科研论文/Publications

2020
Zhang D, Qi J, Ji H, Li S, Chen L, Huang T, Xu C, Chen X, Liu W. Photocatalytic degradation of ofloxacin by perovskite-type NaNbO3 nanorods modified g-C3N4 heterojunction under simulated solar light: Theoretical calculation, ofloxacin degradation pathways and toxicity evolution. Chemical Engineering Journal [Internet]. 2020;400:125918. 访问链接Abstract
Graphitic carbon nitride (g-C3N4) is widely used as a visible-light-driven photocatalyst but limited by the rapid photoexcited electron-hole pairs recombination rate. To promote the photocatalytic activity of g-C3N4, a class of heterojunction photocatalysts, perovskite-type sodium niobate (NaNbO3) nanorods modified g-C3N4 (SNCN), was fabricated through a two-step hydrothermal and thermal polymerization method in this study. X-ray powder diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) demonstrated the successful decoration of NaNbO3 onto g-C3N4, as well as the formation of material interface with high reactivity. The optimal material (SNCN-3) exhibited an extremely high degradation efficiency of ofloxacin (OFL) under simulated solar light, as the kinetic rate constant (k) was 29.6 and 10.4 times of that for the neat g-C3N4 and NaNbO3, respectively. Energy band structure analysis indicated that SNCN-3 was a type II heterojunction. Moreover, surface photovoltage (SPV), photoluminescence (PL) and transient photocurrent response measurements confirmed SNCN-3 had the highest electron-hole separation efficiency compared with NaNbO3, g-C3N4 and the other SNCN composites. Quenching tests indicated that O2– and holes were the primary reactive species for OFL degradation. Density functional theory (DFT) calculation on further revealed the atoms of OFL with high Fukui index (f 0) preferred to be attacked by the produced radicals. Cleavage of piperazine moiety and substitution of F were the key OFL degradation pathways. In addition, the reduced toxicity of transformation products after photocatalysis verified the proposed technique was a green method. This work provided the promising application of g-C3N4/NaNbO3 heterojunction photocatalysts for degradation of antibiotic pollutants in water.
Dang C, Sun F, Jiang H, Huang T, Liu W, Chen X, Ji H. Pre-accumulation and in-situ destruction of diclofenac by a photo-regenerable activated carbon fiber supported titanate nanotubes composite material: Intermediates, DFT calculation, and ecotoxicity. Journal of Hazardous Materials [Internet]. 2020;400:123225. 访问链接Abstract
Pharmaceuticals and personal care products (PPCPs) have been widely detected in ecosystems. However, effective water purification technologies for PPCPs degradation are lacking. In this work, an active activated carbon fiber supported titanate nanotubes (TNTs@ACF) composite was synthesized via one-step hydrothermal process, which was applied for adsorption and photocatalytic degradation of PPCPs under simulated solar light. Characterizations indicated that the successful grafting of TNTs onto ACF was achieved and surface modification occurred. Diclofenac (DCF, a model PPCPs) was rapidly adsorbed onto TNTs@ACF, and subsequently photodegraded (98.8 %) under solar light within 2 h. TNTs@ACF also performed well over a wide range of pH, and was resistant to humic acid. The good adsorption and photocatalytic activity of TNTs@ACF was attributed to the well-defined hybrid structure, enabling corporative adsorption of DCF by TNTs and ACF, and extending the light absorbance to visible region. Furthermore, the description of degradation pathway and evaluation of ecotoxicity for DCF and its intermediates/byproduct were proposed based on experimental analysis, density functional theory (DFT) calculation and quantitative structure–activity relationship (QSAR) analysis, respectively, indicating the photocatalytic degradation of DCF can offer the step-by-step de-toxicity. Our study is expected to offer new strategy as “pre-accumulation and in-situ destruction” for environmental application.
