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
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
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
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 3
·4461-4473
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IF 4.223
Shao Jiang,Zhang Yi,Liu Zongtang,Fei Zhenghao,Sun Yufeng,Chen Ziyan,Wen Xiaoju,Shi Weizhong,Wang Dandan,Gu Chenggang
Organic palygorskite (OP)–supported Pd/Fe nanoparticles composite (OP-Pd/Fe) was prepared by stepwise reduction method. The removal capacity of 4,4′-dibrominated diphenyl ether (BDE15) by OP-Pd/Fe was compared with other various materials. For better understanding the possible mechanism, the synthesized and reacted OP-Pd/Fe materials were characterized by TEM, SEM, XRD, and XPS, respectively. The effects of major influencing parameters on the degradation of BDE15 were also studied. Benefit from the synergistic effect of the carrier and bimetallic nanoparticles, BDE15 could be completely debrominated into diphenyl ether (DE) under suitable conditions. A two-stage adsorption/debromination removal mechanism was proposed. The degradation of BDE15 with OP-Pd/Fe was mainly stepwise debromination reaction, and hydrogen transfer mode was assumed as the dominated debromination mechanism. The removal process fitted well to the pseudo first-order kinetic equation. The observed rate constants increased with increasing Pd loading and OP-Pd/Fe dosage while decreased with increasing initial BDE15 concentration, the tetrahydrofuran/water ratio, and the initial pH of the solution. The work provides a new approach for the treatment of PBDEs pollution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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