Degradation Of Naproxen Research Articles

Development of engineered Zn-MOF/g-C3N4 based photoelectrochemical system for real-time sensors and removal of naproxen in wastewater

Naproxen-contaminated water may lead to the accumulation of the drug in aquatic organisms and can pose high risks to an aquatic environment and human beings. Therefore, this work aimed to develop photoelectrochemical sensing and degradation of naproxen (NPX) using zinc-metal organic framework /graphitic carbon nitride thin film-based fluorine-doped tin oxide (Zn-MOF/g-C3N4/FTO) as anode material for the sensing and degradation of naproxen (NPX). The surface morphology, structure, surface property, surface area, optical property, photocurrent, and charge transfer kinetics abilities were studied using different techniques. The nanocomposites showed a superior photocurrent response (0.815 mA cm-2) compared to the original g-C3N4 (0.328 mA cm-2). The photo-anode made of Zn-MOF@g-C3N4/FTO displayed the highest photocurrent value, indicating that the alignment of the two semiconductor bands prevented the quick recombination of electron-hole pairs. Owing to these attractive features, the Zn-MOF/g-C3N4/FTO electrode was applied for photoelectrochemical detection of NPX using chronoamperometry. Interestingly, the nanocomposites-based FTO ascribed a lower detection limit (2.3 ng l-1) with a wide linear range concentration of NPX (0.5 to 200 µg l-1). Additionally, the analytical assessment of repeatability and reproducibility demonstrated robust performance, with commendable relative standard deviations (RSD%) of 2.54 % and 2.40 %, respectively. On the other hand, a remarkable degradation efficiency of 97.52 % was attained when employing a bias potential of 0.1 V during a 2 h photoelectrocatalytic oxidation of NPX. The degradation process was primarily driven by the active participation of holes and hydroxyl radicals in ring opening and subsequent cleavage of by-products. The notable effectiveness of this degradation can be attributed to the combined and synergistic effects of both electrochemical and photocatalytic degradation techniques. The current state demonstrates its effectiveness in the photoelectrochemical sensing and removal of NPX using MOF/g-C3N4 nanocomposites-based electrode materials in wastewater.

Topological Co(II)-Malonate Polymorph: Degradation Properties of Naproxen and Colorimetric Recognition of Acetone, Cr2O72−, and Fe3+

Two Co(II)coordination polymers namely, [Co(mal)(4,4`-bpy)0.5 (H2O)]n(1) and [Co(mal)(4,4`-bpy)0.5 (H2O)]n(2)are synthesized at ambient temperature, both complexes are based on {Co(RCOO)2}unitserving as 3D network along with sqc and fes topology and corroborated by many analytical techniques. CPs(1) crystallized in a 2D manner and then constructed a 3D hydrogen bonding network which was demonstrated monoclinic crystal system while(2)is a 3D supramolecular network that possesses a tetrahedral crystal system, according to topological analysis CPs(1) shows 5-C net and CPs(2) elaborates a 3-C net which proves both are completely different. A luminescence investigation was performed using both coordination polymers (CPs), which demonstrated effective colorimetric detection of acetone, Cr₂O₇²⁻, and Fe³⁺, with corresponding detection limits of 1.91, 2.57, and 0.29 ppm, respectively, in an ethanolic medium. Additionally, the catalytic degradation of Naproxen was evaluated for both catalysts, revealing significant degradation efficiencies of 90% for catalyst (1) and 38% for catalyst (2).

Ag induced plasmonic TiO2 for photocatalytic degradation of pharmaceutical under visible light: Insights into mechanism, antimicrobial and cytotoxicity studies