Li H, Tian Y, Liu W, Long Y, Ye J, Li B, Li N, Yan M, Zhu C. Impact of electrokinetic remediation of heavy metal contamination on antibiotic resistance in soil. Chemical Engineering Journal [Internet]. 2020;400:125866. 访问链接Abstract
Electrokinetic remediation is an effective technology for soil contaminated with heavy metals. However, little is known about the fate of antibiotic resistance in the process under heavy metal stress, since antibiotic resistance genes (ARGs) are widely distributed and can be co-selected with heavy metals. This study focused on antibiotic resistant bacteria and ARGs over different remediation periods (1, 2, and 5 days), voltages (0.4 and 0.8 V cm−1), and initial concentrations (250–1,000 mg kg−1 for Cu, and 1,000–3,000 mg kg−1 for Zn). The application of polarity-reversal maintained a suitable pH, eliminating possible negative effects on soil quality. In addition to a decrease in total metals, the speciation was modified as residual forms decreased while reactive forms increased. Compared with anti-oxytetracycline bacteria, anti-sulfamethoxazole bacteria were more resistant to the electric field, which might be ascribed to greater constraints on their resistance enzymes. The presence of heavy metals accelerated the spread of ARGs, with a 2.67-fold increase for tetG, and a 3.86-fold increase for sul1. Among the ARGs studied, tetM and tetW, as well as sul genes were more easily removed than tetC and tetG genes. Finally, a significant correlation was found between ARGs and Cu, consistent with the relatively stronger toxicity of Cu and its high potential to induce the SOS response. This study advances the understanding of how electrokinetics influences antibiotic resistance in soil with heavy metals, which has important implications for the simultaneous control of these pollutants in soil.
Ma R, Wang T, Huang T, Sun W, Qiao S, Liu W. Insights into interactions of Cr(III) and organic matters during adsorption onto titanate nanotubes: Differential absorbance and DFT study. Journal of Molecular Liquids [Internet]. 2020;312:113432. 访问链接Abstract
Organic Matter (OM) with different molecular weight and functional groups can impact the adsorptive removal of metal ions, and the influence trend can be facilitated, inhibited or unchanged. However, the association capabilities of different ligands were superficially expounded. Based on the sorption behavior of Cr(III) onto titanate nanotubes (TNTs) with coexisting citric acid (CA), humic acid (HA) and fulvic acid (FA), this study highlighted differential absorbance and DFT simulations to quantitatively detect the mutual effect. As results, adsorption capacities of Cr(III) obviously enhanced from ca. 60 mg/g to 85 mg/g with CA or FA; while HA can slightly promote Cr(III) adsorption. UV spectra scanning proved that FA and HA led to the remarkable red shift of peak A1 (232 nm), A2 (262 nm), A3 (295 nm), A4 (431 nm) of Cr(III), and the area ratio of A2/A3 followed the order Cr-HA > Cr-FA > Cr-CA ≈ Cr. DFT calculations further confirmed that the simultaneous formation of ligand-metal-adsorbents complex and electrostatic effect promoted Cr(III) adsorption, with binding energies of −202.9   −420.8 kJ/mol and − 3958 kJ/mol, respectively. Meanwhile, the bridge connection of OM mainly appeared in the outer sphere of TNTs, as the larger molecular scale prevented their insertion into the inner spacing of TNTs, especially for HA and FA. Therefore, the adsorption mechanism was the combined actions of electrostatic attraction, bridge connection of OM and steric effect. This study can give insights into OM effects on metal adsorption, and quantificationally describe the junction state of ternary complex.
Wang C-C, Wang X, Liu W. The synthesis strategies and photocatalytic performances of TiO2/MOFs composites: A state-of-the-art review. Chemical Engineering Journal [Internet]. 2020;391:123601. 访问链接Abstract
Up to now, titanium dioxide (TiO2) is the most established semiconductor photocatalyst, which is used to achieve photocatalytic H2 evolution, pollutants degradation, CO2 reduction, and N2 reduction under UV light irradiation. TiO2 as photocatalyst is always under the spotlight due to its unique properties like outstanding thermal/chemical stability, wide bandgap with suitable band edge, low cost, non-toxicity, and corrosion resistance. To further improve the photocatalytic activity of TiO2, the versatile and porous metal-organic frameworks (MOFs) can be introduced to constructionTiO2/MOF composites, which can accomplish the enhanced light absorption performance and improved electron-hole pair separation. With this review, the fabrication strategies, characterizations techniques, photocatalytic activities and the mechanisms of some selected TiO2/MOF composites were reviewed and highlighted. The last but not the least, the outlooks and challenges of TiO2/MOF composites as photocatalysts for energy conversion and environment remediation are proposed.
