Degradation Of Diclofenac Sodium Research Articles

Degradation of diclofenac sodium with low concentration from aqueous milieu through polydopamine-chitosan modified magnetic adsorbent-assisted photo-Fenton process

Given the widespread occurrence of low-concentration diclofenac sodium (DCFS) in the aquatic milieu, the development of an efficient and economical purification method is essential. Magnetic polydopamine-chitosan modified adsorbent (MPDA-CS) was successfully prepared by coating polydopamine-chitosan onto Fe3O4 nanoparticles in this study. The favorable adsorption performance towards DCFS was well demonstrated by regulating the solution to various pH values and initial concentrations of DCFS. Furthermore, the convincing fitting of pseudo-second-order model and intraparticle diffusion model suggested that the dominance of chemical processes and intraparticle diffusion. The specific adsorption mechanism was presumed to be the interaction between MPDA-CS and DCFS molecules, including electrostatic attraction, hydrogen bonding and aromatic stacking. Through regulating standing time in acidic solution, the integrated homogeneous and heterogeneous photo-Fenton system was employed to degrade adsorbed DCFS through dissolved and surfaced Fe(II)/Fe(III) of MPDA-CS, which achieved the waste utilization of dissolved iron ions with excellent degradation efficiency of 96.38% in 40 min. The adsorption-degradation efficiency of DCFS decreased slightly by 2.2% during the initial three cycles. This work presents an energy-efficient method for removing low-concentration DCFS by drawing on the strengths of adsorption and degradation.

Polydopamine-Chitosan modified TiO2 nanoparticles for temperature-response removal of diclofenac sodium under visible light irradiation

BackgroundDiclofenac sodium is a kind of classic pharmaceutical and personal care product which has a potential risk to aqueous environment and food chain. The aim of the study is to realize the removal of diclofenac sodium in an energy-efficient and eco-friendly way. MethodTiO2 nanoparticles were modified with aminopropyltriethoxysilane and then were grafted with polydopamine and chitosan sequentially through Schiff-base reaction to realize spatiotemporal coagulation and degradation of diclofenac sodium under visible light irradiation, which was rare reported before. ResultsThe polymer layer of modified TiO2 nanoparticles became swelling and outstretching with cooling the temperature from 313.15±0.2 to 293.15±0.2 K, which led to the exposure of the TiO2 nanoparticle surface and the photocatalysis of which was activated. Photoelectrons migrated to the surface of which due to the protonation of TiO2 nanoparticles in acidic aqueous milieu and reacted with OHˉ forming •OH at the presence of oxygen and the photocatalytic efficiency of which was improved. It further reacted with diclofenac sodium and the coagulant could be directly reused at least twenty times without rinse process in this work, which has a significantly application potential considering future benefits.

Degradation of diclofenac sodium by the UV/chlorine process: Reaction mechanism, influencing factors and toxicity evaluation

This study examined the reaction mechanism, influencing factors and toxicity of diclofenac sodium (DS) degradation by ultraviolet (UV)/chlorine process. The UV/chlorine was capable of eliminating DS from water. The DS degradation during the UV/chlorine process followed a pseudo-first-order kinetic model that was influenced by chlorine dosage, solution pH, humic acid and bicarbonate concentrations. The free chlorine affects not only DS elimination, but the contribution of various active species as well. Increasing free chlorine dosage from 1 to 7 mg·L−1 increased the first-order rate constant of NaClO, ·OH and reactive chlorine species (RCS) from 0.00063, 0.00328 and 0.002030 min−1 to 0.00233, 0.01010 and 0.09740 min−1, respectively, and increased the contribution of RCS from 8.20% to 75.71%, while the contributions of UV, NaClO, and ·OH were declined from 76.02%, 2.54% and 13.24% to 14.63%, 1.81%, and 7.85%, respectively. The contribution of RCS became increasing prominence with the increment of free chlorine dosage. The kobs,UV/chlorine,DS value decreased from 0.07970 to 0.04450 min−1 as pH increased from 5.0 to 8.0. The presence of bicarbonate and natural organic matter both exerted an inhibitory effect on DS degradation. Eleven intermediate products were identified and the degradation pathway involved C-N cleavage, condensation, hydroxylation, and decarboxylation was proposed. The UV/chlorine process effectively reduced acute toxicity and was superior to chlorination. The genotoxicity induced by a chlorinated solution treated by the UV/chlorine process exhibited negative genotoxicity. These results show that the UV/chlorine process is capable for the degradation and detoxification of DS.

