摘要：
Single-atom catalysts have wide application prospects in peroxydisulfate (PDS)-based advanced oxidation process to degrade organic pollutants, but its catalytic performance is limited due to its cost, Metal-N coordination number, and single-atom loading amount. Herein, a novel nitrogen doped algal-based carbon confined singleatom copper catalyst (Cu-N/C-SAC((S))) was synthesized using molten salt assisted pyrolysis and coupling with PDS to degrade tetracycline (TC). AC-HAADF-STEM and XAFS analysis proved that single atom Cu was loaded (Content 1.9 %) successfully and coordinated with two N and two C. XPS and XANES spectra analysis suggested that Cu atoms mainly existed in a positive divalent state in Cu-N/C-SAC(S). When the catalyst dosage of Cu-N/CSAC((S)) was 0.1 g/L, TC was almost completely removed. Moreover, Cu-N/C-SAC(S) had a broad pH adaptation range and strong ability against interference. Singlet oxygen (O-1(2)), superoxide radicals (center dot O-2(-)), and electron transfer had an important contribution for TC removal. DFT calculations confirmed that the activation process of Cu-N/C-SAC((S)) producing SO4 center dot- was easier than the nitrogen doped blue-green algal-based carbon (N-BGAC). In addition, Cu-N/C-SAC((S)) possessed good recyclability and stability. The main degradation pathways of TC were analyzed, and the toxicity of the intermediates was calculated. This study provides a new solution strategy for the resource utilization of waste biomass, and provides technical support and theoretical guidance for the efficient application of single-atom catalysts in organic wastewater.
期刊：
Journal of Hazardous Materials,2023年441:129974 ISSN：0304-3894
通讯作者：
Haiyin Xu
作者机构：
[Xu, Haiyin; Luo, Yuanling] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Zhao, Xiaojing; Xu, Haiyin; Wang, Ping; Yang, Yi] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Luo, Yuanling] Changsha Environm Protect Coll, Changsha 410004, Peoples R China.;[Xie, Huaming; Zhou, Changsheng; Wang, Chuan] Pan China Construction Grp Co Ltd, Changsha 410004, Peoples R China.;[Liu, Zhiming] Eastern New Mex Univ, Dept Biol, Portales, NM 88130 USA.
通讯机构：
[Haiyin Xu] C;College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
摘要：
Wastewater treatment plant (WWTP) has great potential to regulate microplastics (MPs) emissions, but few studies have focused on this subject. The present study performed a long-term investigation in a typically combined sewers WWTP. Compared to dry weather, rainfall contributed approximately 1.5 times more MPs to the inlet of the combined WWTP. The equalization tank served as a primary site for MPs' removal, with a 46.67-87.91 % removal rate. Decreasing surface overflow rate (SOR) was an effective measure for improving MPs removal, and a suitable SOR was recommended at similar to 11 m(3) (d.m(2))(-1)) in the equalization tank. However, MPs' existing settling/rising velocity models failed to obtain a theoretical SOR. In cyclic activated sludge systems, reducing sludge wastage was proposed to facilitate the removal of MPs. As a result, outlet MPs could be reduced by an order of magnitude by adjusting operational parameters on rainy days. Our study highlighted the potential for WWTP to operate as a controlled source of MPs by altering the operational parameters. We also advocated exploiting the mechanisms of MPs' removal by operational parameters and finding an equilibrium between MPs' removal and activated sludge performance.
关键词：
Nitrogen and sulfur co-doped;Persulfate;Porous carbons;Thiamethoxam
摘要：
Nitrogen and sulfur co-doped porous biochar (NSBC) was synthesized through the pyrolysis of Phytolacca aci-nose Roxb biomass in the presence of sodium bicarbonate and L-cysteine monohydrochloride. The resulting NSBC exhibited exceptional adsorption and catalytic degradation properties, demonstrating remarkable effi-ciency in the oxidation and degradation of thiamethoxam (THM) solutions. To elucidate the underlying oxidation mechanism, a combination of radical quenching techniques and advanced in situ electron paramagnetic reso-nance (EPR) spectroscopy was employed. The experimental findings revealed that the enhanced oxidation ef-ficiency observed in the NSBC+PS system could be attributed to the synergistic interaction between singlet oxygen (1O2) and Reactive Oxygen Species (ROS). The introduction of nitrogen and sulfur doped facilitated the formation of point defects, which in turn promoted the generation of 1O2. Furthermore, the degradation path-ways of THM intermediates were successfully elucidated. This study presents a novel approach for the synthesis and application of high-quality catalysts in water treatment.
