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
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Yong Feng,Jie Zhong,Liyuan Zhang,Yiang Fan,Zequn Yang,Kaimin Shih,Hailong Li,Deli Wu,Bo Yan
Nanoscale zero-valent iron (nZVI) is highly promising for oxidative removal of micropollutants by initiating advanced oxidation processes , but its vulnerability to deactivation due to the surface oxidation is challenging. In this study, we propose Fe 0 @Fe 3 O 4 core–shell nanowires (CSNWs) as a novel activator to generate radicals for atrazine, a representative micropollutant, degradation via the activation of peroxymonosulfate (PMS). Fe 0 @Fe 3 O 4 CSNWs with a shell thickness of around 5 nm were synthesized using a facile chemical reduction approach and were comprehensively characterized using a series of surface sensitive techniques. The results showed that the Fe 0 @Fe 3 O 4 CSNW had great reactivity for atrazine degradation via the activation of PMS; near complete degradation of atrazine was achieved after reaction for only 2 min. Under identical conditions, the pseudo-first order rate constant with Fe 0 @Fe 3 O 4 was more than 36 times greater than that with nano Fe 3 O 4 . The surface activation of PMS contributed only a small proportion to the overall degradation. Instead, the iron released from Fe 0 @Fe 3 O 4 CSNWs primarily activated PMS to generate S O 4 ∙ - that degraded atrazine. The Fe 0 @Fe 3 O 4 CSNWs were stable and no deactivation was observed after exposing Fe 0 @Fe 3 O 4 CSNWs to air for 3 months. The results from this study demonstrate a stable nZVI for oxidative removal of organic contaminants.
研究领域:
环境科学
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化学工程
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2018
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IF 4.841
Bing-huang Wang,Qian Zhang,Jun-ming Hong
In this study, the ion-gelation method was applied to fabricate novel Fe–carbon–bentonite–alginate beads (Fe 0 /C-BABs). Fe 0 /C-BABs could effectively control Fe release during persulfate (PS) activation in N -acetyl- p -aminophenol (APAP) oxidation. A novel two-stage approach that combined Fe 0 /C-BABs and an oyster-shell-filled bed (OSFB) column was developed to address the low pH and high Fe concentration of the effluent of the traditional PS process. The application of the Fe 0 /C-BABs and OSFB column regulated pH levels and Fe release during the advanced oxidation of APAP. The characteristics of Fe 0 /C-BABs were also investigated through scanning electron microscopy, energy dispersive spectrometry, and Fourier transform infrared spectroscopy. The long-term operation performance of Fe 0 /C-BABs in a continuous fixed-bed reactor under simultaneous PS and APAP feeding was also evaluated. The effects of initial PS concentration, pH, fixed-bed weight, in-flow rate, and dissolved oxygen (DO) were investigated. Under selected conditions, 86.3% efficiency was achieved during the first stage of APAP degradation (effluent pH of 3.05, Fe contents: 106.25 mg L −1 ). Water quality improved after the effluent was passed through the OSFB column (effluent pH of 6.32, Fe contents: 21.43 mg L −1 ). Moreover, this study analyzed the free radicals and intermediates produced during APAP degradation to identify the possible routes of APAP degradation.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Wenjia Kong,Qinyan Yue,Yue Gao,Qian Li,Xing Xu,Yan Kong,Baoyu Gao
The sever antibiotics pollution in water environment has been a worldwide concern. In this research, a poly acrylic acid (PAA)/graphitic C 3 N 4 (g-C 3 N 4 ) matrix loaded with zero valent iron (Fe 0 ) was synthesized. The PAA/g-C 3 N 4 -Fe 0 was confirmed to be an efficient photocatalyst for the degradation of sulfadimidine (SM2) under visible light. The dosage of g-C 3 N 4 and Fe 0 were optimized in line with photocatalytic performance. The as-prepared samples were comprehensively characterized through chemical structure, morphology, electrochemical and optical measurements. The photodegradation kinetics under different conditions (e.g. pollutant concentration, pH values, various ionic species and common organic component) were studied. The enhanced photocatalytic activity was due to the improved electron transfer efficiency by the evenly dispersed Fe 0 in PAA/g-C 3 N 4 network. The photodegradation of SM2 was confirmed to be driven by ·O 2 – and ·OH radicals originating from the active components induced by visible light. Based on the above experimental analysis, a possible photodegradation mechanism of PAA/g-C 3 N 4 -Fe 0 photocatalyst was thoroughly elucidated. Besides, the degradation intermediates of sulfadimidine were analyzed by liquid chromatography − mass spectrometer (LC-MS), and possible degradation pathways were proposed in coordination with the calculated results based on Density Functional Theory (DFT). Thus, this study revealed the great prospect of the as-prepared PAA/g-C 3 N 4 -Fe 0 photocatalyst in wastewater remediation.
