CHEMICAL ENGINEERING JOURNAL
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2014
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IF 4.058
Deyong Kong,Bin Liang,Hui Yun,Jincai Ma,Zhiling Li,Aijie Wang,Nanqi Ren
Antibiotics existing in wastewaters must be degraded to eliminate its antibacterial activity before discharging into the environment. Electrochemical reduction by continuous electrons supply can degrade various refractory pollutants, however, the information about the feasibility and characterization of the cathodic degradation of nitrofurans antibiotic furazolidone (FZD) is scarce. Here, we investigated the degradation of FZD using a poised cathode electrochemical reactor. The cyclic voltammetry (CV) preliminarily proved the feasibility of FZD degradation on cathode. In contrast to the different buffer solutions concentrations, buffer types, and initial FZD concentrations which only had obvious impact on the FZD degradation efficiency, different cathode potentials had significant effects both on the FZD degradation efficiency and degradation products composition. Catholyte PBS could be replaced by Na 2 CO 3 –NaHCO 3 and NaCl buffer solution for the FZD degradation. The cathodic degradation pathway of FZD was proposed based on intermediate products analysis. When the cathode potential was lower than −0.75 V, both the furan ring and oxazole ring of FZD were destroyed to generate linear chain products after N–N bond disconnection, suggesting that the high toxic biological metabolite of FZD, 3-amino-2-oxazolidinone (AOZ) could be detoxified by cathodic degradation. This study suggests that the electrochemical reduction could serve as a potential strategy for the treatment of FZD and AOZ containing wastewater.
研究领域:
环境科学
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微生物学
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毒理学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2024
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IF 8.3
Qinfeng Rong,Xianlan Chen,Shuying Li,Sijing He
Previous research on covalent organic framework (COF)-based photocatalytic H2O2 synthesis from oxygen reduction focuses more on charge carrier separation but less on the electron utilization efficiency of O2. Herein, we put forward a facile approach to simultaneously promote charge separation and tailor the oxygen reduction pathway by introducing phosphotungstic acid (PTA) into the cationic COF skeleton. Experiments verified that PTA, as an electron transport medium, establishes a fast electron transfer channel from the COF semiconductor conductor band to the substrate O2; meanwhile, the reaction path is optimized by its catalytic cycle for preferable dioxygen capture and reduction in oxygen reduction reaction (ORR) kinetics. The existence of PTA promotes the rate and tendency of converting O2 into •O2– intermediates, which is conducive to boosting the photocatalytic activity and selectivity toward the sequential two-step single-electron ORR. As expected, compared to the pristine TTB-EB, the optimal PTA0.5@TTB-EB achieves a 2.2-fold improvement of visible-light-driven photocatalytic performance with a H2O2 production rate of 897.94 μmol·L–1·h–1 in pure water without using any sacrificial agents. In addition, owing to the robust electrostatic interaction and the confinement effect of porous TTB-EB channels, the PTA@TTB-EB composite possessed favorable stability.
研究领域:
材料科学
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催化化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
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2018
·Vol. 10
·期 16
·1895-1901
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IF 2.073
Jiawei Li,Pan Li,Minghong Bian,Danqun Huo,Changjun Hou,Hui Qin,Suyi Zhang,Liang Zhang
Cu2+ plays an important role in various fundamental physiological processes in organisms. Although Cu2+ probes have been developed, little research has focused on using a direct redox route to quench fluorescence for Cu2+ detection. Herein, a simple, label-free, cost-effective, and sensitive fluorescence method has been developed for Cu2+ detection. In the absence of Cu2+ and presence of NH3+ and SCN−, H2O2 was employed as an oxidant to corrode BSA–Au NCs, resulting in the disappearance of fluorescence. In contrast, in the presence of Cu2+, red fluorescence was maintained because Cu(NH3)62+ can decompose H2O2. Under optimal conditions, good linear correlation between the fluorescent response and Cu2+ concentrations ranging from 5 to 1250 nM was obtained (R2 = 0.9938). Furthermore, this monitoring method has successfully been applied to real urine, tap water, and sorghum extract samples, demonstrating the potential for field applications. Based on this work, we successfully immobilized BSA–Au NCs on wax-printed paper to accomplish real-time field Cu2+ detection. Fluorescence images were captured under UV light (365 nm), and R-values (red value of RGB color model) were analyzed. The obtained linear relationship between the R-value and the Cu2+ concentration demonstrated the potential of this approach. The developed probe also showed satisfactory selectivity and excellent reproducibility. Although previous methods required a masking agent to protect against interference from increasing Hg2+ concentration, Hg2+ and other interfering ions had a near-negligible effect on results in the present work.
