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Water Research Aug 2023The widespread occurrence of p-arsanilic acid (p-ASA) in natural environments poses big threats to the biosphere due to the generation of toxic inorganic arsenic (i.e.,...
The widespread occurrence of p-arsanilic acid (p-ASA) in natural environments poses big threats to the biosphere due to the generation of toxic inorganic arsenic (i.e., As(III) and As(V), especially As(III) with higher toxicity and mobility). Oxidation of p-ASA or As(III) to As(V) followed by precipitation of total arsenic using Fe-based advanced oxidation processes demonstrated to be a promising approach for the treatment of arsenic contamination. This study for the first time investigated the efficiency and inherent mechanism of p-ASA and As(III) oxidation by Fe(II)/peracetic acid (Fe(II)/PAA) and PAA processes. p-ASA was rapidly degraded by the Fe(II)/PAA process within 20 s at neutral to acidic pHs under different conditions, while it was insignificantly degraded by PAA oxidation alone. Lines of evidence suggested that hydroxyl radicals and organic radicals generated from the homolytic OO bond cleavage of PAA contributed to the degradation of p-ASA in the Fe(II)/PAA process. p-ASA was mainly oxidized to As (V), NH, and p-aminophenol by the Fe(II)/PAA process, wherein the aniline group and its para position were the most vulnerable sites. As(III) of concern was likely generated as an intermediate during p-ASA oxidation and it could be readily oxidized to As(V) by the Fe(II)/PAA process as well as PAA alone. The in-depth investigation demonstrated that PAA alone was effective in the oxidation of As(III) under varied conditions with a stoichiometric molar ratio of 1:1. Efficient removal (> 80%) of total arsenic during p-ASA oxidation by Fe(II)/PAA process or during As(III) oxidation by PAA process with additional Fe(III) in synthetic or real waters were observed, mainly due to the adsorptive interactions of amorphous ferric (oxy)hydroxide precipitates. This study systematically investigates the oxidation of p-ASA and As(III) by the Fe(II)/PAA and PAA processes, which is instructive for the future development of arsenic remediation technology.
Topics: Ferric Compounds; Arsenic; Arsanilic Acid; Peracetic Acid; Arsenites; Oxidation-Reduction; Ferrous Compounds; Water Pollutants, Chemical; Hydrogen Peroxide
PubMed: 37262947
DOI: 10.1016/j.watres.2023.120091 -
Journal of Hazardous Materials Jul 2023Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox(V)), an extensively used organoarsenical feed additive, enters soils through the application of Rox(V)-containing...
Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox(V)), an extensively used organoarsenical feed additive, enters soils through the application of Rox(V)-containing manure and further degrades to highly toxic arsenicals. Microplastics, as emerging contaminants, are also frequently detected in soils. However, the effects of microplastics on soil Rox(V) degradation are unknown. A microcosm experiment was conducted to investigate soil Rox(V) degradation responses to polyethylene (PE) microplastics and the underlying mechanisms. PE microplastics inhibited soil Rox(V) degradation, with the main products being 3-amino-4-hydroxyphenylarsonic acid [3-AHPAA(V)], N-acetyl-4-hydroxy-m-arsanilic acid [N-AHPAA(V)], arsenate [As(V)], and arsenite [As(III)]. This inhibition was likely driven by the decline in soil pH by PE microplastic addition, which may directly enhance Rox(V) sorption in soils. The decreased soil pH further suppressed the nfnB gene related to nitroreduction of Rox(V) to 3-AHPAA(V) and nhoA gene associated with acetylation of 3-AHPAA(V) to N-AHPAA(V), accompanied by a decrease in the relative abundance of possible Rox(V)-degrading bacteria (e.g., Pseudomonadales), although the diversity, composition, network complexity, and assembly of soil bacterial communities were largely influenced by Rox(V) rather than PE microplastics. Our study emphasizes microplastic-induced inhibition of Rox(V) degradation in soils and the need to consider the role of microplastics in better risk assessment and remediation of Rox(V)-contaminated soils.
Topics: Roxarsone; Microplastics; Plastics; Soil; Polyethylene
PubMed: 37116328
DOI: 10.1016/j.jhazmat.2023.131483 -
Environmental Pollution (Barking, Essex... Apr 2023Sea level rise (SLR) is estimated to impact 25% of the world's population along coastal areas leading to an increase in saltwater intrusion. Consequently, changes in the...