Degradation of Anti-Inflammatory Drugs in Synthetic Wastewater by Solar Photocatalysis

Due to the high number of anti-inflammatory drugs (AIMDs) used by the public health sector in Iraq and distributed all over the country and due to their toxicity, there is a need for an environmental-friendly technique to degrade any wasted (AIMD) present in aquatic ecosystem. The degradation of diclofenac sodium (DCF), ibuprofen (IBN), and mefenamic acid (MFA) in synthetic hospital wastewater were investigated utilizing locally-made Cu-coated TiO2 nanoparticles in a solar-irradiated reactor. Different key variables were studied for their effects on process efficiency, such as loadings of catalyst (C CU-TiO2 = 100–500 mg/L), AIMDs (100 µg/L), pH (4–9), and hydrogen peroxide (CH2O2 = 200–800 mg/L). The results revealed that degradation percentages of 96.5, 94.2, and 82.3%, were obtained for DCF, IBN, and MFA, respectively, using our Cu-coated TiO2 catalyst within 65 min at pH = 9, while other parameters were C CU-TiO2 = 300 mg/L, and CH2O2 = 400 mg/L. The experimental results revealed coupling photocatalysis with solar irradiation as a clean energy source could be utilized for the degradation of toxic pollutants in surface water.

Permanganate release from silica-based hollow mesoporous coagulant combined with UV for spatiotemporal enrichment and degradation of diclofenac sodium

In this work, the novel hollow mesoporous coagulant was prepared by chitosan-polydopamine coating and permanganate loading into silica nanoparticles for investigating the simultaneous enrichment and degradation of diclofenac sodium (DCFS) combined with ultraviolet irradiation. The enrichment kinetic of DCFS was explained well with pseudo-second-order model, indicating the exist of hydrogen bonding. Based on the correlation coefficients, the enriched isotherms were fitted by models which accorded with the BET > Freundlich > Langmuir sequence. The result showed that, in addition to the coagulant and DCFS, there were aromatic stackings among DCFS molecules. Due to both effects of which, the DCFS enrichment could be realized significantly in the range of pH 4.0–9.0. It was degraded at the copresence of ultraviolet and permanganate released from coagulant in acidic aqueous medium. The release mechanism was simulated through Korsmayer-Peppas model, implying case-II transport and Fickian diffusion. Additionally, Mn (V) and •OH radicals were vital in the DCFS degradation process. The coagulant could be reloaded at least ten times and that from each cycle was used directly for DCFS removal for six times without rinse process, which provided a potential application in environmental remediation.

Titanium-based hollow silica nanocarrier doped hydrogel for ultraviolet assisted removal of diclofenac sodium

In this study, the coagulant was prepared by grafting polydopamine onto chitosan hydrogel which was doped with hollow silica nanoparticles loaded with permanganate and then was coated on the surface of the titanium tablet to realize simultaneous coagulation and degradation of diclofenac sodium (DCFS) combined with UV irradiation. The coagulation kinetics were simulated well with Pseudo-first order and pseudo-second order models compared with Weber-Morris model, inferring the cooperation of chemical and physical processes. The outcomes of isotherm trials were fitted well with Langmuir model except for that at 303.15 K, which was described both well with Langmuir and Tëмкин models, implying monolayer and unsaturated coagulation of DCFS. It was degraded at the copresence of ultraviolet and permanganate released from coagulant in acidic aqueous medium. Hydroxyl and Mn(V) radicals played an important role in DCFS degradation process. Additionally, the coagulant was used directly for DCFS removal for ten times without rinse process, which provided a potential application in environmental remediation.

