APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
·
IF 16.683
Ming Lei,Zhiying Wang,Yao Tang,Huimin Wang,Lihua Zhu,Heqing Tang
The use of palladium deposited TiO 2 (Pd/TiO 2 ) as catalysts yielded complete debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) in isopropanol solution containing NaOH at 40 °C within 60 min. The final organic products were diphenyl ether and dibenzofuran. It was disclosed that two competing reduction paths (hydro-debromination and coupling-debromination) occurred over Pd nanoparticles . The hydro-debromination was dependent on the participation of active H atom species generated by catalytic transfer hydrogenation on metallic Pd. The coupling-debromination proceeded via the oxidative addition of Pd(0) to B r 2 C 12 H 8 OB r 2 ′ , leading to an transition state of B r 2 Pd II C 12 H 8 OB r 2 ′ , the reductive dissociation of which resulted in the elimination of Br − ions, producing a new transition state Pd 0 C 12 H 8 OB r 2 ′ − . A further oxidative addition of Pd 0 C 12 H 8 OB r 2 ′ − generated B r 2 ′ Pd II C 12 H 8 O − , and its final reductive elimination provided dibenzofuran, leading to the regeneration of Pd(0). The integration of the catalytic coupling and hydrogenation reaction on Pd nanoparticles greatly accelerated the removal of the halogenated organic pollutants.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
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IF 14.229
Ming Lei,Zhiying Wang,Lihua Zhu,Wenshan Nie,Heqing Tang
Deep debromination of polybrominated diphenyl ethers (PBDEs) by visible light photocatalysis is still a challenge in the field of halogenated pollutants control. Here, an efficient photocatalyst (Pd/g-C 3 N 4 ) was prepared by a simple impregnation-chemical reduction method with bulk g-C 3 N 4 and PdCl 2 as precursors. Under preferred reaction conditions (visible light irradiation for 120 min), the use of the 0.5% Pd/g-C 3 N 4 composites (0.4 g L −1 ) yielded an almost complete debromination of BDE47 (10 μmol L −1 ) in methanol-water mixture, while the debromination of BDE47 did not occur on pure g-C 3 N 4 . A “Pd-promoted active H atom species attack and C-Br bond cleavage” route was proposed according to the identified degradation intermediates. A catalytic mechanism was further clarified: Pd nanoparticles exerted affinity interaction with bromine atoms, and the storing of electrons on Pd would increase the binding interaction. In the debromination process, methanol acts as both a hole scavenger and a hydrogen donor to provide active H atom species through the reaction of H + and photogenerated electrons on Pd nanoparticles. The initiation of BDE47 debromination on Pd nanoparticles required an induction period to enrich a critical amount of electrons for stretching the C-Br bond and its subsequent being attacked by active H atoms. The generated 2,2′-dibromodiphenyl ether (BDE4) would be further reduced to bromine-free products by hydro-debromination process or coupling reaction.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
ACS ES&T Water
·
2025
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IF 4.3
Kuang Wang,Guan Wang,Bin Zheng,Haowei Zeng,Zhanqiang Fang
The large-scale remediation of polybrominated diphenyl ethers (PBDEs) is often limited by the high manufacturing costs of conventional reductants. We developed a cost-effective method to synthesize submicron pyrite (FeS2bm) through simple ball milling of inexpensive pyrite. The mass-normalized removal rate constant of FeS2bm for BDE-209 reached 1.6 mg min–1 g–1, surpassing previously reported reductants. Ball milling reduced the particle size to 13% of pristine pyrite and increased the specific surface area by 17-fold while removing the oxide layer without altering the crystal structure. The electron transfer capacity of pyrite improved, and kinetic studies showed a positive correlation between the rate constants for BDE-209 removal and milling time, with strong correlations (R2 > 0.97) observed among rate constant, pH, debromination rate, and iron-dissolution rate. Mechanistic investigations indicated that degradation occurred primarily via adsorbed Fe(II) and dissolved Fe2+. Analysis of degradation products indicated a maximum debromination depth of hexa-BDEs, with predominant products distributed in the hepta-BDE to octa-BDE range, possibly exhibiting higher toxicity. Comparative cost analysis showed that the manufacturing cost of FeS2bm is only 1/303 of that of nanoscale zerovalent iron (nZVI). High removal efficiencies of BDE-209 by FeS2bm were achieved in groundwater matrices. Consequently, FeS2bm emerges as a promising reductant for the cost-effective degradation of BDE-209, showcasing significant potential for practical applications.
