Applied Sciences-Basel
·
2025
·Vol. 15
·期 10
·5673
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IF 2.5
Rui Li,Ailin Wen,Jing Li
Chloride ions in zinc refining accelerate equipment corrosion and anode and cathode losses, increase lead content, and reduce zinc quality. Therefore, the removal of chloride ions has become a research priority. The existing copper slag dechlorination process has problems such as the solid film barrier leading to impeded mass transfer, product wrapping triggering active site coverage, and incomplete reactions due to insufficient reaction-driving force, leading to low utilization of copper slag, poor dechlorination efficiency, and long reaction times. To address these issues, a new method of deep dechlorination based on the reduction of Cu2+by liquid-phase mass transfer is proposed in this paper. The process utilizes ascorbic acid as a reducing agent, establishes a homogeneous aqueous phase reaction system, breaks through the solid membrane barrier, and avoids the encapsulation of the product layer, achieving efficient dechlorination. The enol structure of ascorbic acid promotes rapid dechlorination through proton-coupled electron transfer (PCET). Thermodynamic calculations show that compared to the current copper slag dechlorination process, this method increases the reaction-driving force by 18.6%, reduces the Gibbs free energy (ΔGθ) by 59.3%, and increases the equilibrium constant by 6.7 × 109times, making the reaction more complete and achieving a higher degree of purification. The experimental results show that under optimized conditions, the chloride ion concentration in the solution decreases from 1 g/L to 0.0917 g/L within 20 min, with a removal rate of 90.8%. The main precipitate is CuCl. This process provides a more efficient solution to the chloride ion contamination problem in the hydrometallurgical zinc refining process.
研究领域:
冶金工程
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化学工艺
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环境科学
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2013
·
IF 3.258
Yan Xu,Yan He,Xiaoli Feng,Luyi Liang,Jianming Xu,Philip C. Brookes,Jianjun Wu
A novel Fe(III) reducing bacterium, Clostridium beijerinckii Z, was isolated from glucose amended paddy slurries, and shown to dechlorinate pentachlorophenol (PCP). Fifty percent of added PCP was removed by C. beijerinckii Z alone, which increased to 83% in the presence of both C. beijerinckii Z and ferrihydrite after 11 days of incubation. Without C. beijerinckii Z, the surface-bound Fe(II) also abiotically dechlorinated more than 40% of the added PCP. This indicated that the biotic dechlorination by C. beijerinckii Z is a dominant process causing PCP transformation through anaerobic dechlorination, and that the dechlorination rates can be accelerated by simultaneous reduction of Fe(III). A biochemical electron transfer coupling process between sorbed Fe(II) produced by C. beijerinckii Z and reductive dehalogenation is a possible mechanism. This finding increases our knowledge of the role of Fe(III) reducing genera of Clostridium in dechlorinating halogenated organic pollutants, such as PCP, in anaerobic paddy soils.
研究领域:
环境微生物学
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生物修复
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土壤科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Ying Chen,Lei Tian,Wen Liu,Yi Mei,Qiu-Ju Xing,Yi Mu,Ling-Ling Zheng,Qian Fu,Jian-Ping Zou,Daishe Wu
Dechlorination of chloropyridines can eliminate their detrimental environmental effects. However, traditional dechlorination technology cannot efficiently break the C–Cl bond of chloropyridines, which is restricted by the uncontrollable nonselective species. Hence, we propose the carbonate species-activated hydrogen peroxide (carbonate species/H2O2) process wherein the selective oxidant (peroxymonocarbonate ion, HCO4–) and selective reductant (hydroperoxide anion, HO2–) controllably coexist by manipulation of reaction pH. Taking 2-chloropyridine (Cl–Py) as an example, HCO4– first induces Cl–Py into pyridine N-oxidation intermediates, which then suffer from the nucleophilic dechlorination by HO2–. The obtained dechlorination efficiencies in the carbonate species/H2O2 process (32.5–84.5%) based on the cooperation of HCO4– and HO2– are significantly higher than those in the HO2–-mediated sodium hydroxide/hydrogen peroxide process (0–43.8%). Theoretical calculations confirm that pyridine N-oxidation of Cl–Py can effectively lower the energy barrier of the dechlorination process. Moreover, the carbonate species/H2O2 process exhibits superior anti-interference performance and low electric energy consumption. Furthermore, Cl–Py is completely detoxified via the carbonate species/H2O2 process. More importantly, the carbonate species/H2O2 process is applicable for efficient dehalogenation of halogenated pyridines and pyrazines. This work offers a simple and useful strategy to enhance the dehalogenation efficiency of halogenated organics and sheds new insights into the application of the carbonate species/H2O2 process in practical environmental remediation.
