Degradation Of Bezafibrate Research Articles

Evaluating synergy of dual-wavelength deep-UV radiation (222 + 282 nm) for synchronous water decontamination and disinfection

This study is the first to explore a potential synergy of deep dual-wavelength ultraviolet (DWUV) radiation of KrCl (222 nm) and XeBr (282 nm) excilamps towards synchronous elimination of bacteria (105 CFU/mL E. coli and E. faecalis) and pharmaceutical (20 μM bezafibrate) from model and real (natural) water matrices at unadjusted pH. A time-based synergistic effect of DWUV photolysis and DWUV+H2O2 process in terms of 5-log (total) inactivation was found under all experimental conditions with synergistic indices in the range of 1.3–3.9. In the absence of bezafibrate, no inhibition effect of natural water matrix was found for inactivating bacteria by DWUV radiation with and without H2O2. Adding bezafibrate inhibited inactivation in natural water with keeping a synergistic effect and low dose requirements for complete inactivation (below 6 mJ/cm2). Despite the absence of synergistic effect towards degradation of bezafibrate, its synchronous degradation is achievable at higher doses. Unlike inactivation, the pseudo-first-order rate constants showed that degradation was inhibited by water matrix and bacteria (to a lesser degree) in DWUV+H2O2 mode, but not under DWUV photolysis. However, the DWUV+H2O2 process was more efficient than direct photolysis and provided faster decontamination and disinfection. Results show that this advanced oxidation process is applicable for treating real water matrices and represent a promising strategy in controlling microbial pathogens and pharmaceuticals in water.

Photolysis of chlorite by solar light: An overlooked mitigation pathway for chlorite and micropollutants

Chlorite (ClO2−) is an undesirable toxic byproduct commonly produced in the chlorine dioxide and ultraviolet/chlorine dioxide oxidation processes. Various methods have been developed to remove ClO2− but require additional chemicals or energy input. In this study, an overlooked mitigation pathway of ClO2− by solar light photolysis with a bonus for simultaneous removal of micropollutant co-present was reported. ClO2− could be efficiently decomposed to chloride (Cl−) and chlorate by simulated solar light (SSL) at water-relevant pHs with Cl− yield up to 65% at neutral pH. Multiple reactive species including hydroxyl radical (•OH), ozone (O3), chloride radical (Cl•), and chlorine oxide radical (ClO•) were generated in the SSL/ClO2− system with the steady-state concentrations following the order of O3 (≈ 0.8 μΜ) > ClO• (≈ 4.4 × 10−6 μΜ)> •OH (≈ 1.1 × 10−7 μΜ)> Cl• (≈ 6.8 × 10−8 μΜ) at neutral pH under investigated condition. Bezafibrate (BZF) as well as the selected six other micropollutants was efficiently degraded by the SSL/ClO2− system with pseudofirst-order rate constants ranging from 0.057 to 0.21 min−1 at pH 7.0, while most of them were negligibly degraded by SSL or ClO2− treatment alone. Kinetic modeling of BZF degradation by SSL/ClO2− at pHs 6.0 – 8.0 suggested that •OH contributed the most, followed by Cl•, O3, and ClO•. The presence of water background components (i.e., humic acid, bicarbonate, and chloride) exhibited negative effects on BZF degradation by the SSL/ClO2− system, mainly due to their competitive scavenging of reactive species therein. The mitigation of ClO2− and BZF under photolysis by natural solar light or in realistic waters was also confirmed. This study discovered an overlooked natural mitigation pathway for ClO2− and micropollutants, which has significant implications for understanding their fate in natural environments.