Liu F, Nie C, Dong Q, Ma Z, Liu W, Tong M. AgI modified covalent organic frameworks for effective bacterial disinfection and organic pollutant degradation under visible light irradiation. Journal of Hazardous Materials [Internet]. 2020;398:122865. 访问链接Abstract
Covalent organic frameworks (COFs) have recently been demonstrated to have great application potentials in water treatment. Their photocatalytic performance towards bacterial disinfection and organic pollutant degradation yet has seldom been investigated. In this study, AgI modified COFs (using 2,5-diaminopyridine and 1,3,5-triformylphloroglucinol as precursors) (COF-PD/AgI) were fabricated and their applications to photocatalytically disinfect bacteria and degrade organic pollutants were investigated. COF-PD/AgI exhibited effective photocatalytic performance towards Escherichia coli disinfection and organic pollutant (Rhodamine B and acetaminophen) degradation. SEM images were employed to investigate cell disinfection process, while theoretical density functional theory (DFT) calculation and intermediates determination were used to elucidate organic pollutant degradation processes. Scavenger experiments, ESR spectra and chemical probes experiments confirmed O2−, h+ and OH played important roles in the photocatalytic process. The formation of dual-band Z-scheme heterojunction improved photocatalytic performance. COF-PD/AgI remained high photocatalytic activity in the four consecutive cycles and could serve as a promising photocatalyst for water purification.
Peng J, Zhou H, Liu W, Ao Z, Ji H, Liu Y, Su S, Yao G, Lai B. Insights into heterogeneous catalytic activation of peroxymonosulfate by natural chalcopyrite: pH-dependent radical generation, degradation pathway and mechanism. Chemical Engineering Journal [Internet]. 2020;397:125387. 访问链接Abstract
In this study, natural chalcopyrite (NCP) was employed in the activation of peroxymonosulfate (PMS) for bisphenol S (BPS) degradation. Firstly, the NCP catalyst was characterized via X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) techniques. Then, several key parameters such as catalyst dosage, PMS dosage and initial pH were investigated in NCP/PMS system. Furthermore, the transformation of various free radicals (SO4•−, •OH and O2•−) with the changes of initial pH were investigated by quenching experiments and electron spin resonance (ESR) study. Also, sulfur species cycling of copper and iron species were investigated via exogenous Cu2+ and Fe3+ addition experiments and X-ray photoelectron spectroscopy (XPS) analysis, the result indicated that sulfur species promoted Fe3+/Fe2+ and Cu2+/Cu+ cycles on the NCP surface. Furthermore, thirteen major degradation intermediates of BPS were detected by UPLC-QTOF-MS/MS and density functional theory (DFT) method was used to illustrate possible reaction pathways of BPS. Finally, a reasonable reaction mechanism of NCP/PMS system for BPS degradation was proposed on the basis of the comprehensive analysis. In brief, this work helps to provide useful information for the application of natural metallic sulfide minerals in treatment of contaminated waters.
Wang Y, Ji H, Liu W, Xue T, Liu C, Zhang Y, Liu L, Wang Q, Qi F, Xu B, et al. Novel CuCo2O4 Composite Spinel with a Meso-Macroporous Nanosheet Structure for Sulfate Radical Formation and Benzophenone-4 Degradation: Interface Reaction, Degradation Pathway, and DFT Calculation. ACS Applied Materials & Interfaces [Internet]. 2020;12:20522-20535. 访问链接Abstract
A series of CuCo2O4 composite spinels with an interconnected meso-macroporous nanosheet morphology were synthesized using the hydrothermal method and subsequent calcination treatment to activate peroxymonosulfate (PMS) for benzophenone-4 (BP-4) degradation. As-prepared CuCo2O4 composite spinels, especially CuCo-H3 prepared by adding cetyltrimethylammonium bromide, showed superior reactivity for PMS activation. In a typical reaction, BP-4 (10.0 mg/L) was almost completely degraded in 15 min by the activation of PMS (200.0 mg/L) using CuCo-H3 (100.0 mg/L), with only 9.2 μg/L cobalt leaching detected. Even after being used six times, the performance was not influenced by the lower leaching of ions and surface-absorbed intermediates. The possible interface mechanism of PMS activation by CuCo-H3 was proposed, wherein a unique interconnected meso-macroporous nanosheet structure, strong interactions between copper and cobalt, and cycling of Co(II)/Co(III) and Cu(I)/Cu(II) effectively facilitated PMS activation to generate SO4•– and •OH, which contributed to BP-4 degradation. Furthermore, combined with intermediates detected by liquid chromatography quadrupole time-of-flight mass spectrometry and density functional theory calculation results, the degradation pathway of BP-4 involving hydroxylation and C–C bond cleavage was proposed.