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
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Bo Liu,Hao Zhang,Qi Lu,Guanghe Li,Fang Zhang
To address the challenges of low hydrodechlorination efficiency by non-noble metals, a Cu Ni bimetallic cathode with nanostructured copper array film was fabricated for effective electrochemical dechlorination of trichloroethylene (TCE) in aqueous solution. The Cu Ni bimetallic cathodes were prepared by a simple one-step electrodeposition of copper onto the Ni foam substrate, with various electrodeposition time of 5/10/15/20 min. The optimum electrodeposition time was 10 min when copper was coated as a uniform nanosheet array on the nickel foam substrate surface. This cathode exhibited the highest TCE removal, which was twice higher compared to that of the nickel foam cathode. At the same passed charge of 1080C, TCE removal increased from 33.9 ± 3.3% to 99.7 ± 0.1% with the increasing operation current from 5 to 20 mA cm −2 , while the normalized energy consumption decreased from 15.1 ± 1.0 to 2.6 ± 0.01 kWh log −1 m −3 . The decreased normalized energy consumption at a higher current density was due to the much higher removal efficiency at a higher current. These results suggest that Cu Ni cathodes prepared by simple electrodeposition method represent a promising and cost-effective approach for enhanced electrochemical dechlorination.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Xiaokun Liu,Lian Zhang,Rui Shen,Qihong Lu,Qinglu Zeng,Xiaojun Zhang,Zhili He,Simona Rossetti,Shanquan Wang
Chloroethenes (CEs) as common organic pollutants in soil could be attenuated via abiotic and biotic dechlorination. Nonetheless, information on the key catalyzing matter and their reciprocal interactions remains scarce. In this study, FeS was identified as a major catalyzing matter in soil for the abiotic dechlorination of CEs, and acetylene could be employed as an indicator of the FeS-mediated abiotic CE-dechlorination. Organohalide-respiring bacteria (OHRB)-mediated dechlorination enhanced abiotic CEs-to-acetylene potential by providing dichloroethenes (DCEs) and trichloroethene (TCE) since chlorination extent determined CEs-to-acetylene potential with an order of trans-DCE > cis-DCE > TCE > tetrachloroethene/PCE. In contrast, FeS was shown to inhibit OHRB-mediated dechlorination, inhibition of which could be alleviated by the addition of soil humic substances. Moreover, sulfate-reducing bacteria and fermenting microorganisms affected FeS-mediated abiotic dechlorination by re-generation of FeS and providing short chain fatty acids, respectively. A new scenario was proposed to elucidate major abiotic and biotic processes and their reciprocal interactions in determining the fate of CEs in soil. Our results may guide the sustainable management of CE-contaminated sites by providing insights into interactions of the abiotic and biotic dechlorination in soil.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Mingyue Liu,Renliang Huang,Chuanxi Li,Mingda Che,Rongxin Su,Shuzhou Li,Jing Yu,Wei Qi,Zhimin He
Nanoscale zero-valent iron has been widely applied in environmental remediation and toxic waste treatment, especially for the degradation of persistent organic pollutants (POPs). However, the dechlorination activity of Fe nanoparticles (Fe NPs) can be suppressed by the precipitation of iron oxides generated from the corrosion of Fe-Pd NPs under alkaline conditions, leading to a decreased dechlorination efficiency. Faced with this challenge, we report a highly effective dechlorination system that functions over a broad pH range and especially well under alkaline conditions in this work. Procyanidin (PROC), a natural polyphenol, was utilized as a stabilizer to manipulate the size distribution of Fe-Pd NPs and, more importantly, as a scavenger of Fe ions to prevent iron oxide precipitation. Experiments and theoretical calculations reveal that the generated Fe ions was mainly present in the form of bis- and tris-PROC-Fe complexes in the reaction solution. Compared with pristine Fe-Pd NPs, the PROC-modified Fe-Pd NPs had a dechlorination efficiency that was increased 20-fold (pH 9.0). Notably, a normalized rate constant was enhanced by more than 2 orders of magnitude compared to the previously reported dechlorination systems. The PROC-modified Fe-Pd NPs showed excellent dechlorination efficiency over a wide pH range (2.3–13.0).
