摘要：
In this study, the manganese oxide/biochar composites (Mn@BC) were synthesized from Phytolacca acinosa Roxb. The Mn@BC was analyzed via techniques of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). The results show that MnO(x) is successfully loaded on the surface of BC, and the load of MnO(x) can increase the number of surface functional groups of BC. X-ray photoelectron spectroscopy (XPS) shows that MnO(x) loaded on BC mainly exists in three valence forms: Mn(Ⅱ), Mn(Ⅲ), and Mn(Ⅳ). The ability of Mn@BC to activate periodate (PI) was studied by simulating the degradation of methylene blue (MB) dye. The degradation experiment results showed that the MB removal rate by the Mn@BC/PI system reached 97.4% within 30min. The quenching experiment and electron paramagnetic resonance (EPR) analysis confirmed that Mn@BC can activate PI to produce iodate (IO(3)•), singlet oxygen ((1)O(2)), and hydroxyl radical (•OH), which can degrade MB during the reaction. Response surface methodology (RSM) based on Box-Behnken Design (BBD) was used to determine the interaction between pH, Mn@BC and PI concentration in the Mn@BC/PI system, and the optimum technological parameters were determined. When pH=5.4, Mn@BC concentration 0.56mg/L, PI concentration 1.1mmol/L, MB removal rate can reach 98.05%. The cyclic experiments show that Mn@BC can be reused. After four consecutive runs, the removal rate of MB by the Mn@BC/PI system is still 82%, and the Mn@BC/PI system also shows high performance in treating MB in actual water bodies and degrading other pollutants. This study provides a practical method for degrading dyes in natural sewage.
摘要：
Cadmium (Cd) pollution in aqueous solution has caused great threat to human health. A novel chitosan and biochar supported sulfide-modified nZVI composite (CB-S-nZVI) was synthesized by liquid phase reduction method and applied to the removal of Cd2+ from wastewater. The synthesized materials were characterized by SEM, BET, XRD, FTIR, and zeta potential. Batch experiments showed that the optimum synthesis conditions of CB-S-nZVI were the S/Fe molar ratio of 0.56 and the Fe/BC mass ratio of 2. The removal capacity of Cd2+ by CB-S-nZVI increased with the increase of pH and reached the maximum of 249.92 mg/g at pH of 9. Among the competitive cations, Pb2+ and Cu(2+ )had a strong inhibition to the removal ofCd(2+). The removal process of Cd2+ conformed to the pseudo-second-order kinetic model and the Freundlich model, and it was exothermic. XPS analysis suggested that the removal mechanism of Cd2+ was mainly through electrostatic attraction, precipitation, and complexation. Overall, these findings provide new insights into the development of new nZVI-modified material, and CB-S-nZVI is promising in removing heavy metals from wastewater.
期刊：
Separation and Purification Technology,2023年326:124842 ISSN：1383-5866
通讯作者：
Wang, Hui;Hu, XJ
作者机构：
[Hu, Xi; Jiang, Honghui; Hu, Zhenxin; Ouyang, Yuanhao; Hu, Xinjiang; Ouyang, Ke; Wang, Hui; Ji, Xiaodong; Wang, Ping] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Li, Tingting] Liaocheng Univ, Coll Environm & Planning, Liaocheng 252059, Peoples R China.;[Wang, Hui; Hu, Xinjiang] Cent South Univ Forestry & Technol, Changsha, Peoples R China.
通讯机构：
[Wang, H; Hu, XJ ] C;Cent South Univ Forestry & Technol, Changsha, Peoples R China.
关键词：
Biochar;Peroxymonosulfate;Thiamethoxam;Cadmium sulfide;Density functional theory calculation
摘要：
Mounting evidence highlights the negative impacts of thiamethoxam (THM) on non-target organisms and ecosystem. Herein, multi-phase cadmium sulfide loaded on biochar (CdS@BC) was used to photocatalytic activate peroxymonosulfate (PMS) to remove THM. The obtained CdS@BC significantly improved the photocatalytic performance of PMS on THM degradation with a superior rate constant of 0.165 min-1, 60 times more than that of BC. In addition, the catalyst displayed excellent stability and reusability. The mechanism of free radical formation by adsorption activation of PMS adsorbed on CdS@BC was characterized using active species detection and Density functional theory (DFT) calculations. According to the DFT study, the phase junction and & pi;-conjugated structure contribute to the stable migration of & pi;-electrons, thus effectively activating the PMS to produce active substances for the degradation of THM. The findings provide a theoretical basis for the design and synthesis of effective catalysts for AOPs to remove emerging organic contaminants from wastewater.