Degradation of Diclofenac Sodium by Pre-magnetization Fe0/Persulfate System: Efficiency and Degradation Pathway Study

The degradation of diclofenac sodium (DCF) in pre-magnetization Fe0/persulfate (Pre-Fe0/PS) and Fe0/PS systems were studied in detail in this study. The influencing operational conditions (initial PS dosage, Fe0 dosage, and pH) were studied for their effects on the DCF degradation. The removal rate constant for DCF by the Pre-Fe0/PS system was 2.1–6.2 times higher than that of the Fe0/PS system. A higher TOC removal efficiency (81.5%) was observed during the mineralization of DCF in the Pre-Fe0/PS process than that of the Fe0/PS process (70%). The results of electron paramagnetic resonance (EPR) confirmed that the Pre-Fe0/PS system could produce much more •OH and SO4−• at a faster rate than the Fe0/PS system. Moreover, the degradation mechanism of DCF by the Pre-Fe0/PS process was elucidated. This work would provide a perspective on the Pre-Fe0/PS process for efficient degradation of DCF, exhibiting advantages to removing DCF, such as broaden the range of working pH and reduce the amount of chemicals. So, it is an efficient and potential method to remove DCF from wastewater by the Pre-Fe0/PS process.

Hydrothermal synthesis of FeS2 as a highly efficient heterogeneous electro-Fenton catalyst to degrade diclofenac via molecular oxygen effects for Fe(II)/Fe(III) cycle

In this study, we demonstrated that hydrothermal synthesized FeS2 was highly efficient to catalyze the H2O2 decomposition for diclofenacsodium (DCF) degradation in a wide range of initial pH (3–9) by heterogeneous electro-Fenton (EF) process, and this “Pyrite-EF” showed a better performance for the mineralization of DCF in comparison with the classic EF process. Effect of pyrite content on the hydroxyl radicals generation and iron dissolution produced by the decomposition of hydrogen peroxide (H2O2), and applied current density on the degradation kinetics and mineralization efficiency were studied. Moreover, toxicity assessment by means of microtox method showed the solution toxicity was removed after treatment. Experimental results revealed that the enhancement of DCF degradation rate in the Pyrite-EF process was attributed to the molecular oxygen activation induced by more surface bound ferrous ions on FeS2, generating superoxide anions to accelerate the Fe(II)/Fe(III) cycle on the FeS2 surface, which favored the H2O2 decomposition to generate more hydroxyl radicals for the DCF degradation via a heterogeneous EF-like process. These findings could provide some new insights into the molecular oxygen activation induced by FeS2 and the subsequent heterogeneous Pyrite-EF degradation of organic pollutants from wastewater.

Magnetic Template Anion Polyacrylamide-Polydopamine-Fe3O4 Combined with Ultraviolet/H2O2 for the Rapid Enrichment and Degradation of Diclofenac Sodium from Aqueous Environment.

In this study, a novel system was set up by preparing a magnetic flocculant combining with ultraviolet/H2O2 to realize the rapid enrichment and degradation of diclofenac sodium (DCFS). For the magnetic flocculant, template anion polyacrylamide (TAPAM) with anion micro-block structure was prepared. Thereafter, polydopamine was used to modify TAPAM, Fe3O4 nanoparticles was grafted to the modified TAPAM by chelation, named template anion polyacrylamide-polydopamine-Fe3O4 (TAPAM-PDA-Fe3O4). Furthermore, the TAPAM-PDA-Fe3O4 preparation protocol was optimized by the response surface method (RSM). In the DCFS enrichment section, the rapid separation of flocs from water was realized by an external magnetic field and it indicated that the π–π stacking effect was dominant in neutral/alkaline condition, whereas charge neutralization was favored in acidic conditions. Meanwhile, a DCFS enrichment kinetic curve was much fitted by the pseudo-second-order kinetic model and DCFS enrichment isothermal curve was close to the Freundlich isothermal model, indicating the dependence of DCFS quantity enriched by TAPAM-PDA-Fe3O4 and a multilayer heterogeneous enrichment process. The degradation experiment confirmed that DCFS was effectively degraded by ultraviolet/H2O2/TAPAM-PDA-Fe3O4 and the maximum value of DCFS degradation efficiency reached 98.1%. Furthermore, the regeneration experiment showed that the enrichment and degradation efficiency of DCFS could maintain a relatively high level in the initial three recycles.

