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The use of 5-azidomethyl-7-morpholinomethyl-8-hydroxyquinoline (AMH) as a corrosion inhibitor for AISI 321 stainless steel in 5.5 M polluted phosphoric acid was investigated using the hydrogen evolution technique, linear polarization curves, and impedance spectroscopy. Impedance measurements revealed that the dissolution of AISI 321 in 5.5 M polluted phosphoric acid was controlled by an activation mechanism, unchanged even with the addition of AMH at different concentrations. Polarization results showed that the inhibition ability was enhanced with increasing inhibitor concentration. AMH acted as a mixed-type inhibitor by random adsorption on the alloy surface, whatever the nature of the reaction that is taking place. The adsorption of AMH on the AISI 321 surface was also discussed via the Langmuir adsorption isotherm. The influence of elevating the solution temperature on the corrosion inhibition performance was studied. A quantum chemistry study with the DFT method was also conducted, which supplied a logical and exploitable theoretical explanation of the adsorption and the inhibition action of AMH on AISI 321.

The corrosion protection of C38 steel in 1M HCl solution with hydro-alcoholic used coffee grounds extract (HECG) was studied using measurements of hydrogen gas evolution, potentiodynamic polarization and electrochemical impedance spectroscopy. This work revealed that the HECG studied acts as a mixed type inhibitor. It has also been shown that the corrosion inhibition efficiency (IE) increases with increasing extract concentration, an IE value of 97.4% was reached with 2 g/L HECG. The inhibitory action of the inhibitor was mainly due to the adsorption of HECG molecules on the C38 steel surface. The studies have shown that HECG adsorbs on the C38 steel surface according to Langmuir's isotherm, with a standard free energy (ΔG0ads) of −18,477 KJ mol−1, which means that HECG delays the corrosion process by physical adsorption. The scanning electron microscope (SEM) study confirmed that corrosion inhibition of C38 steel occurs by adsorption of inhibiting molecules on the metal surface. These results show that the HECG can be used as an excellent corrosion inhibitor for C38 steel in a hydrochloric acid medium. Keywords: Hydro-alcoholic extract of coffee grounds, C38 steel, Hydrochloric acid, Adsorption, Electrochemical impedance, Polarisation curves

A reusable heterogeneous catalyst was obtained from eggshell by a simple heat treatment method. Calcined eggshell was used in the transesterification of vegetable oil with methanol to produce biodi...

In the present work, corrosion behavior of 290 Mo super-ferritic stainless steel was studied in an industrial phosphoric acid and a synthetic solution of phosphoric acid containing some aggressive impurities, for 24 h, with temperatures ranging from 30 to 70 °C. The electrochemical and semiconducting properties of oxide films grown on 290 Mo stainless-steel surface in both solutions were investigated by potentiodynamic polarization curves, impedancemetry and Mott–Schottky analysis. The resistance and stability of the passive film grown on 290 Mo stainless-steel surface were found to decrease as the temperature increased for both corrosive solutions used. The passive film is less stable in the industrial acid than in the synthetic acid. The results have shown that the passive film formed on 290 Mo stainless-steel surface, in a simulated phosphoric acid, is compact with a thickness of the order of 1.2 nm and a resistance that decreases with the increase in temperature but remains at high values in the studied range of temperature. On the other side, the presence of two layers, an internal compact layer under another porous layer, characterizes the passive film grown on 290 Mo stainless-steel surface in industrial phosphoric acid. The resistance of this bilayer structure is severely influenced by the temperature rise. The electronic properties of the passive film and its relation to the corrosion resistance in the studied environments are also discussed.