Factors hindering the degradation of pharmaceuticals from human urine in an iron-activated persulfate system

This study investigated the degradation of clofibric acid (CFA), bezafibrate (BZF), and sulfamethoxazole (SMX) in synthetic human urine using a novel mesoporous iron powder-activated persulfate system (mFe-PS system), and identified the factors limiting their degradation in synthetic human urine. A kinetic model was established to expose the radical production in various reaction conditions, and experiments were conducted to verify the modeling results. In the phosphate-containing mFe-PS system, the 120 min removal efficiency of CFA decreased from 95.1% to 76.6% as the phosphate concentration increased from 0.32 to 6.45 mmol/L, but recovered to 90.5% when phosphate concentration increased to 16.10 mmol/L. Meanwhile, the increased concentration of phosphate from 0.32 to 16.10 mmol/L reduced the BZF degradation efficacy from 91.5% to 79.0%, whereas SMX removal improved from 37.3% to 62.9%. The mFe-PS system containing (bi)carbonate, from 4.20 to 166.70 mmol/L, reduced CFA and BZF removal efficiencies from 100% to 76.8% and 80.4%, respectively, and SMX from 83.5% to 56.7% within a 120-min reaction time. In addition, alkaline conditions (pH ≥ 8.0) inhibited CFA and BZF degradations, while nonacidic pH (pH ≥ 7.0) remarkably inhibited SMX degradation. Results of the kinetic model indicated the formation of phosphate (H2PO4·/HPO4·−) and/or carbonate radicals (CO3·−) could limit pharmaceutical removal. The transformation products (TPs) of the pharmaceuticals revealed more incompletely oxidized TPs occurred in the phosphate- and (bi)carbonate-containing mFe-PS systems, and indicated that H2PO4·/HPO4·− mainly degraded pharmaceuticals via a benzene ring-opening reaction while CO3·− preferentially oxidized pharmaceuticals via a hydroxylation reaction.

Bezafibrate removal by coupling ozonation and photocatalysis: Effect of experimental conditions

The pseudo-first order rate constants of bezafibrate (BZF) degradation by photocatalytic ozonation (PCO) in the presence of commercial TiO2, P25, were studied under different experimental conditions. Removal percentage of BZF was positively affected by the increase of ozone inlet concentration and catalyst amount, while initial pollutant concentration presented a negative influence. In addition to the importance of catalyst during BZF removal, its presence plays a crucial role in terms of mineralisation level, achieving a significant degradation of the intermediates in a short period of reaction. The BZF was mainly removed by direct reaction with molecular O3, regardless of the experimental conditions. In addition to the higher affinity of direct O3 reactions to remove BZF and the first by-products at pH 4.4, the adsorption capacity is enhanced due to BZF deprotonated form (pH > pKa) and the catalyst surface positively charged (pH < pHpzc).The estimated pseudo-first order rate constant revealed that BZF degradation is more inhibited by humic acid, especially at high concentrations, than tert-butanol, suggesting that HO radicals are not the main responsible for BZF decay.

Enhanced bezafibrate degradation and power generation via the simultaneous PMS activation in visible light photocatalytic fuel cell

A collaborative system including peroxymonosulfate (PMS) activation in a photocatalytic fuel cell (PFC) with an BiOI/TiO2 nanotube arrays p-n type heterojunction as photoanode under visible light (PFC(BiOI/TNA)/PMS/vis system) was established. Xenon lamp was used as the light source of visible light. A 4.6 times higher pseudo-first-order bezafibrate (BZF) degradation rate constant was achieved in this system compared with the single PFC(BiOI/TNA)/vis system. The radical quenching experiments revealed that the contribution of reactive oxidative species (ROS) followed the order of 1O2 ≈ h+ >> •OH > SO4•− >>O2•−. The EPR tests demonstrated that PMS addition enlarged the formation of 1O2, •OH and SO4•−, but suppressed O2•− yield. Interestingly, 1O2 was further proved to dominantly originated from the priority reaction between positive photoinduced holes (h+) and negatively charged PMS. Besides, N2-purging tests and density functional theory calculation indicated that PMS probably reacted with residual photoinduced electron (e−) on the more negative conduction band (CB) of BiOI to form •OH and SO4•−, but competed with dissolved oxygen. Other e− transferred to the less negative CB of TNA through p-n junction will efficiently move to cathode through the external circuit. The greatly promoted power generation of PFC system was observed after PMS addition due to extra h+ consumption and efficient e− separation and transfer. Besides, three possible pathways for BZF degradation were proposed including hydroxylation, fibrate chain substituent and amino bond fracture. This study can provide new insights into the mechanisms of PMS assisted photocatalysis and accompanying energy recovery.

