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In this paper, we describe the synthesis of cerium molybdate (Ce 2 (MoO 4) 3) and different compositions of Bi-doped cerium molybdate (Ce 2-x Bi x (MoO 4) 3) where x = 0.01, 0.03, 0.05, 0.07, and 0.09, through simple co-precipitation method. The synthesized materials were optically, structurally, and morphologically characterized by various sophisticated techniques, including UV–visible, FTIR, Raman, PXRD, BET, and SEM-EDX. Upon addition of bismuth, the optical band gaps are reduced from 3.35 eV (Ce 2 (MoO 4) 3) to 2.83 eV Ce 1.93 Bi 0.07 (MoO 4) 3. The charge storage potential and AC conductivity of the synthesized materials were investigated through dielectric studies where the dielectric constant increased by increasing dopant concentration up to 7 %. At 20 Hz, Ce 1.93 Bi 0.07 (MoO 4) 3 showed a significantly greater dielectric constant (3.597 × 106) compared to undoped Ce 2 (MoO 4) 3 (3.262 × 105). Similarly, the AC conductivity of Ce 1.93 Bi 0.07 (MoO 4) 3 increased up to 4.758 S m−1 compared to the undoped Ce 2 (MoO 4) 3 (2.270 S m−1) at 20 MHz. The photocatalytic efficiency was investigated against diclofenac potassium, which also considerably improved by increasing bismuth content. The maximum photodegradation efficiency of 87.9 % was observed for Ce 1.93 Bi 0.07 (MoO 4) 3 in 180 min under UV light irradiation at optimized conditions (pH = 4, catalyst dosage = 20 mg, and initial concentration of drug = 5 mg L−1). The photocatalytic reaction followed pseudo-first-order kinetics with a rate constant of 0.0108 min−1 with stability up to five successive runs of photocatalytic activity indicating its good recyclability. These findings suggest that Bi-doped cerium molybdate could be used as a promising material for photocatalysis and energy storage devices. [ABSTRACT FROM AUTHOR]

The built‐in electric field induced by piezoelectric effect for suppressing the electron–hole recombination has gained substantial attention recently. In this study, a novel Z‐scheme ZnSnO3/Bi2WO6 (ZSO/BWO) piezo‐photocatalyst with synergistic polarized electric field was synthesized by a simple impregnation method. The optimized 1% ZSO/BWO shows high piezo‐photodegradation efficiency (99.9%, 60 min) and mineralization (42%, 60 min) of diclofenac (DCF) under the synergistic action of ultrasound and light, far exceeding that under sole ultrasound or illumination. The remarkable enhanced piezo‐photocatalytic activity of ZSO/BWO composite was attributed to the increased absorption, improved charge transfer, Z‐scheme heterojunction, and tight surface contact between ZSO and BWO. Moreover, the Z‐scheme mechanism of ZSO/BWO composites is studied in depth and confirmed by the free radical capture experiment and electron spin resonance technology. In addition, the corresponding intermediates of DCF degradation and the possible degradation pathways that were proposed on ZSO/BWO composites were analyzed by liquid chromatography–mass spectrometry and DFT. This work offers an efficient approach for constructing and preparing the highly efficient piezo‐photocatalysts for converting solar and mechanical vibration energies. [ABSTRACT FROM AUTHOR]

Degradation of pharmaceuticals in water by TiO2 photocatalysis often suffers from low efficiency due to low activity and mass transfer limitation. In this work, diclofenac removal in tap water was performed by photocatalysis on TiO2 nanotube growth on Ti mesh substrate assisted by ozone (O3), which was generated from a hole-arrayed boron-doped diamond (HABDD) film electrode. The vertically oriented TiO2 nanotubes were used as the heterogeneous photocatalyst. The HABDD, as a self-standing diamond electrode, was designed and custom-made by MWCVD technology. The microstructures and crystalline of the TiO2 nanotubes and HABDD were characterized by a scanning electronic micrograph (SEM) and X-ray diffraction (XRD). Unlike other ozone generation methods, direct generation of ozone in the flowing water was applied in the photocatalysis process, and its effect was discussed. The diclofenac removal performance of the electrochemical-photocatalytic system was studied depending on O3 generation efficiency, flowing rate, and the initial diclofenac concentration. The enhanced degradation effect from O3 molecules on TiO2 photocatalysis was attributed to the larger active surface area, the increased photo-generated charge separation rate, and the contact area of O3. The degradation efficiency in the combined electrochemical-photocatalytic TiO2/O3/UV system was higher than that of the O3/UV and TiO2/UV routes individually. Furthermore, a theoretical calculation was used to analyze the TiO2/O3 interface in aqueous media in terms of the final energy. This system created an almost in situ feeding channel of oxidants in the TiO2 photocatalysis process, thus increasing photocatalytic efficiency. This synergetic system is promising in the treatment of pharmaceuticals in water. [ABSTRACT FROM AUTHOR]

