The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies. Sulfate radical-based advanced oxidation has emerged as an attractive solution, offering ...high selectivity, enduring efficacy, and anti-interference ability. Among many technologies, sulfite activation, leveraging its cost-effectiveness and lower toxicity compared to conventional persulfates, stands out. Yet, the activation process often relies on transition metals, suffering from low atom utilization. Here we introduce a series of single-atom catalysts (SACs) employing transition metals on g-C3N4 substrates, effectively activating sulfite for acetaminophen degradation. We highlight the superior performance of Fe/CN, which demonstrates a degradation rate constant significantly surpassing those of Ni/CN and Cu/CN. Our investigation into the electronic and spin polarization characteristics of these catalysts reveals their critical role in catalytic efficiency, with oxysulfur radical-mediated reactions predominating. Notably, under visible light, the catalytic activity is enhanced, attributed to an increased generation of oxysulfur radicals and a strengthened electron donation-back donation dynamic. The proximity of Fe/CN's d-band center to the Fermi level, alongside its high spin polarization, is shown to improve sulfite adsorption and reduce the HOMO-LUMO gap, thereby accelerating photo-assisted sulfite activation. This work advances the understanding of SACs in environmental applications and lays the groundwork for future water treatment technologies.
Display omitted
•The electronic structures of transition metals are key on sulfite activation.•The intense spin polarization of Fe leads to its strong activation of sulfite.•The rate constant for the Fe single-atom exceeds that of Ni and Cu.•Oxysulfur radical-triggered oxidative degradation mechanism was revealed.•Fe single-atom catalyst presents promising prospect for sulfite activation.
To enhance the generation of hydrogen peroxide (H
2
O
2
), a modified graphite felt cathode doped with nitrogen and boron was developed and used in peroxi-coagulation system to degrade dimethyl ...phthalate (DMP). After a simple modification method, the yield of H
2
O
2
on cathode increased from 9.39 to 152.8 mg/L, with current efficiency increased from 1.61 to 70.3%. Complete degradation of DMP and 80% removal of TOC were achieved within 2 h at the optimal condition with pH of 5, cathodic potential of − 0.69 V (vs. SCE), oxygen aeration, and electrode gap of 1 cm. Possible mechanism with synergistic effect of electro-Fenton and electrocoagulation process in the peroxi-coagulation system was revealed via quenching experiments. The prospect of this system in the effluent of landfill leachate and domestic sewage was studied, achieving 50% and 61% of DMP removal in 2 h. This efficient system with simple modified cathode had promising prospects in practical applications.
The human diploid cell line Medical Research Council -5 (MRC-5) is commonly utilized for vaccine development. Although a rabies vaccine developed in cultured MRC-5 cells exists, the poor ...susceptibility of MRC-5 cells to the rabies virus (RABV) infection limits the potential yield of this vaccine. The underlying mechanism of MRC-5 cell resistance to RABV infection remains unknown. In this study, we demonstrate that viral infection increased exosomal release from MRC-5 cells; conversely, blocking exosome release promoted RABV infection in MRC-5 cells. Additionally, RABV infection up-regulated microRNA (miR)-423-5p expression in exosomes, resulting in feedback inhibition of RABV replication by abrogating the inhibitory effect of suppressor of cytokine signaling 3 (SOCS3) on type I interferon (IFN) signaling. Furthermore, intercellular delivery of miR-423-5p by exosomes inhibited RABV replication in MRC-5 cells. We also show that RABV infection increased IFN-β production in MRC-5 cells and that blocking the type I IFN receptor promoted RABV infection. In conclusion, MRC-5 cells were protected from RABV infection by the intercellular delivery of exosomal miR-423-5p and the up-regulation of IFN-β. These findings reveal novel antiviral mechanisms in MRC-5 cells against RABV infection. miR-423-5p, exosomes, and IFN signaling pathways may therefore be potential targets for improving MRC-5 cell-based rabies vaccine production.
Influenza virus is an acute and highly contagious respiratory pathogen that causes great concern to public health and for which there is a need for extensive drug discovery. The small chemical ...compound ABMA and its analog DABMA, containing an adamantane or a dimethyl-adamantane group, respectively, have been demonstrated to inhibit multiple toxins (diphtheria toxin,
toxin B,
lethal toxin) and viruses (Ebola, rabies virus, HSV-2) by acting on the host's vesicle trafficking. Here, we showed that ABMA and DABMA have antiviral effects against both amantadine-sensitive influenza virus subtypes (H1N1 and H3N2), amantadine-resistant subtypes (H3N2), and influenza B virus with EC
values ranging from 2.83 to 7.36 µM (ABMA) and 1.82 to 6.73 µM (DABMA), respectively. ABMA and DABMA inhibited the replication of influenza virus genomic RNA and protein synthesis by interfering with the entry stage of the virus. Molecular docking evaluation together with activity against amantadine-resistant influenza virus strains suggested that ABMA and DABMA were not acting as M2 ion channel blockers. Subsequently, we found that early internalized H1N1 virions were retained in accumulated late endosome compartments after ABMA treatment. Additionally, ABMA disrupted the early stages of the H1N1 life cycle or viral RNA synthesis by interfering with autophagy. ABMA and DABMA protected mice from an intranasal H1N1 challenge with an improved survival rate of 67%. The present study suggests that ABMA and DABMA are potential antiviral leads for the development of a host-directed treatment against influenza virus infection.