Peroxymonosulfate enhancing visible light photocatalytic degradation of bezafibrate by Pd/g-C3N4 catalysts: The role of sulfate radicals and hydroxyl radicals

For efficient usage of visible light, Pd loading graphitic carbon nitride (Pd/g-C3N4) hybrids were synthesized and peroxymonosulfate (PMS) was accompanied to improve the photoactivities of Pd/g-C3N4. The photocatalytic system consisting of Pd/g-C3N4, PMS and visible light (Pd/g-C3N4-PMS-Vis) exhibited higher bezafibrate (BZF) removal efficiency than Pd/g-C3N4-PMS, Pd/g-C3N4-Vis, g-C3N4-PMS, g-C3N4-Vis, and g-C3N4-PMS-Vis systems, which can be ascribed to the electron transfer from Pd/g-C3N4 to PMS. Density functional theory (DFT) calculation proved that the chemical bond interaction forming between Pd and g-C3N4 inspired the electron excitation, separation and transportation. Meanwhile, Pd particles with local surface plasma resonance (LSPR) phenomenon could also enhance the visible light adsorption. Notably, the photocurrent response of Pd/g-C3N4 was significantly improved with PMS, demonstrating the photoinduced electrons on Pd/g-C3N4 are capable to immigrate to PMS. The added PMS can perform as electron acceptors, thus favoring the quantum efficiency of photoinduced charge carriers to form SO4−. The BZF degradation mechanism was clarified by the addition of different scavengers and the major reaction active species were hydroxyl radicals (OH) and sulfate radical (SO4−). Four possible pathways in the degradation of BZF were also put forward via LC-MS/MS analysis (R-oxy substituent, oxidation dichlorination, OH-addition and oxidation deaminization). In the 2%Pd/g-C3N4-PMS-Vis system, an obvious decrease of genetic toxicity was observed because of the high removal efficiency and final low concentration of BZF. The results of this research underlined great prospective of Pd/g-C3N4 catalysts and provided a potential approach to photocatalytically remedy the polluted water by micropollutants.

Photodegradation mechanism and genetic toxicity of bezafibrate by Pd/g-C3N4 catalysts under simulated solar light irradiation: The role of active species

Fibrate pharmaceuticals are a group of ubiquitous emerging pollutants, which pose a potential threat to ecosystem and human health. Photocatalysis with inexhaustible solar energy is a sustainable option for fibrate pharmaceuticals photolysis removal from water. For high-efficiency use of solar light, the designed low-cost and high-activity solar-driven Pd/g-C3N4 photocatalysts took full advantages of the Pd plasmonic and electrons transformation for photocatalysis. The Pd/g-C3N4 photocatalysts with different Pd deposition were systematically designed and applied to investigate the degradation of bezafibrate (BZF), a representative fibrate pharmaceutical with two benzene rings and a fibrate chain in its structure. The as-prepared Pd/g-C3N4 catalysts presented promising photocatalytic activities in BZF degradation with respect to that of g-C3N4 under simulated solar (2.9 times) and visible light irradiation (2.4 times), as well as photocatalytic stability. The possible active species produced during the photocatalytic process of BZF were unveiled and verified by quenching electron spin resonance (ESR) analysis. Results revealed that hydroxyl radical (OH) contributed 79.39% of BZF degradation. Three main possible photocatalytic pathways of BZF were also proposed with the calculation of frontier election density (FED), including R-oxy substituent, OH-addition and oxidative dechlorination. The utilization of Pd/g-C3N4 catalysts was considered to be low toxicity and safe, and the genotoxicity of BZF solution could be decreased after photodegradation. This study presents a feasible approach for the enhancement removal of fibrate pharmaceuticals with the energy utilization from natural sunlight.

