Degradation Of Naproxen Research Articles

UV degradation of naproxen adsorbed on graphite oxide

UV degradation of naproxen adsorbed on graphite oxide

Preparation and characterization of phase pure monoclinic ɑ-Bi2O3 nanoparticles and influence of Ni2+and Cu2+ impregnation on their photocatalytic properties

Nowadays, pharmaceutical waste, Naproxen (NPX) as well as the dye fuchsin blue (FB) become hazardous pollutant due to their toxic behavior. Because of toxicity, the efficient removal of them from water has become one of the most vital challenge. Yet, due to high cost, low degradation efficiency, of the known catalyst restrict their real life applications. In this perspective, metal ions impregnated (Ni2+ and Cu2+) Bi2O3 heterostructures have been investigated as a potential material for photocatalytic degradation of NPX and FB. These materials are synthesized by simple wet-impregnation method and thoroughly characterized by various methods such as XRD, DLS, SEM, EDS, HRTEM, XPS, etc. The diffraction patterns confirm formation of phase pure α-Bi2O3 nanoparticles. The zeta potential (−25 mV) of Bi2O3 nanoparicles confirms presence of negatively charges oxide groups in its surface that can act as anchors for divalent anions. The impregnated hybrids shows considerably smaller zeta potential values (−15 and −17 mV for Ni2+-Bi2O3 and Cu2+-Bi2O3 respectively). The XPS studies reveal presence of surface bound divalent metal ions. The adsorption edge of Ni2+-Bi2O3 and Cu2+-Bi2O3 nanostructures were shifted slightly towards lower frequency. The photoluminescence spectrum impregnated materials shows significant quenching compare to pristine Bi2O3. suggesting lesser degree electron-hole recombination upon metal loading. Due to the photocatalytic degradation efficiencies of both Ni2+-Bi2O3 (87% for FB and 79% for NPX) and Cu2+-Bi2O3 (73% for FB and 70% for NPX) heterostructures are significantly higher compare to the pristine one (43% for FB and 40% for NPX). The photo-degradation process obeys the pseudo first order kinetics. Due to simpler synthesis and enhanced activity metal ion loaded Bi2O3 photocatalysts can be potential photo-catalysts for removing NPX and FB from wastewater.

Catalytic oxidation of naproxen in cobalt spinel ferrite decorated Ti3C2Tx MXene activated persulfate system: Mechanisms and pathways

Naproxen (NPX) is a nonsteroidal anti-inflammatory drug that, at concentrations of 20 ng/L to several µg/L in aqueous environments, can cause detrimental effects to human and ecosystem health. A heterogeneous nanocatalyst composed of two-dimensional MXene nanosheets functionalized with CoFe2O4 nanoparticles was fabricated by liquid self-assembly for the activation of persulfate (PS) to degrade NPX. Approximately 99.1% of NPX was degraded within 90 min with the addition of 0.5 mM PS at 1 g/L of CoFe2O4@MXene dosage. To better understand the removal process, different influencing parameters, including the solution pH, catalyst dosage, and PS concentration, during NPX removal were studied. Radical scavenging and electron spin resonance experiments revealed that both radical (i.e., O2−, OH, SO4−, and S2O8−) and nonradical (i.e., 1O2) pathways were involved in the catalytic degradation of NPX. The results suggest that CoFe2O4@MXene/PS is a promising catalytic system for the treatment of water polluted with NPX.

Novel FeII/EDDS/UV/PAA advanced oxidation process: Mechanisms and applications for naproxen degradation at neutral pH and low FeII dosage

