for β-blockers degradation: a review

Kovács

Tóth

Wojnárovits

2021

Water Science and Technology

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This study summarizes the results of scientific investigations on the removal of the three most-often used ß-blockers (atenolol, metoprolol and propranolol) by various advanced oxidation processes (AOP). The free radical chemistry, rate constants, degradation mechanism and elimination effectiveness of these compounds are discussed together with the technical details of experiments. In most of AOP the degradation is predominantly initiated by hydroxyl radicals. In sulfate radical anion based oxidation processes (SROP) both hydroxyl radical and sulfate radical anion greatly contributes to the degradation. The rate constants of reactions with these two radicals are in the 109–1010 M−1 s−1 range. The degradation products reflect ipso attack, hydroxylation on the aromatic ring and/or the amino moiety and cleavage of the side chain. Among AOP photocatalysis and SROP are the most effective for degradation of the three ß-blockers. The operating parameters have to be optimized to the most suitable effectiveness.

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Section: Rate Constants Of Reactive Radicals In Reaction With β-Blockerssupporting

confidence: 59%

Evaluation of advanced oxidation processes for β-blockers degradation: a review

Kovács

Tóth

Wojnárovits

2021

Water Science and Technology

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“…At the working pH (4-5), SO4 −• is believed to be the major contributing radical responsible for the destruction of the organic contaminants in the PS/SR system [69]. Accordingly, both Ph and MTP, with comparable SO4 −• rate constant values (kPh = 8.8 × 10 10 M −1 s −1 [70] and kMTP = 1.0 × 10 10 M −1 s −1 [71]), showed similar removal profiles. When MIL-53(Fe) was used in combination with simulated solar radiation and PS, better photocatalytic performance in terms of Ph and MTP removal rates was obtained as illustrated in Figure 14.…”

Section: Photocatalytic Activity Of Mil-53(fe) Under Simulated Solar ...mentioning

confidence: 99%

Insights into the Stability and Activity of MIL-53(Fe) in Solar Photocatalytic Oxidation Processes in Water

et al. 2021

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MIL-53(Fe) is a metal organic framework that has been recently considered a heterogeneous photocatalyst candidate for the degradation of water pollutants under visible or solar radiation, though stability studies are rather scarce in the literature. In this work, MIL-53(Fe) was successfully synthesized by a solvothermal method and fully characterized by X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), N2 adsorption–desorption isotherm, Thermogravimetric analysis coupled with mass spectrometry (TGA-MS), UV-visible diffuse reflectance spectroscopy (DRS), elemental analysis and wavelength dispersive X-ray fluorescence (WDXRF). The effects of pH, temperature, solar radiation and the presence of oxidants (i.e., electron acceptors) such as ozone, persulfate and hydrogen peroxide on the stability of MIL-53(Fe) in water were investigated. The as-synthetized MIL-53(Fe) exhibited relatively good stability in water at pH 4 but suffered fast hydrolysis at alkaline conditions. At pH 4–5, temperature, radiation (solar and visible radiation) and oxidants exerted negative effect on the stability of the metal–organic framework (MOF) in water, resulting in non-negligible amounts of metal (iron) and linker (terephthalic acid, H2BDC) leached out from MIL-53(Fe). The photocatalytic activity of MIL-53(Fe) under simulated solar radiation was studied using phenol and metoprolol as target pollutants. MIL-53(Fe) on its own removed less than 10% of the pollutants after 3 h of irradiation, while in the presence of ozone, persulfate or hydrogen peroxide, complete elimination of pollutants was achieved within 2 h of exposure to radiation. However, the presence of oxidants and the formation of some reaction intermediates (e.g., short-chain carboxylic acids) accelerated MIL-53(Fe) decarboxylation. The findings of this work suggest that MIL-53(Fe) should not be recommended as a heterogeneous photocatalyst for water treatment before carrying out a careful evaluation of its stability under actual reaction conditions.

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