The degradation of imazapyr (C13H15N3O3), an active element in the aqueous solution of commercial herbicide, was investigated. This study was the first to evaluate in a comprehensive manner the efficiency of advanced oxidation processes for imazapyr degradation. Results showed that Imazapyr degradation is significantly affected by operational conditions such as TiO2 concentration, ozone concentration, initial concentration of imazapyr and pH. The kinetics of Imazapyr consumption was the first order with respect to Imazapyr concentration and zero order with respect to ozone concentration with a constant rate of 0.247 min&minus, 1 and 0.128 min&minus, 1 for photocatalytic ozonation and heterogeneous photocatalysis, while it was the first order with respect to Imazapyr and the first order with respect to ozone concentrations when only ozone was used with a constant rate of 0.053 mol L&minus, 1 min&minus, 1 at pH 7. The results revealed that more than 90 percent of the removal efficiency representing the elimination of imazapyr was held up to 7 &mu, M. Further increase in the concentration of imazapyr leads to a drop in the removal efficiency, however the total imazapyr degradation was reached in 20 min utilizing photocatalytic ozonation for 5 &mu, M of Imazapyr in the presence of 100 mg L&minus, 1 of TiO2, 10 mg L&minus, 1 of ozone at pH 7. Photocatalytic ozonation and heterogeneous photocatalysis utilizing TiO2 as a semiconductor process appeared possible and well suited for the treatment of organic contaminants such as imazapyr herbicides, although at certain dosages of pH and common time for wastewater treatment, imazapyr was not degraded with ozonation on its own. The association of two oxidation processes, ozonation and photocatalysis, has improved oxidation efficiencies for water treatment under optimal conditions, leading to the development of non-selective hydroxyl and more reactive radicals in the oxidation medium, as well as the resulting synergistic effects between photocatalysis and ozonation that react more rapidly with imazapyr herbicide.

Biodiesel is a potential alternative for fossil fuel. However, its large-scale application is held up by the disadvantage of a homogenous process, the scarce availability of raw materials and the production cost, which is higher than for fossil diesel. In this work, biodiesel production was carried out using both refined and used cooking oils. The process was investigated in a batch reactor, in the presence of CaO as a heterogeneous catalyst prepared by the calcination of the natural Waste Grooved Razor Shell (GRS). Characterizations by X-Ray Diffraction (XRD) and Thermal Gravimetric (TG)/Differential Thermal Analysis (DTA) showed that the as-received GRS consists of aragonite, (i.e., CaCO3) as the main component and of water and organic matter in a lower amount. After calcination at 900 &deg, C, CaO was formed as the only crystalline phase. The effects of several experimental parameters in the transesterification reactions were studied, and their impact on the produced biodiesel properties was investigated. The studied variables were the methanol/oil molar ratio, the catalyst weight percentage (with respect to the oil mass), the calcination temperature of the parent GRS and the recycling and regeneration of the catalyst. The physico-chemical and fuel properties, i.e., viscosity, density and acid value of used oils and of the produced biodiesel, were determined by conventional methods (American Society for Testing and Materials (ASTM) methods) and compared with the European standards of biodiesel. The optimal identified conditions were the following: the use of a 15: 1 methanol/oil molar ratio and 5 wt% of CaO with respect to the oil mass. After 3 h of reaction at 65 &deg, C, the biodiesel yield was equal to 94% and 99% starting from waste and refined oils, respectively.

The present work investigates the influence of temperature on C38 steel corrosion in a 1 M HCl medium with and without different concentrations of a hydro-alcoholic extract of used coffee grounds (HECG). The potentiodynamic polarization technique and the electrochemical impedance spectroscopy were performed in temperatures ranging from 293.15 to 323.15 K. It was observed that the inhibition efficiency decreased with increased temperature and inhibitor concentration. The HECG adsorption process on C38 steel surface was found to be spontaneous and obeyed to Langmuir isotherm at all studied temperatures. The associated thermodynamic parameters of adsorption led to suggest the occurrence of physical adsorption of the HECG compounds on the C38 steel surface.

This work aims to characterize and determine the dehydroxylation enthalpy variations of two natural Moroccan clays from the Nador region (denoted K1) and the Settat region (denoted by K2). The variations of dissolution enthalpies were determined by dissolving clays in hydrofluoric acid. They have a minimum value for dehydroxylation of clays made between 600°C and 700°C. The analysis of the two clays shows that they consist of kaolinite in significant proportion. The optimum calcination parameters, for which dehydroxylation is total, are 700°C with a heating time of 6 H. The conversion of the kaolinite to metakaolinite was confirmed by IR analyses of the starting and thermally treated kaolin samples. The result confirms previous observations about obtaining metakaolinite with optimum reactivity when hydrated with calcium hydroxide as chemical activator.

Polyaniline film was prepared by using the repeated potential cycling technique in an acidic solution at the surface of glassy carbon electrode. Then transition metal ions of Ni and Cu were incorporated to the polymer by immersion of the modified electrode. A comparative study of the electrocatalytic oxidation of methanol is made in NaOH, on Ni and Cu on polyaniline film covered glassy carbon electrode (Ni-PANI-GC, Cu-PANI-GC) at 25℃. Catalytic activity for the oxidation of methanol was studied by using cyclic voltammetry.