The application of the integrated FeII/EDDS/UV/PAA (FEUP) process (EDDS = ethylenediamine-N,N’-disuccinic acid; PAA = peracetic acid) as a novel advanced oxidation process (AOP) for the degradation of a model contaminant, namely, naproxen (NAP), at neutral pH was investigated. The enhanced NAP degradation in this system at pH 7 was primarily attributable to the continuous activation of PAA via the UV-assisted FeII/FeIII cycle. A four-phase conceptual process of NAP degradation was established. The instantaneous degradation stage (IDS), in which FeII and PAA instantaneous react within 1 s, resulted in the degradation of ~ 20% of NAP. The rapid degradation stage (RDS), in which the regenerated FeII rapidly activates PAA to produce the hydroxyl radicals (•OH) and organic radicals including CH3C(O)O•, CH3C(O)OO•, CH3OO• and •CH3 (defined as R-C•) without being scavenged by the FeII/FeIII-EDDS complexes, contributed to the degradation of ~ 55% of NAP. The slow degradation stage (SDS), during which FeII/FeIII-EDDS complexes started competing for radicals, and resulted in the degradation of ~ 15% of NAP. The continuous degradation stage (CDS), in which hydrogen peroxide (H2O2) was the only oxidant because PAA was exhausted, corresponded to the degradation of another ~ 10% of NAP. The effect of water matrices including Cl-/Br-, HCO3–/CO32–, and humic acid (HA) was evaluated: Br-, HCO3–/CO32–, and HA exhibited an inhibiting effect on NAP degradation, while Cl- showed no influence on NAP degradation in the FEUP process. A superior degradation performance was achieved under a low FeII dosage and neutral conditions, demonstrating the great potential of the FEUP process for practical applications.

Rational design of novel ternary Ag/rugby ball shaped ZnO/SmFeO3 nanocomposite: An affordable photocatalyst for the degradation of naproxen

A novel ternary Ag/rugby ball-shaped ZnO@SmFeO3 nanocomposite was prepared by a simple hydrothermal approach. The Ag particles were effectively incorporated in the surface of rugby ball-shaped ZnO and SmFeO3. Herein, Ag/ZnO@SmFeO3 nanocomposite had an obvious enhanced photocatalytic degradation of naproxen under the visible light with outstanding chemical stability. This novel three-component system will provide a valuable route to develop cost-effective as well as effective sunlight harvesting photocatalyst material. The improved catalytic performance of Ag/ZnO@SmFeO3nanocomposite could be ascribed to the synergetic effects of all ternary mixtures.

Occurrence and fate of pharmaceuticals in a wastewater treatment plant from southeast of Spain and risk assessment

Pharmaceutical and personal care products (PPCPs) can be incorporated into ecosystems and pose potential environmental and health hazards. These pollutants are becoming omnipresent in the environment because they are introduced by several sources, being particularly important the contribution of human-derived pharmaceuticals. The presence of PPCPs in waters has received increasing attention in recent years, resulting in great concern regarding their occurrence, transformation, fate and environmental risk. For that reason, the pharmaceuticals carbamazepine (CBZ), diclofenac (DIC), ibuprofen (IBU), ketoprofen (KET) and naproxen (NPX) were measured in the waters and sludge of several parts of a double step activated sludge wastewater treatment plant (WWTP) from Murcia (Spain). With these results, the biological degradation constant, the sorption coefficient and the pharmaceutical removal were calculated. Possible risks to humans and ecosystems were also evaluated.These showed good degradation of IBU and NPX (74.4 and 84.9%, respectively), while CBZ didn't display any degradation. DIC was the compound most likely to be sorbed into the sludge (3.09 L kg−1). The PPCPs removal in this double stage WWTP was compared to a previous data obtained in a WWTP of the same region with an activated sludge (single biological batch reactor). The results showed a decrease in the removal of the double stage plant, probably due to the lower hydraulic retention time employed. The study of the human and ecological risk quotients indicates a low risk of the selected pharmaceuticals (RQ < 0.1).

Optimization of photocatalytic degradation of naproxen from aqueous solutions with UV/ZnO process: Response Surface Methodology (RSM)

&lt;p&gt;The aim of this study was to optimize the removal of Naproxen (NPX) by the UV/ZnO photocatalytic process using response surface methodology based on Central Composite Design (CCD). The effect of parameters such as ZnO concentration, contact time, pH, temperature, and initial NPX concentration were studied. The ANOVA results indicated high coefficient values of adjusted R2 (0.9843) and predicted R2 (0.9695). The quadratic model with the highest R-squared designation was chosen to predict the NPX removal efficiency of the UV/ZnO process. Under optimal conditions that include an optimum initial NPX concentration of 21.59 mg/L, ZnO concentration of 371.15 mg/L, contact time of 73.92 min, pH of 6.87, and temperature of 24.35°C, a NPX removal efficiency value of 71.19% was obtained. The results show that the removal of NPX is most affected by the variables- initial NPX concentration, time, pH, and ZnO concentration, respectively, but temperature as a variable does not have a significant effect on the efficiency of the process. Moreover, the NPX photodegradation kinetics can be explained through the pseudo-first-order model. The UV/ZnO photocatalytic method has high potential for the removal of NPX, and that CCD is an appropriate method to optimize the operating conditions for NPX photodegradation.&lt;/p&gt;&#x0D;

