Single-Ni-atom catalyzes aqueous phase electrochemical reductive dechlorination reaction

2020 ◽  
Vol 277 ◽  
pp. 119057 ◽  
Author(s):  
Yinghua Xu ◽  
Zeqing Yao ◽  
Zhechuan Mao ◽  
Meiqin Shi ◽  
Xiaoyong Zhang ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Reductive Dechlorination ◽  
Dechlorination Reaction

scholarly journals Evaluation of the Bioelectrochemical Approach and Different Electron Donors for Biological Trichloroethylene Reductive Dichlorination

Toxics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Edoardo Dell’Armi ◽  
Marta Maria Rossi ◽  
Lucia Taverna ◽  
Marco Petrangeli Papini ◽  
Marco Zeppilli
Keyword(s):  
Reductive Dechlorination ◽  
Molecular Hydrogen ◽  
Batch Reactor ◽  
Electron Donors ◽  
Utilization Efficiency ◽  
Batch Reactors ◽  
Organic Substrates ◽  
Chlorinated Aliphatic Hydrocarbons ◽  
Low Solubility ◽  
Dechlorination Reaction

Trichloroethylene (TCE) and more in general chlorinated aliphatic hydrocarbons (CAHs) can be removed from a contaminated matrix thanks to microorganisms able to perform the reductive dechlorination reaction (RD). Due to the lack of electron donors in the contaminated matrix, CAHs’ reductive dechlorination can be stimulated by fermentable organic substrates, which slowly release molecular hydrogen through their fermentation. In this paper, three different electron donors constituted by lactate, hydrogen, and a biocathode of a bioelectrochemical cell have been studied in TCE dechlorination batch experiments. The batch reactors evaluated in terms of reductive dechlorination rate and utilization efficiency of the electron donor reported that the bio-electrochemical system (BES) showed a lower RD rate with respect of lactate reactor (51 ± 9 µeq/d compared to 98 ± 4 µeq/d), while the direct utilization of molecular hydrogen gave a significantly lower RD rate (19 ± 8 µeq/d), due to hydrogen low solubility in liquid media. The study also gives a comparative evaluation of the different electron donors showing the capability of the bioelectrochemical system to reach comparable efficiencies with a fermentable substrate without the use of other chemicals, 10.7 ± 3.3% for BES with respect of 3.5 ± 0.2% for the lactate-fed batch reactor. This study shows the BES capability of being an alternative at classic remediation approaches.

scholarly journals REDUCTIVE DECHLORINATION REACTION OF CHLORINATED ALIPHATICS BY ZERO-VALENT IRONS AND ITS DURABILITY OF REACTION RATE

2006 ◽  
Vol 62 (2) ◽  
pp. 268-277
Author(s):  
Masanori NEGISHI ◽  
Masanori SHIMOMURA ◽  
Yuichi HIGUCHI ◽  
Masaki TAKAOKA ◽  
Nobuo TAKEDA
Keyword(s):  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Chlorinated Aliphatics ◽  
Dechlorination Reaction

scholarly journals Degradation of 2,4,6-Trichlorophenol by Phanerochaete chrysosporium: Involvement of Reductive Dechlorination

1998 ◽  
Vol 180 (19) ◽  
pp. 5159-5164 ◽  
Author(s):  
G. Vijay Bhasker Reddy ◽  
Maarten D. Sollewijn Gelpke ◽  
Michael H. Gold
Keyword(s):  
Phanerochaete Chrysosporium ◽  
Reductive Dechlorination ◽  
Oxidation Products ◽  
Ring Cleavage ◽  
Fungal Metabolites ◽  
Subsequent Degradation ◽  
Metabolic Conditions ◽  
The Common ◽  
Dechlorination Reaction