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
Journal of Cleaner Production
·
2024
·
IF 9.7
Tao Chen,Chuan Ma,Ben Wang,Linlin Xu,Wu Yang,Lushi Sun
Pyrolysis has proven an effective method of recycling waste printed circuit boards (WPCBs) for high-value product generation. The kinetics and debromination studies on the pyrolysis of WPCBs with copper species was performed using a thermogravimetric-mass spectroscopy analyzer and a vertical quartz-tube reactor. A multiple distributed activation energy model (M-DAEM) was applied to illustrate the potential multiple reactions over the thermal decomposition process. The introduction of copper species into WPCBs reduced the initial activation energies, resulting in lower decomposition temperatures. Meanwhile, several distinct subprocesses were observed and resolved by three-reaction models. The addition of CuO obtained the lowest liquid yield (53.9 wt %) and the maximum gas yield (8.9 wt %), and the introduction of Cu 2 O resulted in the highest solid yield (40.4 wt %). Copper particles preserved 57 % of bromine in residual solid, while CuO and Cu 2 O particles resulted in approximately 65 % and 74 % retention of bromine in the residues, respectively. Particularly, less than 3.7 % of bromine was transferred into the liquid when Cu 2 O was added. The optimal debromination performance of Cu 2 O was attributed to its effective capture capacity of HBr/Br 2 , fairly high catalytic efficiency on dissociating C–Br bond, and multipath conversion of organobromine to cross-linked carbonaceous compounds.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Libin Fu,Xueqin Peng,Qi Chen,Yaobin Ding,Jizhou Jiang
Photolysis and debromination of bromophenols were widely investigated previously. However, the role of reactive species especially hydrated electrons (e aq − ) in their degradation was overlooked. Therefore, in the study, generation and role of the reactive species generated during the photolysis of bromophenols were identified and evaluated by using 2,4,6-tribromophenol (TBP) as a model at different pH values from 4 to 11 under anaerobic condition. It was found that photolysis of TBP solution under UV irradiation (254 nm) yielded organic radicals (C•), hydrogen radicals (H•) and e aq − . By using nitrite and monochloroacetic acid (MCAA) as scavengers of H•/e aq − , the role of UV direct photolysis, H• and e aq − in degradation of TBP was quantitatively assessed at different initial pH (pH 0 ) values. UV irradiation induced direct photolysis of TBP was mainly dependent on its molar absorbance coefficient (ε) at 254 nm. Contribution rate of UV irradiation to degradation of TBP was about 60% at pH 0 4, 7 and 11. Interestingly, the contribution rate of e aq − was high as 35.8%-40% at pH 0 4–11, while the contribution rate of H• was negligible (<2.5%) at these pH values. Accordingly, UV and e aq − induced degradation and debromination pathways of TBP under UV irradiation were proposed. This work gains deep insight into the photolysis process of bromophenols, and clarifies the important role of e aq − in photo-degradation of bromophenols.
研究领域:
环境科学
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化学
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DOI
高影响因子
Frontiers of Environmental Science & Engineering
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2020
·Vol. 14
·期 3
·1-13
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IF 4.053
Jiang Chaojin,Jiang Xiaoqian,Zhang Lixun,Guan Yuntao
A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH = 4.00 using the solvent of methanol/H 2 O (v:v = 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.