Bisphenol (BP) analogues in wastewater effluent and groundwater pose a potential threat to human health due to their ability to disrupt steroidogenesis. A new solar-assisted electrochemical process ...(SECP) was developed and evaluated for the degradation of BP analogues. The effects of quenchers, current density, initial pH, supporting electrolyte, and aqueous matrix on the removal kinetics of bisphenol AF (BPAF) and bisphenol A (BPA) were investigated. The kinetic constants of BPAF, BPA, and bisphenol S (BPS) in the SECP with irradiation intensity of 500 mW cm−2 were 0.017 ± 0.002 min−1, 0.022 ± 0.002 min−1, and 0.012 ± 0.001 min−1, respectively. The changes in the degradation rates of BPAF, BPA, and BPS in the presence of quenchers indicated the relative contribution of hydroxyl radical (●OH) oxidation, anodic electrolysis, and singlet (1O2) oxygenation in the degradation of BPs in the SECP. The enhanced rate of generation of ●OH and 1O2 was observed in the SECP compared with those in the conventional electrochemical system. The identification of the transformation products (TPs) of BPAF demonstrated that hydroxylation, ring cleavage, β-scission, and defluorination were the major processes during the oxidation in the SECP. The conversion to fluoride ions (76%) and mineralization of total organic carbon (72%) in the SECP indicated further degradation of TPs. The results from this study improved our understanding of the degradation of BP analogues in the electrooxidation irradiated by solar light and help to establish the application potential of the SECP for the effective degradation of emerging contaminants in wastewater.
Display omitted
•The enhanced performance of SECP was investigated for removal of bisphenol analogues.•SECP showed a synergistic effect on generation of.●OH and 1O2 for BPAF and BPA removal.•Transformation products and degradation pathways of BPAF in SECP were identified.•SECP exhibited hydroxylation, ring cleavage, β-scission, and defluorination process of BPAF removal.
This study reported the isolation and identification of bioactive compounds from Dioscorea nipponica Makino, a plant used in traditional medicine for various ailments. Nine compounds were isolated, ...including a new compound named as diosniposide E, which was elucidated by analyzing its
H-NMR,
C-NMR, DEPT, COSY, HMBC and MS data and comparing them with data available in literature. The other eight compounds were identified as known compounds. Theoretical calculations of energy and the generation of a molecular electrostatic potential surface map were employed to assess the antioxidant capacity of nine compounds, the calculation results exhibited that compounds 5 and 6 had strong antioxidant capacities. To further evaluate the antioxidant activities of the investigated compounds, the DPPH and ABTS assays were conducted. The results from the DPPH scavenging activity test revealed that compounds 4-6 exhibited enhanced scavenging activities compared to L-ascorbic acid, while displaying similar efficacy to trolox. Moreover, the ABTS scavenging activities of compounds 4-6 were found to surpass those of L-ascorbic acid and trolox. In terms of α-glucosidase inhibition, compounds 3 and 4 displayed remarkable inhibitory activities that surpassed the effects of acarbose. Additionally, compound 2 exhibited potent anticholinesterase activities, outperforming donepezil. This research provides insights into the potential bioactive compounds present in Dioscorea nipponica Makino and may contribute to its use in traditional medicine.
Display omitted
•A dual Z-scheme BiVO4/g-C3N4/NiFe2O4 was developed with good visible light response.•The BiVO4/g-C3N4/NiFe2O4 catalyst presented efficient removal performance of OFL.•This catalyst ...efficiently separated charge carriers and extended the range of visible light.•The magnetic property of BiVO4/g-C3N4/NiFe2O4 catalyst facilitated the recovery of catalyst.•Transformation products and removal mechanisms of OFL were identified and proposed.
Inefficient utilization of photo-induced charge carriers and low recyclability are limitations for photocatalyst to get access to the practical application. A novel ternary BiVO4/g-C3N4/NiFe2O4 composite with dual Z-scheme heterojunction was successfully developed and constructed to enhance the separation of photo-induced charge carriers and the absorption range of visible light. The structure, composition, morphology, magnetic, and optical properties of this photocatalyst were investigated comprehensively. The photocatalytic performance, mechanism, and pathway of ofloxacin degradation under visible light were studied. Results indicated that the internal interaction between different semiconductors presented the successful fabrication of ternary composite, and its red shift of adsorption range of visible light contributed to an enhancement of photocatalytic ability. The as-prepared ternary composite exhibited highest photocatalytic removal rate constant for ofloxacin, which was 3.8, 16.3 and 71.2 times as much as that of the pure BiVO4, pure g-C3N4 and pure NiFe2O4, respectively. The five successive recycling experiments exhibited the high photocatalytic stability of the as-prepared catalyst, with simple recovery operation due to its magnetic property. The holes and superoxide radicals dominated the photocatalytic degradation process of pollutants. A dual Z-scheme heterojunction other than conventional heterojunction was responsible for the enhancement on redox capacity and the separation of charge carriers. Different transformation products during ofloxacin photocatalytic degradation were identified and transformation pathway was put forward. This study provides a promising strategy on the application of visible-light-driven photocatalysts in water treatment.
