scholarly journals Experimental and Theoretical Study on the Transformation Behavior of Bisphenol S by Radicals Driven Persulfate Oxidation

2021 ◽  
Author(s):  
Junyan Wei ◽  
Linning Yin ◽  
Ruijuan Qu ◽  
Gadah Al-Basher ◽  
Xiaoxue Pan ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Transformation Behavior ◽  
Bisphenol S ◽  
Persulfate Oxidation ◽  
Water Matrix ◽  
Two Systems ◽  
Initial Ph ◽  
Depth Study ◽  
Reaction Potential ◽  
Reaction Barriers

Abstract An in-depth study on the degradation of bisphenol S (BPS) by both single-walled carbon nanotubes and heat activated persulfate (PS) was investigated in detail. The factors like materials dosage, initial substrate concentration, initial pH and water matrix on removal of BPS were evaluated and 10 µM BPS could be completely removed in 90 min under the optimal conditions of [BPS]0: [PS]0 = 1: 100, T = 25 ℃, pH0 = 7.0, [N-SWCNTs] = 20 mg·L− 1. Fast removal of BPS was also obtained when reaction temperature reached 65 ℃ without catalyst. There were 15 intermediates identified in total; and hydroxylation, sulfate addition, carboxylation, the cleavage of S − C bond and polymerization were considered as the main transformation pathways of BPS in both two systems based on LC-MS analysis. The proportion discrepancy of •OH and SO4•− involved in two systems led to different distribution and abundance of observed products. The results of transition state calculation further confirmed the reaction potential of hydroxylation, hydrogen atom abstraction and sulfate addition, and the minimum reaction barriers were 22.20, 25.06 and 13.85 kJ/mol, respectively. The present work firstly reveals the overall transformation behavior of BPS in radicals-triggered PS system by combining experimental and theoretical study.

Experimental and quantum chemical study on the transformation behavior of bisphenol S by radical-driven persulfate oxidation

2021 ◽  
Author(s):  
Junyan Wei ◽  
Linning Yin ◽  
Ruijuan Qu ◽  
Xiaoxue Pan ◽  
Zunyao Wang
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Transformation Behavior ◽  
Sulfate Radicals ◽  
Bisphenol S ◽  
Persulfate Oxidation

The discrepancy between the proportion of hydroxyl and sulfate radicals involved in the PS/N-SWCNTs and PS–heat systems led to different distributions and abundance of products.

Modeling of iron activated persulfate oxidation treating reactive azo dye in water matrix

2011 ◽  
Vol 172 (1) ◽  
pp. 109-121 ◽  
Author(s):  
Hrvoje Kusic ◽  
Igor Peternel ◽  
Sime Ukic ◽  
Natalija Koprivanac ◽  
Tomislav Bolanca ◽  
...  
Keyword(s):  
Azo Dye ◽  
Persulfate Oxidation ◽  
Water Matrix ◽  
Activated Persulfate

scholarly journals Theoretical study on the reaction of triallyl isocyanurate in the UV radiation cross-linking of polyethylene

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37095-37104 ◽  
Author(s):  
Hong Zhao ◽  
Junqi Chen ◽  
Hui Zhang ◽  
Yan Shang ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Uv Radiation ◽  
Theoretical Investigation ◽  
High Voltage ◽  
Energy Surface ◽  
Theoretical Study ◽  
Cross Linking ◽  
Surface Information ◽  
Reaction Potential

Herein, a theoretical investigation on the reaction potential energy surface information of triallyl isocyanurate (TAIC) in the UV radiation cross-linking process of polyethylene is conducted at the B3LYP/6-311+G(d,p) level for the production of high voltage cable insulation materials.