期刊：
Journal of Environmental Chemical Engineering,2023年11(3):109704 ISSN：2213-3437
通讯作者：
Meifang Li<&wdkj&>Ping Wang
作者机构：
College of Environmental Science and Engineering, Central South University of Forestry and Technology, Shaoshan South Road, Tianxin, Changsha 410004, PR China;Faculty of Life Science and Technology, Central South University of Forestry and Technology, Shaoshan South Road, Tianxin, Changsha 410004, PR China;[Wu, Shaohua] Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, Key Laboratory of Petrochemical Pollution Control of Guangdong Higher Education Institutes, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, PR China;College of Environmental Science and Engineering, Hunan University, Lushan South Road, Yuelu, Changsha 410082, PR China;Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Lushan South Road, Yuelu, Changsha 410082, PR China
通讯机构：
[Meifang Li; Ping Wang] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Shaoshan South Road, Tianxin, Changsha 410004, PR China<&wdkj&>Faculty of Life Science and Technology, Central South University of Forestry and Technology, Shaoshan South Road, Tianxin, Changsha 410004, PR China
摘要：
Tetracycline (TCN) is a typical antibiotic with ecological toxicity, which is easy to cause bacterial drug resistance. Single-atom catalysts have a broad application prospect in the remediation of antibiotic polluted water by activated persulfate (PDS), but its catalytic properties are limited because of its high surface energy and easy aggregation. Therefore, in our manuscript, a novel nitrogen doped magnetic graphene oxide confined Fe-Co dual single-atom catalyst (Fe/Co(1:1)(S)-NMGO) was prepared by one-step molten salt assisted high temperature pyrolysis. XPS and AC-HAADF-STEM analysis indicated single-atom Fe and Co existed. Fe and Co atoms were bound to the material mainly through coordination with pyridinic N and pyrrolic N. While single-atom Fe and Co were simultaneously introduced into the modified materials, the removal rate of TCN reached 93.1%, implying the significant synergistic effect of single-atom Fe and Co on TCN removal. Molten salt assisted high-temperature pyrolysis significantly improved the TCN degradation rate. In addition, this research showed that the existence of magnetite nanoparticles was beneficial to improve the separation performance of the single-atom catalysts as well as the catalytic performance. At the same time, the effects of some key parameters (Fe/Co molar ratio, catalyst dosage, PDS dosage, initial pH, coexisting anions and humic acids) on TCN degradation in Fe/Co(1:1)(S)-NMGO/PDS system were also investigated. The catalytic potential in actual water and regeneration performance of the material were also evaluated. The possible activation mechanism and degradation pathway of TCN were proposed. These findings will provide important reference for the future design and application of single-atom-involved catalysts.
作者机构：
[Liu, Yuwei; Lin, Baining; Luo, Lukai; Liu, Hongyang; Zhou, Yonghua] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Wang, Hanqing; Wang, Ping; Mao, Yu] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Hunan Engn Res Ctr Full Life Cycle Energy Efficien, Changsha 410004, Peoples R China.