Global concerns include water scarcity and shortage, which are escalated by organic pollutants such as naproxen (NPX) that deteriorate drinking water and taint access to safe drinking water by humans. Moreover, NPX may cause gastrointestinal difficulties, cardiovascular risks, kidney damage, allergic reactions, liver toxicity, bleeding issues and pregnancy risks, hence it is essential to remove it in water. Ag-TiO2 was synthesized by hydrothermal method for NPX degradation. Ag on TiO2 reduced the band gap and surface area of TiO2 and resulted in a plasmonic Ag-TiO2 composite of 0.2 % Ag. The photocatalytic degradation of 0.2 % Ag-TiO2 was 80 % in 180 minutes using a solar simulator during NPX degradation with a first order reaction rate that was 3.6 times faster than that of pure TiO2 and the catalyst showed good stability for four cycles. The dual activity of Ag0 surface plasmon resonance improved light absorption capability and enhanced charge transfer for increased photodegradation rate and stability. The antibacterial studies demonstrated that 0.2 % Ag-TiO2 posted strong antibacterial properties under light irradiation and less in the dark, with a greater effect on gram-negative than gram-positive bacteria. The minimum inhibitory concentration (MIC) values of 620, 1250, 2500, 2500 µg/mL were attained against B. subtilis, S. aureus, E. coli and S. typhimurium bacteria, respectively. The low cell toxicity of 0.2 % Ag-TiO2 was determined using human embryonic kidney (HEK293) cells with an inhibitory concentration (IC50) of 61.09 ± 0.24 µg/mL under light irradiation. Radical trapping experiments demonstrated that hydroxyl radicals (OH•) played a vital role during the degradation and bactericidal activity of NPX under light irradiation. This work advances new insights on the synthesis of less toxic nanoparticles with high photocatalytic and bactericidal activity for possible applications at industrial scale.

The surface functional groups-driven fast and catalytic degradation of naproxen on sludge biochar enhanced by citric acid

In this work, a sludge biochar (CA-SBC-300) with efficient activation of peroxymonosulfate (PMS) was prepared by citric acid modification. CA-SBC-300 achieved efficient degradation of naproxen (NPX) (95.5%) within 10 min by activating PMS. This system was highly resilient to common disruptive factors such as inorganic anions, humic acid (HA) and solution pH. The results of XPS and Raman showed that the content of oxygenated functional groups (OFGs) and the degree of defects on the sludge biochar increased after citric acid modification, which may be an important reason for the enhanced catalytic performance of SBC. In the CA-SBC-300/PMS system, 1O2 and O2•− made the main contributions to the degradation of NPX. XPS analysis and DFT calculations demonstrated that C=O/C−O and pyridine N on CA-SBC-300 were the crucial active sites for PMS activation. According to the results of UPLC-MS analysis, three possible pathways for NPX degradation were inferred. This study provided a feasible strategy for sludge resource utilization combined with efficient catalytic degradation of toxic organic contaminants in wastewater.

Attuned band structure in triple S-scheme heterojunctions for naproxen degradation under visible light

The limited charge carrier separation and transportation in single semiconductor photocatalysts has lobbied research and development in rational design and fabrication of heterojunction photocatalysts which has become a hot topic in the last decade. In-depth investigation of a four-component semiconductors interfacial charge transfer analysis considering the contribution of all components was done for the first time to deduce triple S-scheme heterojunction. This work investigated four-component semiconductors (Cu3(PO4)2, BaWO4, C-MgO and LDH) heterojunction photocatalyst formation by the solvothermal method for visible light degradation of NPX. The degradation rate of CBLM-B (0.0429 min−1) with high BaWO4 content was two times the degradation rate of CBLM-A (0.0203 min−1) with high LDH/C-MgO content. XPS, electrochemistry, and band structure analysis were used to propose a triple S-scheme heterojunction with high electron mobility and charge separation that enhanced the formation of OH• >•O2− > h+ species as supported by radical trapping experiments due to presence of two oxidative and two reductive sites for stable generation of ROSs. Internal electric field (IEF) and band bending modulated an S-S interfacial strategy at the three junctions. Cu leaching affected the catalyst stability, and NPX degradation pathways were investigated with QTOF-HPLC-MS. This work demonstrated band structure adjustment for design of highly efficient triple S-Scheme heterojunctions application in environmental pollution remediation as a new development to advance scientific knowledge on four-component heterojunctions which may also be described using the Z-scheme charge transfer model.

Visible light-assisted activation of peroxymonosulfate for naproxen degradation with biochar-based catalysts: Sandwich structure construction and synergy of free and non-free radicals

Visible light-assisted activation of peroxymonosulfate for naproxen degradation with biochar-based catalysts: Sandwich structure construction and synergy of free and non-free radicals

Comparative study on solar photocatalytic degradation of naproxen using nitrogen doped ZnO and nitrogen doped TiO2: Kinetics and Intermediates analysis