Degradation of pharmaceuticals in water by TiO2 photocatalysis often suffers from low efficiency due to low activity and mass transfer limitation. In this work, diclofenac removal in tap water was performed by photocatalysis on TiO2 nanotube growth on Ti mesh substrate assisted by ozone (O3), which was generated from a hole-arrayed boron-doped diamond (HABDD) film electrode. The vertically oriented TiO2 nanotubes were used as the heterogeneous photocatalyst. The HABDD, as a self-standing diamond electrode, was designed and custom-made by MWCVD technology. The microstructures and crystalline of the TiO2 nanotubes and HABDD were characterized by a scanning electronic micrograph (SEM) and X-ray diffraction (XRD). Unlike other ozone generation methods, direct generation of ozone in the flowing water was applied in the photocatalysis process, and its effect was discussed. The diclofenac removal performance of the electrochemical-photocatalytic system was studied depending on O3 generation efficiency, flowing rate, and the initial diclofenac concentration. The enhanced degradation effect from O3 molecules on TiO2 photocatalysis was attributed to the larger active surface area, the increased photo-generated charge separation rate, and the contact area of O3. The degradation efficiency in the combined electrochemical-photocatalytic TiO2/O3/UV system was higher than that of the O3/UV and TiO2/UV routes individually. Furthermore, a theoretical calculation was used to analyze the TiO2/O3 interface in aqueous media in terms of the final energy. This system created an almost in situ feeding channel of oxidants in the TiO2 photocatalysis process, thus increasing photocatalytic efficiency. This synergetic system is promising in the treatment of pharmaceuticals in water.

This study proposed methods of synthesizing Bio-Ru0 by microbial in-situ reduction and modified bio-anode to construct Bio-Ru0-anode-MFC for the diclofenac (DCF) degradation and bioelectricity generation performance. By analyzing XRD, XPS and observing SEM, TEM, Ru0 (Bio-Ru0) in-situ synthesized by anodic microorganisms, was distributed on surface of carbon felt electrode uniformly and formed reticular wire structure with cell secretion. Electrochemical tests demonstrated that the reticular structure promoted direct electron transfer between Bio-Ru0 and microorganisms. Under anaerobic conditions with sufficient carbon source, the DCF degradation efficiency of Bio-Ru0-anode MFC reached 67.20%, where Ru catalyzed reaction, microbial reaction, electrochemical reaction, and adsorption contributed to the DCF degradation by 34.32%, 30.20%, 21.67% and 13.81%, respectively. Benefitting from the synergistic effects of DCF-degrading bacteria, electroactive microorganisms, and Bio-Ru0 catalysis, DCF could achieve initially dechlorinated in Bio-Ru0-anode MFC, then completely converted to chlorine-free products after 2.68 d. Ru-tolerant bacteria such as Geobacter , Desulfovibrioceae, and Pseudomonas were enriched in bio-Ru0-anode and played a key role in DCF degradation. This study could provide new ideas for microbial in-situ synthesis of Bio-Ru0-anode to promote degradation of halogenated organic pollutants. [Display omitted] • Ru3+ could be in-situ reduced to Ru0 by anodic microbes. • The electrochemical performance of MFC was improved by in-situ synthetic bio-Ru0. • Ru-tolerant bacteria and DCF-degradation bacteria were enriched in the anode. • DCF degradation by Bio-Ru0-anode MFC was a detoxification process. [ABSTRACT FROM AUTHOR]

