The degradation of diethyl phthalate (DEP) during ozonation: oxidation by-products study

The degradation of diethyl phthalate (DEP) in an aqueous solution during ozonation was investigated by identifying the oxidation intermediates using GC–MS. The experiments were carried out in semi-batch mode with a 1.5 mg l−1-min ozone dose. The proposed degradation pathways were divided into hydrolysis of the aliphatic chain (pathway (A)) and hydroxylation resulting from ∙OH attack in the aromatic ring (pathway (B)). With increasing ozone dose, the aromatic ring of DEP was opened and acidic compounds, such as malonic acid, succinic acid and glutaric acid were formed. In addition, the ozonation of DEP for 18 min induced hydrogen peroxide (H2O2) generation at levels six times higher than pure water. Of the intermediates indentified, phthalic acid (PA) and phthalic anhydride (PAH) enhanced the degradation of DEP by promoting ozone decomposition.

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Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc2008019 ◽

2009 ◽

Vol 74 (1) ◽

pp. 29-42 ◽

Cited By ~ 9

Author(s):

Vilve Nummert ◽

Mare Piirsalu ◽

Signe Vahur ◽

Oksana Travnikova ◽

Ilmar A. Koppel

Keyword(s):

Alkaline Hydrolysis ◽

Rate Constants ◽

Pure Water ◽

Substituent Effects ◽

Benzoic Acids ◽

Resonance Effects ◽

The Media ◽

Substituted Benzoic Acids ◽

Hydrolysis Of ◽

Ortho Substituent

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.

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Post-Plasma Catalysis for Trichloroethylene Abatement with Ce-Doped Birnessite Downstream DC Corona Discharge Reactor

Catalysts ◽

10.3390/catal11080946 ◽

2021 ◽

Vol 11 (8) ◽

pp. 946

Author(s):

Grêce Abdallah ◽

Jean-Marc Giraudon ◽

Rim Bitar ◽

Nathalie De Geyter ◽

Rino Morent ◽

...

Keyword(s):

Corona Discharge ◽

Active Oxygen Species ◽

Surface Acidity ◽

Good Stability ◽

Ozone Decomposition ◽

Moist Air ◽

Plasma Catalysis ◽

Dry Air ◽

Water Tolerance ◽

By Products

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.

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Modulation of PPAR receptor subtype selectivity of the ligands: Aliphatic chain vs aromatic ring as a spacer between pharmacophore and the lipophilic moiety

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/j.bmcl.2008.10.062 ◽

2008 ◽

Vol 18 (24) ◽

pp. 6471-6475 ◽

Cited By ~ 7

Author(s):

Harikishore Pingali ◽

Mukul Jain ◽

Shailesh Shah ◽

Pravin Patil ◽

Pankaj Makadia ◽

...

Keyword(s):

Aromatic Ring ◽

Receptor Subtype ◽

Aliphatic Chain ◽

Subtype Selectivity

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Novel Greener Microwave-Assisted Deprotection Methodology for the 1,3-Dioxolane Ketal of Isatin Using Calix[n]arenes

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20210165 ◽

2022 ◽

Author(s):

Lucas Barbosa ◽

Tiago da Silva ◽

Michelle Rezende ◽

Bianca da Silva ◽

Rodrigo Guzzo ◽

...

Keyword(s):

Aromatic Ring ◽

Sulfonic Acid ◽

Microwave Energy ◽

Protecting Group ◽

Additional Advantage ◽

Microwave Assisted ◽

Combined Use ◽

Ketone Carbonyl ◽

First Time ◽

Hydrolysis Of

In this work, the combined use of p-sulfonic acid-calix[n]arene and microwave energy to hydrolyze the 1,3-dioxolane ketal of isatin was evaluated with excellent results. This is the first time that p-sulfonic acid-calix[n]arene has been used as the catalyst in a ketal hydrolysis reaction and the deprotection of the ketone carbonyl of isatin is reported. The presence of 2.5 mol% of p-sulfonic acid-calix[4,6]arene at 160 ºC resulted in over 96% conversion of this ketal in 10 min, with the additional advantage of using water as a solvent. This catalytic system (aqueous phase containing p-sulfonic acid-calix[4]arene) was reused for five consecutive cycles, with a conversion above 96% maintained. This reusable system is not practicable using p-toluenesulfonic acid and p-hydroxybenzenesulfonic acid as catalysts since both are extracted to the organic phase with the reaction product. The hydrolysis of 1,3-dioxolane ketal of isatins with different substituents (CH3, I, Br, Cl, F, NO2) in the aromatic ring was also evaluated. The protecting group of 5-methyl-isatin was removed with 73% conversion using 2.5 mol% of p-sulfonic acid-calix[4]arene at 160 ºC for 5 min. In contrast, the ketal of 5-nitro-isatin reached 80% conversion using the same conditions after 40 min.