Solar photocatalytic degradation of Naproxen (NPX) in a synthetic wastewater was evaluated with synthesized nitrogen doped TiO2 and nitrogen doped ZnO and compared with commercial TiO2 and ZnO. The effect of operating parameters such as initial NPX concentration (1–3.5 mg/l), catalyst dosage (0.15–0.5 g/l), pH (4.5–9.0), and contact time (0–330 min) on NPX degradation was investigated in detail. The batch study showed 93 %, 90 %, 71 % and 85 % NPX degradation on average solar intensities (1200–1420 W/m2) with ZnO, N-ZnO, TiO2 and N-TiO2 respectively for optimised conditions (initial NPX concentration-2 mg/l, (ZnO & N-ZnO)−0.35 g/l, (TiO2 & N-TiO2)−0.15 g/l, pH-4.5 and contact time-180 min). Kinetic investigations on photocatalytic degradation of NPX were carried out for the initial 1 h duration and it complied with pseudo-first order kinetics with the four catalysts, whereas ZnO showed the highest rate constant (k = 0.0331/minutes). Depth of reactor solution had no significant impact on NPX degradation. Continuous process was conducted along with TOC analysis for HRT of 60 min, which showed mineralization efficiencies of 36 %, 26 % and 16 % for N-TiO2, ZnO and N-ZnO respectively. The 90th percentile solar light intensity corresponding to the maximum NPX degradation was found to be 1100 W/m2. Quantum yield were calculated for NPX degradation with and without catalyst, it showed 35 % for ZnO and 3.5 % for photolysis. The intermediates and mineralization efficiency was analysed using LC-MS and TOC analyzer respectively. This study concluded that N-TiO2 had better NPX removal and mineralization efficiency along with formation of simpler compounds and organic acids as the end products.

Naproxen electrooxidation using carbon paper electrodes modified with reduced graphene oxide and platinum nanoparticles

This research study investigates the electrooxidation of naproxen (NPX), an anti-inflammatory pharmaceutical, on modified carbon paper (CP) electrodes. Electrochemical modification of CP electrodes was accomplished with Pt or reduced graphene oxide (RGO)-Pt coatings, resulting in the production of electroactive electrodes. RGO coatings synthesized by cyclic voltammetry (CV) for 10 scans provided the optimal coverage for the CP electrode surface. The deposition of Pt nanoparticles (Pt NPs) on the electrodes (CP or CP-RGO) by CV produced a good electrode surface coverage with 20 synthesis scans. The voltammetric analysis of the electrodes in 230 mg/L NPX solution showed oxidation peaks around 1.0 to 1.2 V. Moreover, the inclusion of RGO in the coating led to an increase in the current density of these oxidation peaks and a decrease of the electrode electron transfer resistance as measured by electrochemical impedance spectroscopy.The electrolysis of NPX in different electrolytes (Na2SO4 and Na2SO4/NaCl) was conducted at 1.4 V, and the removal of NPX was analyzed using high-performance liquid chromatography. The CP-RGO-Pt electrode in Na2SO4/NaCl media showed the fastest NPX degradation kinetics, resulting in a 90 % degradation in only 90 min with low charge consumption (0.07 A·h·L-1). The smaller size of Pt NPs deposited on CP-RGO, as observed by field emission scanning electron microscopy and transmission electron microscopy, contributed to the higher electrochemical response in CV and a faster kinetic degradation of NPX.

Comprehensive spectroscopy and photocatalytic activity analysis of TiO2-Pt systems under LED irradiation

This study presents a thorough spectroscopic analysis of TiO2-Pt systems under LED irradiation, with a focus on elucidating the photodeposition process of Pt nanoparticles onto TiO2 surfaces. The methodology leverages an innovative LED photoreactor tailored to a specific spectral range, enabling precise characterization of the excitation spectrum of TiO2-Pt composites. Through the identification of Pt precursor species and their excitation under LED-UV light, a photodeposition mechanism is proposed involving concurrent excitation of both the TiO2 semiconductor and the H2PtCl6 precursor. The LED photoreactors are employed to scrutinize the excitation profile of TiO2-Pt materials, revealing that the incorporation of Pt nanoparticles does not expand TiO2's absorption spectrum. Furthermore, UV-A exposure in the absence of Pt did not induce the formation of surface defects, underscoring the lack of visible light activity in TiO2-Pt systems. Spectroscopic analyses, complemented by naproxen photooxidation experiments, indicate the absence of a significant plasmonic effect in Pt nanoparticles within the experimental framework. Mass spectroscopy results corroborate the presence of distinct naproxen degradation pathways, suggesting minimal influence from photocatalyst properties. This research provides a detailed spectroscopic insight into TiO2-Pt photocatalysis, enriching the knowledge of photocatalytic materials in LED lighting.