Zheng M, Ji H, Duan J, Dang C, Chen X, Liu W. Efficient adsorption of europium (III) and uranium (VI) by titanate nanorings: Insights into radioactive metal species. Environmental Science and Ecotechnology [Internet]. 2020;2:100031. 访问链接Abstract
Radioactive wastewater containing high concentration of radionuclides poses severe threats to ecosystem and human health, so efficient removal of these toxic heavy metals is urgently needed. Titanate nanomaterials have been demonstrated good adsorbents for heavy metals due to ion exchange property. In this study, titanate nanorings (TNRs) were synthesized using the facile hydrothermal-cooling method. The TNRs were composed of sodium trititanate, with a chemical formula of Na0.66H1.34Ti3O7•0.27H2O and a Na content of 2.38 mmol/g. The TNRs demonstrated sufficient adsorption performance to radionuclides europium (Eu) and uranium (U) ions. Specifically, even at a high initial concentration of 50 mg/L, 86.5% and 92.6% of the two metal ions can be rapidly adsorbed by the TNRs within 5 min, and equilibrium was reached within 60 min at pH 5. The maximum adsorption capacity (Qmax) obtained by the Langmuir isotherm model was 115.3 mg/g for Eu(III) and 282.5 mg/g for uranium U(VI) at pH 5, respectively. The adsorption capacities of the two metals under various water chemical conditions were highly related to their species. Ion exchange between metal cations and Na+ in the TNR interlayers was the dominant adsorption mechanism, and adsorption of U(VI) was more complicated because of the co-existence of various uranyl (UO22+) and uranyl-hydroxyl species. The spent TNRs were effectively regenerated through an acid-base or ethylenediamine tetraacetic acid (EDTA) treatment and reused. Considering the large adsorption capacity and quick kinetic, TNRs are promising materials to remove radionuclides in environmental purification applications, especially emergent treatment of leaked radionuclides.
Tao X, Pan P, Huang T, Chen L, Ji H, Qi J, Sun F, Liu W. In-situ construction of Co(OH)2 nanoparticles decorated urchin-like WO3 for highly efficient degradation of sulfachloropyridazine via peroxymonosulfate activation: Intermediates and DFT calculation. Chemical Engineering Journal [Internet]. 2020;395:125186. 访问链接Abstract
Sulfachloropyridazine (SCP) was commonly used as a broad-spectrum sulfonamide antibiotic and hard to be removed through traditional sewage treatment process. In this study, we developed a simple and controllable strategy to realize in-situ construction of Co(OH)2 nanoparticles decorated urchin-like WO3 (Co(OH)2/WO3), which could efficiently remove SCP through peroxymonosulfate (PMS) activation. Some tiny nanoparticles of Co(OH)2 decorated on the spines/nanorods or surfaces of urchin-like WO3 by transmission electron microscopy (TEM) analysis. The obtained 10 wt% Co(OH)2/WO3 realized completely removal of SCP (degradation efficiency 100%) with a high reaction rate constant (k1) of 0.88 min−1 within 3 min at optimal pH 7. That was because the urchin-like WO3 with numerous adsorption functional groups on its surface (e.g., W = O and –OH bonds) could adsorb the Co2+ easily to form CoOH+, which was perceived the rate-limiting step for PMS activation and generating radicals. Radical quenching experiments indicated that SO4•− played a more significant role than HO• radicals. Density functional theory (DFT) calculation revealed that the atoms of SCP with high Fukui index (f−) were active sites, which preferred to be attacked by the electrophilic SO4•− and HO• radicals. The toxicity of the intermediates by SCP degradation was evaluated by quantitative structure–activity relationship (QSAR) prediction through Toxicity Estimation Software Tool (T.E.S.T.). The possible degradation pathway and catalytic mechanism for SCP removal were proposed. Considering the good catalytic properties of Co(OH)2/WO3-PMS, the material will show great application potential in the removal of emerging contaminants in water.