Biodegradation kinetics of individual and mixture non-steroidal anti-inflammatory drugs in an agricultural soil receiving alkaline treated biosolids

Land application of biosolids is one potential source of pharmaceuticals and personal care products (PPCPs) into agricultural soils. Degradation is an important natural attenuation pathway that affects the fate and transport of PPCPs in the soil system and biosolids application could alter the process. The present study assessed the effect of individual and mixture compound environments on the biodegradation rate and half-life of three non-steroidal anti-inflammatory drugs (NSAIDs), naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF), in a loamy sand textured agricultural soil receiving an alkaline treated biosolid (ATB) amendment. A prolonged half-life of the target NSAIDs was determined for sterile soils and shorter half-lives in unsterile soils, indicating the loss of target compounds in all treatments was mainly attributed to biodegradation and followed first-order kinetics. IBF and NPX showed low to moderate persistence in soil and ATB amended soil, with half-lives ranging from 4.9 to 14.8 days, while KTF appeared to be highly persistent with an average half-life of 33 days. The order in which the target NSAIDs disappeared in both soil and ATB amended soil was: IBF > NPX > KTF, for both individual and mixture compound treatments. Soils that received the ATB amendment demonstrated inhibited degradation of NPX in all treatments, as well as IBF and KTF in individual compound treatment over the 14-day incubation study. We also observed an inhibition effect from the ATB amendment in sterile soil treatments. In mixture compound treatments, IBF degradation was inhibited in both soil and ATB amended soil. The degradation rate of KTF in mixture compound environment in soil was lower, while the opposite effects were observed in ATB amended soils. For NPX, the degradation was enhanced in mixture compound environment in ATB amended soil, while the same degradation rate of NPX was calculated in soil.

Iron-based metal organic framework MIL-88-A for the degradation of naproxen in water through persulfate activation

In this work, particular interest is given to synthetized iron-based MOF e.g. MIL-88-A especially for its ability to catalytically activate persulfate (PS) in an advanced oxidation process (AOP) toward the degradation of naproxen (NPX) in solution in batch systems. NPX solution (50 mg L-1) was subjected to specific added amount of MIL-88-A followed by PS spiking after equilibrium was reached. The system was optimized for its recyclability and matrix variations by studying parameters including ionic strength, pH, phosphates and bicarbonates content, oxidant nature (S2O82-- vs H2O2) as well as UVA irradiation. Results showed that (i) MIL-88-A is a good activator of PS where 65–70% degradation of NPX was noticed within 2 h of reaction at room temperature; (ii) MIL-88-A is recyclable up to 4 successive cycles with significant removal extent; (iii) phosphates had no effect on the degradation of NPX however, bicarbonates exhibited a strong inhibition; (iv) PS activation and NPX degradation were optimal at acidic conditions (pH = 4) and (v) PS generated HRs and SRs in the medium and was shown to be superior oxidant over H2O2 in the presence of MIL-88-A. Moreover, experiments under UVA irradiation showed significant improvement of the degradation process of NPX in solution reaching almost complete vanishing after 2 h of reaction. The removal mechanism of NPX was investigated using, for the first time, in addition to traditional analytical techniques e.g. HPLC/DAD/MS-Ion trap, XPS and EPR, the Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). TOF-SIMS technique confirmed that adsorption/degradation mechanism of NPX took place at the surface of MIL-88-A making this heterogeneous catalysis AOP-based technology very successful for the elimination of pharmaceutical compounds from water effluents.

