Synergistic Effect of Microwave Calcination and Sonophotocatalytic Activity of TiO2-Montmorillonite on The Degradation of Direct Yellow 106 and Disperse Violet 1

The TiO2-pillared montmorillonite nanoparticles (TiO2-Mt) were prepared by the sol-gel method, then applied for the elimination of dyes in solution: CI Direct Yellow 106 (DY106) (azo dye) and CI Disperse Violet 1 (DV1) (anthraquinone dye) by the sonocatalytic, photocatalytic and sonophotocatalytic processes, in order to test the efficiency of photocatalysts, while photolysis, sonolysis, and sonophotolysis tests have been done previously. The photocatalysts (TiO2-Mt) were characterized by X-ray Diffraction (XRD), X-ray Fluorescence analysis (XRF), Brunauer-Emmet-Teller (BET), Scanning Electron Microscopy (SEM) methods, thermal and thermogravimetric analysis (TG/DTA) and the zero load point (pHpzc). Aqueous solutions of dye of an initial concentration (50 mg/L), in the presence of 1 g/L of photocatalyst, were irradiated using a mercury lamp (Hg) of 40 Mw/cm2 and put in contact with an ultrasonic probe with a frequency of 20 kHz and a power of 750 W, providing the ultrasound. The results obtained indicate that a weak, good and better dye degradation rate has been observed successively by the application of the sonocatalytic, photocatalytic and sonophotocatalytic processes, where the latter has shown a synergistic effect, while the photocatalyst TiO2-Mt/MW showed significant efficiency during the degradation, due to the beneficial effect of the microwave calcination mode. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Priprema kromatografskog medija iz alžirskog dijatomita

X-ray photoelectron spectrometry combined with FTIR spectroscopy, X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) allowed highlighting the different interactions of grafts or impregnated polymers on the mineral surface of diatomite obtained by treatment of raw diatomite under reflux with a 5 M solution of hydrochloric acid for 24 h. This acid treatment led to almost total elimination of organic impurities with a total decalcification of the diatomite, leading to its deferrization and partial dealumination, and the obtaining of a support with a homogeneous siliceous surface mainly constituted of Si−OH and Si−O−Si functional groups. The surface of the diatomite washed with HCl became totally saturated with PEG-20M and SE30 with respective impregnation rates of 5 and 2 %. However, the grafting and/or impregnation of this diatomite with octadecyltrichlorosilane (C18) and docosane (C22) led to the formation of perfectly homogeneous surfaces. This work is licensed under a Creative Commons Attribution 4.0 International License.Rendgenska fotoelektronska spektroskopija u kombinaciji s FTIR spektroskopijom, rendgenskom difrakcijskom analizom (XRD) i skenirajućom elektronskom mikroskopijom (SEM) omogućila je uvid u različite interakcije graftova ili impregniranih polimera na mineralnoj površini dijatomita dobivenih obradom sirova dijatomita pod refluksom 5 M otopine klorovodične kiseline tijekom 24 h. Navedena kiselinska obrada gotovo je u potpunosti uklonila organske nečistoće uz potpunu dekalcifikaciju dijatomita, deferizaciju i djelomičnu dealuminaciju, uz dobivanje kvarcne površine koja se uglavnom sastojala od funkcionalnih skupina Si−OH i Si−O−Si. Površina dijatomita isprana HCl-om u postala je u potpunosti zasićena PEG-20M-om i SE30-icom s impregnacijom od 5 odnosno 2 %. Graftiranje i/ili impregnacija dijatomita oktadeciltriklorosilanom (C18) i dokozanom (C22) dovela je do stvaranja savršeno homogenih površina. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Influence of Operational Parameters on Photocatalytic Degradation of Linuron in Aqueous TiO2 Pillared Montmorillonite Suspension

TiO2 pillared clay was prepared by intercalation of titan polyoxocation into interlamelar space of an Algerian montmorillonite and used for the photocatalytic degradation of the linuron herbicide as a target pollutant in aqueous solution. The TiO2 pillared montmorillonite (Mont-TiO2) was characterized by X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), X-Ray fluorescence (XRF), scanning electronic microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), Fourier transformed infra-red (FT-IR), specific area and porosity determinations. This physicochemical characterization pointed to successful TiO2 pillaring of the clay. The prepared material has porous structure and exhibit a good thermal stability as indicated by its surface area after calcination by microwave. The effects of operating parameters such as catalyst loading, initial pH of the solution and the pollutant concentration on the photocatalytic efficiency and COD removal  were evaluated. Under initial pH of the solution around seven, pollutant concentration of 10 mg/L and 2.5 g/L of catalyst at room temperature, the degradation efficiency and COD removal of linuron was best then the other operating conditions. It was observed that operational parameters play a major role in the photocatalytic degradation process. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis and characterization of TiO2–Montmorillonite/Polythiophene-SDS nanocomposites: Application in the sonophotocatalytic degradation of rhodamine 6G