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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分析化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yudong Huo,Shiqi Yuan,Na Zhang,Chun Pei,Yuwei Pan,Ying Zhang,Xiang Mei,Weichuan Qiao,Lijie Xu,Lu Gan
The mechanism of producing iron-carbon composites with different crystal structures by varied wood-based biomass remains unclear. Herein, cellulose and lignin as the important components of wood-based biomass were used to investigate the influence on the crystal structure of iron-carbon composites. Results showed that Fe 3 C could only be produced in cellulose-containing pyrolysis processes, while the pyrolysis of lignin could reduce the iron salt to Fe 0 . Additionally, prolonging pyrolysis time and increasing the ratio of cellulose to Fe also favored the production of Fe 3 C. When applied to activate peroxymonosulfate (PMS), the Fe@Cel 0.5 -4 typically dominated by Fe 3 C showed better performance than Fe@Ln 1.0 -4 which was dominated by Fe 0 in the aspects of adsorption, electron transfer, retaining the iron species, sustainability, adaptability to complex water conditions, and the catalytic capability to degrade diclofenac (DCF). Quenching experiments and electron spin resonance results indicated the presence of free radicals ( OH, SO 4 − , SO 5 − and O 2 − ) and non-radical ( 1 O 2 and electron transfer process) pathways in both processes. However, the degradation of DCF in Fe@Cel 0.5 -4/PMS process was mainly dominated by 1 O 2 and electron transfer while was contributed by radical and nonradical pathways almost equally in Fe@Ln 1.0 -4/PMS process. This study may cast some light on the development of iron-carbon composites using wood-based biomass as the carbon source to synthesize the highly efficient catalyst for PMS activation.
研究领域:
材料科学
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环境化学
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催化
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Xiao Feng,Hao Chen,Siyuan Guo,Xiaoyu Wang,Tengfeng Xie,Dejun Wang,Yanhong Lin
Efficient photocatalysts are key to achieving efficient photoactivation of AOPs based on PMS. In this work, a sulfur-rich vacancy magnetically separable Fe 0 /CoS 2 -S v photocatalyst with high surface adsorption capacity and rapid PMS activation capacity was designed for the efficient degradation of typical antibiotics. A tetracycline removal rate of 92.2 % and a high TOC mineralization rate were achieved within 4 min in the PMS/Vis system. The excellent catalytic performance was attributed to the synergistic effect of Fe, Co, and S on PMS activation and the generation of sulfur-oxygen vacancies by the composites. These vacancies greatly enhanced the catalytic performance of the PMS system, where the generated singlet oxygen ( 1 O 2 ) was identified as the main active substance in the degradation process. In addition, the SO 4 2- based photocatalytic-assisted advanced oxidation processes (SR-AOPs) for the degradation of organic pollutants were thoroughly investigated. XPS comparisons before and after the catalyst reaction revealed that the reducing nano-Fe 0 and metastable S 2 2- promoted the cycling between Co 3+ and Co 2+ , thus accelerating the rapid activation of PMS. This work provides a new perspective for the further development of efficient and rapid PMS photo-activators for environmental remediation in water bodies.
研究领域:
环境科学
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化学工程
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材料科学
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水处理
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Wenji Ruan,Menglin Wu,Yuanhua Xia,Jiupai Ni,Chengsheng Ni
This study aimed at improving electrocatalytic activity of solid oxide electrolysis cell (SOEC) cathode via in-situ exsolved nanoparticles. La 0.67 Sr 0.33 Fe 0.67 Ti 0.33 O 3-δ (LSFT) and La 0.67 Sr 0.33 Fe 0.6 Ni 0.067 Ti 0.33 O 3-δ (LSFNT-67) cathodes with a La/Sr ratio about 2.0 showed the exsolution of Fe 0 and FeNi 3 alloy nanoparticles, respectively, under a reducing atmosphere. The SOEC with LSFT of electrocatalysis is better than LSFNT-67 at 800 °C for direct electrolysis of CO 2 , the current density of LSFT and LSFNT-67 reach − 0.54 A cm −2 and − 0.29 A cm −2 , respectively, and the Faradaic efficiency is close to unity during the 25 h′ durability under a − 1.3 V bias. The better cell performance for the cell with LSFT than LSFNT-67 could be related to the larger distortion and the less amount of insulating LaSrGa 3 O 7 in the former, causing its unexpectedly larger quantity of metal exsolution and electron conduction for more active reaction sites for CO 2 activation. This work demonstrated that apart from thermodynamic consideration, steric effect of the B site cation could be important for the exsolution of metal particles from a perovskite with high La/Sr ratio and the resultant electrocatalysis of CO 2 electrolysis.