Pang D, Wang C-C, Wang P, Liu W, Fu H, Zhao C. Superior removal of inorganic and organic arsenic pollutants from water with MIL-88A(Fe) decorated on cotton fibers. Chemosphere [Internet]. 2020;254:126829. 访问链接Abstract
Arsenic contamination has attracted worldwide concerns, owing to its toxicity and severe threat to human and environment. It is urgent to develop efficient adsorbents to remove arsenic pollutants. Within this paper, both pristine MIL-88A(Fe) and MIL-88A(Fe) decorated on cotton fibers were successfully fabricated using an eco-friendly method. The pristine MIL-88A(Fe) displayed outstanding adsorption performances towards four selected arsenic pollutants, in which the adsorption capacities toward As(III), As(V), ROX and ASA were 126.5, 164.0, 261.4 and 427.5 mg g−1, respectively. Additionally, MIL-88A(Fe) exhibited excellent removal efficiencies in a wide pH range and with the presence of different co-existing ions. It was proposed that the coordinative interactions of As–O–Fe between arsenic pollutants and MIL-88A(Fe) contributed to the superior adsorption performances. Furthermore, two MIL-88A(Fe)/cotton fibers composites were synthesized by both post synthesis (MC-1) and in-situ synthesis (MC-2), which demonstrated identically outstanding adsorption activities toward four selected arsenic pollutants. MC-1 and MC-2 enhanced the stability and reusability of MIL-88A(Fe), which was challenging issues of pristine MIL-88A(Fe) powder. Additionally, the fixed-bed column packed by MC-1 or MC-2 can continuously eliminate arsenic pollutants from the water flow. This work provided a new possibility of metal-organic frameworks to accomplish potentially large-scale application to purify the arsenic-contaminated water.
Zhang Y, Ji H, Liu W, Wang Z, Song Z, Wang Y, Liu C, Xu B, Qi F. Synchronous degradation of aqueous benzotriazole and bromate reduction in catalytic ozonation: Effect of matrix factor, degradation mechanism and application strategy in water treatment. Science of The Total Environment [Internet]. 2020;727:138696. 访问链接Abstract
Ozone-based technologies are used for micro-pollutants removal in wastewater treatment. However, the generation of the toxic by-product bromate (BrO3−) is of a great concern. LaCoO3 (LCO) catalytic ozonation has been used to overcome this significant drawback in the sole ozonation, achieving better BrO3− elimination efficiency. However, a key challenge is how to enhance micro-pollutant (benzotriazole, BZA) degradation efficiency and to eliminate formed BrO3− synchronously under various water qualities in drinking water or wastewater treatment. Therefore, the objective of this study is to propose a practical strategy of BZA removal and BrO3− reduction synchronously in water or wastewater treatment. In this study, important factors influencing BZA removal and BrO3− reduction were investigated, including [catalyst], [BZA], initial pH solution, [NH4+-N] and [(bi)carbonate alkalinity]. Based on the performance and mechanism of these effects, a practical strategy for BZA degradation and BrO3− elimination with and without Br− in the influent was developed. Additionally, the density functional theory (DFT) calculation successfully predicted the attack site on BZA by molecular ozone and formed hydroxyl radical (HO·) during LCO catalytic ozonation. Fukui indexes of f+ and f0 were calculated to forecast direct ozone molecule and HO· attack, respectively. Combination of DFT calculation with intermediates that identified through liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS), BZA degradation pathway was established more accurately. Additionally, four new intermediates were identified in this study. Overall, this study proposes a useful strategy for synchronous micro-pollutants degradation and BrO3− elimination, while also suggesting the feasibility of LCO catalytic ozonation for water or wastewater purification.