摘要：
Abstract: The COVID-19 epidemic has changed people’s life manners and also impacted the thinking ways of college students greatly. Nowadays, people have a new understanding of ecological civilization. Students majoring in environmental engineering, environmental science and other related majors with professional knowledge of environmental remediation have more ability to make suggestions for environmental protection. When teaching professional knowledge, vivid examples of the epidemic should be highlighted, and the ideological and political elements such as patriotism, social responsibility and benevolence should also be integrated, so that the specialized knowledge would be more valuable. “Environmental engineering microbiology” was taken as an example of the professional basic course in environment engineering and the related majors in this paper. In order to achieve better teaching effect and moral cultivation, digging ideological education resources, strengthening political education in practice course, highlighting the typical cases and paying attention to students’ feedback were discussed.#@#@#摘要: 新冠疫情改变了人们的生活方式，也给当今大学生的思想带来了极大的冲击。现如今，人们对于生态文明教育有了新的思考和认识。有着专业环保知识的环境工程、环境科学等相关专业学生对于环境保护有着更多建言献策的能力。在课程专业知识传授中突显此次疫情中的鲜活典型，融入家国情怀、社会责任、仁爱之心等思政元素，将使得知识传播在价值引领下大放异彩。本文以《环境工程微生物学》这门环境类专业基础课程为例，从挖掘专业知识中蕴含的思政教育资源、强化实践课程中体现的思政教育价值、以案例为载体开展启发式教学和注重学生反馈、避开“课程思政”误区四个方面进行探讨，以期达到更好的教书育人效果。
摘要：
The chitosan-stabilized biochar supported S-nZVI (CS@BC/S-nZVI) composite with low aggregation and superior antioxidation were successfully synthesized by liquid-phase reduction method for the outstanding removal of Cr (VI) from wastewater and characterized by SEM, BET, FTIR, XRD, and XPS. The optimized synthesis parameters of CS@BC/S-nZVI were determined as a 0.14 molar ratio of S/Fe and a 0.25 mass ratio of BC/Fe. The CS@BC/SnZVI possessed a specific surface area of 199.246 m2/g and an average pore size and pore volume of 1.186 nm and 0.272 cc/g. The CS@BC/S-nZVI could remain reductive activity after Cr(VI) removal and present a remarkable tolerance to the coexisting ions during Cr(VI) removal. The adsorption data were fitted well by the pseudo-second order model and the Langmuir model. The removal of Cr(VI) by CS@BC/S-nZVI was an exothermic process with prominent Cr(VI) removal capacities of 244.07 mg/g at 120 min and 221.84 mg/g at 15 min at 25 celcius. Further mechanism analysis proved that the binding of Cr(VI) to CS@BC/S-nZVI was mainly a synergistic effect of reduction and electrostatic attraction. Overall, these findings shed new light on the research of a novel S-nZVI compound and revealed the potential practical application of CS@BC/S-nZVI in the future heavy metal removal from wastewater.