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Hemisinteza derivata tiona i tiola iz eteričnog ulja biljke Artemisia judaica L. i antimikrobni testovi

The applications of organosulfur compounds, especially thioketones are varied which concerns both synthetic and biological chemistry. In this context, from the essential oil of Artemisia judaica L., extracted by hydrodistillation, and consisting mainly of piperitone (91.77 %), thione, and thiol derivatives were hemi-synthesized via a thionylation reaction byphosphorus pentasulphide (P2S5). The possible thione-thiol tautomerism in solution followed spectrophotometrically revealed the predominance of thiol form in solution. The antimicrobial activity of essential oils showed that the thionylation of essential oil caused a considerable increase in antimicrobial activity in particular against Escherichia coli. This work is licensed under a Creative Commons Attribution 4.0 International License.Iz eteričnog ulja biljke Artemisia judaica L., koje se uglavnom sastoji od piperitona (91,77 %), a dobiveno je hidrodestilacijom, reakcijom tionilacije pomoću fosforova pentasulfida (P2S5) hemisintetizirani su tion i tiol derivati. Moguća tion-tiolna tautomerija praćena je spektrofotometrijski. Analiza je pokazala da u otopini dominira tiolni oblika. Također, pokazalo se da tionilacija eteričnog ulja uzrokuje znatno povećanje antimikrobne aktivnosti, osobito kad je u pitanju bakterija Escherichia coli. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Thionation of Essential Oils from Algerian Artemisia Herba-alba L. and Ruta Montana L.: Impact on their Antimicrobial and Insecticidal Activities

Essential oils were extracted from Artemisia herba-alba L. and Ruta montana L. by means of steam distillation and thionated with a reagent combination of phosphorus pentasulfide and sodium bicarbonate. Both parent essential oils and their modified ones were screened for their biological and insecticidal activities. The results showed that essential oils were composed mainly of ketones; essential oils from Artemisia herba-alba L. and those from Ruta montana L. consisted of bicyclic monoterpenes and acyclic aliphatic ketones (thujone, camphor and 2-undecanone), respectively. The antimicrobial activity of essential oils was substantially improved upon thionation (from 10 to 34 mm and from 11 to 32 mm). The insecticidal effect of the thionated essential oil from Ruta montana L. was observed to be very significant, but that of the essential oil from Artemisia herba-alba L. was observed to decrease (from 100% to 70% after 24 hrs. The extracted essential oils as well as their thionated forms were characterized by GC-MS, FT-IR, and UV-visible

<i>Mentha pulegium</i> extract as a natural product for the inhibition of corrosion. Part I: electrochemical studies

<div><p>The inhibitory effect of <i>Mentha pulegium</i> extract (MPE) on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy. The inhibition efficiency of MPE was found to increase with the concentration and reached 88% at 33% (v/v). Polarisation measurements show that the natural extract acted as a mixed inhibitor. The remarkable inhibition efficiency of MPE was discussed in terms of blocking of electrode surface by adsorption of inhibitor molecules through active centres. The adsorption of MPE was found to accord with the Temkin isotherm.</p></div

Antimicrobial Activity of the Thio-Cyclized Lippia citriodora Leaf Essential Oil Cultivated in Algeria

peer reviewedThe essential oil of Lippia citriodora extracted by hydrodistillation from dry leaves with a yield of 0.3 % which characterization by TLC, UV-Vis, and IRTF analyses make it possible to distinguish the presence of aldehydes functions within the chemical composition. The GC-MS has permitted to confirm and to identify the neral and the geranial in appreciable proportions in the chemical composition of Lippia citriodora essential oil. The thionation of the carbonyl compounds of the essential oil has led to the transformation of the carbonyl compounds into corresponding thiones. The UV-Vis spectroscopy and the FT-IR spectra have shown the disappearance of the aldehyde function and its replacement by thione and thiol functions in solution by tautomery. The GC-MS has permitted to identify the formation of unsaturated cyclic compounds such as the 2-Isopropyl-5-methyl-cyclohexa-2,5-dienethione, the 6-Isopropyl-3-methyl-cyclohexa-2,4-dienethione and the 5-Isopropenyl-2-methyl-cyclohex-2-enethione, as well as an aromatic compound namely the thiothymol (2-Isopropyl-5-methyl-benzenethiol).The antibacterial and especially antifungal activity of the essential oil of Lippia citriodora has been greatly improved with the replacement of the oxygen by the sulphur and therefore the increase of the hydrophobic character and the volatility of the chemical composition of the oil