Kinetics and mechanisms of pH-dependent direct photolysis of p-arsanilic acid under UV-C light

Xu, Jing; Shen, Xiangyi; Wang, Duanli; Zhao, Chuxuan; Liu, Zizheng; Pozdnyakov, Ivan P.; Wu, Feng; Xia, Jun

doi:10.1016/j.cej.2017.12.037

Cited by 30 publications

(4 citation statements)

References 43 publications

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“…Under ultraviolet-C light (254 nm) irradiation without dissolved oxygen, p-ASA removal rate ranged from 0.077 μM min −1 at pH 1.0 to 3.78 μM min −1 at pH 11.0. 8 When dissolved oxygen exists, hydroxyl radical and singlet oxygen would form and enhance the removal of p-ASA. 9,10 After H 2 O 2 was added into photo degradation system, pseudo first order reaction rate constants increased to 36.4 × 10 −3 min −1 at pH 2.0.…”

Section: Introductionmentioning

confidence: 99%

Removal of Organoarsenic with Ferrate and Ferrate Resultant Nanoparticles: Oxidation and Adsorption

Yang

Wang

Liu

et al. 2018

Environ. Sci. Technol.

140

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Many investigations focused on the capacity of ferrate for the oxidation of organic pollutant or adsorption of hazardous species, while little attention has been paid on the effect of ferrate resultant nanoparticles for the removal of organics. Removing organics could improve microbiological stability of treated water and control the formation of disinfection byproducts in following treatment procedures. Herein, we studied ferrate oxidation of p-arsanilic acid (p-ASA), an extensively used organoarsenic feed additive. p-ASA was oxidized into As(V), p-aminophenol (p-AP), and nitarsone in the reaction process. The released As(V) could be eliminated by in situ formed ferric (oxyhydr) oxides through surface adsorption, while p-AP can be further oxidized into 4,4′-(diazene-1,2-diyl) diphenol, p-nitrophenol, and NO 3 − . Nitarsone is resistant to ferrate oxidation, but mostly adsorbed (>85%) by ferrate resultant ferric (oxyhydr) oxides. Ferrate oxidation (ferrate/p-ASA = 20:1) eliminated 18% of total organic carbon (TOC), while ferrate resultant particles removed 40% of TOC in the system. TOC removal efficiency is 1.6 to 38 times higher in ferrate treatment group than those in O 3 , HClO, and permanganate treatment groups. Besides ferrate oxidation, adsorption of organic pollutants with ferrate resultant nanoparticles could also be an effective method for water treatment and environmental remediation.

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Section: Introductionmentioning

confidence: 99%

Removal of Organoarsenic with Ferrate and Ferrate Resultant Nanoparticles: Oxidation and Adsorption

Yang

Wang

Liu

et al. 2018

Environ. Sci. Technol.

140

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“…By comparatively analyzed the elemental composition of the CAFM@PAC surface before and after the reaction, the enrichment of N and As elements was detected, which indirectly indicated the successful trapping of p-ASA on the material surface and its degradation products, which might include inorganic arsenic and nitrogen groups from -NH 2 (Figure S3 (iv-xiii)). It was worth noting that according to previous studies, the breakage of C–N bonds in the structure might occur during the degradation of p-ASA, releasing -NH 2 groups and inorganic arsenic ions, and thus the material composition of the N and As elements on the surface of the material will be explored in more detail in subsequent studies.…”

Section: Resultsmentioning

confidence: 99%

Organic Arsenic Removal by Using Covalently Bonded Iron–Aluminum Loaded Activated Carbon: Synergistic Mechanisms of Enhanced Adsorption and in Situ Hydrogen Peroxide Oxidation

Kong,

Lu,

Huang

et al. 2024

ACS EST Water

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In this study, iron–aluminum covalently bonded modified activated carbon (CAFM@PAC) was prepared by a constant-temperature infiltration method, which demonstrated highly efficient removal capability against p-aminobenzoic acid (p-ASA). The complete degradation of 30 μM p-ASA was achieved within 6 h at a dosage of 2.0 g/L CAFM@PAC, which was attributed to the enhanced adsorption mechanism involving electrostatic, hydrogen bonding, and π–π EDA interactions, as well as synergistic interactions between the Fe/Al/C fractions for the in situ production of H2O2 under acidic conditions, which triggered a Fenton-like reaction for the generation of ROS. The Fe/Al covalent structure promotes rapid electron transfer and accelerated Fe2+/Fe3+ cycling, resulting in a highly efficient H2O2 generation system. DFT calculations and product analysis confirmed that the C3 and C6 sites of p-ASA were the key sites for ROS attack. CAFM@PAC exhibited strong environmental adaptability and high recyclability, and maintains excellent removal efficiencies even in a multi-ionic system, with very low leakage of metal ions. CAFM@PAC showed excellent removal efficiency even in a polyconic system and very low metal ion leakage, demonstrating its potential as a sustainable water treatment material.

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“…In their study with p -arsanilic acid, Xu et al pointed out that two possible causes for the pH-dependent photolysis of the compound were (I) the molecule ionization and (II) changes in absorbance at the irradiation wavelength as the pH varies [ 19 ]. As highlighted by Iovino et al, a compound can behave differently when exposed to UV radiation if it is found in the molecular form (pH < pKa) or in the anionic form (pH > pKa) [ 15 ].…”

Section: Resultsmentioning

confidence: 99%

Pharmaceutical compounds photolysis: pH influence

Fuziki¹,

Ribas²,

Tusset³

et al. 2023

Heliyon

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Kinetics and mechanisms of pH-dependent direct photolysis of p-arsanilic acid under UV-C light

Cited by 30 publications

References 43 publications

Removal of Organoarsenic with Ferrate and Ferrate Resultant Nanoparticles: Oxidation and Adsorption

Removal of Organoarsenic with Ferrate and Ferrate Resultant Nanoparticles: Oxidation and Adsorption

Organic Arsenic Removal by Using Covalently Bonded Iron–Aluminum Loaded Activated Carbon: Synergistic Mechanisms of Enhanced Adsorption and in Situ Hydrogen Peroxide Oxidation

Pharmaceutical compounds photolysis: pH influence

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