ABSTRACT Under secondary metabolic conditions, the lignin-degrading basidiomycete Phanerochaete chrysosporium mineralizes 2,4,6-trichlorophenol. The pathway for the degradation of 2,4,6-trichlorophenol has been elucidated by the characterization of fungal metabolites and oxidation products generated by purified lignin peroxidase (LiP) and manganese peroxidase (MnP). The multistep pathway is initiated by a LiP- or MnP-catalyzed oxidative dechlorination reaction to produce 2,6-dichloro-1,4-benzoquinone. The quinone is reduced to 2,6-dichloro-1,4-dihydroxybenzene, which is reductively dechlorinated to yield 2-chloro-1,4-dihydroxybenzene. The latter is degraded further by one of two parallel pathways: it either undergoes further reductive dechlorination to yield 1,4-hydroquinone, which isortho-hydroxylated to produce 1,2,4-trihydroxybenzene, or is hydroxylated to yield 5-chloro-1,2,4-trihydroxybenzene, which is reductively dechlorinated to produce the common key metabolite 1,2,4-trihydroxybenzene. Presumably, the latter is ring cleaved with subsequent degradation to CO2. In this pathway, the chlorine at C-4 is oxidatively dechlorinated, whereas the other chlorines are removed by a reductive process in which chlorine is replaced by hydrogen. Apparently, all three chlorine atoms are removed prior to ring cleavage. To our knowledge, this is the first reported example of aromatic reductive dechlorination by a eukaryote.

scholarly journals Reductive Dechlorination of Chloroacetamides with NaBH4 Catalyzed by Zero Valent Iron, ZVI, Nanoparticles in ORMOSIL Matrices Prepared via the Sol-Gel Route

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 986
Author(s):  
Michael Meistelman ◽  
Dan Meyerstein ◽  
Amos Bardea ◽  
Ariela Burg ◽  
Dror Shamir ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Sol Gel ◽  
Reaction Medium ◽  
Zero Valent Iron ◽  
Catalyst Structure ◽  
Organically Modified ◽  
Plausible Mechanism ◽  
Zero Valent Iron Nanoparticles ◽  
Insight Into ◽  
Dechlorination Reaction

The efficient reductive dechlorination, as remediation of dichloroacetamide and monochloroacetamide, toxic and abundant pollutants, using sodium borohydride catalyzed by zero valent iron nanoparticles (ZVI-NPs), entrapped in organically modified hybrid silica matrices prepared via the sol-gel route, ZVI@ORMOSIL, is demonstrated. The results indicate that the extent of the dechlorination reaction depends on the nature of the substrate and on the reaction medium. By varying the amount of catalyst or reductant in the reaction it was possible to obtain conditions for full dechlorination of these pollutants to nontoxic acetamide and acetic acid. A plausible mechanism of the catalytic process is discussed. The present work expands the scope of ZVI-NP catalyzed reduction of polluting compounds, first reports the catalytic parameters of chloroacetamide reduction, and offers additional insight into the heterogeneous catalyst structure of M0@ORMOSIL sol-gel. The ZVI@ORMOSIL catalyst is ferromagnetic and hence can be recycled easily.

Atomically dispersed Pd electrocatalyst for efficient aqueous phase dechlorination reaction

2021 ◽  
pp. 138886
Author(s):  
Zhechuan Mao ◽  
Linghui Liu ◽  
Hong Bin Yang ◽  
Yangliang Zhang ◽  
Zeqing Yao ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Dechlorination Reaction

Synthesis, electrochemistry, spectroelectrochemistry and catalytic properties in DDT reductive dechlorinationin of iron(II) phthalocyanine, 2,3- and 3,4-tetrapyridinoporphyrazine complexes

2013 ◽  
Vol 17 (04) ◽  
pp. 317-330 ◽  
Author(s):  
Jianguo Shao ◽  
Kema Richards ◽  
Dwayne Rawlins ◽  
Baocheng Han ◽  
Christopher A. Hansen
Keyword(s):  
Reductive Dechlorination ◽  
Catalytic Properties ◽  
Catalytic Performance ◽  
Iron Complex ◽  
Binding Property ◽  
Iron Compounds ◽  
Electrocatalytic Mechanism ◽  
Reductive Degradation ◽  
Uv Visible ◽  
Dechlorination Reaction