Facile synthesis of solar light-driven Z-scheme Ag2CO3/TNS-001 photocatalyst for the effective degradation of naproxen: Mechanisms and degradation pathways

The development of efficient solar light-driven catalyst materials is considered a promising strategy for the photocatalytic eradication of contaminants. Herein, a novel Z-scheme Ag2CO3/TNS-001 nanocomposite photocatalyst with excellent solar-light response was synthesized using a simple hydrothermal and deposition reaction. The morphology, chemical structure, and optical property of Z-scheme composites were systematically investigated by TEM, XRD, FI-IR, XPS, and UV–vis, etc. techniques. The Ag2CO3/TNS-001 exhibited superior photocatalytic activity for removal of naproxen (NAP) under solar light irradiation, demonstrating kinetics of 40.7, 23.9, and 6.9 times higher than that of Ag2CO3, P25, and TNS-001, respectively. This remarkably improved photocatalytic efficiency was attributed to the synergistic effects of highly active (001) facets, efficient solar light response, and enhanced separation of photogenerated carriers. The scavenging experiments indicated that h+ was the dominant species during the photocatalytic degradation of NAP. Together with the analyses of EPR and band structure, a potential Z-scheme mechanism was confirmed. Moreover, the degradation pathway of NAP was revealed via intermediate detection and density functional theory (DFT) calculations. The chlorella acute toxicity test further indicated that mineralization translated to a reduction in the toxicity of the NAP solution. This work offers a promising strategy for the design of efficient Z-scheme photocatalysts, while exploring new insights into the elimination of emerging organic pollutants.

Rapid TLC with Densitometry for Evaluation of Naproxen Stability

The purpose of the work was to develop such chromatographic conditions that allowed to separate as many naproxen degradation products as possible. In order to follow this process, thin-layer chromatography (TLC) coupled with densitometry and spectrodensitometry was used. A forced degradation study was performed using an ethanolic solution of naproxen spotted on silica gel plates, existing in the form of an aqueous solution at various pH values, and as solution prepared in saline and in hydrogen peroxide. Degradative effect of UV light on naproxen was watched in the context of naproxen spotted on plates precoated with silica gel and exposed to UV light, and also for its solution treated with UV light. However, the solution of naproxen prepared in water at pH ≈ 2.60 undergoes the largest changes as the results of its exposure to UV light during 10 h. Stressed samples of naproxen were analyzed by using a new and well validated TLC procedure including toluene (TOL)—acetone (ACE)—chloroform (CHL) (2:5:12, v/v/v) as mobile phase A and glacial acetic acid (AcOH)—n-hexane (Hex)—acetone (ACE)-(0.10:10:10, v/v/v) as mobile phase B. As the newly developed TLC-densitometric method can effectively separate the substances about pharmaceutical significance from products of its degradation, which are formed as a result of stress studies, is considered to be a good alternative and important tool in routine quality control and stability testing of naproxen in pharmaceutical formulations. These results indicate that proposed TLC-densitometric method is cost-effective, rapid, specific, accurate, and precise. This TLC procedure is comparable to HPLC and UPLC method in terms of detection the number of degradation products of naproxen. In addition, it realizes the criterion of linearity. A major advantage and novelty of proposed method is its low cost and ability to analyze examined drug and all degradation products simultaneously, including those which can be observed under intensive UV radiation exposure of naproxen solution which are not described by previous HPTLC studies available in the literature.

Enhanced Naproxen Elimination in Water by Catalytic Ozonation Based on NiO Films

This study evaluates naproxen (NP) degradation efficiency by ozonation using nickel oxide films (NiO(F)) as a catalyst. The NiO films were synthesized by chemical vapor deposition and characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. NP degradation was conducted for 5 min using 10 films of NiO(F) comparing against ozonation using 100 mg/L NiO powder in suspension (NiO(S)) and conventional ozonation (O3-conv). Total organic carbon analysis demonstrated a mineralization degree of 12% with O3-conv, 35% with NiO as powder and 22% with NiO(F) after 60 min of reaction. The films of NiO(F) were sequentially used 4 times in ozonation demonstrating the stability of the synthesized material, as well as its properties as a catalyst for ozonation. A proposed modeling strategy using robust parametric identification techniques allows the comparison of NP decomposition pseudo-monomolecular reaction rates.