DENSITY FUNCTIONAL STUDY OF SELECTED MONO-ZINC AND GEM-DIZINC RADICAL CARBENOID CYCLOPROPANATION REACTIONS: OBSERVATION OF AN EFFICIENT RADICAL ZINC CARBENOID CYCLOPROPANATION REACTION AND THE INFLUENCE OF THE LEAVING GROUP ON RING CLOSURE

2003 ◽  
Vol 02 (03) ◽  
pp. 357-369 ◽  
Author(s):  
CUNYUAN ZHAO ◽  
DONG-QI WANG ◽  
DAVID LEE PHILLIPS
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Radical Reaction ◽  
Ring Closure ◽  
Functional Study ◽  
Reaction Step ◽  
Leaving Group ◽  
Reaction Barriers ◽  
Leaving Groups ◽  
Zinc Carbenoid

We report a theoretical study of the cyclopropanation reactions of EtZnCHI, (EtZn)2CH EtZnCHZnI, and EtZnCIZnI radicals with ethylene. The mono-zinc and gem-dizinc radical carbenoids can undergo cyclopropanation reactions with ethylene via a two-step reaction mechanism similar to that previously reported for the CH2I and IZnCH2 radicals. The barrier for the second reaction step (ring closure) was found to be highly dependent on the leaving group of the cyclopropanation reaction. In some cases, the (di)zinc carbenoid radical undergoes cyclopropanation via a low barrier of about 5–7 kcal/mol on the second reaction step and this is lower than the CH2I radical reaction which has a barrier of about 13.5 kcal/mol for the second reaction step. Our results suggest that in some cases, zinc radical carbenoid species have cyclopropanation reaction barriers that can be competitive with their related molecular Simmons-Smith carbenoid species reactions and produce somewhat different cyclopropanated products and leaving groups.

Role of inorganic ions and dissolved natural organic matters on persulfate oxidation of acid orange 7 with zero-valent iron

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99935-99943 ◽  
Author(s):  
Huanxuan Li ◽  
Jinquan Wan ◽  
Yongwen Ma ◽  
Yan Wang ◽  
Zeyu Guan
Keyword(s):  
Organic Matter ◽  
Inorganic Ions ◽  
Zero Valent Iron ◽  
Acid Orange 7 ◽  
Organic Matters ◽  
Acid Orange ◽  
Persulfate Oxidation ◽  
Initial Ph ◽  
Natural Organic Matters

The impacts of common anions and organic matter, initial pH and PS dosage on the oxidation of acid orange 7 (AO7) by persulfate (PS) activated with zero-valent iron (ZVI) were investigated.

scholarly journals Influence of water matrix species on persulfate oxidation of phenol: reaction kinetics and formation of undesired degradation byproducts

2018 ◽  
Vol 2017 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Jie Ma ◽  
Haiyan Li ◽  
Yongqi Yang ◽  
Xuening Li
Keyword(s):  
Reaction Kinetics ◽  
Phenol Degradation ◽  
Control Treatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Persulfate Oxidation ◽  
Water Matrix ◽  
Halogenated Phenols ◽  
Influence Of Water ◽  
Oxidation Of Phenol ◽  
Hydrolysis Of

Abstract The present study explored the influence of Cl−, Br−, CO32−, HCO3−, PO43−, HPO42−, NO3−, SO32− and natural organic matter (NOM) on the reaction kinetics and the formation of undesired degradation byproducts during phenol oxidation by heat-activated persulfate (PS). CO32− and PO43− promoted the phenol degradation, because the hydrolysis of CO32− and PO43− created basic pH conditions which were conducive to enhanced PS oxidation rate. Br− promoted the reaction by reacting with sulfate radicals (SO4•−) to produce bromine radicals that can selectively react with electron-rich phenol. NOM scavenged reactive SO4•−, thus inhibiting the reaction. As a strong reducing agent, SO32− rapidly reduced PS, thus completely suppressing the reaction. HCO3−, HPO42−, Cl−, and NO3− had negligible impact on PS oxidation of phenol. Six intermediates were detected in the no anion control using gas chromatography–mass spectrometry (GC-MS). Various toxic halogenated phenols and halogenated hydroquinones were detected in the treatment containing Cl− and Br−. In contrast, in the treatment containing CO32−, HCO3−, PO43−, HPO42−, and NO3−, no new intermediates were identified except for the intermediates already detected in the control treatment. Based on intermediates identified, reaction pathways for PS oxidation of phenol without anions and in the presence of halides were proposed respectively.

scholarly journals REVIEW OF THE BOOK “THE MEANING OF LIFE” WRITTEN BY PROF. RUMEN STAMATOV, D.SC.