研究领域:
环境科学
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纳米技术
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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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 22
·期 1
·555-564
·
IF 2.757
Wu Yingxin,Wu Zihao,Huang Xiongfei,Simonnot Marie-Odile,Zhang Tao,Qiu Rongliang
Effective dehalogenation by nanoscale zerovalent iron (nZVI) has been reported. In this study, the effects of Ni 2+ , Cu 2+ ions, and the nonionic surfactant Tween-80 on dechlorination of 2,2’,5,5’-tetrachlorinated biphenyl (PCB-52) by nZVI were investigated in aqueous solution. The rate of dechlorination was significantly enhanced by Ni 2+ , while Cu 2+ had a less significant catalytic effect. Ni 2+ and Tween-80 used in combination synergistically enhanced dechlorination of PCB-52 by nZVI, although the enhancement by Tween-80 was inhibitory in the presence of Cu 2+ and insignificant in the absence of both metal ions. Congener specificity in the dechlorination pathway resulted from the preferential retention of ortho-chlorine, which restricted the formation of environmentally toxic coplanar PCB congeners. The application of nZVI dehalogenation enhanced by Ni 2+ and Tween-80 is a promising technique for posttreatment of PCB-contaminated soil washing solutions.
研究领域:
环境科学
·
化学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2021
·
IF 9.028
Weiting Yu,He Jiang,Jinhui Fang,Shuang Song
Reducing the Pd loading on electrodes is critical in the electrocatalytic hydrodechlorination (EHDC) of chlorinated organic compounds (COCs). The EHDC reaction of COCs on Pd involves three steps: H* formation, H* adsorption, and dechlorination. It has been established that the initial hydrogen evolution reaction (HER) occurs on Pd0 and the dechlorination steps occur on Pd2+. A strategy is proposed to design new electrodes by adding a reducible HER-active interlayer to replace Pd0, fulfilling the responsibility of producing hydrogen, and to facilitate the formation of more Pd2+ for following C–Cl bond cleavage. Keeping the atomic hydrogen adsorption energy on the Pd/interlayer similar to that on pure Pd is also necessary for H* adsorption as well as to maintain a high EHDC activity. For the first time, the NiCo2O4-interlayer-modified Pd/Ni-foam electrode was applied in the EHDC of COCs, which enhanced the EHDC efficiency to 100% within 90 min and reduced 88.6% of Pd consumption. The Pd/NiCo2O4/Ni-foam electrode with enhanced EHDC activity was also observed with almost 100% product selectivity and good stability. A synergistic mechanism is proposed for the enhanced EHDC activity on the Pd/NiCo2O4/Ni-foam. This work offers a simple and useful strategy to design robust electrocatalysts for the EHDC of COCs.
研究领域:
化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yu-Jia Nong,Qian-Yuan Wu,Yun-Peng Wu,Ju-Won Lee,Min-Yong Lee,Wen-Long Wang
The KrCl-excimer lamp, emitting far-UVC light at 222 nm (UV222), offers a promising alternative to conventional UVC light at 254 nm (UV254) for the photolysis of organic pollutants and the activation of radical sensitizers. This study was aimed to investigate the efficiencies of UV222 in the treatment of halogenated aromatics, focusing on its performance in degradation, dechlorination and detoxification. Chlorophenols, representative recalcitrant and toxic halogenated aromatics, were used as target pollutants. The pathways of direct photolysis, photooxidation and photoreduction under UV222 illumination were compared. UV222 outperformed UV254 in photolyzing chlorophenols (1.4−34.1 times faster), especially protonated chlorophenols, due to substantially higher UV absorption (17.1−108.0 times) and quantum yields (2.1−3.4 times). The quantum yields of chlorophenols were influenced by the inducive electron-withdrawing effect of Cl-substitutes. Moreover, UV222 improved the dechlorination of chlorophenols to 95 % compared to 60 % by UV254. The introduction of radical sensitizer (e.g., H 2 O 2 , nitrate, and sulfite) reduced 4-chlorophenol photolysis by competing for UV222 absorption, though the sensitizers partially increased radical oxidation via generating • OH or e aq − . UV222 photolysis of 4-chlorophenol increased the toxicity by 88.6 times through forming toxic intermediates (e.g., hydroquinone and resorcinol). Notably, • OH and e aq − (i.e., UV222/H 2 O 2 and UV222/sulfite) increased the dechlorination and • OH (i.e., UV222/H 2 O 2 ) detoxified the mixture solution. Moreover, UV222 photolysis remained effective for 4-chlorophenol removal in real paper-mill wastewater, indicating the potential application of KrCl* lamp UV222.
