Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Shaoru Liu,Weizi Zhang,Peng Zhu,Songlin Zuo,Haian Xia
The study reports a facile synthesis of Ag-g-C 3 N 4 /AC composites with highly photocatalytic activity and good adsorption capacity by an impregnation-thermal polycondensation process. The resulting Ag-g-C 3 N 4 /AC composites were used for treatment of different pollutants in water including Rhodamine B (RhB), Cr(VI) ions and pathogens . When the precursor mass ratio of urea and AC was 2:2, the resultant Ag-g-C 3 N 4 /AC catalyst showed the best photocatalytic performances. In particular, the composite photocatalysts exhibited highly bactericidal efficiency, which could reach 99.9% after 120 min of irradiation. The higher photocatalytic performances of Ag-g-C 3 N 4 /AC composites were attributed to the surface plasmon resonance (SPR) effect of Ag nanoparticles (NPs) together with the interfacial synergistic effects. Meanwhile, AC not only exhibited excellent adsorption capacity, but also decreased aggregation of g-C 3 N 4 , which could enhance the separation efficiency of photogenerated charge carriers. It was uncovered through Electron Spin Resonance (ESR) and radical scavenger experiments that • OH radicals, • O 2 − and h + participate in the RhB degradation under the visible light. This work shows that the high-efficient and stable Ag-g-C 3 N 4 /AC composites have a great potential in the treatment of organic pollutants , toxic heavy metals and pathogenic bacteria by adsorption/photocatalysis for practical water treatment .
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Weilu Yang,Minghua Zhou,Lei Mai,Huase Ou,Nihal Oturan,Mehmet A. Oturan,Eddy Y. Zeng
Low yields of H 2 O 2 and a narrow range of appropriate pH values have been two major drawbacks for electro-Fenton (EF) process. Herein, metal-free electrochemical advanced oxidation processes (EAOPs) were developed with nitrogen and sulfur co-doped electrochemically exfoliated graphene (N, S-EEGr) electrocatalysts, which was confirmed as an outstanding bifunctional catalyst for synchronous generation and activation of H 2 O 2 via (2 + 1) e − consecutive reduction reactions. Specifically, two elements (N, S) in metal-free N, S-EEGr-CF cathode synergize to promote the formation of H 2 O 2 followed by its activation. With N, S-EEGr-CF cathode, phenol of initial 50 mg L −1 could be effectively removed within pH 3–11 and 6.25 mA cm −2 , and 100% removal efficiency could be achieved within 15-min even at neutral pH. The pseudo-first-order rate constant for phenol removal in metal-free EAOPs with N,S-EEGr-CF at neutral pH was 10 times higher than that with EF process. Detection of active species, coupled with decay kinetics with specific trapping agents, confirmed that OH was the dominant oxidizing species promoting removal efficiencies of organics (phenol, antibiotics and dyes) at pH 3 and pH 7. In the actual wastewater treatment, the synergistic effect of bifunctional catalyst would also be used for improving the degradation efficiency of organics. Thus, the metal-free EAOPs with N,S-EEGr-CF cathode may serve as an alternative in wastewater treatment with a broadened range of solution pH values and avoiding Fe 2+ (catalyst) addition.
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CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Jianhua Sha,Lulu Li,Zexiu An,Maoxia He,Haiyan Yu,Yao Wang,Baoyu Gao,Shiping Xu
Coexistence of heavy metals usually shows great impact on antibiotics removal. In this study, we firstly reported that Cu 2+ shows diametrically opposite effect on adsorption-photodegradation of sulfamerazine (SMZ) and ciprofloxacin (CIP) in g-C 3 N 4 /visible light system. Cu 2+ can greatly promote CIP adsorption, but showed negligible impact on its degradation, whereas, no obvious influence on SMZ adsorption was recorded, but strong inhibition to its photodegradation was observed. With help of several spectroscopy approaches and DFT calculation, functional mechanism of Cu 2+ on the adsorption-photodegradation of SMZ and CIP was proposed. The main reasons for their different behaviors were found to be their distinct surface charge, spatial structure, electron distribution and complexation with Cu 2+ . Among them, effect of complexation played the most important role in depressing the reactivity of antibiotics during photodegradation . Aiming at retarding this inhibition, an effective approach with idea of complexation replacement was proposed. This study indicated that interactions between antibiotics and heavy metals are very specific, and an appropriate treatment scheme should be given based on systematic study targeting at the specific pollution system.
