Invited for this month's cover picture is the group of Prof. Susana I. Córdoba de Torresi from Universidade de São Paulo (Brazil). The cover picture shows SO2 oxidation and the interfacial water ...dependence. Read the full text of the Article at 10.1002/celc.201902122.
“A detailed electrochemical and spectroelectrochemical investigation is handled to figure out how the electrolyte chaotropicity affects the reaction pathway. Adsorption properties and water behavior at different media help in the understanding of why the intermediates responsible for oscillations are observed just at chaotropic media and why the “neutral” chaotropicity is the most active one…” Learn more about the story behind the research featured on the front cover in this issue's Cover Profile. Read the corresponding Article at 10.1002/celc.201902122.
•Wastewater treatment plants effluents constitute the major source of PhACs in aquatic environment.•Nano-filtration is an effective technique for PhACs removal from wastewater.•Coupling of AOPs with ...membrane filtration as pre/post-treatment or hybrid process.•Hybrid process is only possible with photocatalysis or EAOPs.•EAOPs–membrane filtration is an efficient hybrid wastewater treatment technique.
Pharmaceuticals as emerging pollutants have become a major concern not only because of the threat posed to health and safety of the aquatic life but also due to their continuous accumulation in aquatic environment and development of antibiotic-resistant microbial strains. Single classical water treatment techniques have been generally inadequate for the removal of these hazardous substances. Combined treatment techniques such as membrane separation and advanced oxidation processes (AOPs) is an exciting technology for complete removal of these pollutants because each technique complements the advantages and overcomes the challenges of the other. Technical flexibility of membrane separation technology has allowed possible integration/coupling with several AOPs as: pretreatment stage for removal of organics (which may cause membrane fouling) from membrane feed stream; post-treatment stage for oxidation of organics in both membrane permeate and concentrate streams or one pot/hybrid process for concurrent separation and oxidation of pollutants in the feed stream. AOPs such as ozonation, peroxone (O3/H2O2), UV/H2O2, photo-Fenton, photocatalysis and electrochemical advanced oxidation processes (EAOPs) have been successfully integrated with membrane separation for removal of pharmaceuticals from water and they are critically examined in this review.
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•Exhaustive review of applied electrochemical oxidation to treat actual effluents.•Electrogenerated active chlorine species and hydroxyl radicals are the main oxidants of organic ...pollutants.•Disinfection of wastewaters also feasible by electrochemical oxidation.•Combined electrochemical oxidation with other technologies as integrated, pre- or post-treatment.
Fate and health risks associated with persistent organic pollutants present in water effluents are one of the major environmental challenges of this century. In this paper, the electrochemical advanced oxidation process electrochemical oxidation is reviewed for its performance over the treatment of actual industrial and urban effluents. The electrochemical treatment of industrial effluents resulting from textile dyeing, petrochemical, paper mill, tannery industry as well as the treatment of domestic and urban wastewaters are discussed. Furthermore, the combination of electrochemical oxidation with other water treatment technologies as pre-treatment, post-treatment, and integrated treatment is also examined.
Invited for the cover of this issue is Ariela Burg from the Sami Shamoon College of Engineering, Beer‐Sheva, Israel. The cover image shows a sol–gel electrode in which a nickel complex is entrapped. ...This system serves as an electrocatalyst for the oxidation of amines.
By selecting the appropriate precursors, sol–gel matrices can be prepared with entrapped redox reagents that can be applied as electrocatalysts and/or redox catalysts for the decomposition of pollutants...
Read more about the story behind the cover in the Cover Profile and about the research itself on p. 459 ff.
The first synthesis of gracilioetherF, a polyketide natural product with an unusual tricyclic core and five contiguous stereocenters, is described. Key steps of the synthesis include a Lewis acid ...promoted ketene-alkene 2+2cycloaddition and a late-stage carboxylic acid directed C(sp3)H oxidation. The synthesis requires only eight steps from norbornadiene.
Silver nanoclusters capped with bovine serum albumin (AgNC@BSA) were synthesized and applied for the electrocatalytic reduction of CO2. Inspired by the fact that many enzymes function only in the ...presence of coenzymes/cofactors that transfer electrons/protons or other groups, an electron transfer mediator was introduced to facilitate the electrical communication between the electrode and the strongly protected catalyst. The AgNC@BSA catalyst mediated by alpha-SiW12O404- anions showed high electrocatalytic activity for CO2 reduction, which was not observed with either component on its own, in dimethylformamide containing 1% (v/v) water. CO was the major product with excellent faradaic efficiency (>75%). The onset potential for this catalytic CO2 reduction process is about 400mV more positive than that found at a bulk silver electrode. This mediator-enhanced catalysis concept provides a general approach to investigate the electrocatalytic activities of nanoclusters, which remain largely unexplored.
The direct functionalization of an aliphatic C-H bond within a complex molecule through a free-radical pathway is a valuable tool in synthetic chemistry. Herein, we developed an efficient ...transition-metal-free approach to generate Delta2-isoxazolines from oximes by radical-mediated C(sp3)-H oxidation. Investigation of the mechanism suggested that in the presence of Selectfluor and Bu4NI, the homolysis of the in situ formed O-I bond generated an iminoxyl radical that facilitated subsequent 1,5-H transfer and C(sp3)-H oxidation.
Physicochemical properties constitute a key factor for the success of a drug candidate. Whereas many strategies to improve the physicochemical properties of small heterocycle-type leads exist, ...complex hydrocarbon skeletons are more challenging to derivatize because of the absence of functional groups. A variety of CH oxidation methods have been explored on the betulin skeleton to improve the solubility of this very bioactive, yet poorly water-soluble, natural product. Capitalizing on the innate reactivity of the molecule, as well as the few molecular handles present on the core, allowed oxidations at different positions across the pentacyclic structure. Enzymatic oxidations afforded several orthogonal oxidations to chemical methods. Solubility measurements showed an enhancement for many of the synthesized compounds.
: Water is a scarce resource and is considered a fundamental pillar of sustainable development. The modern development of society requires more and more drinking water. For this cleaner wastewater, ...treatments are key factors. Among those that exist, advanced oxidation processes are being researched as one of the sustainable solutions. The main objective of this manuscript is to show the scientific advances in this field.
: In this paper, a systematic analysis of all the existing scientific works was carried out to verify the evolution of this line of research.
: It was observed that the three main countries researching this field are China, Spain, and the USA. Regarding the scientific collaboration between countries, three clusters were detected-one of Spain, one of China and the USA, and one of Italy and France. The publications are grouped around three types of water: industrial, urban, and drinking. Regarding the research, 15 clusters identified from the keywords analyzed the advanced oxidation process (alone or combined with biological oxidation) with the type of wastewater and the target pollutant, removal of which is intended. Finally, the most important scientific communities or clusters detected in terms of the number of published articles were those related to the elimination of pollutants of biological origin, such as bacteria, and of industrial nature, such as pesticides or pharmaceutical products.
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