Temperature effects on VO2 thin films deposited by RF sputtering for the degradation by photocatalysis of methylene blue and naproxen

AbstractThe temperature effect on VO2 thin films synthesized by RF sputtering on their morphological, optical, electrical properties and their activity in the photocatalytic degradation of methylene blue and naproxen was studied. Characterization results presented microcrystallinity for VO2 films treated at 50 and 100 °C. Nevertheless, the untreated films and films treated at 200 °C revealed characteristic peaks of monoclinic and tetragonal phases. SEM micrographs with elemental mapping of VO2 films showed granular morphology and a good oxygen dispersion along the film surface, possibly due to a restructuring on the film occasioned by particle coalescence and vanadium oxide island conformation. The electronic transmittance spectra showed the d–d transition characteristic for the square-pyramidal stereochemistry of vanadium (IV) ion, where the optical band interval was high for films treated at 50 °C. Raman spectroscopy results presented an increment in the V = O/V–O ratio as a function of temperature, probably related to superficial vanadium species formation. X-ray spectroscopy results showed the Onon-lattice/Olattice ratio values higher for films treated at 50 °C than the other films, related to an oxide character. The V 2p fit results presented V4+, V5+ regions and satellites for VO2 films thermal treated at 50 °C. The electrical resistivity on the VO2 films decreased as a function of temperature. Finally, the VO2 films thermal treated at 50 °C had higher photocatalytic activity in the degradation of methylene blue and naproxen compared to the other VO2 films, possibly associated with high electron mobility between the surface and the bulk, where the oxygen vacancies act as recombination sites for the e−/h+ pairs during photocatalytic degradation.

Kinetics and pathways of the degradation of PPCPs by carbonate radicals in advanced oxidation processes

The carbonate radical (CO3•−) is a typical secondary radical observed in engineering and natural aquatic systems. This study investigated the degradation kinetics of 20 pharmaceuticals and personal care products (PPCPs) by CO3•− and the transformation pathways of a typical PPCP (naproxen) that is susceptible to CO3•−. CO3•− is highly selective for compounds containing aniline and phenolic hydroxyl groups as well as naphthalene rings, such as sulfamethoxazole, sulfamethazine, salbutamol, propranolol, naproxen, and macrolide antibiotics such as azithromycin, for which the second-order rate constants range from 5.6 × 107 M−1s−1 to 2.96 × 108 M−1s−1. A good linear relationship is observed between the natural logarithms of kCO3•− and the negative values of the Hammett Σσp+ constant for aromatic PPCPs, indicating that electron-donating groups promote the attack of benzene derivatives by CO3•−. The contribution of CO3•− to naproxen degradation is significant in different processes such as UV/H2O2, UV/persulfate, UV/chlorine, and UV/monochloramine, in the presence of HCO3−, which compensates for the decreased contributions of primary radicals. In particular, the formation of CO3•− increases the first-order rate constant of naproxen by 127% in UV/monochloramine in the presence of 50 mM HCO3− compared to that without HCO3−. Natural organic matter (NOM) exerts a slight scavenging effect on CO3•−, decreasing the inhibition effect of NOM on the degradation of naproxen by UV/H2O2 in the presence of HCO3−. The pathways involved in the transformation of naproxen by CO3•− include decarboxylation, hydroxylation, ketonization, demethylation and aldolization. In addition, the alteration of the genotoxicity during naproxen degradation by CO3•− was negligible.

Three dimensional electro-Fenton oxidation of diclofenac and naproxen with magnetic bentonite as a novel particle electrode