Modelling study on the effects of chloride on the degradation of bezafibrate and carbamazepine in sulfate radical-based advanced oxidation processes: Conversion of reactive radicals

The degradation rates of pharmaceuticals contaminants (such as bezafibrate and carbamazepine) in the UV/S2O82− process at different Cl− concentrations (0.01, 0.1, 1.0, 10, and 100 mM) and pH values (3, 5, 7, 9 and 11) were investigated in this study. The degradation rate of bezafibrate showed an upward trend before the critical point (Cl− = 1.0 mM), the maximum enhancement was 51%, then the degradation rate decreased. The degradation rate of carbamazepine increased continuously, and the maximum enhancement was 66% when the Cl− concentration was 100 mM. The degradation rate of bezafibrate showed the maximum value at pH = 7 while the most rapid degradation rate of carbamazepine was observed at pH = 3. To explain these interesting results, a kinetic model was used to investigate the conversion of reactive radicals (such as SO4−, OH, Cl, and Cl2−) at different Cl− concentrations and pH values. Simulation results showed that low concentrations (<1.0 mM) of Cl− transformed SO4− into OH and Cl. With the further increased concentration of Cl− from 1.0 mM to 100 mM, OH and Cl can be converted into Cl2−. Furthermore, Cl2− was the dominant reactive species when pH < 7, whereas OH dominated when pH > 7. Few organic chlorinated products were observed in the UV/S2O82−/Cl− process, indicating that the reactions between bezafibrate/carbamazepine and the reactive chlorine radicals Cl/Cl2− occurred mainly through electron transfer and H-extraction, whereas the substitution reaction leading to the formation of organic chlorinated products was not dominated. This study positively demonstrated the absence of chlorinated product formation during SR-AOPs application.

Kinetics and pathways of Bezafibrate degradation in UV/chlorine process.

UV/chlorine, as a novel disinfection method, has attracted great interest due to its effective removal for pathogenic microorganism and degradation of trace organic contaminants existed in water environment. This paper investigated the degradation kinetics and pathways of Bezafibrate (BZF), a typical antilipemic drug, during UV/chlorine process. The results showed that 92.3% of BZF was degraded after 20min in UV/chlorine process. This indicated HO• and reactive chlorine species (RCSs) formed in UV/chlorine played the dominant role in degrading BZF. Observed rate constants of BZF degradation (k obs,BZF) in UV/chlorine process increased linearly in a wide chlorine dosage from 0.1 to 1.0mM, which implied that ClO• generated from the reactions of chlorine with HO• and Cl• could react with BZF rapidly. The steady-state kinetic modeling result proved this deduction and the rate constant of ClO• with BZF was fitted to be 5.0×108M-1s-1. k obs,BZF was affected by Cl- and HA. The total contribution of RCSs (including Cl•, Cl2•-, and ClO•) to the degradation of BZF was determined to be ~80%, which is much higher than that of HO•. Thirteen degradation products of BZF were identified by LC-MS/MS. Initial degradation products were arisen from hydroxylation, chlorine substitution and cyclization by HO• and RCSs, and then further oxidized to generate acylamino cleavage and demethylation products.

VUV-Photocatalytic Degradation of Bezafibrate by Hydrothermally Synthesized Enhanced {001} Facets TiO2/Ti Film.

In the present study, a novel TiO2/Ti film with enhanced {001} facets was synthesized by the hydrothermal technique followed by calcination for studying the removal of bezafibrate (BZF), from an aqueous environment. The synthesized photocatalyst was characterized by FE-SEM, XRD, HR-TEM, and PL-technique. The second-order rate constant of (•)OH with BZF was found to be 5.66 × 10(9) M(-1) s(-1). The steady state [(•)OH] was measured as 1.16 × 10(-11) M, on the basis of oxidation of terephthalic acid. The photocatalytic degradation of BZF followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model (k1 = 2.617 mg L(-1) min(-1) and k2 = 0.0796 (mg L(-1))(-1)). The effects of concentration and the nature of various additives including inorganic anions (NO3(-), NO2(-), HCO3(-), CO3(2-), Cl(-)) and organic species (fulvic acid) and initial solution pHs (2, 4, 6, 9) on photocatalytic degradation of BZF were investigated. It was found that the nature and concentration of studied additives significantly affected the photocatalytic degradation of BZF. The efficiency of the photocatalytic degradation process in terms of electrical energy per order was estimated. Degradation schemes were proposed on the basis of the identified degradation byproducts by ultraperformance liquid chromatography.