Hydrogen peroxide enhanced Cu(II)/peroxymonosulfate system for naproxen degradation in natural water matrix and simultaneously reduced the formation potential of halogenated by-products

The susceptibility to the natural water matrix and the risk-generating halogenated by-products in the Cu(II)/peroxymonosulfate system heavily restricted its practical application. This study first demonstrated hydrogen peroxide (H2O2) could remarkably improve the anti-interference capacity of the Cu(II)/peroxymonosulfate system in the natural water matrix through promoting the copper species cycle [Cu(II)/Cu(I)]. A complete naproxen (NPX) removal was achieved at pH 10.0 for 180 s with the H2O2/Cu(II)/peroxymonosulfate system, and the degradation rate of NPX was 28 times greater than its counterpart without H2O2·H2O2 functioned as an electron donor to reduce Cu(II) to Cu(I), while the formed Cu(I) preferentially interacting with peroxymonosulfate to generate reactive species. Several reactive species, including Cu(III), •OH and SO4•−, participated in NPX degradation, while Cu(III) primarily contributed to NPX abatement. The NPX abatement in the H2O2/Cu(II)/peroxymonosulfate system was strongly pH-dependent, with weakly alkaline circumstances being more beneficial to its removal. Additionally, Cl−, H2PO42− and humic acid in the natural water matrix had the slight impact on NPX elimination with the H2O2/Cu(II)/peroxymonosulfate system, whereas H2PO42− and humic acid strongly suppressed NPX elimination in the Cu(II)/peroxymonosulfate system. Furthermore, the generation of halogenated by-products could be suppressed in treating halide-containing wastewater with the H2O2/Cu(II)/peroxymonosulfate system. To sum up, this research offered a new strategy to strengthen the anti-interference capacity of the Cu(II)/peroxymonosulfate system and simultaneously inhibiting halogenated by-product production. The finding should be important for studying the synergistic effect of dual oxidants in treating Cu(II)-containing wastewater.

Fabrication of nano-dandelion magnetic TiO2/CuFe2O4 doped with silver as a highly visible-light-responsive photocatalyst for degradation of Naproxen and Rhodamine B

Nano-dandelion TiO2 and magnetic CuFe2O4 were synthesized with hydrothermal and sol–gel processes, respectively. A series of composites containing different amounts of CuFe2O4 and Ag were also prepared using a photoreduction method. The composites were subsequently used for photodegradation of Naproxen and Rhodamine B under UV–Vis light irradiation. The synthesized photocatalysts were characterized by XRD, FTIR, FESEM, EDX, TEM, BET-BJH, DRS, and PL analyses. XRD and FESEM results confirmed the successful synthesis of the dandelion structure for the composites. The VSM analysis also demonstrated the enhancement of magnetic properties of composites. DRS results indicated that CuFe2O4 loading and Ag doping resulted in a decrease in the band gap energy and enhanced absorption of light in the visible region as compared with pure TiO2. The presence of CuFe2O4 and Ag also increased charge transfer by decreasing electron-hole recombination rates by creating a Schottky-barrier interface which was indicated by the PL spectra. The composite containing 20% CuFe2O4 and 3% Ag (designated as TC20-3Ag) showed better performance as compared with other photocatalysts for photodegradation of Naproxen (92.56%) and Rhodamine B (91.16%) over a 150-minute reaction time. The sample also exhibited good stability after 5 cycles. The effects of operating parameters such as the pH of the solution, the photocatalyst dosage, and initial pollutant concentration were also investigated. It was found that a pseudo-first-order model adequately described the photodegradation kinetics. The results indicated that superoxide and holes were reactive species, and a possible mechanism for the photodegradation of Naproxen by TC20-3Ag was suggested.

Photocatalytic Degradation of Naproxen: Intermediates and Total Reaction Mechanism.