2020 ◽  
Vol 13 (2) ◽  
pp. 486-490
Author(s):  
Stoil Mavrodiev
Keyword(s):  
Positive Psychology ◽  
Theoretical Study ◽  
Meaning Of Life ◽  
Depth Study ◽  
Past Life

The review of the book "The Meaning of Life" presents a theoretical study conducted by Rumen Stamatov, dedicated to one of the most complex constructs in psychology. The question of the meaning of life is posed in the field of existential and positive psychology. The author accepts that the understanding of the question of meaning can be represented by four separate questions: Why should I live?; What to do with the rest of my life ?; What meaning can I draw from my past life ?; What could be different in my life? These questions reveal different perspectives in which the problem of meaning arises. The book is perhaps the most in-depth study of these issues written by a Bulgarian author.

scholarly journals Strong adsorption of phosphate by amorphous lanthanum carbonate nano-adsorbents

2021 ◽  
Vol 83 (7) ◽  
pp. 1605-1618
Author(s):  
Yifan Lu ◽  
Huawei Wu ◽  
Yan Xia ◽  
Mei Huang
Keyword(s):  
Lanthanum Carbonate ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Water Matrix ◽  
Wide Range ◽  
Initial Ph ◽  
Wide Ph Range ◽  
Equilibrium Data ◽  
Ph Range ◽  
P Removal

Abstract Phosphorus removal is a crucial aspect of controlling water pollution and eutrophication. In this study, the preparation of lanthanum carbonate (LC) nano-adsorbents for the efficient removal of phosphate (P) from water and wastewater was investigated. Results from XRD, SEM and Zeta potential analyses revealed that addition of magnesium ions and adjustment of the reaction temperature could control the morphology and microstructure of LC. Effects of initial pH, adsorbent dosage, contact time, and the water matrix on P adsorption were investigated. Batch adsorption experiments revealed that LC showed strong performance on P removal over a wide pH range (3.0 to 11.0). The kinetic data followed a pseudo-second-order model, and equilibrium data were well fitted by the Langmuir model with a maximum adsorption capacity of 112.9 mg P/g. Adsorption thermodynamics showed that the adsorption process was exothermic and spontaneous. Results of a monolayer model for single adsorption indicated that P could completely interact with two or more functional groups from the LC surface. In the presence of competing ions (F−, Cl−, SO42−, NO3−, and HCO3−), LC maintained high selectivity for phosphate. For a real effluent, the P concentration was efficiently reduced from 3.2 mg P/L to below 0.5 mg P/L at a dose of 0.5 g/L LC. All the results suggested that LC can serve as a promising adsorbent for P removal in a wide range of pH, and thus could meet the stricter discharge regulations from actual wastewater.

scholarly journals Absence of Non-Linear Effects Despite Evidence for Catalyst Aggregation

2021 ◽  
Author(s):  
Yannick Geiger ◽  
thierry achard ◽  
aline maisse-françois ◽  
Stephane Bellemin-Laponnaz
Keyword(s):  
Catalytic System ◽  
Theoretical Study ◽  
Competition Model ◽  
Catalyst Loading ◽  
Chiral Ligand ◽  
Non Linear ◽  
Catalytically Active ◽  
Depth Study ◽  
Linear Effects ◽  
Linear Product

<p>An in-depth study of the catalytic system, consisting of the enantioselective addition of ZnEt<sub>2</sub> to benzaldehyde with (1<i>R</i>,2<i>S</i>)-(-)-N-Methylephedrine (NME) as chiral ligand, suggests the presence of dimeric and trimeric aggregates, as deduced from product ee vs catalyst loading and NMR investigations (<sup>1</sup>H, DOSY). Formation of catalyst aggregate was excluded in earlier studies as this system displays a linear product ee vs ligand ee-correlation, which is usually taken as an indication for the <i>absence</i> of catalyst aggregation. A subsequent theoretical study, using the monomer-dimer competition model we recently have developed, highlights the possible parameter configurations leading to linear product ee vs ligand ee plots – despite the presence of catalyst dimers. It shows that, while the Kagan and Noyori models allow linearity in very specific cases only, a multitude of scenarios may lead to linearity here, especially if heterochiral dimers are catalytically active.</p>

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