Cerium doped red mud catalytic ozonation for bezafibrate degradation in wastewater: Efficiency, intermediates, and toxicity.

In this study, the performance of bezafibrate (BZF) degradation and detoxification in the aqueous phase using cerium-modified red mud (RM) catalysts prepared using different cerium sources and synthesis methods were evaluated. Experimental results showed that the surface cerium modification was responsible for the development of the catalytic activity of RM and this was influenced by the cerium source and the synthesis method. Catalyst prepared from cerium (IV) by precipitation was found to show the best catalytic activity in BZF degradation and detoxification. Reactive oxygen species including peroxides, hydroxyl radicals, and super oxide ions were identified in all reactions and we proposed the corresponding catalytic reaction mechanism for each catalyst that prepared from different cerium source and method. This was supported by the intermediates profiles that were generated upon BZF degradation. The surface and the structural properties of cerium-modified RM were characterized in detail by several analytical methods. Two interesting findings were made: (1) the surface texture (specific surface area and mesoporous volume) influenced the catalytic reaction pathway; and (2) Ce(III) species and oxygen vacancies were generated on the surface of the catalyst after cerium modification. This plays an important role in the development of the catalytic activity.

Cobalt modified red mud catalytic ozonation for the degradation of bezafibrate in water: Catalyst surface properties characterization and reaction mechanism

A systematic investigation of the catalytic reaction mechanism of surface cobalt-loaded red mud (RM) was carried out using the reaction kinetics analysis and catalyst surface property characterization. First, multiple characterization methods (XRD, FT-IR and XPS) were used to investigate the variation of surface texture and chemical properties of the catalyst after surface cobalt loading. Second, the contributions of molecular ozone (39.22%), hydroxyl radicals (45.20%), and surface adsorption (15.57%) for bezafibrate (BZF) degradation by Co/RM were identified by the reaction kinetic analysis using the tertiary butanol used as an organic quencher, confirming that surface cobalt loading promoted the role of the hydroxyl radical reaction. The phosphate was used as an inorganic probe to study the role of the solution and surface reactions in catalytic ozonation. The presence of phosphate inhibited 17.5%, 25.1%, and 27.2% efficient when phosphate concentration was 0.0104, 0.0208, and 0.0416mM, respectively. The kinetics analysis showed that the inhibiting effect of phosphate on BZF degradation was due to quenching of HO in solution, and not the surface chelation reaction. However, surface cobalt loading enhanced this surface interface reaction. Finally, the relationship between surface texture/chemical properties and catalytic activity was established, confirming that surface cobalt loading developed mesopores leading to an increase of the specific surface area. This was favorable for the catalytic activity. Co3O4 covered over the mesopore surface of RM and developed the surface hydroxyl group by the chemical water deduced from the cobalt surface loading. This is the main catalytic reaction site.

Degradation of bezafibrate in wastewater by catalytic ozonation with cobalt doped red mud: Efficiency, intermediates and toxicity

The bezafibrate (BZF) degradation and mineralization performances of a red mud (RM) catalyst doped with cobalt (i.e. Co/RM) during the ozonation reaction have been evaluated experimentally. The purposes of this study were to study the performance reaction mechanism and intermediate. In a next stage of our study also economic evaluations for a large scale application will be considered. Results of this study showed that catalytic ozonation using Co/RM not only led to the successful degradation of BZF, but also mineralized the corresponding intermediates, in ultrapure water as well as the effluent of wastewater. Detoxification was also achieved in this reaction process. The surface and structure properties of Co/RM were characterized by several analytical methods. The leaching of toxic heavy metal from the catalyst used in this process was very low, with the heterogeneous reaction dominating the decomposition of BZF, which made the reuse of the catalyst highly feasible. The enhanced generation of hydroxyl radical was critical to the success of the catalytic activity. Furthermore, 22 of the intermediates generated during this process were identified and several degradation pathways were proposed