Photochemical and photocatalytic oxidation of naproxen (NPX) with UV-A light and commercial TiO2 under constant flow of oxygen have been investigated. Adsorption experiments indicated that 90% of the solute remained in the solution. Combined chemical analysis of samples on the photochemical degradation indicated that NPX in an aqueous solution (20 ppm) is efficiently transformed into other species but only 18% of the reactant is mineralized into CO2 and water after three hours of reaction. Performing the photocatalytic oxidation in the presence of TiO2, more than 80% of the organic compounds are mineralized by reactive oxidation species (ROS) within four hours of reaction. Analysis of reaction mixtures by a combination of analytical techniques indicated that naproxen is transformed into several aromatic naphthalene derivatives. These latter compounds are eventually transformed into polyhydroxylated aromatic compounds that are strongly adsorbed onto the TiO2 surface and are quickly oxidized into low-molecular-weight acids by an electron transfer mechanism. Based on this and previous studies on NPX photocatalytic oxidation, a unified and complete degradation mechanism is presented.

Peroxymonosulfate activation by superparamagnetic mixed-valent Cu/N-(L-cysteine)-O-(carboxymethyl)chitosan/cobalt ferrate-rice hull hybrid nanocomposite for efficient degradation of naproxen: Synergetic adsorption-catalysis, kinetics, pathway, and relevant mechanism

Naproxen (NPX) as an emerging anthropogenic contaminant was detected in many water sources, which can pose a serious threat to the environment and human health. Peroxymonosulfate (PMS) decomposed by Cu(I) has been considered an effective activation method to produce reactive species. However, this decontamination process is restricted by the slow transformation of Cu(II)/Cu(I) by PMS. Herein, new N-(L-cysteine/triazine)-O-(carboxymethyl)-chitosan/cobalt ferrate-rice hull hybrid biocomposite was constructed to anchor the mixed-valent Cu(I)-Cu (II) (CuI, II-CCCF) for removing pharmaceutical pollutants (i.e., naproxen, ciprofloxacin, tetracycline, levofloxacin, and paracetamol). The structural, morphological, and catalytic properties of the CuI,II-CCCF have been fully identified by a series of physicochemical characterizations. Results demonstrated that the multifunctional, hydrophilic character, and negative ζ-potential of the activator, accelerating the redox cycle of Cu(II)/Cu(I) with hydroxyl amine (HA). The negligible metal leaching, well-balanced thermodynamic-kinetic properties, and efficient adsorption-catalysis synergy are the main reasons for the significantly enhanced catalytic performance of CuI,II-CCCF in the removal of NPX (98.6 % at 7.0 min). The main active species in the catalytic degradation of NPX were identified (●OH > SO4●− > 1O2 > > O2●−) and consequently suggested a degradation path. It can be noted that these types of carbohydrate-based nanocomposite offer numerous advantages, encompassing simple preparation, excellent decontamination capabilities, and long-term stability.

0D/1D CuO-Cu2O/ZnO p-n heterojunction with high photocatalytic activity for the degradation of dyes and Naproxen

The development of highly active photocatalysts with broad spectrum response is of paramount importance for photocatalytic applications. Herein, heterostructured CuO-Cu2O/ZnO photocatalysts were prepared in a single step and under mild conditions using a photodeposition process which allows to deposit CuO-Cu2O particles with an average size of ca. 2.4 nm on the surface of ZnO nanorods. The p-n heterojunction built between CuO-Cu2O and ZnO allows to increase both the visible light response of the photocatalyst and the charge separation. The CuO-Cu2O(10%)/ZnO catalyst exhibits the highest activity for the degradation of dyes (Rhodamine B and Remazol Brilliant Blue R) and of Naproxen under simulated solar light irradiation. Based on scavenging experiments, holes, superoxide radicals O2●- and singlet oxygen 1O2 are the dominant species involved in the photocatalytic degradation and a mechanism is proposed. Due to its high stability and photocatalytic performance in various water matrices, the CuO-Cu2O(10%)/ZnO nanohybrid is of high potential for the large scale remediation of organic pollutants in wastewater.

Efficient photochemical conversion of naproxen by butanedione: Role of energy transfer

Photochemical active species generated from photosensitizers, e.g., dissolved organic matter (DOM), play vital roles in the transformation of micropollutants in water. Here, butanedione (BD), a redox-active moiety in DOM and widely found in nature, was employed to photo-transform naproxen (NPX) with peracetic acid (PAA) and H2O2 as contrasts. The results obtained showed that the BD exhibited more applicable on NPX degradation. It works in the lake or river water under UV and solar irradiation, and its NPX degradation efficiency was 10–30 times faster than that of PAA and H2O2. The reason for the efficient transformation of pollutants is that the BD system was proved to be a non-free radical dominated mechanism. The quantum yield of BD (Ф254 nm) was calculated to be 0.064, which indicates that photophysical process is the dominant mode of BD conversion. By adding trapping agents, direct energy transfer from 3BD* to NPX (in anoxic environment) or dissolved oxygen (in aerobic environment) was proved to play a major role (> 91 %). Additionally, the BD process reduces the toxicity of NPX and promotes microbial growth after irradiation. Overall, this study significantly deepened the understanding of the transformation between BD and micropollutants, and provided a potential BD-based process for micropollutants removal under solar irradiation.