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
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Bo Yang,Jiaxing Zhang,Yunfei Zhang,Shubo Deng,Gang Yu,Jinhua Wu,Hong Zhang,Jianhong Liu
The low-cost Al–Ni alloy particles could achieve high dechlorination activity for 2-chlorophenol (2-CP) with the addition of tetrasodium EDTA (EDTA-4Na) in this study. The species of chelating agent, pH values, and the dosages of chelating agent were investigated for their effects on dechlorination efficiency of 2-CP in solution. EDTA-4Na presented the highest promoting effect for Al–Ni alloy in dechlorination process compared with other chelating agents, which is closely correlated with the conditional stability constant ( K f ′ ) of chelates formed. The optimized result showed that 0.389 mM of 2-CP was completely dechlorinated into phenol using 10 g L −1 of Al–Ni alloy and 10 mM of EDTA-4Na at initial pH 11.0 within 45-min reaction. Recycling tests of the alloy particles showed that Al–Ni alloy coupling with EDTA in aqueous solution exhibited high dechlorination activity and stability before being exhausted. The maintenance of Al–Ni alloy activity for dechlorination was mainly attributed to the promoting effect of EDTA-4Na on Al corrosion, the inherent structure of alloy with Ni crystal homogeneously dispersing into Al substrate, and the change of its surface morphology with more active sites formed by EDTA corrosion.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yuan Chen,Yuancai Chen,Jianbo Jia,Bing Yan
The present study focuses on the successful preparation of microbial palladium nanoparticles (Pd-NPs). The even distribution of Pd in the periplasmic space of B. megaterium Y-4 cells is characterized using a transmission electronic microscopy (TEM) and scanning electron microscope (SEM). X-Ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) revealed the domination of Pd (0) in Pd-NPs. The microbial Pd-NPs were selected to detoxify triclosan (TCS). Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the intermediate products of dechlorination and oxidization. Free radicals quenching and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) capturing experiments confirmed the crucial contribution of atomic H• and O 2 ·– to TCS degradation. Besides, TCS degradation by microbial Pd-NPs could alleviate the cytotoxicity of TCS polluted water. Meanwhile, great circulating utilization of microbial Pd-NPs was obtained in degrading TCS. Corresponding findings in the present study could provide new insight into the role of microbial Pd-NPs in detoxifying pollutants.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Li-Zhi Huang,Xiang Zhan,Weiguo Chen,Changye Li,Liandong Zhu,Yitao Dai,Jia Deng
Carbon tetrachloride (CT), a common persistent pollutant in groundwater, has attracted widespread attention from environmental researchers. The dechlorination from CT to combustible hydrocarbons not only represents the removal of contaminants, but also offers the possibility of recovering carbon resources from water. In this work, we used the coprecipitation of Fe(II) and Pd(II) to synthesize Pd-Fe hydroxides for the dechlorination of CT. When Pd and Fe dosages were 0.4 and 5 mM respectively, CT with 26 µM concentration can be fast removed within 5 min, and 43.3 % of CH 4 and 11.6 % of C 2 H 6 (mol%) were generated after 110 min. The alkaline condition was more conducive to the complete dechlorination of CT comparing with acidic and neutral conditions. During the olation process, Fe(II) as electron donor transferred electrons to Pd(II) to form Pd(0) clusters. Pd(0) active sites act on the binding of CT and transfer electron to H + /H 2 O to form adsorbed atomic hydrogen (H ads •). The adsorbed CT molecules on the surface of Pd-Fe hydroxides undergo continuous dechlorination to form CH 4 and C 2 H 6 through the attack of H ads • and direct electron transfer. In real groundwater applications, CT was rapidly removed, with CH 4 and C 2 H 6 yields reaching 24.5 % and 4.6 % (mol%), respectively. Encouragingly, incomplete dechlorinated products, including chloroform and dichloromethane, did not show signs of subsequent rebound even after 60 min. Furthermore, Pd-Fe hydroxides also exhibit resistance to the oxidation effects of dissolved oxygen, which demonstrates the promising application prospects.
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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催化
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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）