scholarly journals UV and (V)UV irradiation of sitagliptin in ultrapure water and WWTP effluent: Kinetics, transformation products and degradation pathway

Chemosphere ◽  
2021 ◽  
pp. 132393
Author(s):  
Dániel Krakkó ◽  
Ádám Illés ◽  
Attila Domján ◽  
Attila Demeter ◽  
Sándor Dóbé ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Transformation Products ◽  
Degradation Pathway ◽  
Ultrapure Water ◽  
Wwtp Effluent

scholarly journals Ozone-Based Advanced Oxidation Processes for Primidone Removal in Water using Simulated Solar Radiation and TiO2 or WO3 as Photocatalyst

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1728 ◽  
Author(s):  
Manuel A. Figueredo ◽  
Eva M. Rodríguez ◽  
Manuel Checa ◽  
Fernando J. Beltran
Keyword(s):  
Transformation Products ◽  
Degradation Pathway ◽  
Secondary Effluent ◽  
Ultrapure Water ◽  
Visible Radiation ◽  
Beneficial Effects ◽  
Photocatalytic Ozonation ◽  
Toc Removal ◽  
Water Matrix ◽  
Environmentally Safe

In this work, primidone, a high persistent pharmacological drug typically found in urban wastewaters, was degraded by different ozone combined AOPs using TiO2 P25 and commercial WO3 as photocatalyst. The comparison of processes, kinetics, nature of transformation products, and ecotoxicity of treated water samples, as well as the influence of the water matrix (ultrapure water or a secondary effluent), is presented and discussed. In presence of ozone, primidone is rapidly eliminated, with hydroxyl radicals being the main species involved. TiO2 was the most active catalyst regardless of the water matrix and the type of solar (global or visible) radiation applied. The synergy between ozone and photocatalysis (photocatalytic ozonation) for TOC removal was more evident at low O3 doses. In spite of having a lower band gap than TiO2 P25, WO3 did not bring any beneficial effects compared to TiO2 P25 regarding PRM and TOC removal. Based on the transformation products identified during ozonation and photocatalytic ozonation of primidone (hydroxyprimidone, phenyl-ethyl-malonamide, and 5-ethyldihydropirimidine-4,6(1H,5H)-dione), a degradation pathway is proposed. The application of the different processes resulted in an environmentally safe effluent for Daphnia magna.

Photodegradation of quinestrol in waters and the transformation products by UV irradiation

Chemosphere ◽  
2012 ◽  
Vol 89 (11) ◽  
pp. 1419-1425 ◽  
Author(s):  
Tao Tang ◽  
Kun Qian ◽  
Tianyu Shi ◽  
Fang Wang ◽  
Pingliang Li ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Transformation Products

scholarly journals Assessing the Photocatalytic Degradation of Fluoroquinolone Norfloxacin by Mn:ZnS Quantum Dots: Kinetic Study, Degradation Pathway and Influencing Factors

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 964 ◽  
Author(s):  
Jyoti Patel ◽  
Ajaya K. Singh ◽  
Sónia. A. C. Carabineiro
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Uv Irradiation ◽  
Chemical Precipitation ◽  
Degradation Pathway ◽  
Precipitation Method ◽  
Optical Parameters ◽  
Human Beings ◽  
Photodegradation Efficiency ◽  
Transmission Electron

Norfloxacin (NOFX), a broadly used fluoroquinolone antibiotic, has been a subject of great concern in the past few years due to its undesirable effect on human beings and aquatic ecosystems. In this study, novel Mn doped ZnS (Mn:ZnS) quantum dots (QDs) were prepared through a facile chemical precipitation method and used as photocatalysts for NOFX degradation. Prior to photodegradation experiments, morphological and optical parameters of the QDs were examined through transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, fluorescence spectroscopy, Brunauer–Emmett–Teller analysis, and differential thermal and thermogravimetric analyses. Mn:ZnS QDs exhibited excellent properties of photodegradation, not only under UV irradiation but also in sunlight, which induced NOFX to photodegrade. The utmost photodegradation efficiency was obtained under optimal conditions (25 mL of NOFX, 15 mg/L, pH 10, 60 min UV irradiation, 60 mgs QDs), adopting first order kinetics. In addition, hydroxyl radicals produced by the conduction band electrons were found to be the primary reason dominating the transformation of NOFX in basic conditions, while holes, oxygen atoms, as well as the doped metal (Mn) enhanced the degradation. The QDs showed excellent reusability and stability in four repeated cycles. Finally, four different pathways were predicted, derived from the identified intermediates, with piperazinyl ring transformation being the primary one. It is expected that the synthesized Mn:ZnS QDs could be utilized as efficient photocatalytic materials for energy conversion and ecological remediation.

scholarly journals Degradation of norfloxacin in aqueous solution with UV/peroxydisulfate

2019 ◽  
Vol 79 (12) ◽  
pp. 2387-2394 ◽  
Author(s):  
Honghai Xue ◽  
Siyu Gao ◽  
Na Zheng ◽  
Ming Li ◽  
Xue Wen ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Removal Rate ◽  
Inorganic Ions ◽  
Transformation Products ◽  
Neutral Condition ◽  
Advanced Treatment ◽  
Ultrapure Water ◽  
Toc Removal ◽  
Laboratory Results ◽  
Removal Technology