Efficient degradation of naproxen in wastewater using Ag-deposited ZnO nanoparticles anchored on a house-of-cards-like MFI-type zeolite: Preparation and physicochemical evaluations of the photocatalyst

We utilized Pr6-diquat-5 as an organic structure-directing agent (OSDA) to synthesize hierarchically intergrown ZSM-5 (HI-ZSM-5) as a catalytic support. ZnO particles were deposited onto HI-ZSM-5 via precipitation to remediate naproxen (NPX) in wastewater, while Ag was photo-deposited onto ZnO to prevent electron-hole pair recombination. XRD analysis revealed crystalline structures and particle sizes influenced by synthesis temperatures, and FT-IR confirmed ZnO and Ag deposition onto HI-ZSM-5 surfaces. Based on N2 adsorption-desorption isotherms, all samples exhibited Type I and IV isotherms with H4-type hysteresis loops, indicating the presence of both micro- and mesopores within HI-ZSM-5. XPS analysis confirmed the presence of peaks indicating Zn in ZnO and metallic Ag interacting with ZnO. TEM analysis identified aggregated Ag/ZnO nanoparticles in the photocatalysts, while EDX confirmed uniform element distribution. FE-SEM images revealed a uniform distribution of ZnO and Ag on HI-ZSM-5 with “house-of-cards” morphologies. PL analysis indicated reduced electron-hole recombination and an extended lifespan. NPX photodegradation experimental results showed that the reaction rate constant of the 3 %AZ composite was 2.8 times higher than that of ZnO/HI-ZSM-5 (0.0163 vs. 0.059 min−1, respectively). Evaluation of influential operating parameters demonstrated 90.8 % elimination of NPX under optimum conditions: a catalyst dosage of 1.5 g L−1 at pH 5 within 120 min. The impact of common anions on NPX decontamination and the catalyst's capability for COD and TOC removal (up to 62.6 and 53.4 %, respectively) was also discussed. The 3 %AZ optimum catalyst could be recycled for 5 cycles with remarkable reusability, maintaining 80.1 % removal efficiency after five regeneration cycles.

Microcontaminants degradation in tertiary effluent by modified solar photo-Fenton process at neutral pH using organic iron complexes: Influence of the peroxide source and matrix composition

Peroxymonosulfate (HSO5–) and persulfate (S2O82–), both sources of sulfate radicals (SO4*–), were evaluated for the first time in modified solar photo-Fenton using Fe-chelating agents (nitriloacetic acid (NTA), ethylene diaminetetraacetic acid (EDTA), ethylenediamine-N,N′-disuccinic acid (EDDS) and citrate (Cit)) in comparison with hydrogen peroxide (H2O2) to degrade benzophenone-3 (BP-3), fipronil (FIP) and propylparaben (PPB) (100 µg L–1 each) in municipal tertiary effluent. Increasing HSO5– concentrations from 1.5 to 5.9 mmol L–1 reached ≥ 96 % removal for all iron complexes, while treatment efficiencies for all tested S2O82– concentrations (1.5–5.9 mmol L–1) were limited to 20 % to 55 %. This difference can be attributed to a pH decrease in the HSO5– system. The influence of pH and matrix composition upon treatment performance were also assessed in the FeNTA/S2O82– system, which was more efficient at pH < 7.0 due to higher availability of soluble iron, and partial removal of bicarbonate and humic acids caused by acidification. Matrix composition significantly influenced the process as higher degradation rates were achieved after isolated or combined removals of chloride, bicarbonate and sulfate. The comparison between naproxen (a high electron density compound) degradation and that of BP-3, FIP, and PPB by SO4*– - based advanced oxidation processes (SR-AOPs) was used to evaluate the influence of target compound structures upon treatment performance. S2O82− and HSO5– were ineffective for treatment at pH 7.0. Thus, H2O2 was the best peroxide source for target compounds degradation at neutral pH as this is the natural pH of municipal tertiary effluent and results indicated that the assessment and choice for SR-AOPs should consider the chemical structure of target compounds.