研究领域:
分析化学
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生物医学工程
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环境科学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Zhen Bi,Wenjing Zhang,Min Ni,Ge Song,Yong Huang
The anammox bacteria (AnAOB) have been suggested to perform dissimilatory Fe0/Fe2+-dependent nitrate reduction to ammonium (DNRA), with nitrite as intermediate. However, evidence at genetic and transcriptional levels for how AnAOB reduces nitrate is still lacking, making their roles in this process obscure and questionable. The short-term batch assays and long-term operation of bioreactor combined with 16S rDNA sequencing and transcription analysis were used for the first time to investigate the nitrate reduction pathway in anammox consortia. It is shown that AnAOB metabolically well grew with nitrate as the sole nitrogen source. They reduced nitrate to nitrite with highly expressed narG gene. However, the DNRA-enabling gene nrfA was not expressed by AnAOB. Abiotic reduction by Fe0/Fe2+ contributed to the nitrate and nitrite reduction to ammonium. The correlation analysis of microbial community structure and metabolic functions indicated that amino acid and carbohydrate transport and metabolism interactions in coexisting bacteria could facilitate the AnAOB growth with nitrate as the only nitrogen source. Our findings suggest that the contribution of enzymatic DNRA by AnAOB to the observed nitrate reduction has been probably overestimated in previous publications, and it should be questioned until the clear enzymatic mechanism responsible for nitrate reduction is identified.
研究领域:
微生物学
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环境科学
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生物技术
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DOI
高影响因子
PLoS One
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2014
·Vol. 9
·期 4
·e93815
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IF 3.534
Haishan Qi,Shanshan Li,Sumin Zhao,Di Huang,Menglei Xia,Jianping Wen
To rationally guide the improvement of isobutanol production, metabolic network and metabolic profiling analysis were performed to provide global and profound insights into cell metabolism of isobutanol-producing Bacillus subtilis . The metabolic flux distribution of strains with different isobutanol production capacity (BSUL03, BSUL04 and BSUL05) drops a hint of the importance of NADPH on isobutanol biosynthesis. Therefore, the redox pathways were redesigned in this study. To increase NADPH concentration, glucose-6-phosphate isomerase was inactivated (BSUL06) and glucose-6-phosphate dehydrogenase was overexpressed (BSUL07) successively. As expected, NADPH pool size in BSUL07 was 4.4-fold higher than that in parental strain BSUL05. However, cell growth, isobutanol yield and production were decreased by 46%, 22%, and 80%, respectively. Metabolic profiling analysis suggested that the severely imbalanced redox status might be the primary reason. To solve this problem, gene udhA of Escherichia coli encoding transhydrogenase was further overexpressed (BSUL08), which not only well balanced the cellular ratio of NAD(P)H/NAD(P) + , but also increased NADH and ATP concentration. In addition, a straightforward engineering approach for improving NADPH concentrations was employed in BSUL05 by overexpressing exogenous gene pntAB and obtained BSUL09. The performance for isobutanol production by BSUL09 was poorer than BSUL08 but better than other engineered strains. Furthermore, in fed-batch fermentation the isobutanol production and yield of BSUL08 increased by 11% and 19%, up to the value of 6.12 g/L and 0.37 C-mol isobutanol/C-mol glucose (63% of the theoretical value), respectively, compared with parental strain BSUL05. These results demonstrated that model-driven complemented with metabolic profiling analysis could serve as a useful approach in the strain improvement for higher bio-productivity in further application.
研究领域:
代谢工程
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生物技术
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微生物学
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系统生物学
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2019
·Vol. 44
·期 4
·1245-1252
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IF 3.069
Shi-Wen Lv,Jing-Min Liu,Ning Zhao,Chun-Yang Li,Zhi-Hao Wang,Shuo Wang
The issue of environmental pollution is currently more and more serious, and developing an effective method with universal applicability for removing various contaminants is pretty necessary. Herein, a novel photocatalyst denoted as Co-doped MIL-53-NH2(Fe : Co 4 : 1) was constructed via a feasible solvothermal method, which served as an efficient mediator to activate peroxydisulfate for degrading various organic pollutants. Results from the current work indicated that doping Co with an appropriate proportion could enhance the optical absorption intensity of MIL-53-NH2 and reduce the band gap. Furthermore, a Co ion acting as a mediator could facilitate the charge transfer through a Co3+/Co2+ redox pathway, and thereby suppress the recombination of photogenerated electron–hole pairs. More interestingly, the Co-doped MIL-53-NH2 exhibited excellent and extensive degradation abilities for various organic pollutants including bisphenol A (BPA), antibiotics and organic dyes in the presence of peroxydisulfate (PS) under visible light irradiation. It was also found that ˙OH and SO4−˙ were the major contributors to the catalytic process. Total organic carbon (TOC) analysis indicated that the majority of the contaminants were degraded into CO2 and H2O. Even in the real samples, the developed Co-doped MIL-53-NH2/PS/solar system still possessed excellent performance for the degradation of BPA. Possible photocatalytic mechanisms and the kinetics were also investigated. Besides, the Co-doped MIL-53-NH2 had good catalytic reusability and stability. To sum up, this study provides a promising approach for removing organic pollutants from wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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光化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）