The application of bimetallic catalysts in heterogeneous electro-Fenton (Hetero-EF) is limited due to its poor performance over a wide pH range. In this work, the Hetero-EF/sulfite process was constructed with FeMn@C as the catalyst to improve the degradation of pollutants under neutral pH. The removal efficiency of diclofenac (DCF) (97.8%) was significantly higher than that of Hetero-EF (15.0%) at pH 7, in which the degradation rate constant k was increased by 19.75 times. The existence and transformation process of various active species (•OH, SO 4 •-, O 2 •-, and 1O 2) in the process were verified by capture experiments and electron paramagnetic resonance (EPR) test. The possible DCF degradation pathway was also proposed. The introduction of sulfite could reduce Fe3+ and Mn3+, promote the Fe(II)/Fe(III) and Mn(II)/Mn(III) cycles, strengthen the generation of active species, and thus promote the degradation of pollutants. The removal efficiency was still maintained 76.6% after five cycles. The Hetero-EF/sulfite process is a simple, feasible, and efficient method to degrade pollutants, which has a broad application prospect. [Display omitted] [ABSTRACT FROM AUTHOR]

The demand for efficient wastewater treatment is becoming increasingly urgent due to the rising threat of pharmaceutical residues in water. As a sustainable advanced oxidation process, cold plasma technology is a promising approach for water treatment. However, the adoption of the technology encounters several challenges, including the low treatment efficiency and the potentially unknown environmental impact. Here, microbubble generation was integrated with cold plasma system to enhance treatment of wastewater contaminated with diclofenac (DCF). The degradation efficiency depended on the discharge voltage, gas flow, initial concentration, and pH value. The best degradation efficiency was 90.9% after 45 min plasma-bubble treatment under the optimum process parameters. The hybrid plasma-bubble system exhibited strongly synergistic performance heralded by up to seven-times higher DCF removal rates than the two systems operated separately. The plasma-bubble treatment remains effective even after addition of SO 4 2−, Cl−, CO 3 2−, HCO 3 −, and humic acid (HA) as interfering background substances. The contributions of •O 2 −, O 3 , • OH, and H 2 O 2 reactive species to the DCF degradation process were specified. The synergistic mechanisms for DCF degradation were deduced through the analysis of the degradation intermediates. Further, the plasma-bubble treated water was proven safe and effective to stimulate seed germination and plant growth for sustainable agriculture applications. Overall, these findings provide new insights and a feasible approach with a highly synergistic removal effect for the plasma-enhanced microbubble wastewater treatment, without generating secondary contaminants. [Display omitted] • A flexible approach for wastewater treatment and toxicity control using plasma. • Synergistic system showed seven times more removal rate than plasma and microbubbles operating separately. • Treated water was proven effective for sustainable agriculture application. • Effects of various key operating parameters were analyzed and optimized. • New mechanism of hybrid plasma-microbubble system were proposed. [ABSTRACT FROM AUTHOR]

In order to improve the selectivity in photocatalytic process, molecularly imprinted photocatalysts containing a low loading of TiO 2 (from 6.6 to 16.6% of total mass) were prepared for photocatalytic degradation of an organic pollutant, diclofenac (DIC). The photocatalytic component TiO 2 (P25), with and without being doped with Cu 2 O, was embedded in diclofenac-imprinted polymers. The molecularly imprinted polymers (MIPs) and the composite photocatalysts exhibited a superior specific target recognition for selective degradation of DIC over non-target reference molecules, fluoxetine (FLU) and paracetamol (PARA). In contrast to the non-selective commercial sample of TiO 2 , the average value of selectivity of the imprinted catalysts for photocatalytic degradation of DIC was estimated to be 2.8, which suggests that the specific binding sites created by the molecular imprinting are essential for gaining high catalytic selectivity and efficiency. After 6 cycles of testing under UV-light, the imprinted catalysts maintained almost the same efficiency for photo degradation of DIC. In addition, the morphology and the structure of the imprinted catalysts remained after repeated uses. The results suggest that it is feasible to use MIPs to control the selectivity of photocatalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