Photocatalytic performance and mechanism of Z-Scheme CuBi2O4/Ag3PO4 in the degradation of diclofenac sodium under visible light irradiation: Effects of pH, H2O2, and S2O82−

Highly efficient visible-light-responsive Z-Scheme CuBi2O4/Ag3PO4 photocatalysts were prepared by a hydrothermal synthesis and in-situ deposition method and characterized comprehensively. Under visible-light irradiation, the photocatalytic performance of CuBi2O4/Ag3PO4 in the degradation of diclofenac sodium (DS) in aqueous solutions was studied under different conditions such as different catalyst composition, solution pH, and concentration of S2O82− or H2O2, and the response surface methodology (RSM) was used to analyze the interaction effect of the parameters. The optimal activity of CuBi2O4/Ag3PO4 was achieved at the mass ratio of 3:7 and pH of 4.42. Moreover, the introduced S2O82− could significantly enhance the catalytic activity of CuBi2O4/Ag3PO4; when 1 mM S2O82− was added to the catalytic system, 10 mg/L of DS could be completely degraded within 60 min, but the structure of CuBi2O4/Ag3PO4 was severely destroyed. While when H2O2 was introduced into the system, both the activity and stability of CuBi2O4/Ag3PO4 were improved significantly. Finally, the photodegradation pathway of DS is proposed and the photocatalytic mechanism of CuBi2O4/Ag3PO4 under different conditions is explained. CuBi2O4/Ag3PO4 and CuBi2O4/Ag3PO4 (S2O82−) photocatalytic systems follow the Z-Scheme theory, and Ag0 formed on the surface of catalyst serves as the recombination center for the photogenerated e− from the conduction band (CB) of Ag3PO4 and h+ from the valence band (VB) of CuBi2O4; meanwhile, the catalytic degradation of DS by CuBi2O4/Ag3PO4 in the presence of H2O2 follows the heterojunction energy band theory.

Ag3PO4 Deposited on CuBi2O4 to Construct Z-Scheme Photocatalyst with Excellent Visible-Light Catalytic Performance Toward the Degradation of Diclofenac Sodium.

CuBi2O4/Ag3PO4 was synthesized through a combination of hydrothermal synthesis and an in situ deposition method with sodium stearate as additives, and their textures were characterized with XRD, XPS, SEM/HRTEM, EDS, UV-Vis, and PL. Then, the photodegradation performance of CuBi2O4/Ag3PO4 toward the degradation of diclofenac sodium (DS) was investigated, and the results indicate that the degradation rate of DS in a CuBi2O4/Ag3PO4 (1:1) system is 0.0143 min−1, which is 3.6 times that in the blank irradiation system. Finally, the photocatalytic mechanism of CuBi2O4/Ag3PO4 was discussed, which follows the Z-Scheme theory, and the performance enhancement of CuBi2O4/Ag3PO4 was attributed to the improved separation efficiency of photogenerated electron–hole pairs.

Enhanced photocatalytic Cr(VI) reduction and diclofenac sodium degradation under simulated sunlight irradiation over MIL-100(Fe)/g-C3N4 heterojunctions

Metal-organic framework MIL-100(Fe) and g-C3N4 heterojunctions (MG-x, x = 5%, 10%, 20%, and 30%, x is the mass fraction of MIL-100(Fe) in the hybrids) were facilely fabricated through ball-milling and annealing, and characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, UV-visible diffuse-reflectance spectrometry, and photoluminescence emission spectrometry. The photocatalytic activities of the series of MG-x heterojunctions toward Cr(VI) reduction and diclofenac sodium degradation were tested upon irradiation with simulated sunlight. The influence of different organic compounds (ethanol, citric acid, oxalic acid, and diclofenac sodium) as hole scavengers and the pH values (2, 3, 4, 6, and 8) on the photocatalytic activities of the series of MG-x heterojunctions was investigated. MG-20% showed superior photocatalytic Cr(VI) reduction and diclofenac sodium degradation performance than did the individual MIL-100(Fe) and g-C3N4 because of the improved separation of photoinduced electron-hole charges, which was clarified via photoluminescence emission and electrochemical data. Moreover, the MG-x exhibited good reusability and stability after several runs.