研究领域:
材料科学
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电化学
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催化
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能量转换
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2024
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IF 0
Xu Xiangwei,Ying Yunzhan,Liang Shikun,Song Wenkai,Wu Zenglong,Zhang Fayang,Yan Haoxiang,Yao Yuyuan
Developing highly effective iron-based catalyst to selectively remove organic contaminants has garnered considerable attention. Herein, a magnetic Fe 0 /FeS 2 -doped carbon nanolayer (S-Fe@NC) was synthesized through a straightforward one-step pyrolysis method, pyrolyzing a mixture composed of 4,6-dihydroxypyrimidine, trithiocyanuric acid, and FeCl 3 ·6H 2 O. With the presence of PMS, S-Fe@NC demonstrated the ability to remove almost 100% bisphenol-A (50 μM) within 3 min, attributed to its excellent graphitization degree and high FeS 2 /Fe 0 content. Furthermore, the S-Fe@NC catalyst demonstrated an impressive k obs value of 1.476 min −1 , which surpassed the traditional Fenton system by 77 times and even exceeded the commercial Fe 0 catalyst by 127 times. More importantly, the S-Fe@NC/PMS system succeeded in selectively removing organic contaminants based on the hydrophobic interaction between catalyst and contaminants. Besides, the result of electron paramagnetic resonance and the radical quenching experiments indicated that ·OH, SO 4 ·− , 1 O 2 , and O 2 ·− were involved in the organic contaminants removal. Interestingly, after adding ascorbic acid (AA) to the S-Fe@NC/PMS system, more ROS could be generated to result in the k obs augmenting by 4.16 times (6.133 min −1 ), completely different from the common sense that AA was usually used as a radical quencher. Additionally, the magnetically separable catalyst also exhibited excellent reusability and broad pH adaptability (2.0–12.0). This study provided a valuable insight for developing highly selective and effective Fe-based catalyst for practical wastewater treatment.
研究领域:
环境科学
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催化
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水处理
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材料科学
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产品关联
DOI
PubMed
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
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IF 8
Yan Xu
The pursuit of clean energy generation and environmental preservation is of utmost importance for societal progress. However, couple clean energy production and pollution control is still a difficulty. In this study, a novel electrospun composite mat, with nano zero valent iron (Fe 0 , nZVI) encapsulated into polyacrylonitrile (PAN) nanofibers was acted as a catalyst. The activation energy (E a ) for the hydrolysis of NaBH 4 to produce hydrogen is 22 kJ·mol −1 , hydrogen atom utilization efficiency (HGE) of NaBH 4 is 60.80%. Three kinds of organic dyes 4-nitrophenol (4-NP), methylene blue (MB), and Rhodamine B (RhB) were served as the model pollutant, to construct NaBH 4 -organic system for energy production and pollution reduction. The NaBH 4 -organic system demonstrates a collaborative capability to simultaneously remove organic pollutants and generate hydrogen, with a coupling equilibrium point between the two processes. The hydrogen generation rate (HGR) and HGE increased with the concentration of pollutants increased. The degradation of 4-NP, MB, and RhB followed pseudo-first-order kinetics, with RhB degrading dosage 20 and 44 times higher than 4-NP and MB, respectively. H 2 and H· contributed to the organic degradation. nZVI directly participated in the formation H 2 and H·. PAN@Fe 0 possessed good recyclability and moderate cost. The degradation process adhered to the classical surface reaction controlled Langmuir-Hinshelwood (L-H) model. The integration of synergistic production capacity and pollutant degradation aligns well with the principles of green chemistry and sustainable development. This study demonstrates a novel approach to no precursor loss catalysts preparation, efficient production clean H 2 , advanced treatment of dye-containing wastewater, carbon neutral operation of sewage treatment plant.