Kim J, Du P, Liu W, Luo C, Zhao H, Huang C-H. Cobalt/Peracetic Acid: Advanced Oxidation of Aromatic Organic Compounds by Acetylperoxyl Radicals. Environmental Science & Technology [Internet]. 2020;54:5268-5278. 访问链接Abstract
Peracetic acid (PAA) is increasingly used as an alternative disinfectant and its advanced oxidation processes (AOPs) could be useful for pollutant degradation. Co(II) or Co(III) can activate PAA to produce acetyloxyl (CH3C(O)O•) and acetylperoxyl (CH3C(O)OO•) radicals with little •OH radical formation, and Co(II)/Co(III) is cycled. For the first time, this study determined the reaction rates of PAA with Co(II) (kPAA,Co(II) = 1.70 × 101 to 6.67 × 102 M–1·s–1) and Co(III) (kPAA,Co(III) = 3.91 × 100 to 4.57 × 102 M–1·s–1) ions over the initial pH 3.0–8.2 and evaluated 30 different aromatic organic compounds for degradation by Co/PAA. In-depth investigation confirmed that CH3C(O)OO• is the key reactive species under Co/PAA for compound degradation. Assessing the structure–activity relationship between compounds’ molecular descriptors and pseudo-first-order degradation rate constants (k′PAA• in s–1) by Co/PAA showed the number of ring atoms, EHOMO, softness, and ionization potential to be the most influential, strongly suggesting the electron transfer mechanism from aromatic compounds to the acetylperoxyl radical. The radical production and compound degradation in Co/PAA are most efficient in the intermediate pH range and can be influenced by water matrix constituents of bicarbonate, phosphate, and humic acids. These results significantly improve the knowledge regarding the acetylperoxyl radical from PAA and will be useful for further development and applications of PAA-based AOPs.
Li H, Sun S, Ji H, Liu W, Shen Z. Enhanced activation of molecular oxygen and degradation of tetracycline over Cu-S4 atomic clusters. Applied Catalysis B: Environmental [Internet]. 2020;272:118966. 访问链接Abstract
It is quite important and challenging for efficient activating the molecular oxygen (O2) to reactive oxygen species (ROS), especially in environmental remediation. Herein, the CuS4 atomic clusters are constructed on the surface of ZnInS4 nanosheet (CuS4-ZIS), which shows much better ability for activating O2 to ROS than pristine ZnInS4 nanosheet (ZIS) and the CuS3.6 atomic clusters counterpart (CuS3.6-ZIS). Results display that CuS4-ZIS can energetic favorably adsorb the O2 and more electrons could transfer from the CuS4-ZIS to O2 than ZIS and CuS3.6-ZIS. Besides, a better charge separation and transfer is observed on CuS4-ZIS. Thus, higher concentration of superoxide radicals (·O2−, partially transformed into ·OH) can be generated over Cu-S4 atomic clusters under light illumination. Therefore, CuS4-ZIS exhibits higher degradation efficiency of tetracycline (TC) than pristine ZIS and CuS3.6-ZIS. Moreover, the degradation pathway of TC is proposed based on the results of HPLC-MS and the theoretical calculations.
He K, Borthwick AG, Lin Y, Li Y, Fu J, Wong Y, Liu W. Sale-based estimation of pharmaceutical concentrations and associated environmental risk in the Japanese wastewater system. Environment International [Internet]. 2020;139:105690. 访问链接Abstract
Information on sales and emission of selected pharmaceuticals were used to predict their concentrations in Japanese wastewater influent through a >300 of pharmaceuticals data sink. A combined wastewater-based epidemiology and environmental risk analysis follow was established. By comparing predicted environmental concentrations (PECs) of pharmaceuticals in wastewater influent against measured environmental concentrations (MECs) reported in previous studies, it was found that the model gave accurate results for 17 pharmaceuticals (0.5 < PEC/MEC < 2), and acceptable results for 32 out of 40 pharmaceuticals (0.1 < PEC/MEC < 10). Although the majority of pharmaceuticals considered in the model were antibiotics and analgesics, pranlukast, a receptor antagonist, was predicted to have the highest concentration in wastewater influent. With regard to the composition of wastewater effluent, the Estimation Program Interface (EPI) suite was used to predict pharmaceutical removal through activated sludge treatment. Although the performance of the EPI suite was variable in terms of accurate prediction of the removal of different pharmaceuticals, it could be an efficient tool in practice for predicting removal under extreme scenarios. By using the EPI suite with input data on PEC in the wastewater influent, the PEC values of pharmaceuticals in wastewater effluent were predicted. The concentrations of 26 pharmaceuticals were relatively high (>1 μg/L), and the PECs of 6 pharmaceuticals were extremely high (>10 μg/L) in wastewater effluent, which could be attributed to their high usage rates by consumers and poor removal rates in wastewater treatment plants (WWTPs). Furthermore, environmental risk assessment (ERA) was carried out by calculating the ratio of predicted no effect concentration (PNEC) to PEC of different pharmaceuticals, and it was found that 9 pharmaceuticals were likely to have high toxicity, and 54 pharmaceuticals were likely to have potential toxicity. It is recommended that this is further investigated in detail. The priority screening and environmental risk assessment results on pharmaceuticals can provide reliable basis for policy-making and environmental management.