The reported pilot-scale development of hybrid process alternatives, combines in-situ regenerated powdered activated carbon (PAC), H 2 O 2 -based advanced oxidation techniques and membrane ultrafiltration (UF). Commercial PAC and special iron-impregnated PAC (PAC-Fe) were used as adsorbents, whereas diclofenac (DCF), a commonly detected pharmaceutical in water-sources, was employed as representative micro-pollutant. For PAC regeneration, modest on-line H 2 O 2 dosage was adopted, alone or in combination with UV-C irradiation. Large DCF uptake was measured for both PAC (154.5 mg/g) and PAC-Fe (116.7 mg/g), while the regeneration efficiencies achieved with the photo-assisted H 2 O 2 processes were much greater (122.2% and 131.6% for H 2 O 2 +UVC and photo-Fenton, respectively) than those obtained with H 2 O 2 alone (70% and 77.6% for H 2 O 2 and Fenton, respectively). For PAC-Fe, enhanced recovery of adsorption capacity suggests occurrence of heterogeneous Fenton-like reactions on iron-oxide particle surfaces leading to generation of OH and other reactive species by H 2 O 2 -decomposition. The catalytic adsorbent (PAC-Fe) retained its stability and activity after three operating cycles, which would significantly reduce operating cost in practical applications. Considering the rather short regeneration-time of present tests (180 min) and the nearly basic pH of feed solutions, the novel processes investigated herein, involving PAC regeneration in the same equipment employed for water purification, hold distinct advantages over conventional methods. [ABSTRACT FROM AUTHOR]

A novel, fully automated photocatalytic membrane reactor (PMR) pilot unit is presented and evaluated (at different operating process parameters and real treatment conditions) for degradation of the pharmaceutical diclofenac (DCF), a typical recalcitrant micropollutant. The PMR-pilot has a maximum system capacity of 1.2 m 3 /d of treated water, 52 W of UV-C power, and combines two modern processes; i.e. heterogeneous photocatalysis and membrane separation, employing dispersed TiO 2 nanoparticles with UV-C irradiation, and submerged ultrafiltration hollow fibers, respectively. Pilot tests with two types of natural (tap and surface) water under stable, continuous operation, permitted the assessment of the PMR unit performance (for DCF degradation, TOC mineralization) in terms of hydraulic residence time (HRT), TiO 2 loading, UV-C irradiation dose, and DCF feed concentration. Under the specific conditions tested, the catalyst loading and UV-C radiant power significantly affected DCF removal; however, HRT had a rather insignificant effect. Additionally, several transformation products (TPs) were identified by means of liquid chromatography–mass spectrometry using electrospray interfacing technique, thus, shedding light into possible reaction pathways leading to DCF mineralization. [ABSTRACT FROM AUTHOR]

The electrophoretic deposition of titanium dioxide (TiO 2) nanoparticles (Degussa P25) onto a boron-doped diamond (BDD) substrate was carried out to produce a photoanode (TiO 2 /BDD) to apply in the degradation and mineralization of sodium diclofenac (DCF-Na) in an aqueous medium using photoelectrocatalysis (PEC). This study was divided into three stages: i) photoanode production through electrophoretic deposition using three suspensions (1.25%, 2.5%, 5.0% w/v) of TiO 2 nanoparticles, applying 4.8 V for 15 and 20 s; ii) characterization of the TiO 2 /BDD photoanode using scanning electron microscopy and cyclic voltammetry response with the [Fe(CN) 6 ]3-/4- redox system; iii) degradation of DCF-Na (25 mg L−1) through electrochemical oxidation (EO) on BDD and PEC on TiO 2 /BDD under dark and UVC-light conditions. The degradation of DCF-Na was evaluated using high-performance liquid chromatography and UV–Vis spectroscopy, and its mineralization measured using total organic carbon and chemical oxygen demand. The results showed that after 2 h, DCF-Na degradation and mineralization reached 98.5% and 80.1%, respectively, through PEC on the TiO 2 /BDD photoanode at 2.2 mA cm−2 under UVC illumination, while through EO on BDD applying 4.4 mA cm−2, degradation and mineralization reached 85.6% and 76.1%, respectively. This difference occurred because of the optimal electrophoretic formation of a TiO 2 film with a 9.17 μm thickness on the BDD (2.5% w/v TiO 2 , time 15 s, 4.8 V), which improved the electrocatalysis and oxidative capacity of the TiO 2 /BDD photoanode. Additionally, PEC showed a lower specific energy consumption (1.55 kWh m−3). Thus, the use of nanostructured TiO 2 films deposited on BDD is an innovative photoanode alternative for the photoelectrocatalytic degradation of DCF-Na, which substantially improves the degradation capacity of bare BDD. • TiO2/BDD photoanode was prepared by means of electrochemical deposition. • Photoelectrocatalytic degradation of diclofenac was assessed using TiO2/BDD and BDD. • Degradation efficiency obtained by PEC under UVC light was 2.38 times better than the one obtained by EO. • The by-products of diclofenac degradation by PEC involves changes in the color of the solution. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate-based advanced oxidation process (PMS-AOPs) is one of most effective approaches for eliminating emerging organic pollutants (EOPs). To develop high-performance and stable PMS activators is the key to the further development of PMS-AOPs. Cobalt-based catalysts have been proved to be the excellent PMS activators. Here, cobalt bismuth oxide (Bi 7.53 Co 0.47 O 11.92) prepared by facile one-step calcination method was employed as the new PMS activator. As expected, diclofenac (DCF), one kind of EOPs, were quickly decomposed and even mineralization by the Bi 7.53 Co 0.47 O 11.92 activated PMS system. Within 10 min of reaction, 100% degradation efficiency and 82.1% mineralization rate were achieved. The toxicity of degraded products was assessed to be much lower than pristine DCF. Moreover, six-cycle experiments verified the good reusability of Bi 7.53 Co 0.47 O 11.92. This work contributes to develop new stable and high-efficiency PMS heterogeneous activators, being beneficial to build high-performance PMS-AOPs for EOPs treatment. [Display omitted] • Cobalt bismuth oxide with stable surface Co active site was synthesized. • Efficient mineralization and detoxification of DCF was achieved. • The stable reusability of cobalt bismuth oxide in activating PMS was determined. • Superoxide radicals were mainly responsible for the quick decomposition of DCF. [ABSTRACT FROM AUTHOR]