ABSTRACT Magnetic bentonite (MBt) and Ti/TiO2 nanotube/PbO2, for the first time, were investigated as particle electrodes and anode of three dimensional electro-Fenton process (3DEF) for the degradation of diclofenac (DCF) and naproxen (NPX). The characteristics of the electrodes were determined by X-ray diffraction(XRD), scanning electron microscope(SEM) and energydispersive X-ray spectroscopy(EDS) analyses and the effects of operating parameters on degradation were studied. The results showed that adsorption and electrochemical processes have lower removal efficiency than the 3DEF process at neutral pH. This efficiency was due to the greater production of hydroxyl radical (•OH) through the anode and MBt surface. The results of the scavenging experiments confirmed an increase in the amount of production of •OH. The maximum removal efficiency of DCF and NPX was obtained at pH of 6, MBt dosage of 500 mg/L, current density of 25 mA/cm2and electrolysis time of 120 min. The electrodes reusability was confirmed by consecutive reaction cycle and the Fourier-transform infrared spectroscopy (FTIR) and SEM-mapping analysis explained their stability. The results of continuous electro-oxidation reactor showed proper removal of the chemical oxygen demand(COD) from real wastewater. The degradation by-products were identified by gas chromatography mass-spectrometry (GC-MS) analysis coupled with dispersive liquid–liquid microextraction (DLLME). Based on comparative tests and products identification, the possible mechanism and pathway of drugs degradation were suggested.

Single-atom silver induced amorphization of hollow tubular g-C3N4 for enhanced visible light-driven photocatalytic degradation of naproxen

In this work, a novel strategy for building single-atom silver-induced amorphous graphitic carbon nitride (g-C3N4) with a hollow tubular morphology is developed. By forming a tubular supramolecular gel, silver is successfully isolated by the nitrogen atoms in both melamine and nitrate anions, impeding agglomeration in the subsequent thermal polymerization. The high density of single-atom-dispersed silver (atomic ratio up to 11.6%) selectively breaks the hydrogen bonds in layered g-C3N4, leading to a fully amorphous structure. Silver-induced full amorphization not only enhances the visible light absorption of g-C3N4 but also accelerates charge transfer, endowing the as-prepared photocatalyst having the optimal silver content with 52 times higher surface area specific naproxen (NPX) removal activity than pure g-C3N4. Both density functional theory (DFT) calculations and steric effects are applied to explain the degradation pathway of NPX. The toxicity of NPX is reduced by sufficient irradiation. This work provides useful insights into the design and morphology control of single metal ion-dispersed g-C3N4 for environmental applications.

Photoprotective Effects of Selected Amino Acids on Naproxen Photodegradation in Aqueous Media.

It is important to develop a photostabilization strategy to ensure the quality of photosensitive compounds, including pharmaceuticals. This study focused on the protective effects of 20 amino acids on the photodegradation of naproxen (NX), a photosensitive pharmaceutical, to clarify the important nature of a good photostabilizer. Our previous report indicated the photodegradability of NX and the protective effects of some antioxidants on its photodegradation, therefore, this compound was used as a model compound. The degradation of NX in aqueous media during ultraviolet light (UV) irradiation and the protective effects of selected amino acids were monitored through high-performance liquid chromatography (HPLC), equipped with a reverse-phase column. Addition of cysteine, tryptophan, and tyrosine induced the significant suppression of NX photodegradation after UV irradiation for 3 h (residual amount of NX; 15.35%, 6.82%, and 15.64%, respectively). Evaluation of the antioxidative activity and UV absorption spectrum showed that cysteine suppressed NX degradation through its antioxidative ability, while tryptophan and tyrosine suppressed it through their UV filtering ability. Furthermore, three amino acids at higher concentrations (more than 100 µmol/L) showed more protective effects on NX photodegradation. For 10 mmol/L, residual amounts of NX with cysteine, tryptophan, and tyrosine were 58.51%, 69.34%, and 82.40%, respectively. These results showed the importance of both photoprotective potencies (antioxidative potency and UV filtering potency) and stability to UV irradiation for a good photostabilizer of photosensitive pharmaceuticals.

Reduced Graphene Oxide/ZnIn2S4 Nanocomposite Photocatalyst with Enhanced Photocatalytic Performance for the Degradation of Naproxen under Visible Light Irradiation

The development of photocatalysts with visible light response is of great significance to cope with energy crisis and environmental remediation. In this study, a visible light-driven photocatalyst reduced graphene oxide/ZnIn2S4 (rGO/ZIS) was prepared by a facile one-pot hydrothermal method. The photocatalyst was used for the degradation of naproxen under visible light illumination and it exhibited remarkably degradation efficiency (nearly 99% within 60 min). The improved photocatalytic degradation performance can be attributed to the enhancement of light adsorption capacity and effective separation of photoinduced electron–hole pairs. The reactive species quenching experiments and EPR measurements demonstrated that superoxide radical (–O2−) and hole (h+) play a dominant role in the photocatalytic degradation reactions. In addition, the degradation intermediates were identified and the degradation pathway was suggested.