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ACS Omega
·
2021
·
IF 3.512
Yuqing Zhao,Hang Yang,Jianfa Sun,Yi Zhang,Shibin Xia
In this study, the utilization of secondary pyrolysis oil-based drilling cuttings ash (OBDCA-sp) to activate peroxymonosulfate (PMS) for pollutant removal was investigated. The chemical and physical properties of OBDCA-sp were explicitly analyzed via multiple characterization. The activation efficiency of OBDCA-sp for PMS was tested using humic acid (HA) as the target pollutant. 92% of HA and 52% of total organic carbon in solution could be removed using OBDCA-sp-activated PMS under optimal conditions: OBDCA-sp dosage at 4 g/L, PMS concentration at 4 mmol/L, HA concentration at 10 mg/L, and pH value at 7. After four cycles, 84% removal rate of HA could still be achieved using OBDCA-sp to activate PMS. The main catalysis elements for PMS activation in OBDCA were postulated to be Fe(III), Co(III), and Mn(III), based on X-ray photoelectron spectroscopy and X-ray diffraction results. The results of the quenching experiment indicated that SO4•–, •OH, and 1O2 were the main reactive oxygen species (ROS) and that 1O2 was the dominant ROS in the HA removal process. Radical trapping experiments indicated the presence of SO4•–, •OH, and 1O2 in the reaction system. This study presented a novel utilization path of OBDCA in the field of environmental remediation.
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CHEMOSPHERE
·
2021
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IF 7.086
Yu Li,Yong Feng,Bin Yang,Zequn Yang,Kaimin Shih
The activation of persulfate by ferrous iron (Fe(II)) is of great interest to the environmental remediation community, but the reduction of ferric iron (Fe(III)) to Fe(II) is slow and the accumulation of iron sludge resulted from the precipitation of Fe(III) is a great concern. Here, molybdenum disulfide (MoS 2 ) was studied as a co-catalyst to improve the activation of peroxymonosulfate (PMS) by Fe(III) for sulfadiazine (SDZ) degradation and different characterization technologies were used to reveal the reactive species. The results showed that a strong synergy existed between MoS 2 and Fe(III); approximately 94.3% of the SDZ was removed by MoS 2 -Fe(III)-PMS after reaction for 30 min, while only 8.5% and 56.4% of the SDZ was removed by Fe(III)-PMS and MoS 2 -PMS, respectively. Both hydroxyl radicals and sulfate radicals were generated and the latter was the primary species. In addition to the radicals, singlet oxygen was found to be generated and contributed to the degradation of SDZ. The chemical probe reaction with methyl phenyl sulfoxide showed that the generation of high-valent iron-oxo species was not obvious by MoS 2 -Fe(III)-PMS under both acidic and neutral conditions. MoS 2 had good stability. No noticeable deactivation was observed during the 1st to 5th run and no obvious oxidation of surface Mo(IV) occurred. Based on the characterization of catalyst and oxidizing species, a mechanism for the activation of PMS by MoS 2 -Fe(III) was proposed. The results from this study are expected to clarify the reactive species and deepen the understanding of MoS 2 -promoted persulfate activation by Fe(II)/Fe(III).
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CARBOHYDRATE POLYMERS
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2021
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IF 9.381
Wentao Wang,Qicheng Zhang,Ming Zhang,Xintong Lv,Zihan Li,Mohsen Mohammadniaei,Ninglin Zhou,Yi Sun
Wound bacterial infections and tumor recurrence are the main reasons for the poor prognosis after primary tumor resection. Here, we fabricated a novel therapeutic nanocomposite using chitosan (CS) hydrogel combined with black phosphate nanosheets (BPNSs) and in situ grown copper nanoparticles (CuNPs). The obtained hydrogel ( [email protected] @CuNPs), possessing a remarkable temperature-sensitive spongy-like state, offered 24.98 % blood clotting index. The released [email protected] could produce reactive oxygen species (ROS) to kill infected invasive bacteria (98.1 %) and inhibit local residual tumor cell regeneration (11.3 %). Moreover, by coupling the photothermal properties of BPNSs , the [email protected] showed 19.6 % penetration rate to cross the blood tumor barrier (BTB) for treating brain tumors. The hydrogel platform was further combined with aPD-L1-based immunotherapy to employ its synergetic therapeutic effect in the prevention of tumors. The in vivo studies showed that biodegradable hydrogel could hold a great potential as a novel strategy for improving postoperative therapy and multi-tumor treatments.