Laccase was immobilized on a novel conductive polyvinyl alcohol (PVA)/chitosan (CS)/multi-walled carbon nanotubes (MWNTs) composite nanofibrous membrane. Its stabilities and catalytic activity for diclofenac degradation were comprehensively investigated. Laccase was covalently immobilized on the surface of PVA/CS/MWNTs nanofibrous membranes with an average fiber diameter of 100–200 nm. Both enzyme loading and activity retention of the immobilized laccase were found to be significant higher on the nanofibrous membranes with MWNTs (907 mg laccase/g membrane, 76.7% of free laccase) than those without (862 mg laccase/g membrane, 63.5% of free laccase). Immobilized laccase on the PVA/CS/MWNTs nanofibrous membranes exhibited high stabilities, reuse capabilities and removal efficiency for diclofenac. Cyclic voltammetry measurements demonstrated that MWNTs enhanced the electrochemical capacitance of the nanofibrous membrane. It suggests carbon nanotubes may play a significant role on the enhancement of laccase activity immobilized on the nanofibers by improving electron transfer between the enzyme and substrate molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] Successful application of submerged-type PMR system for diclofenac degradation. [•] Steady state operation with more than 96% diclofenac degradation. [•] Highest TOC removal with near optimum operating parameters pH∼6, TiO2 0.5g/L. [•] Significant effect of feed water composition on diclofenac mineralization. [•] Negligible membrane fouling in long-term continuous operation of the PMR system. [ABSTRACT FROM AUTHOR]