Abstract The frequent detection of antibiotics in water bodies gives rise to concerns about their removal technology. In this study, the degradation kinetics and mechanisms of norfloxacin (NOR), a typical fluoroquinolone pharmaceutical, by the UV/peroxydisulfate (PDS) was investigated. NOR could be degraded effectively using this process, and the degradation rate increased with the increasing dosage of PDS but decreased with the increasing concentration of NOR. In real water, the degradation of NOR was slower than that in ultrapure water, which indicated that laboratory results cannot be directly used to predict the natural fate of antibiotics. Further experiments suggested that the degradation of NOR was the most fast under neutral condition, the existence of HA or FA inhibited the degradation of NOR, and the presence of inorganic ions (NO3−, Cl−, CO32− and HCO3−) had no significant effect on degradation of NOR. Total organic carbon (TOC) removal rate (40%) indicated NOR was not completely mineralized, and six transformation products were identified, and possible degradation pathways of NOR had been proposed. It can be prospected that UV/PDS technology could be used for advanced treatment of wastewater containing fluoroquinolones.

scholarly journals Biotransformation of Indole to 3-Methylindole byLysinibacillus xylanilyticusStrain MA

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Pankaj Kumar Arora ◽  
Kartik Dhar ◽  
Rafael Alejandro Veloz García ◽  
Ashutosh Sharma
Keyword(s):  
Acetic Acid ◽  
Sodium Succinate ◽  
16S Rrna Gene Sequencing ◽  
Transformation Products ◽  
Degradation Pathway ◽  
Gas Chromatography Mass Spectrometry ◽  
Broth Culture ◽  
Rrna Gene ◽  
Monooxygenase Activity ◽  
Indole 3 Acetic Acid

An indole-biotransforming strain MA was identified asLysinibacillus xylanilyticuson the basis of the 16S rRNA gene sequencing. It transforms indole completely from the broth culture in the presence of an additional carbon source (i.e., sodium succinate). Gas-chromatography-mass spectrometry identified indole-3-acetamide, indole-3-acetic acid, and 3-methylindole as transformation products. Tryptophan-2-monooxygenase activity was detected in the crude extracts of indole-induced cells of strain MA, which confirms the formation of indole-3-acetamide from tryptophan in the degradation pathway of indole. On the basis of identified metabolites and enzyme assay, we have proposed a new transformation pathway for indole degradation. Indole was first transformed to indole-3-acetamide via tryptophan. Indole-3-acetamide was then transformed to indole-3-acetic acid that was decarboxylated to 3-methylindole. This is the first report of a 3-methylindole synthesis via the degradation pathway of indole.

scholarly journals Degradation pathway of triazole fungicides and synchronous removal of transformation products via photo-electrocatalytic oxidation tandem MoS2 adsorption

2021 ◽  
Author(s):  
Junwen Wang ◽  
Xiaoxin Chen ◽  
Xiaoli Sun ◽  
Miao Liu ◽  
Xingqiang Wu ◽  
...  
Keyword(s):  
Electrocatalytic Oxidation ◽  
Aquatic Toxicity ◽  
Water Environment ◽  
Transformation Products ◽  
Degradation Pathway ◽  
Stir Bar Sorptive Extraction ◽  
Secondary Effluent ◽  
Triazole Fungicides ◽  
Irradiation Intensity ◽  
Tandem Process

AbstractA simple and effective tandem process of photo-electrocatalytic oxidation (PECO)-MoS2 adsorption was developed for the synchronous removal of triazole fungicides (TFs) and toxicological transformation products (TPs). In order to accurately identify trace TPs and evaluate degradation pathway during water treatment, a sensitive analytical method was developed on the basis of the stir bar sorptive extraction (SBSE) pretreatment tandem LC-MS/MS technique. Firstly, the typical TFs (PRO, TET, and DIN, C0 = 1.0 mg/L) in actual water samples were treated under the optimal process (bias voltage 1.8 V, pH 4, irradiation intensity 50 mW/cm2, 0.05 g MoS2/100 mL, 350 rpm, adsorption of 5 min). The result indicated that the residues of PRO, TET, and DIN in secondary effluent were 0.0973, 0.0617, and 0.0012 mg/L, respectively, with the removal rates of 90.3%, 93.8%, and 99.9%, respectively, undergoing 30-min photo-electrocatalysis and 5-min adsorption. The alkaline medium was favorable for the adsorption of MoS2 to TFs. The assessment results of potential cancer risk indicated that the residues of TFs in secondary effluent were safe for drinking water consumption. Besides, the major TPs were identified via the SBSE-HRLC-MS/MS technique, and one possible transformation pathway of TFs was proposed. TFs mainly underwent dehydrochlorination, cyclization, hydroxylation, etc. to produce a series of nitrogenous heterocyclic compounds that possess higher polarity than parents, hinting that TPs might pose potential aquatic toxicity. However, TPs can be removed synchronously by this tandem technique. The current study can provide a theoretical basis for the harmless treatment of TFs in the water environment.