Ozonation of bezafibrate promoted by carbon materials

Two carbon materials (multi-walled carbon nanotubes, MWCNT, and activated carbon, AC) were investigated as ozonation catalysts for the mineralization of bezafibrate (BZF) in water. For comparative purposes, kinetic results obtained in the absence of catalyst (single ozonation) and adsorption experiments were also presented. Removal of BZF in the presence of MWCNT is mainly due to a catalytic process, contrarily to what occurs in the presence of activated carbon, which acts mainly as adsorbent. 3-[(4-chlorophenyl)formamido]propanoic acid (BBR), 4-chorobenzoic acid (pCBA) and 4-chloro-N-[2-(4-hydroxyphenyl)ethyl]benzamide (BBV) were detected as primary products of single and catalytic ozonation of BZF, whereas oxalic, pyruvic and oxamic acids were identified as refractory final oxidation products. The original chlorine of BZF is completely converted to chloride ion and part of nitrogen is converted to NH4+, NO3− and NO2−. The presence of the radical scavenger tert-butanol during catalytic and single ozonation evidenced the participation of HO• radicals in the oxidation process, especially in the mineralization of several intermediates. Microtox tests revealed that simultaneous use of ozone and AC originated lower acute toxicity, which may be due to the contribution of adsorption for the removal from the solution of BZF and its oxidation compounds. The time course of all detected compounds is studied and, as a result, the transformation pathway for the complete mineralization of BZF by single and catalytic ozonation in the presence of the selected carbon materials is also elucidated. Successive experimental runs of BZF degradation carried out with MWCNT show that the catalyst suffers some deactivation as a result of the introduction of oxygenated surface groups on the surface.

Degradation of Bezafibrate with UV/H2O2 in Surface Water and Wastewater Treatment Plant Effluent

AbstractBezafibrate (BZF), a widely used lipid regulator, is a potential threat to ecosystems and human health in water, and the recent research showed that advanced oxidation processes (AOPs) are much more effective for BZF degradation. In this study, we investigated the photochemical decomposition of BZF in surface water and effluent from waste water treatment plants (WWTP) by UV/H2O2 process. The results showed that the UV/H2O2 process was a promising method to remove BZF at low concentration, generally at µg L−1 level. When initial concentrations reach 100 µg L−1 in the deionized water, &gt;99.8% of BZF could be removed in 16 min under UV intensity of 61.4 µm cm−2, at the H2O2 concentration of 0.1 mg L−1, and neutral pH condition. Moreover, BZF degradation was inhibited in this process when humic acid (HA) and inorganic solution anions were added to the deionized water solutions, including chloride, nitrate, bicarbonate, and sulfate, significantly. In the surface water and effluent of WWTP, however, the removal efficiency of BZF was lower than that in the deionized water because of the interference of complex constituents in the surface water and effluent. Some main intermediates at the m/z range of 100–400 were observed by high performance LC‐MS (HPLC/MS) and a simple pathway of BZF degradation by UV/H2O2 was proposed.

Photodegradation of the pharmaceuticals amoxicillin, bezafibrate and paracetamol by the photo-Fenton process—Application to sewage treatment plant effluent

Photodegradation of the pharmaceuticals amoxicillin (AMX), bezafibrate (BZF) and paracetamol (PCT) in aqueous solutions via the photo-Fenton process was investigated under black-light and solar irradiation. The influences of iron source, initial H 2O 2 concentration and matrix (distilled water and sewage treatment plant effluent) on degradation efficiency were discussed in detail. The results showed that (i) the degradation of the drugs was favored in the presence of potassium ferrioxalate (FeOx) in comparison to Fe(NO 3) 3; (ii) the increase of the H 2O 2 concentration improved the efficiency of AMX and BZF oxidation; however, the same was not observed for PCT; (iii) the influence of the matrix was observed for the degradation of BZF and PCT; (iv) under solar irradiation, the oxidation of the BZF and PCT is faster than under black-light irradiation. All these pharmaceuticals can be efficiently degraded employing the process evaluated.