Sea level rise (SLR) is estimated to impact 25% of the world's population along coastal areas leading to an increase in saltwater intrusion. Consequently, changes in the soil biogeochemistry of currently non-saline and/or well-drained soils due to saltwater intrusion are of major concern. Saltwater intrusion is expected to affect farmland across large broiler producer regions, where large amounts of manure containing organic arsenicals were applied over the past decades. To determine how SLR may impact the speciation and mobility of adsorbed inorganic and organic As, we used in situ real-time attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) to determine the adsorption and desorption mechanisms of As(V) and 4-aminophenylarsonic (p-ASA, a poultry feed additive) on ferrihydrite (Fh) in the presence of sulfate at varying pH. The adsorption of As(V) and p-ASA increased at lower pH, with As(V) showing IR features consistent with the formation of inner-sphere of As-Fh surface complexes, while p-ASA also formed others structures as H-bonded As-surface complexes, likely mediated by outer-sphere complexes, based on our FTIR and batch experiments data. No observable As(V) or p-ASA desorption from the Fh surface was promoted by sulfate, however sulfate adsorption on the Fh surface was remarkably larger for p-ASA than for As(V). Complimentary, we carried out batch studies of As(V) and p-ASA desorption by Fh, using artificial seawater (ASW) at varying concentrations. The 1% ASW desorbed ∼10% of initially sorbed p-ASA, while at 100% ASW desorbed ∼40%. However, <1% of As(V) was desorbed by 1% ASW solution and only ∼7.9% were desorbed at 100% ASW. The spectroscopic data support the more extensive desorption of p-ASA compared to As(V) observed in batch experiments, suggesting that organoarsenicals may be easily desorbed and, after conversion to inorganic forms, pose a risk to water supplies.
Topics: Animals; Arsenates; Arsanilic Acid; Adsorption; Sulfates; Sea Level Rise; Chickens; Ferric Compounds; Soil; Spectroscopy, Fourier Transform Infrared; Sulfur Oxides; Hydrogen-Ion Concentration
PubMed: 36804144
DOI: 10.1016/j.envpol.2023.121302 -
Environmental Science and Pollution... Mar 2023As a typical wide band gap photocatalyst, titania (TiO) cannot use the visible light and has fast recombination rate of photogenerated electron-hole pairs. Simultaneous...
As a typical wide band gap photocatalyst, titania (TiO) cannot use the visible light and has fast recombination rate of photogenerated electron-hole pairs. Simultaneous introduction of erbium ion (Er) and graphene oxide (rGO) into TiO might overcome these two drawbacks. In this study, Er and rGO were co-doped on TiO to synthesize Er-rGO/TiO photocatalyst through a two-step sol-gel method. Based on the UV-visible diffuse reflectance spectra and photoluminescence spectrum, the introduction of Er and rGO increased the visible light absorption efficiency and enhanced the migration of photogenerated electron. Pure TiO has almost no photocatalytic activity for arsanilic acid (p-ASA) degradation under visible light irradiation. However, while doping with 2.0 mol% Er and 10.0 mol% rGO, the p-ASA could be completely degraded within 50 min by the Er-rGO/TiO photocatalyst under visible light irradiation, and most of produced inorganic arsenic was in situ removed by adsorption from the solution. The reactive oxygen species (ROS) reacting with p-ASA was determined and superoxide radical (O) and singlet oxygen (O) were the dominant ROS for the oxidation of p-ASA and arsenite. This work provides an approach of introducing Er and rGO to enhance the visible light photocatalytic efficiency of TiO.
Topics: Arsanilic Acid; Reactive Oxygen Species; Graphite
PubMed: 36525183
DOI: 10.1007/s11356-022-24627-9 -
Journal of Hazardous Materials Jan 2023Plastic additives widely existed in plastic mulching films, but their roles in microplastics (MPs) derived from these plastics as vectors of pollutants were not clear....
Plastic additives widely existed in plastic mulching films, but their roles in microplastics (MPs) derived from these plastics as vectors of pollutants were not clear. This work clarified the role of plastic additives on the sorption-desorption behaviors of four arsenic species (arsenite (As(Ⅲ)), arsenate (As(Ⅴ)), roxarsone (ROX), and p-arsanilic acid (p-ASA)) on/from virgin polyethylene (V-PE), white PE mulching film (W-PE, with Si-containing additives), and black PE mulching film (B-PE, with CaCO and TiO additives) MPs. The maximum sorption amounts of arsenic species on V-PE (3.33-20.10 mg/kg) and W-PE MPs (4.78-21.93 mg/kg) had no significant difference, while those on B-PE (43.02-252.19 mg/kg) facilitated by its additives were up to one order of magnitude greater than V-PE or W-PE (p < 0.05). Desorption hysteresis index (HI) indicated the irreversible arsenic sorption on three PE MPs, especially for B-PE containing additives that can co-precipitate and complex with arsenicals. The effects of pH, humic substances, and coexisting anions on arsenic sorption by B-PE were more obvious than that by V-PE or W-PE MPs, attributing to electrostatic interaction enhanced by CaCO and TiO additives. This work provides theoretical basis for migration of arsenic species on MPs containing plastic additives and their potential environmental risk assessment.