关键词：
boron defects;direct dehydrogenation of ethylbenzene;metal-free catalysis;phosphorus doped boron nitride;styrene
摘要：
Ethylbenzene dehydrogenation: The m‐PBN with the optimal concentration of B defects improved the styrene production rate to 22.54 mmolST g−1 h−1. Meanwhile, when it was further in‐situ grown on Al2O3, the styrene production rate increased to 23.22 mmolST g−1 h−1 and stably run for more than 300 h. Abstract Phosphorus‐doped boron nitride (PBN) has been confirmed as an effective metal‐free catalyst for the direct dehydrogenation (DDH) of ethylbenzene to styrene. In this paper, we further used barbituric acid as co‐reactant sources to create B defects in both PBN and mesoporous PBN (m‐PBN) materials. The XPS, N2 adsorption‐desorption, UV‐vis DRS, EPR, 11B SS NMR characterizations indicated both the electronic and pore structures of the catalyst with B defects were adjusted. Except for the improvement of mass transfer caused by B defects, DFT calculations showed the increase of electron density in B defects areas could enhance the breaking of C−H in ethylbenzene and the bond‐forming of H−H, which was acted to improve the catalytic activity. The m‐PBN with B defects delivered the styrene production rate of 22.54 mmolST g−1 h−1 and stably run 300 h when in‐situ grown on Al2O3, proving that defect tuning strategy is useful to construct efficient catalysts for styrene production.
作者机构：
[Huang, Chenxi; Cao, Jingxiao; Li, Meifang; Wang, Ping] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Shaoshan South Rd, Changsha 410004, Peoples R China.;[Huang, Chenxi; Cao, Jingxiao; Li, Meifang; Wang, Ping] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Peoples R China.;[Liu, Yunguo; Tan, Xiaofei] Hunan Univ, Coll Environm Sci & Engn, Lushan South Rd, Changsha 410082, Hunan, Peoples R China.;[Liu, Yunguo; Tan, Xiaofei] Hunan Univ, Key Lab Environm Biol & Pollut Control, Minist Educ, Lushan South Rd, Changsha 410082, Hunan, Peoples R China.;[Liu, Shaobo] Cent South Univ, Sch Architecture & Art, Lushan South Rd, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Wang, Ping] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Tianxin District, Changsha, People’s Republic of China<&wdkj&>Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, People’s Republic of China
摘要：
Humic acids (HAs) widely exist in water environment, and has an important impact on the adsorption of pollutants. Herein, HAs (both dissolved and coated) was employed to assess the effect on the removal of the organic contaminant tetracycline (TC) by K2CO3 modified magnetic biochar (KMBC). Results showed that low concentration of dissolved HAs promoted TC removal, likely due to a bridging effect, while higher concentration of dissolved HAs inhibited TC adsorption because of the competition of adsorption sites on KMBC. By characterization analysis, coated HAs changed the surface and pore characteristics of KMBC, which suppressed the TC removal. In a sequential adsorption experiment involving dissolved HAs and TC, the addition of HAs at the end of the experiment led to the formation of HAs-TC ligands with free TC, which improved the adsorption capacity of TC. TC adsorption by KMBC in the presence of dissolved HAs and coated HAs showed a downward trend with increasing pH from 5.0 to 10.0. The TC adsorption process was favorable and endothermic, and could be better simulated by pseudo-second-order kinetics and Freundlich isotherm model. Hydrogen bonds and pi-pi interactions were hypothesized to be the underlying influencing mechanisms.
摘要：
Cadmium (Cd) pollution is a widespread environmental problem. In this study, we explored the transcriptome and biochemical responses of goldenrain tree (Koelreuteria paniculata Laxm.) leaves and roots to Cd stress. Leaf and root growth decreased substantially under Cd stress (50 mg/L CdCl2), but leaf and root antioxidant mechanisms were significantly activated. In RNA-seq analysis, roots treated with 25 mg/L CdCl2 featured enriched GO terms in cellular components related to intracellular ribonucleoprotein complex, ribonucleoprotein complex, and macromolecular complex. In leaves under Cd stress, most differentially expressed genes were enriched in the cellular component terms intrinsic component of membrane and membrane part. Weighted gene co-expression network analysis and analysis of module-trait relations revealed candidate genes associated with superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and malondialdehyde (MDA). Ten transcription factors responded to Cd stress expression, including those in C2H2, MYB, WRKY, and bZIP families. Transcriptomic analysis of goldenrain tree revealed that Cd stress rapidly induced the intracellular ribonucleoprotein complex in the roots and the intrinsic component of membrane in the leaves. The results also indicate directions for further analyses of molecular mechanisms of Cd tolerance and accumulation in goldenrain tree.