Lan S, Chen Y, Zeng L, Ji H, Liu W, Zhu M. Piezo-activation of peroxymonosulfate for benzothiazole removal in water. Journal of Hazardous Materials [Internet]. 2020;393:122448. 访问链接Abstract
Piezoelectricity, as a kind of physical phenomenon, is a coupling between a material’s mechanical and electrical behavior. Herein, the local accumulated charges on the surface of piezoelectric material were used to break OO bond of peroxymonosulfate (PMS) to induce its activation for the benzothiazole (BTH) removal. Taking BaTiO3 as a model piezocatalyst, up to 97 % of BTH was degraded within 30 min in BaTiO3/PMS/force system, which was respective 40 %, 79 %, 83 % higher than that in BaTiO3/force piezocatalysis, force/PMS oxidation, and BaTiO3/PMS adsorption. A significant synergistic effect was observed since the reaction rate constant of BaTiO3/PMS/force was 3 times higher than the sum of those later three processes. The possible activated mechanism was proposed based on reactive species analysis, DFT calculation and LCMS determination. The stability of the piezocatalyst and the treatment performance for real wastewater were studied to investigate the potential in practical applicability. All the results demonstrated that the BaTiO3 piezoelectricity can efficiently activate PMS to enhance BTH removal, which is a promising strategy for PMS activation, as well as a valuable insight for the piezoelectrical application in wastewater remediation.
Duan J, Ji H, Zhao X, Tian S, Liu X, Liu W, Zhao D. Immobilization of U(VI) by stabilized iron sulfide nanoparticles: Water chemistry effects, mechanisms, and long-term stability. Chemical Engineering Journal [Internet]. 2020;393:124692. 访问链接Abstract
Carboxymethyl cellulose stabilized iron sulfide (CMC-FeS) nanoparticles have been shown promising for reductive immobilization of U(VI) in water and soil. This work aimed to fill some critical knowledge gaps on the effects of the stabilizer and water chemistry, reaction mechanisms, and long-term stability of stabilized uranium. The optimal CMC-to-FeS molar ratio was determined to be 0.0010. CMC-FeS performed effectively over pH 6.0–9.0, with the best removal being at pH 7.0 and 8.0. The retarded first-order model adequately interpreted the kinetic data, representing a mechanistically sounder model for heterogeneous reactants of decaying reactivity. The presence of Ca2+ (1 mM) or bicarbonate (1 mM) lowered the initial rate constant by a factor of 1.6 and 9.5, respectively, while 1 mM of Na+ showed negligible effect. Humic acid at 1.0 mg/L (as total organic carbon) doubled the removal rate, but inhibited the removal at elevated concentrations (≥5.0 mg/L). Fourier transform infrared spectroscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, and extraction studies indicated that reductive conversion of UO22+ to UO2(s) was the primary reaction mechanism, accounting for  90% of U removal at pH 7.0. S2− and S22− were the primary electron sources, whereas sorbed and structural Fe(II) acted as supplementary electron donors. The immobilized U remained stable under anoxic conditions after 180 days of aging, while  26% immobilized U was remobilized when exposed to air for 180 days. The long-term stability is attributed to the protective reduction potential of CMC-FeS, the formation of uraninite and associated structural resistance to oxidation, and the high affinity of FeS oxidation products toward U(VI).