Topics: Microplastics; Plastics; Arsenic; Arsenates; Polyethylene; Arsenites; Roxarsone; Humic Substances; Arsanilic Acid; Adsorption; Arsenicals; Environmental Pollutants; Water Pollutants, Chemical
PubMed: 36179620
DOI: 10.1016/j.jhazmat.2022.130037 -
Biomedicines Aug 2022Damage to the peripheral vestibular system is known to generate a syndrome characterized by postural, locomotor, oculomotor, perceptual and cognitive deficits. Current...
Damage to the peripheral vestibular system is known to generate a syndrome characterized by postural, locomotor, oculomotor, perceptual and cognitive deficits. Current pharmacological therapeutic solutions for these pathologies lack specificity and efficacy. Recently, we demonstrated that apamin, a specific SK channel blocker, significantly reduced posturo-locomotor and oculomotor deficits in the cat and the rat. The aim of the present study was to test the antivertigo potential of compounds belonging to the SK antagonists family, such as Acacetin and Fluoxetine. Young rats were subjected to unilateral ototoxic lesions of the vestibular organ using transtympanic administration of arsanilic acid (TTA) to evoke unilateral vestibular loss (UVL). Vestibular syndrome was monitored using behavioural evaluation allowing appreciation of the evolution of static and dynamic posturo-locomotor deficits. A significant effect of the TTA insult was only found on the distance moved, the mean body velocity and the not moving time. From day 2 to week 2 after TTA, the distance moved and the mean body velocity were significantly decreased, while the not moving time was significantly increased. Acacetin does not evoke any significant change in the vestibular posturo-locomotor parameters' kinetics. Administration of Fluoxetine two weeks before TTA and over three weeks after TTA (preventive group) does not evoke any significant change in the vestibular posturo-locomotor parameters' kinetics. Administration of Fluoxetine from three weeks after TTA significantly delayed the functional recovery. This study demonstrates that Acacetin or Fluoxetine in TTA vestibulo-injured rats does not bring any significant benefit on the posture and locomotor balance deficits.
PubMed: 36140199
DOI: 10.3390/biomedicines10092097 -
Journal of Colloid and Interface Science Jan 2023Organic arsenic pollutant p-arsanilic acid (p-ASA) in wastewater can be converted into highly toxic inorganic arsenic under natural conditions, causing serious harm to...
HYPOTHESIS
Organic arsenic pollutant p-arsanilic acid (p-ASA) in wastewater can be converted into highly toxic inorganic arsenic under natural conditions, causing serious harm to the environment and human health. In this study, an Fe-based metal-organic framework (MOF) material, activated MIL-88A, was synthesized as an adsorbent to remove p-ASA in water.
EXPERIMENTS
Various influencing factors in the material synthesis process, including temperature, time, solution, and annealing process, were investigated to obtain the optimal reaction conditions. The synthesized activated MIL-88A had great porosity and excellent adsorption capacity for p-ASA in a wide pH range (3 ∼ 10). When the pH of the solution was 6, the activated MIL-88A achieved a great adsorption capacity of 813 mg·g for the p-ASA solution with an initial concentration of 0.334 mmol·L. In addition, it still had excellent adsorption capacity after 4 times of repeated usage and washing.
FINDINGS
The adsorption kinetics of p-ASA on the activated MIL-88A followed the pseudo-second-order models, and the adsorption isotherms can be fitted by the Langmuir models well. The adsorption behavior was spontaneous and endothermic, and was dominated by Fe-O-As coordination and hydrogen bonding.
Topics: Humans; Arsanilic Acid; Adsorption; Metal-Organic Frameworks; Arsenic; Wastewater; Water Pollutants, Chemical; Water
PubMed: 36095897
DOI: 10.1016/j.jcis.2022.08.133 -
Chemosphere Dec 2022Organoarsenical antibiotics pose a severe threat to the environment and human health. In aquatic environment, dissolved organic matter (DOM)-mediated photochemical...