期刊：
International Journal of Environmental Research and Public Health,2020年17(18) ISSN：1661-7827
通讯作者：
Wang, Ping;Liu, Yunguo
作者机构：
[Hu, Xinjiang; Wang, Hui; Zhou, Yiming; Wang, Ping] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Hu, Xinjiang; Wang, Hui; Zhou, Yiming; Wang, Ping] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.;[Guo, Yuan; Liu, Chunjie] Chinese Acad Agr Sci, Inst Bast Fiber Crops, Changsha 410205, Hunan, Peoples R China.;[Cai, Xiaoxi] Hunan First Normal Univ, Coll Art & Design, Changsha 410205, Hunan, Peoples R China.;[Liu, Yunguo] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Wang, Ping] C;[Liu, Yunguo] H;Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.;Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.
关键词：
magnetic graphene oxide;removal;cadmium;fractional factorial design;optimization
摘要：
Graphene materials have attracted increasing interest in water remediation. In this study, magnetic graphene oxide (MGO) was prepared through the modified Hummers method and the adsorption behaviors of cadmium were investigated. Firstly, the sorption kinetics, isotherms, as well as the effects of pH were investigated. Then, fractional factorial design (FFD) was used to optimize the effects of pH, temperature, time, initial concentration of cadmium ion and NaCl on cadmium adsorption. The results indicate that MGO could effectively remove cadmium ions from an aqueous solution and the sorption data could be described well by pseudo-second-order and Freundlich models, showing that the adsorption rate of cadmium ions on MGO is multilayer adsorption and dominated by the chemical adsorption. According to the FFD results, the maximum adsorption capacity of cadmium ions was 13.169 mg/g under the optimum condition of pH value 8, 45 degrees C, contact time 60 min, initial cadmium concentration of 70 mg/L and NaCl concentration of 100 mg/L. Higher levels of the pH value, temperature and initial cadmium concentration are beneficial to the adsorption process. These results are important for estimating and optimizing the removal of metal ions by MGO composite.
关键词：
Elaeagnusangustifolia L. Gum;Porous Carbon;Electrochemical Analysis;Chloramphenicol
摘要：
In this study, the method for detection of chloramphenicol was investigated by electrochemical sensor; the sensor was constructed by biomass derived porous carbon. At first, porous carbon doped with hetroatoms (nitrogen, sulfur, phosphorus) was synthesized based on the use of pyrolysis and high temperature carbonization methods. Elaeagnusangustifolia L. gum was used as the carbon source in the facile template-free process. The biomass derived porous carbon was then used as the active electrode material for antibiotic sensing. The chemically modified electrodes properties were studied with the cyclic voltammetry and differential pulse voltammetry methods. The effects of the scan rate, accumulation time and pH, were carefully considered. Comparison with other working electrodes at the optimized conditions indicated that the N, S, P triple doped porous carbon modified glassy carbon electrode appeared a well-defined reduction peak towards chloramphenicol. The linear concentration response of chloramphenicol ranged from 1 to 40 mu M (R = 0.9903) and 50 to 500 mu M (R = 0.9923), and a low detection limit of 0.01 mu M (S/N = 3). Furthermore, the constructed novel electrochemical sensor was used for detection of chloramphenicol in real samples and achieved satisfactory recovers.
摘要：
A hydroxyl-functionalized magnetic fungus nanocomposite (MFH@GO) was prepared by a simple one-pot method for the removal of Cr(VI) from wastewater. The adsorption behavior of MFH@GO to Cr(VI) in wastewater was discussed in detail. At pH of 5.0 and temperature of 323.15 K, MFH@GO had higher adsorption capacity to Cr(VI) (58.4 mg/g) than the unmodified fungus and GO. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry and differential thermal analysis (TG-DTA), scanning electron microscopy and energy dispersive X-Ray spectroscopy (SEM-EDX) were employed to determine the characteristics of MFH@GO. Results showed that magnetic graphene oxide nanoparticles significantly enhanced the physiochemical properties of the fungi. In addition, the adsorption mechanisms analyses show that Cr(VI) could be reduced and mineralized into ferric chromate in residues. These results suggested that MFH@GO could be used as an promising and alternative biosorbent for removal of Cr(VI) from industrial wastewater.