Photocatalytic degradation of naproxen using TiO2 single nanotubes

Herein, TiO2 single-tube (TiO2 ST-NT) powders with and without magnetite Fe3O4 nanoparticles (TiO2 ST-NT@Fe3O4NPs) are presented for the first time as excellent photocatalysts for the degradation of one of the most popular non-steroidal anti-inflammatory drugs (NSAIDs), naproxen (NPX). The TiO2 ST-NT powders were synthesized by anodization followed by etching of the double wall, bending, sonication, ultra-centrifugation, and finally annealing at 600°C. A part of the obtained TiO2 ST-NT powders was decorated with Fe3O4 nanoparticles using a simple one-step decoration process. The best photocatalytic performance of TiO2 ST-NT and TiO2 ST-NT@Fe3O4NPs powders was obtained under the white light (6.2 × 10−4 s-1) and the blue light (2.7 × 10−4 s-1), respectively. During NPX photodegradation using TiO2 ST-NT powders, three main NPX transformation products (P1, P2, and P3) were detected. Upon excitation with the blue light illumination, TiO2 ST-NT@ Fe3O4NPs powders exhibited higher performance (∼80%) than TiO2 ST-NT powders (∼23%) within 1 h, resulting in an approximately three times increased photocatalytic rate constant. Moreover, under simulated sunlight conditions, TiO2 ST-NT powders demonstrated remarkable activity, achieving a 94% NPX degradation within 1 h. TiO2 ST-NT and TiO2 ST-NT@Fe3O4NPs powders represent excellent photocatalysts for NPX degradation.

Overlooked Role of Coexistent Hydrogen Peroxide in Activated Peracetic Acid by Cu(II) for Enhanced Oxidation of Organic Contaminants.

Cu(II)-catalyzed peracetic acid (PAA) processes have shown significant potential to remove contaminants in water treatment. Nevertheless, the role of coexistent H2O2 in the transformation from Cu(II) to Cu(I) remained contentious. Herein, with the Cu(II)/PAA process as an example, the respective roles of PAA and H2O2 on the Cu(II)/Cu(I) cycling were comprehensively investigated over the pH range of 7.0-10.5. Contrary to previous studies, it was surprisingly found that the coexistent deprotonated H2O2 (HO2-), instead of PAA, was crucial for accelerating the transformation from Cu(II) to Cu(I) (kHO2-/Cu(II) = (0.17-1) × 106 M-1 s-1, kPAA/Cu(II) < 2.33 ± 0.3 M-1 s-1). Subsequently, the formed Cu(I) preferentially reacted with PAA (kPAA/Cu(I) = (5.84 ± 0.17) × 102 M-1 s-1), rather than H2O2 (kH2O2/Cu(I) = (5.00 ± 0.2) × 101 M-1 s-1), generating reactive species to oxidize organic contaminants. With naproxen as the target pollutant, the proposed synergistic role of H2O2 and PAA was found to be highly dependent on the solution pH with weakly alkaline conditions being more conducive to naproxen degradation. Overall, this study systematically investigated the overlooked but crucial role of coexistent H2O2 in the Cu(II)/PAA process, which might provide valuable insights for better understanding the underlying mechanism in Cu-catalyzed PAA processes.

Remediation of a non-steroidal anti-inflammatory drug from aqueous solutions using cobalt ferrite-photocatalytic membranes

CoFe2O4-PES photocatalytic membranes were assessed for Naproxen degradation in water. The degradation obeyed first-order reaction kinetics (Kapp: 1.25 × 10−3 min−1 - 3.90 × 10−3 min−1). Surface roughness altered the collision dynamics of reactive species. It enhanced the chances of successful collision between Naproxen and reactive radicals. Membrane hydrophilicity improved the generation of reactive radicals by minimizing the blockage of active sites. Intermediates detected by Quadrupole Time-of-Flight Mass Spectrometry showed that Naproxen degraded via demethylation, hydroxylation, and ring-opening reactions. Leaching studies investigated the stability of the prepared membranes. CoFe2O4-PES membranes can be used in advanced oxidation technologies for water treatment.