Enhanced Transformation of Emerging Contaminants by Permanganate in the Presence of Redox Mediators

2019 ◽  
Vol 54 (3) ◽  
pp. 1909-1919 ◽  
Author(s):  
Zhenyu Shi ◽  
Can Jin ◽  
Ruopeng Bai ◽  
Zhanqi Gao ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Redox Mediators

An NADH-Inspired Redox Mediator Strategy to Promote Second-Sphere Electron and Proton Transfer for Cooperative Electrochemical CO2 Reduction Catalyzed by Iron Porphyrin

2020 ◽  
Author(s):  
Peter T. Smith ◽  
Sophia Weng ◽  
Christopher Chang
Keyword(s):  
Proton Transfer ◽  
Co2 Reduction ◽  
Iron Porphyrin ◽  
Redox Mediators ◽  
Reservoir Properties ◽  
Proton Reduction ◽  
Electrochemical Co2 Reduction ◽  
Starting Point ◽  
Rate Improvement ◽  
Molecular Catalysts

We present a bioinspired strategy for enhancing electrochemical carbon dioxide reduction catalysis by cooperative use of base-metal molecular catalysts with intermolecular second-sphere redox mediators that facilitate both electron and proton transfer. Functional synthetic mimics of the biological redox cofactor NADH, which are electrochemically stable and are capable of mediating both electron and proton transfer, can enhance the activity of an iron porphyrin catalyst for electrochemical reduction of CO<sub>2</sub> to CO, achieving a 13-fold rate improvement without altering the intrinsic high selectivity of this catalyst platform for CO<sub>2</sub> versus proton reduction. Evaluation of a systematic series of NADH analogs and redox-inactive control additives with varying proton and electron reservoir properties reveals that both electron and proton transfer contribute to the observed catalytic enhancements. This work establishes that second-sphere dual control of electron and proton inventories is a viable design strategy for developing more effective electrocatalysts for CO<sub>2</sub> reduction, providing a starting point for broader applications of this approach to other multi-electron, multi-proton transformations.

scholarly journals Influence of the phase state of self-assembling redox mediators on their electrochemical activity

AIChE Journal ◽  
2014 ◽  
Vol 60 (4) ◽  
pp. 1381-1392 ◽  
Author(s):  
John P. E. Muller ◽  
Burcu S. Aytar ◽  
Yukishige Kondo ◽  
David M. Lynn ◽  
Nicholas L. Abbott
Keyword(s):  
Phase State ◽  
Electrochemical Activity ◽  
Redox Mediators ◽  
Self Assembling

scholarly journals Environmental impact of emerging contaminants from battery waste: A mini review

2021 ◽  
Vol 3 ◽  
pp. 100104
Author(s):  
Elda M. Melchor-Martínez ◽  
Rodrigo Macias-Garbett ◽  
Alonso Malacara-Becerra ◽  
Hafiz M.N. Iqbal ◽  
Juan Eduardo Sosa-Hernández ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Emerging Contaminants

scholarly journals Removal of Emerging Pollutants from Water Using Environmentally Friendly Processes: Photocatalysts Preparation, Characterization, Intermediates Identification and Toxicity Assessment

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215
Author(s):  
Nina Finčur ◽  
Paula Sfîrloagă ◽  
Predrag Putnik ◽  
Vesna Despotović ◽  
Marina Lazarević ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Sol Gel ◽  
Toxicity Assessment ◽  
Emerging Pollutants ◽  
Simulated Sunlight ◽  
Aquatic Life ◽  
Mgo Nanoparticles ◽  
Emerging Pollutant ◽  
Wheat Germination ◽  
Modern Technologies

Pharmaceuticals and pesticides are emerging contaminants problematic in the aquatic environment because of their adverse effects on aquatic life and humans. In order to remove them from water, photocatalysis is one of the most modern technologies to be used. First, newly synthesized photocatalysts were successfully prepared using a sol–gel method and characterized by different techniques (XRD, FTIR, UV/Vis, BET and SEM/EDX). The photocatalytic properties of TiO2, ZnO and MgO nanoparticles were examined according to their removal from water for two antibiotics (ciprofloxacin and ceftriaxone) and two herbicides (tembotrione and fluroxypyr) exposed to UV/simulated sunlight (SS). TiO2 proved to be the most efficient nanopowder under UV and SS. Addition of (NH4)2S2O8 led to the faster removal of both antibiotics and herbicide fluroxypyr. The main intermediates were separated and identified for the herbicides and antibiotic ciprofloxacin. Finally, the toxicity of each emerging pollutant mixture and formed intermediates was assessed on wheat germination and biomass production.

scholarly journals Chitosan Adsorbent Derivatives for Pharmaceuticals Removal from Effluents: A Review

Macromol ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 130-154
Author(s):  
Efstathios V. Liakos ◽  
Maria Lazaridou ◽  
Georgia Michailidou ◽  
Ioanna Koumentakou ◽  
Dimitra A. Lambropoulou ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Low Cost ◽  
Value Added ◽  
Ph Effects ◽  
Hydroxyl Groups ◽  
Research Papers ◽  
Natural Polysaccharide ◽  
Best Fitting ◽  
Isotherm And Kinetic Models ◽  
Published Research

Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. This review emphasizes on recently published research papers (2013–2021) and briefly describes the chemical modifications of chitosan (grafting, cross-linking, etc.), for the adsorption of a variety of emerging contaminants from aqueous solutions, and characterization results. Finally, tables are depicted from selected chitosan synthetic routes and the pH effects are discussed, along with the best-fitting isotherm and kinetic models.

How anammox responds to the emerging contaminants: Status and mechanisms

2021 ◽  
Vol 293 ◽  
pp. 112906
Author(s):  
Ye Wang ◽  
Xiao-Ming Ji ◽  
Ren-Cun Jin
Keyword(s):  
Emerging Contaminants

scholarly journals Laccases: Versatile Biocatalysts for the Synthesis of Heterocyclic Cores

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3719
Author(s):  
Ana Catarina Sousa ◽  
Lígia O. Martins ◽  
M. Paula Robalo
Keyword(s):  
Membered Ring ◽  
Low Molecular Weight ◽  
Redox Potentials ◽  
Redox Mediators ◽  
Multicopper Oxidases ◽  
Phenothiazine Derivatives ◽  
Ph Values ◽  
Electron Shuttles ◽  
Specific Oxidation ◽  
Optimal Ph

Laccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.

scholarly journals High-Rate Long Cycle-Life Li-Air Battery Aided by Bifunctional InX3 (X = I and Br) Redox Mediators

2021 ◽  
Vol 13 (4) ◽  
pp. 4915-4922
Author(s):  
Sina Rastegar ◽  
Zahra Hemmat ◽  
Chengji Zhang ◽  
Samuel Plunkett ◽  
Jianguo Wen ◽  
...  
Keyword(s):  
Cycle Life ◽  
High Rate ◽  
Redox Mediators ◽  
Long Cycle ◽  
Long Cycle Life ◽  
Air Battery
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