Iron(II) 2,3- and 3,4-tetrapyridinoporphyrazine complexes (2,3-PyD and 3,4-PyD) were synthesized and characterized as to their electrochemistry, UV-visible spectroelectrochemistry and catalytic properties towards the reductive dechlorination of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (p,p′-DDT) in pyridine, dimethyl sulfoxide (DMSO), N,N′-dimethylacetamide (DMA) and N,N′-dimethylformamide (DMF). These properties were compared with those of the unsubstituted iron(II) phthalocyanine ((Pc) Fe ). Electrochemistry indicates that there are up to three reductions and one oxidation in the three investigated derivatives. The easiest reduction takes place for 3,4-PyD while the most difficult one occurs for (Pc) Fe in all of the solvents investigated. The first reduction is metal-centered corresponding to the formation of [P(-2)Fe(I)]- while the second and third reductions are ring-centered leading stepwise to the generation of [P(-3)Fe(I)]2- · and [P(-4)Fe(I)]3- , where P = phthalocyanine or tetrapyridinoporphyrazine rings. Aggregation exists in the solutions of all three iron complexes and its extent depends upon the nature and concentration of the iron compounds and the binding property of each solvent. The order of the extent of aggregation for the three iron derivatives is 3,4-PyD > 2,3-PyD > (Pc) Fe . Stronger binding solvents such as pyridine and DMSO do not favor the aggregation. The singly and doubly reduced species of investigated complexes, [P(-2)Fe(I)]- and [P(-3)Fe(I)]2- · , are active in DDT reductive dechlorination, the latter of which has better catalytic performance. As a result, three products, 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (p,p′-DDD), 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (p,p′-DDE), and 1,1-bis(4-chlorophenyl)-2-chloroethylene (p,p′-DDMU), were obtained after the dechlorination of DDT catalyzed by each iron complex. The increasing order of catalytic performance is 3,4-PyD < 2,3-PyD < (Pc) Fe in pyridine, which is superior to DMSO and DMA for the DDT dechlorination reaction. An overall electrocatalytic mechanism is proposed for DDT reductive degradation based on the electrochemical and UV-visible spectroelectrochemical results.

In Situ Rapid Dechlorination by Microwave-Assisted Catalytic Reduction of Chlorobenzene and 1,4-Dichlorobenzene on Raney Ni-Al Alloy Catalyst

2019 ◽  
Vol 950 ◽  
pp. 110-116
Author(s):  
Bao Ying Lu ◽  
Xu He Hou
Keyword(s):  
Activation Energy ◽  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Al Alloy ◽  
Microwave Assisted ◽  
Raney Ni ◽  
Dechlorination Reaction ◽  
Alloy Catalyst

Microwave-assisted catalytic reductive dechlorination on Raney Ni-Al alloy catalyst is an efficient method for treatment of chlorobenzene (CB) and 1,4-dichlorobenzene (1,4-DCB). The result shows that the Raney Ni-Al alloy catalyst retains its high activity in this in-situ reductive dechlorination reaction. The reductive dechlorination reaction was in accordance of a psendo-second-order reaction kinetics under the microwave irradiation. The apparent reductive reaction rate constant of CB dechlorination was 0.0175 L/mol·min at 30°C and 0.114 L/ mol·min at 50°C, and the activation energy Ea was 76.24 kJ/mol. The reaction rate constant of 1,4-DCB dechlorination was 0.0376 L/ mol·min at 35 °C and 0.151 L/ mol·min at 50 °C, and the activation energy Ea was 76.66 kJ/mol. The dechlorination for CB and 1,4-DCB was rapid and complete under mild conditions. It shows that the microwave-assisted catalytic in-situ reductive dechlorination on Raney Ni-Al alloy catalyst is an effective method for dechlorination of polychlorinated organic compounds.

Simultaneous Removal of Nitrate and Pentachlorophenol from Drinking Water Using Wheat Straw as Carbon Source

2014 ◽  
Vol 522-524 ◽  
pp. 596-599
Author(s):  
Xu Ming Wang ◽  
Tian Lei Qiu ◽  
Min Gao ◽  
Mei Lin Han ◽  
Jun Lian Gao
Keyword(s):  
Drinking Water ◽  
Carbon Source ◽  
Wheat Straw ◽  
Reductive Dechlorination ◽  
Degradation Mechanism ◽  
Chloride Ion ◽  
Contaminated Water ◽  
Biofilm Carrier ◽  
Contaminated Drinking Water ◽  
Dechlorination Reaction

A novel denitrification process with wheat straw as both carbon source and biofilm carrier was developed to simultaneously remove nitrate and pentachlorophenol (PCP) from contaminated drinking water. The experimental results indicated that the reactor packed with wheat straw could be started up readily, and the removal efficiencies of nitrate and PCP reached approximately 98% and 40%, respectively, with 8 h of HRT at 25 °C. A significant increase in PCP removal was observed with prolonged HRT. Approximately 85% of PCP removal efficiency was reached, and 1.61mg/L of chloride ion was released from the contaminated water containing 5 mg/L of PCP with 16 h of HRT. Reductive dechlorination reaction was a major degradation mechanism of PCP under the denitrifying conditions with wheat straw as carbon source.

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