Display omitted
•The feasibility of treating leachate concentrates by EC/EF-like process was examined.•The process reduced 57% of the COD and 60% of the NH4+ at 7 Ah/L in leachate concentrate.•Most ...fulvic and humic acid-like substances in the concentrate were removed.•The multiple removal mechanisms involved in EC/EF-like process were elucidated.
The efficient treatment of leachate concentrate is a key issue in the application of membrane technology to leachate treatment. Here a process coupling electrocoagulation with an electro-Fenton-like process was developed and tested for the treatment of leachate concentrate using a dual-anode system. The effects of pH, electrode gap, electrical charge, and suspended solids on the performance of organics and ammonia removal were evaluated with leachate concentrates from a municipal waste incineration facility. 57% of the organics and 60% of the ammonia were removed at the electrical charge of 7Ah/L, the potential of 7 V, and pH of 7. Electro-oxidation by hypochlorite ions generated in situ, electrocoagulation and electro-Fenton-like reaction via hypochlorite and ferrous ions achieved the removal. Higher levels of suspended solids and a smaller electrode gap both benefitted the removal of organics. Most of the fulvic acid and humic acid-like substances in the concentrate were removed, with the treatment effectiveness following the order coupled process > electro-Fenton-like process > electrocoagulation process. This coupled process shows an alternative potential as a preliminary process in the treatment of leachate concentrates.
In this study, nitrogen self-doping layered graphitic biochar (Na-BC900) was prepared by catalytic pyrolysis of lotus leaves at 900 °C, in the presence of NaCl catalyst, for peroxydisulfate (PDS) ...activation and sulfamethoxazole (SMX) degradation. NaCl as catalyst played a crucial part in the preparation of Na-BC900 and could be reused. The SMX degradation rate in Na-BC900/PDS system was 12 times higher than that in un-modified biochar (BC900)/PDS system. The excellent performance of Na-BC900 for PDS activation was attributed to its large specific surface areas (SSAs), the enhanced graphitization structure and the high graphitic N content. The quenching and electrochemical experiments, electron paramagnetic resonance (EPR) studies inferred that the radicals included SO4•-, •OH, O2•- and the non-radical processes were driven by 1O2 and biochar mediated electron migration. Both radical and non-radical mechanisms contributed to the removal of SMX. Additionally, this catalytic pyrolysis strategy was clarified to be scalable, which can be applied to produce multiple biomass-based biochar catalysts for restoration of polluted water bodies.
Display omitted
•A catalytic pyrolysis strategy was proposed to produce biochar catalysts.•The Na-BC900 presented an efficient performance for SMX degradation.•Molten NaCl enhanced the graphitization process with lower E (KJ mol−1) of pyrolysis.•Molten NaCl could promote the retention of N and the generation of graphitic N.•Both radical and non-radical removal routes contributed to the degradation of SMX.
Display omitted
•The synergism of sunlight and electrooxidation to activate PS in SEOP were elucidated.•PMS was easily activated than PDS to generate more active species in SEOP.•The energy barriers ...between BPS with hydroxyl and sulfate radical were presented.•Degradation pathway and ecotoxicity of BPS and intermediates were proposed.•SEOP with PMS has superiority in BPS removal and energy cost.
Sulfate radical-based advanced oxidation processes had been widely applied in the water treatment. In this study, a novel solar-assisted electrooxidation process (SEOP) to activate peroxymonosulfate (PMS) or peroxydisulfate (PDS) was conducted for the degradation of bisphenol S (BPS). The SEOP with persulfate (PS) demonstrated its synergistic effect for BPS degradation, compared with the electrooxidation/PS and the solar process. The hydroxyl radical, sulfate radical (SO4·-), and singlet oxygen were regarded as primary active species in BPS degradation in SEOP with PS. The transition structure complex (persulfate*) on the anode promoted the efficiency of BPS degradation via the non-radical mechanism. The activation of PMS and PDS in SEOP was dominated through radical and non-radical mechanism, respectively. To effectively supplement experimental work with quantum chemical calculation, density function theory (DFT) showed that the active sites mainly focused on the phenol ring of BPS. The energy barrier calculation indicated that BPS was more susceptible to be attacked by SO4·- through electron transfer. BPS was mainly degraded by ring-opening, substitution, addition, C–C bond breaking, and decarboxylation reactions. Furthermore, the effective decrease in bio-toxicity of BPS intermediates in SEOP with PS was predicted. Experiments under various current densities, initial concentration of PS, electrolyte, and humic acid suggested the feasibility of SEOP with PS. BPS was degraded with lower energy consumption (0.18 kWh·m−3·order−1) in SEOP with PMS than that in SEOP with PDS (0.30 kWh·m−3·order−1) and without PS (0.38 kWh·m−3 order−1), respectively. The SEOP with PS poses the feasible, convenient, and economic potential for the degradation of refractory pollutants.
PDF