Concentration of Diclofenac Sodium Using the Nanofiltration Combined with Laccase Degradation from Trametes Versicolor

An effluent containing diclofenac sodium is treated using a combination of two processes. The first one is the nanofiltration which allows a concentration of the diclofenac molecule, and the second one is an enzymatic biological degradation through an immobilization of laccase on a carbon felt. Optimized parameters have been determined through the treatment of wastes issued from an Algerian pharmaceutical industrial company. The optimal performance of the nanofiltration, using the NF270 membrane, is obtained with a trans-membranous pressure of 3 bars, a pH equal to 7 and a filtration time of 75 min. A diclofenac concentration of about 3 mg/ml is obtained, and the optimal degradation of diclofenac sodium (95%) occurs at a pH equal to 6, while the laccase concentration is 1 mg/ml in a complete reaction time of 7 h. It is noticed that the yield to the enzymatic degradation of the diclofenac sodium by the laccase is increased by the nanofiltration pretreatment.

Immobilized Nanopillars-TiO2 in the efficient removal of micro-pollutants from aqueous solutions: Physico-chemical studies

Nanopillars-TiO2 was immobilized onto a borosilicate glass disk using sol–gel template method. The TiO2 film was immobilized with and without polyethylene glycol as filler media and annealed at 500°C. The prepared films were characterized by the IR, XRD, XRF and XPS analytical methods. The surface morphology was obtained using FE-SEM and AFM images of these thin films and the BET specific surface area was obtained. Further, the Nanopillars TiO2 was employed in the photocatalytic degradation of micro-pollutants viz., diclofenac sodium and tetracycline hydrochloride from aqueous solutions using UV-light under batch reactor operations. Various physico-chemical parametric studies viz., effect of pH, pollutant concentration and interfering ions was studied to deduce the mechanism involved in photocatalytic degradation of these pollutants. The time dependence degradation of these pollutants provided kinetics of degradation of these pollutants from aqueous solutions. The studies were further extended with total organic carbon measurement using TOC analyser to demonstrate an apparent mineralization of these pollutants. The photocatalytic degradation was assessed in presence of scavengers and several co-existing ions to simulate the data for real wastewater matrix. The hydroxyl radical scavengers 2-propanol and sodium bicarbonate greatly suppressed the catalytic activity of the thin films. However, the singlet oxygen scavenger sodium azide could not affect significantly the catalytic activity of these thin films at least the degradation of diclofenac sodium and tetracycline from aqueous solutions.

Degradation of the drug sodium diclofenac by Trametes versicolor pellets and identification of some intermediates by NMR

Degradation of diclofenac sodium, a nonsteroidal anti-inflammatory drug widely found in the aquatic environment, was assessed using the white-rot fungus Trametes versicolor. Almost complete diclofenac removal (≥94%) occurred the first hour with T. versicolor pellets when the drug was added at relatively high (10 mg L −1) and environmentally relevant low (45 μg L −1) concentrations in a defined liquid medium. In vivo and in vitro experiments using the cytochrome P450 inhibitor 1-aminobenzotriazole and purified laccase, respectively, suggested at least two different mechanisms employed by T. versicolor to initiate diclofenac degradation. Two hydroxylated metabolites, 4′-hydroxydiclofenac and 5-hydroxydiclofenac, were structurally elucidated by nuclear magnetic resonance as degradation intermediates in fungal cultures spiked with diclofenac. Both parent compound and intermediates disappeared after 24 h leading to a decrease in ecotoxicity calculated by the Microtox test. Laccase-catalyzed transformation of diclofenac led to the formation of 4-(2,6-dichlorophenylamino)-1,3-benzenedimethanol, which was not detected in in vivo experiments probably due to the low laccase activity levels observed through the first hours of incubation.