摘要：
Cr(VI) contamination has posed great threat to both the ecosystem and human health for its carcinogenic and mutagenic nature. A highly effective adsorbent for the removal of Cr(VI) was prepared and its adsorption mechanism was thoroughly discussed in this study. In detail, magnetic BiFeO3 and kenaf biochar were loaded on cross-linked chitosan to obtain chitosan-kenaf biochar@BiFeO3 (CKB) for improving adsorption capacity towards Cr(VI). The adsorption process of Cr(VI) onto CKB was evaluated as a function of the pH, the existence of competing ions, the initial concentration of Cr(VI) and contact time. The results show that CKB exhibits the highest adsorption capacity under the optimal pH 2.0. The presence of competing ions such as Ca(2+), NO3(-), SO4(2-), and Cl(-) decreases the adsorption capacity; among them, Ca(2+) and NO3(-) show the greatest hindrance. By studying the effect of initial Cr(VI) concentration on the adsorption capacity, it was found that CKB in the solution was enough to remove Cr(VI) for all treatments (10-200 mg/L). The adsorption experimental data were well fitted with pseudo-first-order model, suggesting that chemisorption is not the dominant rate-limiting step. Freundlich isotherm model can better explain the adsorption process, indicating a non-ideal adsorption towards Cr(VI) on a heterogeneous surface of CKB. A 2(5-1) Fractional Factorial Design (FFD) showed that pH and initial concentration of Cr(VI) have significant influence on Cr(VI) adsorption in our reaction system. In general, excellent adsorption efficiency of CKB indicates that it may be a good candidate for the remediation of Cr(VI)-contaminating wastewater.
通讯机构：
[Wang, Hui; Zhao, Yunlin] C;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.
关键词：
g-C3N4 nanosheets;BiFeO3;Cr(VI) photoreduction;Heterojunction;Electrolyte ion
摘要：
A novel ternary composite of graphitic carbon nitride (g-C3N4)/graphene oxide (GO) sheets/BiFeO3 (CNGB) with highly enhanced visible-light photocatalytic activity toward Cr(Vl) photoreduction is prepared and characterized. The characterization and photocatalysis experiments corroborate its reasonable band gap, efficient charge separation and transfer, widened visible-light adsorption, easy solid-liquid separation, good stability and superior catalytic activity of CNGB. Three CNGB samples with different ratios of g-C3N4 and BiFeO3 (CNGB-1, -2, -3 with 2:4, 3:3, and 4:2, respectively), though possessing different adsorption ability, eventually remove all Cr(Vl) ions via photocatalysis within 90 min. The catalytic efficiency of the composite is the highest at pH 2; increases in pH decrease the catalytic ability. The inorganic anions such as SO4-, Cl-, and NO3- only slightly affects the photocatalytic process. The matching of the band structure between BiFeO3 and g-C3N4 generates efficient photogenerated electron migration from the conduction band of g-C3N4 to that of BiFeO3, which is also facilitated by the electron bridging and collecting effects of GO, and holes transfer from the valence band of BiFeO3 to that of g-C3N4, yielding the efficient separation of photogenerated electron-hole pairs and the subsequent enhancement of photocatalytic activity. The research provides a theoretical basis and technical support for the development of photocatalytic technologies for effective application in wastewater treatment and Cr-contaminated water restoration. (C) 2018 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：
A novel graphene oxide supported activated magnetic biochar (GO-AMBC) is fabricated for 17 beta-estradiol (E2) removal from aqueous solution by grafting graphene oxide (GO) and magnetite nanoparticles onto the activated biochar surface with a one-step activation, magnetization, and carbonization method. GO-AMBC is characterized using SEM, TEM, FTIR, VSM, XRD, XPS, BET surface area and zeta potential measurements. The characterization results show that GO-AMBC possesses a larger surface area and more oxygen-containing functional groups than the unmodified biochar. When the E2 initial concentration is 6 mg/L, its adsorption capacity by GO-AMBC (46.22 mg/g) is more than two times higher than that of pristine biochar (23.09 mg/g) at 298 K and pH = 7.0. Adsorption results show that E2 uptake follows by pseudo-second-order kinetic and Freundlich isothermal models. Thermodynamic analysis indicates that the adsorption process is spontaneous and exothermic. E2 removal by GO-AMBC is significantly affected by the actual water conditions, including solution pH, ionic strength, and organic acids. Among them, organic acids have obvious inhibition effect on E2 removal, and the inhibition effect by oxalate is stronger than that of benzoate. The adsorption mechanism of E2 on GO-AMBC is mainly controlled by hydrogen bonds, electrostatic and pi-pi interactions. The experimental results of this study and comparative analysis with other adsorbents suggest that GO-AMBC is an economical, efficient and recyclable adsorbent and has great potential for E2 removal from contaminated water. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