Jiang H, Dang C, Liu W, Wang T. Radical attack and mineralization mechanisms on electrochemical oxidation of p-substituted phenols at boron-doped diamond anodes. Chemosphere [Internet]. 2020;248:126033. 访问链接Abstract
Degradation of phenols with different substituent groups (including –OCH3, –CHO, –NHCOCH3, –NO2, and −Cl) at boron-doped diamond (BDD) anodes has been studied previously based on the removal efficiency and •OH detection. Innovatively, formations of CO2 gas and various inorganic ions were examined to probe the mineralization process combined with quantitative structure-activity relationship (QSAR) analysis. As results, all phenols were efficiently degraded within 8 h with high COD removal efficiency. Three primary intermediates (hydroquinone, 1,4-benzoquinone and catechol) were identified during electrochemical oxidation and degradation pathway was proposed. More importantly, CO2 transformation efficiency ranked as: no N or Cl contained phenols (p-CHO, p-OCH3 and Ph) > N-contained phenols (p-NHCOCH3 and p-NO2) > Cl-contained phenols (p-Cl and o,p-Cl). Carbon mass balance study suggested formation of inorganic carbon (H2CO3, CO32− and HCO3−) and CO2 after organic carbon elimination. Inorganic nitrogen species (NH4+, NO3− and NO2−) and chlorine species (Cl−, ClO3− and ClO4−) were also formed after N- and Cl-contained phenols mineralization, while no volatile nitrogen species were detected. The phenols with electron-withdrawing substituents were easier to be oxidized than those with electron-donating substituents. QSAR analysis indicated that the reaction rate constant (k1) for phenols degradation was highly related to Hammett constant (∑σo,m,p) and energy gap (ELUMO - EHOMO) of the compound (R2 = 0.908), which were key parameters on evaluating the effect of structural moieties on electronic character and the chemical stability upon radical attack for a specific compound. This study presents clear evidence on mineralization mechanisms of phenols degradation at BDD anodes.
Dang C, Xia Y, Zheng M, Liu T, Liu W, Chen Q, Ni J. Metagenomic insights into the profile of antibiotic resistomes in a large drinking water reservoir. Environment International [Internet]. 2020;136:105449. 访问链接Abstract
Reservoirs play a vital role in the control and management of surface water resources. However, the long water residence time in the reservoir potentially increases the storage and accumulation of antibiotic resistant genes (ARGs). The full profiles and potential health risks of antibiotic resistomes in reservoirs are largely unknown. In this study, we investigated the antibiotic resistomes of water and sediment during different seasons in the Danjiangkou Reservoir, which is one of the largest reservoirs in China, using a metagenomic sequencing approach. A total of 436 ARG subtypes belonging to 20 ARG types were detected from 24 water and 18 sediment samples, with an average abundance of 0.138 copies/cell. The overall ARG abundance in the sediment was higher than that in the water, and bacitracin and vancomycin resistance genes were the predominant ARG types in the water and sediment, respectively. The overall ARG abundance in the dry season was higher than that in the wet season, and a significant difference in ARG subtype compositions was observed in water, but not in the sediment, between the different seasons. The potential horizontal gene transfer frequency in the water was higher than that in the sediment, and the ARGs in water mainly came from the sediment upstream of the reservoir. The metagenomic assembly identified 14 contigs as ARG-carrying pathogens including Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, and 3 of 14 carried virulence factors. Overall, the potential public health risks posed by resistomes in the water of the Danjiangkou Reservoir were higher in the dry season than in the wet season. Based on these results, strategies including sediment control and pathogen monitoring are suggested for water safety management in drinking water reservoirs.
Tong M, Liu F, Dong Q, Ma Z, Liu W. Magnetic Fe3O4-deposited flower-like MoS2 nanocomposites for the Fenton-like Escherichia coli disinfection and diclofenac degradation. Journal of Hazardous Materials [Internet]. 2020;385:121604. 访问链接Abstract
Fenton reaction can disinfect bacteria and degrade organic pollutants via the generation of OH through the reaction of Fe(II) and H2O2. However, its high efficiency only at very acidic conditions and the formation of Fe(III) sludge limit its practical application. Herein, magnetic Fe3O4-deposited flower-like MoS2 (MF) composites were fabricated to disinfect Escherichia coli and degrade diclofenac (DCF) with addition of small amount of H2O2 at a wide pH range (from 3.5 to 9.5). MF can efficiently inactivate bacteria and remove DCF at broad pH from 3.5 to 9.5. For example, 1.2 × 106 CFU mL-1 cells are completely disinfected by MF in 30 min at pH 6 with 5 mM H2O2, while 10 mg L-1 DCF is fully degraded in 7 min at pH 6 with 1 mM H2O2. MoS2 facilitates the conversion cycle of Fe(III)/Fe(II) and improves the generation of OH. MF can be easily collected by magnet after use. Confocal image, SEM images, the leakage of K+ and DNA were employed to determine the damage of cell membrane. Meanwhile, the theoretical density functional theory and the degradation intermediates determination were employed to provide the degradation pathway of DCF. MF exhibit excellent reusability and good catalytic performance towards sanitary sewage.

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