Insight into PPCP degradation by UV/NH2Cl and comparison with UV/NaClO: Kinetics, reaction mechanism, and DBP formation

The UV/NH2Cl process is an emerging advanced oxidation process (AOP) that is greatly effective in degrading pharmaceuticals and personal care products (PPCPs). However, detailed information regarding the process is lacking. The degradation of ibuprofen (IBP, an electron-withdrawing PPCP) and naproxen (NPX, an electron-donating PPCP) in UV/NH2Cl and UV/NaClO processes was performed to investigate the applicability and security of the UV/NH2Cl process and compare with those of UV/NaClO. UV/NH2Cl was effective in degrading both IBP and NPX and the degradation followed pseudo-first order kinetics (kIBP = 0.0037 cm2/mJ and kNPX = 0.0044 cm2/mJ). This indicated the broad applicability of UV/NH2Cl to different kinds of PPCPs. Ranges of values of UV intensity (0.3–1.0 mW/cm2) and pH (6.0–8.0) showed little effect on the degradation of PPCPs by UV/NH2Cl based on UV Dose but HCO3− (2–8 mM), natural organic matter (NOM, 2–8 mg/L), and the natural water matrixes were inhibitory. Increasing the dosage of NH2Cl from 0.15 mM to 0.75 mM, resulted in an even increase of kIBP; however, kNPX increased slowly after 0.3 mM NH2Cl. Mechanism experiments involving nitrobenzene showed that •OH was the major radical involved in degrading IBP and NPX via UV/NH2Cl. The electron spin resonance spectroscopy and kinetic modeling results also indicated the larger amount of •OH and weaker reactive chlorine species (mainly ClO• and ClO2•) in UV/NH2Cl compared with UV/NaClO. Compared to UV/NaClO in synthetic and natural water, UV/NH2Cl was a more stable degrader with little pH- and substrate-dependence, while UV/NaClO preferred degrading the electron-donating PPCP and at low pH. The UV/NH2Cl produced less halogenated disinfection byproducts (DBPs) (even nitrogenous DBPs) and was less cytotoxic theoretically than UV/NaClO based on the DBPs included in this study. Thus UV/NH2Cl process may be an effective AOP for water treatment.

A potential natural solar light active photocatalyst using magnetic ZnFe2O4 @ TiO2/Cu nanocomposite as a high performance and recyclable platform for degradation of naproxen from aqueous solution

In this study, naproxen degradation examined using a photocatalytic method under the sunlight and UV light via ZnFe2O4@TiO2/Cu nanocomposite in the batch, continuous and large scale systems. ZnFe2O4@TiO2/Cu nanocomposite was prepared using Solvothermal method, and structure, morphology, and size of the nanoparticles was determined using XRD, VSM, FESEM/EDX, DLS, FTIR, TGA, UV–Vis (DRS), XPS, PL, ESR, Zeta potential and ICP-OES. pH, catalyst concentration, aeration, initial concentration of naproxen, flow rate was investigated on naproxen photodegradation. The results showed that ZnFe2O4@TiO2/Cu nanocomposites exhibited better photocatalytic activity in relation to ZnFe2O4@TiO2 and ZnFe2O4. The ZnFe2O4@TiO2/Cu nanocomposite exhibited naproxen photodegradition efficiency of 80.73% under sunlight. It also revealed high stability and recyclability, where in after 5 cycles of using the catalyst in take, 72.31% removal was achieved. With increasing flow rates i.e. from 5 to 15 ml/min, naproxen degradation decreased. Therefore, it can be safely concluded that ZnFe2O4@TiO2/Cu nanoparticle, due to high efficiency as well as easy separation of nanoparticles from pollutants via a magnet can be used as a practical, reliable, efficient and inexpensive way to remove contaminants from the water resources.