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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2024
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IF 13.3
Fangxian Wang,Junwei Yang,Shihao Li,Junwen Liang,Yuwei Wang,Rong Du,Bo Zhou,Qiong Liu,Changping Li
Bromate is a commonly identified carcinogenic and genotoxic disinfection byproduct in water. Electrochemical debromination is an environmentally friendly and effective approach but it often suffers the limited reducing atomic H (H*) ability and high metal catalyst dosage. In this study, a unique composite catalyst comprised of ultra-low loading Cu single atoms (0.016 wt%) and Fe 2 O 3 nanoparticles supported on a Nb 2 C MXene (denoted as Cu 0.2 /Fe 0.1 /Nb 2 C) was synthesized by one-step high-temperature molten salt method. The Cu 0.2 /Fe 0.1 /Nb 2 C significantly outperformed the Nb 2 C, Cu 0.2 /Nb 2 C and Fe 0.1 /Nb 2 C counterparts in the electrochemical debromination with a 94.2 % removal efficiency of bromate. It is revealed that the introducing of Cu single atoms, efficiently promotes the adsorption of H* and inhibition of competitive H 2 evolution. The incorporation of Fe 2 O 3 nanoparticles significantly increased the electronic metal-support interaction effect between the metal components and Nb 2 C, thereby forming a noticeable electronic cloud bridge to facilitate efficient charge transfer. Ultimately, the synergistic interplay between Cu single atoms and Fe 2 O 3 nanoparticles plays a crucial role in achieving the remarkable removal performance of bromate. This work not only presents a significant instance of a synergistic catalyst involving metal single atoms and metal nanoparticles for effective electrochemical debromination but also advances the understanding of the electronic metal-support interaction.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Ruohan Li,Lixun Zhang,Ying Zhang,Zhengfang Zhang,Yuntao Guan
Tetrabromobisphenol A (TBBPA), currently the most widely used brominated flame retardant, has attracted significant attention. However, traditional methods for deep debromination or mineralization of TBBPA usually include multiple steps and require external oxidants. In this study, we report a complete degradation of TBBPA through a one-step process of only adding a layered double oxide-supported sulfurized nanoscale zero-valent iron (S-nZVI@LDO) under ambient conditions. TBBPA was rapidly removed by S-nZVI@LDO with an efficiency of 95.6 % (10 mg⋅L -1 ) within 12 h. The kinetic rate constant (0.0035 min −1 ) was greater when compared with traditional reductants. The produced Br - ion occupied 76.7 % of total Br content, and the concentration of total organic carbon decreased by over 50 %, suggesting a deep debromination and mineralization of TBBPA by S-nZVI@LDO. It is caused by the substantial improvement of electron transfer, O 2 adsorption, and hydrophobicity of S-nZVI@LDO facilitating synchronous reductive debromination and O 2 activation to produce · O 2 – and · OH, as approved by electrochemical test, O 2 -TPO analysis, EPR analysis, and density functional theory calculations. The enriched structural S(−II) and enhanced Fe(III)/Fe(II) redox cycling exerted vital roles in maintaining the reduction potential of the composite. The degradation pathways analysis confirmed that debromination-mineralization mechanisms dominated the complete degradation of TBBPA. This study demonstrates the feasibility of the one-step mineralization removal of TBBPA only using S-nZVI@LDO under ambient conditions and offers insight into external oxidant-free in-situ elimination of halogenated persistent organic pollutants in a natural environment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
·
IF 13.6
Jing Ma,Yingping Li,Xing Zhang,Jingjing Li,Qingqi Lin,Yanping Zhu,Zhepu Ruan,Zhuobiao Ni,Rongliang Qiu
Polybrominated diphenyl ethers (PBDEs) in soil and groundwater have garnered considerable attention owing to the significant bioaccumulation potential and toxicity. Currently, the coupling treatment method of nano zero-valent iron (nZVI) with dehalogenation microorganisms is a research hotspot in the field of PBDE degradation. In this study, various systems were established within anaerobic environments, including the nZVI-only system, microorganism-only system, and the nZVI + microorganisms system. The aim was to investigate the degradation pathway of BDE-209 and elucidate the degradation mechanism within the coupled system. The results indicated that the degradation efficiency of the coupled system was better than that of the nZVI-only or microorganism-only system. Two modified nZVI (carboxymethyl cellulose and polyacrylamide) were prepared to improve the coupling degradation efficiency. CMC-nZVI showed the highest stability, and the coupled system consisting of microorganisms and CMC-nZVI showed the best degradation effect among all of the systems in this study, reaching 89.53% within 30 days. Furthermore, 22 intermediate products were detected in the coupling systems. Notably, changing the inoculation time did not significantly improve the degradation effect. The expression changes of the two reductive dehalogenase genes, e.g. TceA and Vcr , reflected the stress response and self-recovery ability of the dehalogenating bacteria, indicating such genes can be used as biomarker for evaluating the degradation performance of the coupling system. These findings provide a better understanding about the mechanism of coupling debromination process and the direction for the optimization and on-site repair of coupled systems.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Feiyang Zhang,Penglei Xu,Xueqing Jin,Chen Wang,Qi Shen,Chunyan Sun