This work reports a new bi-metal oxide composite of MnO 2 -Bi 2 O 3 as the peroxymonosulfate (PMS) activator. The reaction system based on MnO 2 -Bi 2 O 3 activated PMS exhibits an excellent mineralization and detoxicity ability towards diclofenac (DCF) in water. The main reaction mechanism is summarized as: (1) surface Mn(II)/(III)/(IV) transformation and PMS activation are interacted to produce active species including 1 O2, SO 4 · -, and · OH; (2) the electrons produced by surface Mn(II)/(III)/(IV) transformation is also able to reduce dissolved oxygen for · O 2 – species production. Under the attack of · O 2 –, 1O 2 , SO 4 · -, and · OH, DCF is quickly decomposed into some non/low harmful products. This work not only demonstrates MnO2-Bi2O3 as a novel oxidation system based on PMS activation, but also provides a general idea for designing highly efficient and robust PMS activator. [Display omitted] • A new bi-metal oxide composite of MnO 2- Bi 2 O 3 was synthesized. • MnO 2 -Bi 2 O 3 activated PMS achieved efficient degradation and toxicity decline of diclofenac. • DFT calculations and experiments demonstrate the superiority of MnO 2 -Bi 2 O 3 in activating PMS. • Mn(II)/(III)/(IV) redox cycle dominates in the activation of PMS. Concerns about the ubiquitous occurrence of diclofenac (DCF, a pain killer) in the natural environment are unprecedently rising because of its toxicity and poor treatability. Herein, we develop and utilize a new bi-metal oxide composite of MnO 2 -Bi 2 O 3 as the peroxymonosulfate (PMS) activator to construct an efficient oxidation system for DCF degradation and de-toxicity. Under optimal reaction conditions of 3.75 g/L for MnO 2 -Bi 2 O 3 , 0.125 g/L for PMS and 5.38 for pH, DCF can be almost totally degraded within 10 mins of reaction (99.5% of degradation efficiency), and the mineralization efficiency reaches up to 70.1%, which are respectively 3.1- and 4.5-fold higher than those of using the PMS alone. Moreover, the toxicity of the degraded products is reduced comparing to the DCF itself as verified by the Toxicity Estimation Software Tool (T.E.S.T.). Six continuous runs for PMS activation and XRD/XPS characterizations confirmed that MnO 2 -Bi 2 O 3 could serve as a reliable PMS activator. Density functional theory calculations together with related characterizations and experiments illustrated why MnO 2 -Bi 2 O 3 exhibits excellent PMS activation for DCF degradation and de-toxicity: (1) MnO 2 -Bi 2 O 3 possesses higher adsorption energy for PMS adsorption and lower energy barrier for PMS activation as a result of enhanced charge transfer between MnO 2 -Bi 2 O 3 and PMS as compared to the seperate tetragonal MnO 2 or monoclinic Bi 2 O 3 controls; and (2) the Mn(II)/(III)/(IV) and Bi(III)/(V) redox cycles at the surface of MnO 2 -Bi 2 O 3 promote PMS activation and thus produce strong oxidizing agents: · O 2 – and 1O 2. Overall, our study not only demonstrates MnO 2 -Bi 2 O 3 as a novel oxidation system based on PMS activation, but also provides a general idea for designing highly efficient and robust PMS activator. [ABSTRACT FROM AUTHOR]

• Sol-gel synthesis produce more active CeO 2 photocatalyst over combustion synthesis. • Metal doping, Ag, Cu, Mn, of CeO 2 increases bandgap but decreases photocatalytic activity. • Efficient photocatalytic degradation of diclofenac with AgI-doped CeO 2. • 2.6-fold increase in quantum efficiency of AgI/CeO 2 over CeO 2 obtained. Diclofenac, an emerging pollutant, has long half-life and can lead to antibiotic resistance, destruction of aquatic ecosystem, etc. We studied the photocatalytic destruction of diclofenac using ceria synthesized through combustion synthesis and sol gel methods. The combustion synthesis method gives a catalyst with a higher surface area, though with a lower photoactivity. Sol gel ceria was then doped with metal ions: Mn, Cu, Ag to give metal-semiconductor and with AgI to give n-p semiconductor-semiconductor heterojunction photocatalysts. Mn/CeO 2 , Cu/CeO 2 and Ag/CeO 2 showed lower photoactivity, while AgI/CeO 2 showed better activity over the native CeO 2. Over 97% removal of diclofenac was obtained in less than 120 min using 125 W UV light. A 2.6-fold increase in the quantum efficiency was obtained on doping CeO 2 with AgI. The enhanced activity of AgI-doped CeO 2 is attributed to improved charge separation of electron-hole pairs generated on irradiation with UV light. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel combination approach of air DBD plasma and nano-Fe0-CeO 2 was investigated. • 96.4% of DCF was removed in 10 min in the DBD-Fe0-CeO 2 system. • The DBD- Fe0-CeO 2 system exhibited efficient removal in practical water quality. • ROS concentration enhanced after nano-Fe0-CeO 2 added in the DBD system. • Mechanisms and possible DCF degradation pathways in the DBD-Fe0-CeO 2 system were proposed. Dielectric barrier discharge (DBD) is an attractive advanced oxidation process (AOP) due to its operational convenience and environmental friendliness. However, DBD plasma suffers from relatively low energy utilization, which limits its commercial application. In this study, nano-Fe0-CeO 2 is successfully synthesized and used for DBD plasma degradation of diclofenac (DCF). The results show that the nano-Fe0-CeO 2 significantly enhances the removal of DCF. A DBD-Fe0-CeO 2 system degrades 96.4% DCF within 10 min, which is higher than the DBD system alone (45.8%). The synergistic factor of the DBD system and nano-Fe0-CeO 2 reaches 3.731. In addition, the composite catalyst shows ideal reusability. Substance activity and production experiments show that reactive oxygen species (ROS), especially OH, play a key role in the degradation of DCF. Nano-Fe0-CeO 2 has synergistic effects with O 3 and H 2 O 2 and significantly promotes the generation of ROS in the DBD system. Based on the intermediates detected by liquid chromatography-mass spectrometry, a reasonable degradation pathway of DCF is proposed. Our findings are helpful for understanding the mechanism of DCF degradation by coupling nano-zero-valent-iron-based nanocomposites in a DBD system; they also provide an effective system for the treatment of refractory organic pollutants in water. [ABSTRACT FROM AUTHOR]