摘要：
A highly efficient inverse-opal structured BiVO4/WO3 photoanode and a MnO2/graphene oxide (GO) nanocomposite modified cathode were successfully synthesized in this paper. The optimized BiVO4/WO3 inverse opal photoanode achieved a photocurrent density of similar to 5.04 mA/cm(2) at 1.2 V vs. Ag/AgCl under simulated AM 1.5 illumination, which was 2.84 and 2.36 times higher than that of WO(3 )inverse opal photoanode and BiVO4/WO3 nanoflake photoanode, respectively. The BiVO4/WO3 inverse opal photoanode was coupled with the MnO2/GO modified cathode to build up a novel visible-light responsive photocatalytic fuel cell (PFC) system. The as-established PFC showed outstanding power production performances in comparison with the PFC equipped with a bare MnO2 modified cathode. For example, in the former PFC system, the maximum power density and the short circuit current density were similar to 66.2 mu W/cm(2) and similar to 593.5 mu/cm(2), respectively, for comparison, in the latter PFC, the values were similar to 30.1 mu W/cm(2) and similar to 255.9 mu A/cm(2), respectively. The degradation experiment for Rhodamine B confirmed successful application of the as-established PFC in pollutant degradation. The mechanism for the significantly enhanced photoelectrocatalytic performances of the PFC was elucidated. The PFC system presented in this paper opened up a new prototype in developing highly efficient devices for energy conversion and environmental protection. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
摘要：
The authors describe a method for synthesis of a nanomaterial consisting of porous carbon encapsulated Mg-Al-Si alloy (denoted as Mg-Al-Si@PC) nanocluster. The nanocluster was synthesis by a solvothermal reaction, followed by high-temperature annealing. The nanoclusters were used as a novel immobilization platform for electrochemical sensing of rutin. The electrochemical behavior of rutin at a modified electrode was investigated by cyclic voltammetry and differential pulse voltammetry. The modified electrode demonstrates a high electrocatalytic activity toward rutin oxidation at a relatively low working potential (0.6 vs. Ag/AgCl). Under optimal conditions, the sensor has a linear response in the 1-10 muM rutin concentration range, and a 0.01 muM lower detection limit (at an S/N ratio of 3). It was successfully applied to the quantification of rutin in pharmaceutical tablets, and satisfactory results were obtained. Furthermore, the results correspond with those with the standard method and with the amounts indicated by the producer, respectively. Graphical abstract Schematic diagram of the Mg-Al-Si@PC nanocluster preparation process and electroanalysis mechanism.
摘要：
Biomass-derived N, S, P-triple-doped porous carbon materials are widely considered as one of the most promising electrode materials for electrochemical detection of pharmaceutical compounds and food analysis. In this regard, we have prepared Elaeagnus gum-derived porous carbon electrodes for use in the simple electrochemical detection of metronidazole. Heteroatom (nitrogen, sulfur, phosphorus) triple-doped functionalized porous carbon synthesized based on the use of simple pyrolysis and high temperature carbonization methods without any hard templates, and was then characterized by several methods, such as scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The electro-analytical performance of the proposed NSP-PC modified electrode was assessed by electro-analytical technique, such as cyclic voltammetry, linear sweep voltammetry. The results indicate that under optimized conditions, this novel constructed sensor shows excellent electrochemical properties toward metronidazole determination. The metronidazole reduction process has two linear dynamic ranges from 0.1 to 45 mu M and 50 to 350 mu M and a low detection limit of 0.013 mu M. The constructed sensor was successfully applied for detect of metronidazole in pharmaceutical, milk samples, where it also yielded acceptable results. (C) 2019 The Electrochemical Society.