scholarly journals Removal of Carbamazepine onto Modified Zeolitic Tuff in Different Water Matrices: Batch and Continuous Flow Experiments

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1084
Author(s):  
Othman A. Al-Mashaqbeh ◽  
Diya A. Alsafadi ◽  
Layal Z. Alsalhi ◽  
Shannon L. Bartelt-Hunt ◽  
Daniel D. Snow
Keyword(s):  
Wastewater Treatment ◽  
Sorption Capacity ◽  
Pure Water ◽  
Treatment Plant ◽  
Hexadecyltrimethylammonium Bromide ◽  
Ultrapure Water ◽  
Zeolitic Tuff ◽  
X Ray ◽  
Wwtp Effluent ◽  
Surfactant Modification

Carbamazepine (CBZ) is the most frequently detected pharmaceutical residues in aquatic environments effluent by wastewater treatment plants. Batch and column experiments were conducted to evaluate the removal of CBZ from ultra-pure water and wastewater treatment plant (WWTP) effluent using raw zeolitic tuff (RZT) and surfactant modified zeolite (SMZ). Point zero net charge (pHpzc), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared (FTIR) were investigated for adsorbents to evaluate the physiochemical changes resulted from the modification process using Hexadecyltrimethylammonium bromide (HDTMA-Br). XRD and FTIR showed that the surfactant modification of RZT has created an amorphous surface with new alkyl groups on the surface. The pHpzc was determined to be approximately 7.9 for RZT and SMZ. The results indicated that the CBZ uptake by SMZ is higher than RZT in all sorption tests (>8 fold). Batch results showed that the sorption capacity of RZT and SMZ in WWTP effluent (0.029 and 0.25 mg/g) is higher than RZT and SMZ (0.018 and 0.14 mg/g) in ultrapure water (1.6–1.8 fold). Batch tests showed that the equilibrium time of CBZ removal in the WWTP matrix (47 h) is much longer than CBZ removal in ultrapure water. The sorption capacity of RZT & SMZ in WWTP effluent (0.03, 0.33 mg/g) is higher than RZT and SMZ (0.02 and 0.17 mg/g) in ultrapure water (1.5–2 fold) using column test. This study has clearly demonstrated that the performance of RZT and SMZ is more efficient for the removal of CBZ from realistic wastewater than ultrapure water. It is evident that the surfactant modification of RZT has enhanced the CBZ removal in both matrices.

scholarly journals Comparison of radical-driven technologies applied for paraben mixture degradation: mechanism, biodegradability, toxicity and cost assessment

2019 ◽  
Vol 26 (36) ◽  
pp. 37174-37192 ◽  
Author(s):  
Marta Gmurek ◽  
João F. Gomes ◽  
Rui C. Martins ◽  
Rosa M. Quinta-Ferreira
Keyword(s):  
Photocatalytic Oxidation ◽  
Degradation Mechanism ◽  
Transformation Products ◽  
Degradation Pathway ◽  
Toxicity Assessment ◽  
Degradation Efficiency ◽  
Lepidium Sativum ◽  
Cost Assessment ◽  
Aqueous Environment ◽  
Photocatalytic Ozonation

AbstractParabens (esters of p-hydroxybenzoic acid) are xenobiosis belonging to endocrine disruptors and commonly used as a preservative in cosmetics, food, pharmaceutical, and personal care products. Their wide use is leading to their appearance in water and wastewater in the range from ng/L to mg/L. In fact, the toxicity of benzylparaben is comparable to bisphenol A. Therefore, it is important to find not only effective but also ecofriendly methods for their removal from aqueous environment since the traditional wastewater treatment approaches are ineffective. Herein, for the first time, such extended comparison of several radical-driven technologies for paraben mixture degradation is presented. The detailed evaluation included (1) comparison of ozone and hydroxyl peroxide processes; (2) comparison of catalytic and photocatalytic processes (including photocatalytic ozonation); (3) characterisation of catalysts using SEM, XRD, DRS, XPS techniques and BET isotherm; (4) mineralisation, biodegradability and toxicity assessment; and (5) cost assessment. O3, H2O2/Fe2+, H2O2/UVC, O3/H2O2, O3/UVA, O3/H2O2/UVA, UVA/catalyst, O3/catalyst and O3/UVA/catalyst were selected from advanced oxidation processes to degrade parabens as well as to decrease its toxicity towards Aliivibrio fischeri, Corbicula fluminea and Lepidium sativum. Research was focused on the photocatalytic process involving visible light (UVA and natural sunlight) and TiO2 catalysts modified by different metals (Ag, Pt, Pd, Au). Photocatalytic oxidation showed the lowest efficiency, while in combining ozone with catalysis and photocatalysis process, degradation efficiency and toxicity removal were improved. Photocatalytic ozonation slightly improved degradation efficiency but appreciably decreased transferred ozone dose (TOD). Results indicate that the degradation pathway is different, or different transformation products (TPs) could be formed, despite that the hydroxyl radicals are the main oxidant.

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