Organoarsenical antibiotics pose a severe threat to the environment and human health. In aquatic environment, dissolved organic matter (DOM)-mediated photochemical transformation is one of the main processes in the fate of organoarsenics. Dicarbonyl is a typical redox-active moiety in DOM. However, the knowledge on the photoconversion of organoarsenics by DOM, especially the contributions of dicarbonyl moieties is still limited. Here, we systematically investigated the photochemical transformation of three organoarsenics with the simplest β-diketone, acetylacetone (AcAc), as a model dicarbonyl moiety of DOM. The presence of AcAc significantly enhanced the photochemical conversion of roxarsone (ROX), whereas only minor effects were observed for 3-amino-4-hydroxyphenylarsonic acid (HAPA) and arsanilic acid (ASA), because the latter two (with an amino (-NH) group) are more photoactive than ROX (with a nitro (-NO) group). The results demonstrate that AcAc was a potent photo-activator and the reduction of -NO to -NH might be a rate-limiting step in the phototransformation of ROX. At a 1:1 M ratio of AcAc to ROX, the photochemical transformation rate of ROX was increased by 7 folds. In O-rich environment, singlet oxygen, peroxide radicals, and ·OH were the main reactive species that led to the breakage of the C-As bond in ROX and the oxidation of the released arsono group to arsenate, whereas the triplet-excited state of AcAc (AcAc*) and carbon-centered radicals from the photolysis of AcAc dominated in the reductive transformation of ROX. In anoxic environment, 3-amino-4-hydroxyphenylarsonic acid was one of the main reductive transformation intermediates of ROX, whose photolysis rate was about 35 times that of ROX. The knowledge obtained here is of great significance to better understand the fate of organoarsenics in natural environment.
Topics: Anti-Bacterial Agents; Arsanilic Acid; Arsenates; Carbon; Humans; Nitrogen Dioxide; Oxidation-Reduction; Pentanones; Peroxides; Photolysis; Roxarsone; Singlet Oxygen; Water Pollutants, Chemical
PubMed: 36084835
DOI: 10.1016/j.chemosphere.2022.136326 -
Water Research Sep 2022As a feed additive, p-arsanilic acid (p-ASA) is hardly metabolized in animal bodies and is excreted chemically unchanged via feces and urine, which can be transformed...
As a feed additive, p-arsanilic acid (p-ASA) is hardly metabolized in animal bodies and is excreted chemically unchanged via feces and urine, which can be transformed into more toxic inorganic arsenic species and other organic by-products upon degradation in the aquatic environment. In this study, UV-LED/persulfate (PS)/Fe(Ⅲ) and UV-LED/peroxymonosulfate (PMS)/Fe(Ⅲ) processes were developed to remove p-ASA and immobilize the formed inorganic arsenic via tuning solution pH. UV-LED/PMS/Fe(Ⅲ) (90.8%) presented the best performance for p-ASA degradation at pH 3.0, and the p-ASA degradation in these processes both followed the pseudo-first-order kinetics. The ∙OH played the major role in UV-LED/PS/Fe(Ⅲ) and UV-LED/PMS/Fe(Ⅲ) systems. Solution pH greatly affected the p-ASA degradation and the maximum removal can be achieved at pH 3.0 due to the presence of more Fe(OH)(HO). The dosages of Fe(III) and PMS (PS), SO and HCO significantly influenced the performance of p-ASA oxidation, while HA, Cl and NO slightly affected the p-ASA degradation. According to quantum chemical calculation, radical addition on the C atom in the C-As bond of p-ASA was corroborated to be the dominant reaction pathway by SO∙ and ∙OH. Additionally, the reactive sites and reasonable degradation pathways of p-ASA were proposed based on DFT calculation and HPLC/MS analysis. The release of inorganic arsenic in both processes can be effectively immobilized and the toxicity of the reaction solution dramatically reduced by adjusting solution pH to 6.0. UV-LED/PMS/Fe(Ⅲ) process was found to be more cost-effective than UV-LED/PS/Fe(Ⅲ) process at the low oxidant dosages.
Topics: Animals; Arsanilic Acid; Arsenates; Arsenic; Ferric Compounds; Oxidants; Oxidation-Reduction; Peroxides; Water Pollutants, Chemical
PubMed: 35998556
DOI: 10.1016/j.watres.2022.118989 -
Molecules (Basel, Switzerland) Dec 2021A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation...
A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation of nanomaterials, polyethyleneimine (PEI) improved the stability of the solution and acted as a reducing agent to generate reduced graphene oxide (rGO) with relatively strong conductivity, thereby promoting the transfer of electrons. The dual conductivity of rGO and silver nanoparticles (AgNPs) improved the sensitivity of the sensor. The synthesis of nanomaterials were confirmed by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. In the optimal experiment conditions, the sensor could achieve the detection range of 0.50-500 ng mL and the limit of detection (LOD) of 0.38 ng mL (S/N = 3). Moreover, the sensor exhibited excellent specificity and acceptable stability, suggesting that the proposed sensor possessed a good potential in ASA detection. Thus, the as-prepared biosensor may be a potential way for detecting other antibiotics in meat and animal-derived foods.
Topics: Arsanilic Acid; Biosensing Techniques; Electrochemical Techniques; Graphite; Immunoassay; Limit of Detection; Metal Nanoparticles; Nanocomposites; Polyethyleneimine; Reproducibility of Results; Silver
PubMed: 35011402
DOI: 10.3390/molecules27010172