Polybrominated diphenyl ethers (PBDEs) have attracted increasing attention due to their biotoxicity and persistence. Herein, rapid degradation of decabromodiphenyl ether (BDE209) was achieved on bromine vacancies enriched BiOBr (BOB-V Br ) nanosheets, with a degradation rate for BDE209 under visible light irradiation (λ > 400 nm) exceeding 95 % within 6 min. The initial two minutes serve as an induction period, during which the Br vacancies were in-situ introduced into the BiOBr (BOB) nanosheets. By precisely controlling the duration of photoinduction, varying concentrations of Br vacancies were successfully generated on the surface of the BOB nanosheets. Consequently, an enhanced degradation rate of BDE209 was observed in direct correlation with the increased concentration of Br vacancies. BOB-V Br showed a remarkable selectivity of 74 % for meta- product (BDE207). This selectivity towards BDE207 surpasses that of other anionic vacancies, as oxygen, sulfur, and iodine vacancies. The in-situ generated Br vacancies help to accommodate the Br atom of BDE209 in atomic size and electronic structure, thus facilitating the activation of the C-Br bond and achieving rapid BDE209 debromination. This work provides a new insight for the treatment of organic halogenated pollutants by photocatalysts with homologous halogen vacancies.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2010
·
IF 4.144
Zhanqiang Fang,Xinhong Qiu,Jinhong Chen,Xiuqi Qiu
Polybrominated diphenyl ethers have been identified as a new class of organic pollutants with ecological risk due to their toxicity, bioaccumulation, and global distribution. Proper remediation technologies are needed to remove them from the environment. In this paper, Ni/Fe bimetallic nanoparticles were synthesized by chemical deposition and used to degrade decabromodiphenyl ether (BDE209). The characteristics of Ni/Fe nanoparticles were analyzed by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and Brunnaer–Emmett–Teller surface area analysis. Ni/Fe bimetallic nanoparticles with diameters in the order of 20–50 nm could effectively degrade BDE209 in the solvent (tetrahydrofuran/water). Influence factors, such as Ni/Fe nanoparticle dosage, initial BDE209 concentration, and Ni loading, on the removal of BDE209 were studied. The results indicated that the degradation of BDE209 followed pseudo-first-order kinetics, and the degradation rate of BDE209 increased with increasing the amount of nano Ni/Fe particles, Ni/Fe ratio, and decreasing the initial concentration of BDE209. Through analyzed the mass balance of the BDE209 removal, degradation was the main process of BDE209 removal. The mechanism of debromination was deduced by analyzing the reaction products using gas chromatography–mass spectrometry, the bromide ion in the solution and varying the solvent conditions. Stepwise hydrogen reduction is the main process of debromination, and the hydrion play an important role in the reaction. Moreover, the experiment of long term performance and leaching of Ni were also carried out to test the stability and durability of Ni/Fe nanoparticles in BDE209 degradation.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
·
IF 10.753
Xiao-Qiu Lin,Jia-Mei You,Ling-Yu Meng,Naoko Yoshida,Jing-Long Han,Cong-Ju Li,Ai-Jie Wang,Zhi-Ling Li
Tetrabromobisphenol A (TBBPA), a hazardous and persistent flame retardant , has been widely detected in the natural aquatic system. The acceleration of reductive debromination (rate-limiting process) is vital during the decomposition and detoxification of TBBPA. This study achieved superior TBBPA electrochemical reductive debromination performance by nano Pd doped Ni foam electrode (4.8 times higher than Ni foam electrode). The optimal TBBPA reductive debromination performance was obtained under −1.2 V of cathode potential, 1.2 wt% of Pd loading, 10 mg L −1 of TBBPA and 100 mM of Na 2 SO 4 as the electrolyte solution. UPLC-QTOF-MS verified that Br atoms in TBBPA were removed sequentially to form bisphenol A as the major product. Most TBBPA was reductively debrominated by atomic H* through indirect hydrodebromination, evidenced by the atomic H* quenching test. The higher solution conductivity and appropriate TBBPA concentration would contribute to the debromination efficiency. Excessive H 2 generation whether by over negative potential or H atom richness electrolyte largely disturbed the reaction process and restricted the debromination. The improved generation of reductant (H*) ads Pd was the most significant, while excessive Pd loading would make aggregation and limit the debromination efficiency. The study confirmed the optimization strategies of conditions for Pd/Ni foam electrode and revealed the related function mechanism for stimulating TBBPA electrochemical reduction, giving suggestions for the efficient removal of TBBPA in the aquatic environment.
研究领域:
环境科学
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电化学
·
污染控制
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）