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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可持续能源
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Yun-fei Zhang,Chun-hui Zhang,Yu-feng Liu,Dan Li,Jian-hui Xu,Lei Li,Qi Wu,Jin-hong Fan,Lu-ming Ma
Herein, the SiC-Fe 0 powders were mechanically synthesized and employed for activation of peroxymonosulfate (PMS) to remove florfenicol (FLO). Compared to Fe 0 /PMS system, up to a 3.97-fold increase in degradation rates of 20 mg/L FLO was observed by 25% ( w / w ) SiC-Fe 0 /PMS system in 5 mins, which could be attributed to the increased specific surface area and electron transfer rate of SiC-Fe 0 . Both the radical and non-radical processes were involved in the SiC-Fe 0 /PMS system, in which 1 O 2 and • O 2 − played the dominant role in the FLO degradation and SO 4 •− as well as • OH also participated in the system. ROSs investigation suggested that 1 O 2 , • O 2 − , SO 4 •− were mainly generated from the decomposition of PMS and • OH was mainly derived from the ZVI (or Fe 2+ )-catalyzed activation of O 2 . Meanwhile, H* has a nonnegligible role in PMS activation or the transformation of iron species. Five intermediates of FLO in SiC-Fe 0 /PMS system were identified and a significant removal of the overall toxicity was observed. The degradation pathways of FLO were proposed to be hydrolysis, hydroxylation and dechlorination. Besides, this SiC-Fe 0 /PMS system shows effective removal rate for 2-chlorophenol, acetaminophen, tetrabromobisphenol A and carbamazepine, and the FLO-polluted surface water and artificial wastewater. Overall, this study demonstrated that SiC-Fe 0 was promising in practical application and provided new insights into the generation mechanisms of ROSs in the ZVI/PMS system.
研究领域:
环境科学
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化学工程
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水处理
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高级氧化工艺
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产品关联
DOI
高影响因子
CHEMOSPHERE
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2018
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IF 4.427
Huafeng Li,Jin Wang,Rui Wang,Kaibo Huang,Wanying Luo,Xueqin Tao,Zhi Dang,Hua Yin,Chuling Guo,Guining Lu
Polybrominated diphenyl ethers (PBDEs) belong to a class of persistent organic pollutants (POPs), with potential toxicity to the liver, reproductive system, and development of mammals. The highly toxic and concentrated congener, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), was chosen to investigate debromination mechanisms by the two synthetic iron-based bimetals (Pd/Fe 0 and Cu/Fe 0 ) in two protic solvents (water and ethanol). SEM, XPS, and BET analyses showed that the synthetic bimetals Pd/Fe 0 and Cu/Fe 0 were spherical with diameters of about 100 nm and loaded with ∼1% (wt%) of Pd and Cu, respectively. GC-MS was used for the analysis of degradation products and the chromatograms showed that both Pd/Fe 0 and Cu/Fe 0 bimetals had effective reducing properties in water solvent. In ethanol solvent, debromination of BDE-47 by Pd/Fe 0 showed a similar high activity, but BDE-47 could be hardly degraded by Cu/Fe 0 . The dominant debromination products of BDE-47 by Pd/Fe 0 and Cu/Fe 0 were ortho -substituted and para -substituted BDEs, respectively. Active H-atomic transfer was found to play a key role in the debromination of BDE-47 by Pd/Fe 0 in both, water and ethanol, with a preference for para -debromination along with the formation of dibenzo-p-furan (DF) as the by-product, mainly in water. In contrast, electron transfer with a preference for ortho -debromination was found to play a predominant role for Cu/Fe 0 system in water. More importance should be provided to active H-atomic transfer for its high efficiency. In-depth study on the mechanism of formation of by-product DF would be significant for its higher toxicity, possibility of accumulation and migration in the environment.
研究领域:
环境科学
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毒理学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Yusi Tian,Xuyang Zhang,Minghua Zhou,Ying Zhang
A bifunctional cathode with MoS 2 powder and carbon black deposited on carbon felt (MCB@CF) was prepared and first applied as bifunctional cathode to heterogeneous electro-Fenton (EF). This cathode presented higher H 2 O 2 production compared with other cathodes. Fe 0 modified by sulfidation coupled with pre-magnetization (pre-S/Fe 0 ) was used as a catalyst in the EF process. Compared to the conventional EF process, the established pre-S/Fe 0 -EF-MCB@CF process showed higher sulfamethazine (SMT) removal (removal rate constant improved by 3.01 times) and TOC removal (40% in 1 h) within wide pH range (pH 4–10). According to the radical quenching experiment, •OH was proved to be the main oxidation species for SMT degradation and O 2 •- played a marginal role. MoS 2 surface presented Mo 4+ active sites that could promote the conversion of Fe 3+ to Fe 2+ , during which Mo 4+ was oxidized to Mo 6+ . The promoted reduction of Fe 3+ to Fe 2+ enhanced the utilization of H 2 O 2 and thus the generation of ∙OH. The six consecutive runs of pre-S/Fe 0 -EF-MCB@CF process proved the excellent stability and reusability of prepared MCB@CF cathode. Compared with that by Fe 0 -EF-CB@CF process, the removal rates of pesticides, phenols, dyes and drugs by pre-S/Fe 0 -EF-MCB@CF process was enhanced more than two times, demonstrating the potential of this process for wide application. This study provides a green and sustainable approach for the treatment of refractory pollutants by heterogeneous EF process in a wide pH range.
研究领域:
环境科学
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水处理技术
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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）