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WATER RESEARCH
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2021
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IF 11.236
Lifa Ge,Yamei Yue,Wei Wang,Fatang Tan,Shenghua Zhang,Xinyun Wang,Xueliang Qiao,Po Keung Wong
Currently existing Fenton-like catalysts were limited in wastewater treatment owing to their potential transition-metal poisoning, narrow applicable pH range and high dependence on external energy excitation. In this work, the MgNCN/MgO nanocomposites were firstly synthesized by a facile one-pot calcination of melamine and basic magnesium carbonate, and used as novel H 2 O 2 activator for antibiotic removal. It was found that the MgNCN/MgO composite calcined at 550°C with the mass ratio of melamine to basic magnesium carbonate at 2:1, exhibited an excellent catalytic ability to tetracycline (TC) degradation in a wide pH range of 4-10 without any external energy input. More than 90% of TC (100 mL, 50 mg/L) could be degraded within 30 min by 10 mg of the nanocomposite in the presence of 0.2 mL of 30 wt% H 2 O 2 . Based on the experimental results, it was concluded that the Mg-N coordination between MgNCN and MgO in MgNCN/MgO nanocomposites activated H 2 O 2 to produce primary singlet oxygen ( 1 O 2 ) and minor hydroxyl radicals (·OH), responding for TC degradation. In addition, the degradation pathways of TC were deduced by determining the generated intermediates during the degradation process. This work provided a novel idea for designing transition-metal-free catalysts for nonradical activation of H 2 O 2 in the absence of external energy excitation.
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Journal of the Taiwan Institute of Chemical Engineers
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2021
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IF 5.876
Zichen Wang,Hongbin Li,Wei Ma,Yinglong Wang,Peizhe Cui,Jianguang Qi,Zhengrun Chen,Zhaoyou Zhu,Fanqing Meng
Peroxymonosulfate (PMS) activation have provided a new direction to eliminate the organic pollutant . Current challenges that must be solved include secondary pollution by the metal ions and limitation in the recyclability of the catalysts. The waste 1D-FeOOH adsorbent with adsorption of metal elements (As, Cr or Mo ions) has been reused as an efficient electro-catalyst for PMS activation and used to metronidazole (MTD) degradation for the first time. The effects of current density, initial reaction pH, stirring rate, PMS dosage and solution temperature on MTD degradation was studied. The used 1D-FeOOH with adsorption of Mo ions showed the highest PMS activation ability and 99.6% MTD could be removed after 30 min degradation. The •OH and Found that SO 4 •− is the main free radical for MTD degradation. DFT calculation and characterization results were demonstrated that the high PMS electro-catalysis activation ability of the 1D-FeOOH@Mo has resulted from the special composition-dependent interactions among FeOOH@Mo and PMS, including stable adsorption properties, easy electron transfer and weak O O bond. The possible PMS electro-catalysis activation mechanism and MTD degradation pathway have been proposed. (ECOSAR) was used to evaluate the toxicity of metronidazole during degradation. The results showed that the toxicity of MTD and its intermediates could be effectively reduced by prolonging the degradation time in 1D-FeOOH@Mo solution. This work provides new insights for waste adsorbent disposal and gives a new perspective for PMS activation to degradation of antibiotics in water.
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Catalysis Science & Technology
·
2021
·Vol. 11
·期 11
·3715-3723
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IF 6.119
Daoqing Liu,Qianwei Li,Jinbao Hou,Huazhang Zhao
The coexistence of aliovalent cations may facilitate the formation of electronic and ionic defects, altering the catalytic properties of manganese oxide. In this paper, a series of mixed-valent manganese oxides (MnOx) were prepared by a hydrothermal route and tested for heterogeneous activation of peroxydisulfate for Orange II degradation in aqueous solution. The morphology, crystal structure and surface chemistry of the MnOx were adjusted by the addition of ethanol in the hydrothermal process. The physicochemical properties were characterized and evidence from X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) indicated that MnOx exhibited a mixed crystal phase structure of Mn2O3, Mn3O4 and MnO2. The catalytic properties of the three samples prepared with 5%, 10%, and 20% volume fractions of ethanol (denoted as MnOx-5, MnOx-10, and MnOx-20) were found to be related to the valent states of Mn, and MnOx-10 exhibited a better performance with a mole ratio of Mn4+/ Mn2+ close to 1.0. The electrochemical characterization demonstrated that MnOx-10 performed a more effective redox process which may determine the catalytic activity of MnOx. Moreover, quenching tests, electron paramagnetic resonance (EPR) and gas chromatography-mass spectrometry (GC-MS) were used to evaluate the possible activation processes of peroxydisulfate (PDS) and the intermediates of Orange II degradation. This catalyst preparation strategy provides a new idea for the preparation of high-efficiency environmental catalysts.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Yang You,Zekai Shi,Yunhe Li,Zhuanjun Zhao,Bo He,Xiuwen Cheng