Microbial fuel cells (MFCs) are an environmentally friendly technology that can recover electricity directly from several wastes at ambient temperatures. This work explores the use of mineral oil refinery wastewater as feedstock in single-chamber air-cathode MFC devices. A polymer inclusion membrane based on the ionic liquid methyltrioctylammonium chloride, [MTOA+][Cl−], at a concentration of 70% w/w, was used as separator, showing a good efficiency in power production and chemical oxygen demand (COD) removal. The power and the chemical oxygen demand removal reached values of 45 mW/m3 and over 80%, respectively. The evolution of other parameters of the wastewater including nitrites, phosphates and sulphates were also studied. Kjeldahl nitrogen and sulphates were significantly reduced during MFC operation. The results show that mineral oil refinery wastewater can be used as feedstock in air breathing cathode-microbial fuel cells based on polymer ionic liquid inclusion membranes. This configuration could represent a good alternative for wastewater depuration while producing energy during the process This work was partially supported by the Spanish Ministry of Science and Innovation (MICINN) and by the FEDER (Fondo Europeo de Desarrollo Regional), Ref. CICYT ENE2011-25188 and by the SENECA Foundation 18975/JLI/2013 grants.

In this paper, several physical and chemical analyses have been performed to determine the composition of the dust naturally deposited on photovoltaic panels installed in our RDI Solar Energy Platform in Rabat. The mineralogical composition was determined by X-Ray Diffraction (XRD) and X-Ray Fluorescence Analysis (XF). Additional characterization has also been performed by Thermal Analysis and Infrared Spectroscopy (IR). XF results show that silica, alumina, iron oxide, calcium oxide, magnesium oxide and potassium oxide are the most abundant elements in the dust. Mineralogical analysis shows that this dust also contains quartz, calcite, kaolin and dolomite. The paper presents also the effect of dust layer thickness on the optical transmittance of Petri dish glass and photo-optical effects and modifications of various materials in the dust on the solar panels.

The reactions of 2-amino-4,5-dicyanoimidazole 1 with lactone 2 in refluxing alcohol has been carried out for the first time and afforded imidazo(1,2-a)pyrimidines 4 and 5a-d. Condensation of compound 1 with 3-acetyl-4-hydroxy-6-methylpyran-2-one in refluxing n-butanol afforded bis(imidazopyrimidine) derivative 6. Reaction of hydrazine hydrate with ester 5 yielded the corresponding hydrazides 8. Condensation of o-phenylenediamines 9 with compound 5 in refluxing xylene or with hydrazides by melting reagents afforded 2,3-dicyano-5-(benzimidazol- 2-yl)methyl-7-methylimidazo(1,2-a) pyrimidines 10a-d.

L'etude in situ de l'oxydation electrocatalytique du 1,2-propanediol sur des electrodes de platine et d'or en milieu aqueux acide ou basique a ete realisee par spectroscopie infrarouge de reflexion. L'objectif de cette etude est l'identification des especes adsorbees et des produits de la reaction. Les spectres IR montrent plusieurs bandes d'absorption notamment deux bandes attribuables au monoxyde de carbone CO adsorbe et au dioxyde de carbone CO 2 . La bande autour de 1720 cm -1 est attribuee a la liaison carbonyle (C=O) d'un aldehyde ou/et d'un acide. A partir des resultats de la spectroscopie infrarouge et des electrolyses prolongees, nous avons propose un mecanisme reactionnel pour l'oxydation electrocatalytique du 1,2-propanediol.

Condensation of 4-hydroxy-6-methyl pyran-2-one 2 with 3-amino-1,2,4-triazole 1 in refluxing alcohol afforded 5-alkoxycarbonylmethyl-7-methyl-1,2,4-triazolo〚1,5-a〛pyrimidines and their isomers 5-alkoxycarbonylmethyl-7-methyl-1,2,4-triazolo〚4,3,-a〛pyrimidines 4. Reaction of hydrazine hydrate with compounds 4 and 5 yielded the corresponding hydrazid acids 6 and 7. Condensation of o-phenylenediamines 8 with esters 3(4) in refluxing xylol or with hydrazid acid 6(7) by melting reagents afforded 7(5)-〚benzimidazol-2-yl〛methyl-5(7)methyl-1,2,4-triazolo〚1,5-a〛(〚4,3-a〛)pyrimidines 9(10). The structures of the annealed compounds have been elucidated by their 1H, 13C NMR and Mass Spectroscopy data.