In this paper, a two dimensional/two dimensional (2D/2D) heterostructure of Ti 3 C 2 /g-C 3 N 4 (T/CN) was constructed and used to activate peroxymonosulfate (PMS) for the degradation of diclofenac (DCF) in water in the presence of light illumination. Compared with single photocatalytic process by T/CN (0.040/min) and with pure g-C 3 N 4 nanosheets in PMS system (0.071/min), 5.0 and 3.0 times enhanced activities were achieved in the T/CN-PMS system at optimum Ti 3 C 2 (1.0 wt%) loading under light illumination (0.21/min). Moreover, the decomposing processes of DCF in T/CN-PMS system were applicable in a wide initial pH range (3∼14), therefore, overcoming the limitation of pH dependence in traditional PMS system. Based on the synergistic effect of photocatalysis and PMS oxidation processes, the 1O 2 was generated as primary reactive species for the removal of DCF in T/CN-PMS system. The DCF degradation mechanism was further proposed through the results of liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT) calculations. Image 1 • 2D/2D heterostructure of Ti 3 C 2 /g-C 3 N 4 was used to activate peroxymonosulfate (PMS). • The performance of PMS activation to remove diclofenac is improved by light assisted. • The degradation of DCF by Ti 3 C 2 /g-C 3 N 4 activated PMS over a broad pH range (pH = 3∼14). [ABSTRACT FROM AUTHOR]

• Ru/Fe modified electrode was prepared by reduction and coating. • DCF-degradation efficiency was enhanced by using Ru/Fe-MFC compared to CF-MFC. • Bacteria for degrading DCF and producing electricity were enriched in Ru/Fe-MFC. • Mechanisms of synergistic reaction of Ru/Fe and bacteria were revealed. A microbial fuel cell (MFC) was constructed with a Ru/Fe-modified-anode prepared by reduction and coating for enhancing diclofenac (DCF) degradation. Results showed that Ru0 and Fe0 were dispersed uniformly on Ru/Fe-modified-electrode surface, and Ru/Fe existed as an alloy structure. Due to catalysis of Ru/Fe, both electrochemical activity and DCF-degradation performance of Ru/Fe-modified-anode-MFC (Ru/Fe-MFC) were enhanced compared to carbon-felt-anode-MFC (CF-MFC). The maximum power density of Ru/Fe-MFC reached 0.600 W m−2, and DCF-degradation in Ru/Fe-MFC followed the pseudo-first-order-kinetic model with k obs of 0.711 d−1 which was 1.08, 1.34 and 2.21 times higher than that of Ru-modified-anode-MFC (Ru-MFC), Fe-modified-andoe-MFC (Fe-MFC) and CF-MFC, respectively. Results also showed that DCF-degradation and power generation would compete for electrons in Ru/Fe-MFC. Ru/Fe-modified-anode accelerated the enrichment of electro-active bacteria and DCF-degrading bacteria such as Geobacter, Clostridium, Sedimentibacter, Pseudomonas and Desulfovibrionaceae. Stepwise dechlornation occurred for DCF-degradation mainly due to synergistic reaction of Ru/Fe and DCF-degrading bacteria within Ru/Fe-MFC. [ABSTRACT FROM AUTHOR]