In this work, cost-effective peroxymonosulfate (PMS) was used as oxidants and magnetic cobalt ferrite biochar composite was used as catalyst to remove lomefloxacin hydrochloride (LFH), a new pollutant in water. PMS activation by CoFe 2 O 4 was promoted by compositing with biochar. The MBC/CoFe 2 O 4 /PMS system degraded 86.9% of LFH in 20 min. MBC/CoFe 2 O 4 measured by vibrating sample magnetometer (VSM) had good magnetic properties and was convenient for separation and recovery. Furthermore, the main active oxide species were determined by EPR measurement. The catalytic mechanism of MBC/CoFe 2 O 4 /PMS system was attributed to the generation of sulfate radicals (SO 4 ∙- ), hydroxyl radicals (∙OH), singlet oxygen ( 1 O 2 ) and superoxide radicals (∙O 2 – ) additionally, of which SO 4 ∙- played the leading role. Moreover, a possible degradation pathway of LFH was proposed. MBC/CoFe 2 O 4 /PMS system still had 85.7% LFH removal efficiency after five times of reuse. Thence, the MBC/CoFe 2 O 4 composite material might be a candidate for removing difficult pollutants in environmental remediation.
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CHEMOSPHERE
·
2021
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IF 7.086
Yong Chen,Junfeng Zhao,Lu Hu,Jing Tian,Yong Liu
Most metal-organic frameworks (MOFs) are synthesized from carboxylate and metal precursors by hydrothermal process, which will consume a large amount of solvent and carboxylate. To address this issue, a new strategy for Cu-based MOFs was developed, in which the Cu-based MOFs was obtained by using abundant natural polymer (tannic acid) as one of the precursors and using high-energy ball milling to achieve a self-assembly of tannic acid and copper sulfate. Based on this strategy, a novel Cu-based MOFs derivative (Cu x O@C composite) was synthesized by high-temperature sintering of Cu-based MOFs and used for sulfamerazine (SMR) removal via O 2 activation. The BET specific surface area and average pore size of Cu x O@C composite were 110.34 m 2 g −1 and 21.06 nm, respectively, which made Cu x O@C composite had the maximum adsorption capacity ( Q max ) for SMR of 104.65 mg g −1 and favored the subsequent degradation of SMR. The results from XRD and XPS indicated that Cu x O@C composite contained a lot of Cu 0 and Cu 2 O with the sizes of 76.6 nm and 9.8 nm, respectively, which led to its high performance of O 2 activation. The removal efficiency of SMR and 90.2% TOC achieved 100% and 90.2%, respectively in the Cu x O@C/air system at initial pH of 4.0, air flow rate of 100 mL min −1 , Cu x O@C dosage of 1 g L −1 and reaction time of 30 min. Reactive species, including H 2 O 2 , OH and O 2 - radicals were detected in the Cu x O@C/air system, and OH and O 2 - were mainly responsible for the degradation of SMR.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Jun Cao,Qing Sun,Ai-Guo Shen,Bing Fan,Ji-Ming Hu
Killing harmful bacteria in biofilms is a major challenge for current root canal therapy. Although traditional chemical disinfectants have a good bactericidal effect on plankton, they have little efficiency for the removal and sterilization of bacterial biofilms, and even lead to the emergence of bacterial resistance and high toxic side effects. Herein, we propose for the first time biosafe nanocomposites that integrate photothermal and peroxidase-like catalytic activity for efficient removal and killing of bacterial biofilms in root canals. The integration of gold (core) and copper (Ⅰ, Ⅱ) sulfide (shell) shows excellent catalytic effect, which can catalyze the decomposition of hydrogen peroxide at biosafe concentrations to hydroxyl radicals for efficient removal of biofilms. Moreover, studies on the mechanism of antibiofilm showed that the nanocomposites ( [email protected] 2-x S) have significant degradation effects on proteins and polysaccharides-the main components of biofilm. The in vitro results indicated that the synergism of free radical and heat shows higher sterilization rate against both gram-positive Enterococcus faecalis and gram-negative Fusobacterium nucleus , compared with free radical and heat treatment alone. More importantly, the bactericidal results on isolated dental slices and in root canal models and beagle dog demonstrated the [email protected] 2-x S is highly effective in inactivating the bacteria in biofilms. Hence this safe and synergistic antimicrobial system has great potential in antibiofilm-oriented root canal therapy.
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