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Remediation of Diethyl Phthalate in Aqueous Effluents with TiO2-Supported Rh0 Nanoparticles as Multicatalytic Materials

Catalysts ◽

10.3390/catal11101166 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1166

Author(s):

Audrey Denicourt-Nowicki ◽

Carl-Hugo Pélisson ◽

Isabelle Soutrel ◽

Lidia Favier ◽

Alain Roucoux

Keyword(s):

Aromatic Ring ◽

Endocrine Disrupting Compounds ◽

Diethyl Phthalate ◽

Aquatic Environments ◽

Wet Impregnation ◽

Advanced Material ◽

Endocrine Disrupting ◽

Arene Hydrogenation ◽

Aqueous Effluents

An innovative “domino” process, based on an arene hydrogenation followed by a photocatalytic step, was designed for the remediation of endocrine disrupting compounds, in highly concentrated aqueous effluents. The novelty relies on the use of TiO2-supported zerovalent Rh nanoparticles as multicatalytic materials (MCMs) for this two-step treatment, applied on diethyl phthalate, which is a model aromatic pollutant frequently present in aquatic environments. This nanocomposite advanced material, which was easily prepared by a green, wet impregnation methodology, proved to be active in the successive reactions, the reduction in the aromatic ring, and the photodegradation step. This sustainable approach offers promising alternatives in the case of photoresistive compounds.

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FTIR as a rapid tool for monitoring molecular weight distribution during enzymatic protein hydrolysis of food processing by-products

Analytical Methods ◽

10.1039/c7ay00865a ◽

2017 ◽

Vol 9 (29) ◽

pp. 4247-4254 ◽

Cited By ~ 17

Author(s):

Sileshi Gizachew Wubshet ◽

Ingrid Måge ◽

Ulrike Böcker ◽

Diana Lindberg ◽

Svein Halvor Knutsen ◽

...

Keyword(s):

Molecular Weight ◽

Molecular Weight Distribution ◽

Weight Distribution ◽

Food Processing ◽

Protein Hydrolysis ◽

Multivariate Approach ◽

Hydrolysis Of ◽

By Products ◽

Rapid Tool

An FTIR-based multivariate approach is developed for monitoring molecular weight distribution during enzymatic protein hydrolysis of byproducts.

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Utilization of Silica from Indonesian Solid Wastes as Catalyst Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.849.72 ◽

2020 ◽

Vol 849 ◽

pp. 72-77

Author(s):

Firman Kurniawansyah ◽

Amila D. Istiqomah ◽

Aisyah J. Malahayati ◽

Himawan Tri Bayu Murti Petrus ◽

Achmad Roesyadi

Keyword(s):

Acidic Solution ◽

Agricultural Waste ◽

Sulphuric Acid Solution ◽

Solid Catalyst ◽

Glucose Yield ◽

Active Metal ◽

Alternative Sources ◽

Hydrolysis Of ◽

Seaweed Industry ◽

By Products

Synthesizing materials can be attempted by utilizing alternative sources such as wastes or disposed/by-products of certain activities. In this article, exploration of silica from agricultural waste and from geothermal sludgefor production of silica catalysts, are presented. The first silica catalyst was synthesized from rice husk. The husk was initially heated until silica ashes could be formed. After immersion in acidic solution, impregnation with nickel and molybdenum were conducted to introduce active metal of nickel (Ni) and molybdenum (Mo) in the support structure. The catalyst formed, Ni-Mo/SiO2 was applied to convert crude palm oil into biofuels. The other silica catalyst was obtained from geothermal sludge. After washing, the catalyst was soaked in sulphuric acid solution to form acidic silica solid catalyst. The catalyst was applied in hydrolysis of seaweed-industry solid waste to produce glucose. The catalyst was relatively successful to facilitate 19-20% glucose yield, or up to 21% glucose selectivity from waste material.

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Influence of Initial Alkalinity of Lignocellulosic Waste on Their Enzymatic Degradation

Archives of Environmental Protection ◽

10.2478/aep-2014-0019 ◽

2014 ◽

Vol 40 (2) ◽

pp. 103-113

Author(s):

Marcin Wołczyński ◽

Marta Janosz-Rajczyk

Keyword(s):

Enzymatic Hydrolysis ◽

Enzymatic Degradation ◽

Suspended Solids ◽

Lignocellulosic Waste ◽

Initial Exposure ◽

Total Sugars ◽

Physical Chemical ◽

Effect Of Treatment ◽

Hydrolysis Of ◽

By Products

Abstract The presented results of research on the effectiveness of enzymatic hydrolysis of lignocellulosic waste, depending on their initial depolymerisation in alkaline medium were considered in the context of the possibility of their further use in the fermentation media focused on the recovery of energy in the form of molecular hydrogen. The aim of this study was to determine the appropriate dose and concentration of a chemical reagent, whose efficiency would be high enough to cause decomposition of the complex, but without an excessive production of by-products which could adversely affect the progress and effectiveness of the enzymatic hydrolysis and fermentation. The effect of treatment on physical-chemical changes of homogenates’ properties such as pH, COD, the concentration of monosaccharide and total sugars and the concentration of total suspended solids and volatile suspended solids was determined. The enzymatic decomposition of lignocellulosic complex was repeatedly more efficient if the sample homogenates were subjected to an initial exposure to NaOH. The degree of conversion of complex sugars into simple sugars during enzymatic hydrolysis of homogenates pre-alkalized to pH 11.5 and 12.0 was 83.3 and 84.2% respectively, which should be sufficient for efficient hydrogen fermentation process.

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