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A serious environmental problem can arise from the presence of pesticides in soils and waters. Hence, in this study we have carried out the adsorption of the Thiabendazole fungicide onto four soils collected from several areas in Morocco as Larache, Laouamra, Ksar kebir and Tlata drissana. Physicochemical properties, elemental analysis, X-ray diffraction (XRD) were investigated to characterise the four selected soils. The experimental equilibrium data were analysed using Langmuir, Freundlich models. The equilibrium data were best described by a Langmuir model for all adsorbents. The maximum estimated adsorption capacity was 0.747 mg∙g−1, 0.751 mg∙g−1, 0.473 mg∙g−1 and 1.083 mg∙g−1, for Larache, Laouamra, Ksar kebir and Tlata drissana soils, respectively.

The present paper focuses on a hybrid system combining electrochemical oxidation (EO) and activated carbon (AC) adsorption in a concept known as three-dimensional (3D) electrocatalytic technology f...

Photocatalytic degradation of Doxycycline in heterogeneous media constituted by nanoparticles of Fe2O3 and Fe2O3-Bi2WO6 was studied. The Bi2WO6 was prepared by hydrothermal method, and the Fe2O3-Bi2WO6 was obtained by mechanical mixing of Bi2WO6 to an amount of Fe2O3 and their photocatalytic activity to degrade doxycycline (Dox) under UV irradiation supported by H2O2 were studied. The H2O2 reacts with photogenerated electrons leading to the production of hydroxyl radicals (OH●). The Fe2O3 acts like a Fenton reagent, accelerating the production of OH●. In the present study Bi2WO6-Fe2O3/ H2O2 system demonstrate much higher photocatalytic efficiency to degrade Dox than pure Bi2WO6.

Quantum chemical calculations were performed on amitrole used as herbicide in agriculture to investigate its interaction with humic substances which are the main components of soil organic matter. They contain carboxylic, phenolic, amine and quinonic groups as well as specific structural configurations. Global and local reactivity have been studied to predict reactive centers and to determine the favorable site for interaction with surface. The results suggest us that hydrogen bonds are formed between this compound and the amino acids of soil organic matter. The effect of water as solvent is considered since adsorption of pesticide commonly occurs in aqueous environment.

A theoretical study of metalloporphyrins molecules (OEP) M (CH3) (M=Al, Ga, In and Tl) are brought to a few experimental data and to give background for future development of these complexes. The Quantum Chemistry Program (ORCA) program package based on Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TDDFT) for transitions at the B3LYP level with ANO 2ζ+P base was used for calculations and determination of structural properties, electronic properties and orbitals with associated electronic transitions. A structural, energy and orbital analysis was performed to study the interactions between metal and porphyrinic macrocycle, to establish different electronic transitions to understand the influence of the metal’s nature. The results obtained are in good accord with some previous theoretical results and experimental investigations.

The present study focuses on topological analysis of electron density population, structural and thermodynamic properties involved in the reaction between Boric Acid (H3BO3) and Ammonia (NH3) in the synthesis of boron nitride (BN) used in cancer therapy medication and biomedical applications. The compound above has similar properties to carbonaceous materials. Indeed, it exists mainly in the two cubic and hexagonal forms, which are respectively identical to diamond and graphene surfaces. DFT/ M06-2X/aug-cc-pVDZ calculations were performed to determine global reactivity indices and the reaction process that operates via three transition states. ELF function has been achieved to describe the evolution of forming bonds along the IRC path.

Adsorption of imazethapyr, an imidazolinone herbicide, was measured from dilute suspensions onto montmorillonite clay and complexes of montmorillonite with Cu and humic acid. Adsorption of imazethapyr was found to be greater for the Cu-montmorillonite and Cu-humic acid-montmorillonite complexes than by montmorillonite alone. Isotherm shape was similar for all supports studied. Adsorption of imazethapyr varied with pH for montmorillonite and for Cu-humic acid-montmorillonite complex. The pH had no apparent effect on imazethapyr adsorption to the Cu-montmorillonite complex. This might be due to imazethapyr retention at high pH by Cu ions linked to the clay. Imazethapyr adsorption kinetics was faster for Cu-montmorillonite (15 min) and Cu-humic acid-montmorillonite (30 min) than for montmorillonite (240 min). The copper-humic acid complexes with montmorillonite might be used to detoxify water contaminated with imazethapyr.

Complexes of metal (II) halides with N-methyl-1,2,4-triazoles have been prepared, characterized, and studied by magnetism, and electronic and vibrational spectroscopies. The complex with 1:4 stoichiometry is monomeric; those of 1:1 or 1:2 stoichiometries are polymeric. It is seen from electronic studies that metal ions are trans-octahedrally coordinated and chromophores are MX4N2 or MX2N4. These structural results are in accordance with the magnitude of magnetic exchange between metallic ions. The effects of metal–ligand bond formation on the vibrational modes of the studied N-methyl-triazoles show the coordination mode of the ligand. In the low-frequency range, assignments of metal–nitrogen and metal-halide stretching vibrations confirm advanced structural proposals.

Des complexes polymériques de stoechiométrie 1:1 de la 1,2,4-triazole-3-thione avec des halogénures de cuivre(II) ont été préparés et caractérisés par analyse élémentaire des atomes de carbone, d’azote et d’hydrogène. L’analyse de leurs spectres du champ des ligands a permis de situer les transitions d-d et de conclure à une géométrie trans-octaédrique au niveau de l’ion métallique. Une étude approfondie des spectres vibrationnels des complexes et de certains de leurs homologues deutériés, dans les régions des vibrations du ligand et du squelette métallique, a permis de faire une attribution de la plupart des vibrations, de déterminer le mode de coordination du ligand triazolique et de confirmer la géométrie octaédrique proposée. En outre, une modification de la forme tautomère de la 1,2,4-triazole-3-thione au cours de la complexation a été notée comme cela a été le cas pour des complexes analogues du 1,2,4-triazole et du C-bromo-1,2,4-triazole., Journal Marocain de Chimie Hétérocyclique, Vol 8, No 1 (2009)

Les résultats d’études électroniques, vibrationnelles et magnétiques des complexes d’halogénures du nickel(II) et du cuivre(II) avec le 1-methyl-3-chloro-1,2,4- triazole en tant que ligand sont reportés. L’analyse des spectres du champ des ligands a permis d’approcher la géométrie de l’ion métallique, la nature du chromophore et le mode de coordination du ligand organique. Elle a permis d’en conclure que les complexes sont polynucléaires, probablement polymériques. Les valeurs du moment magnétique effectif sont bien dans la zone des ions NiII et CuII octaédriques. De plus, les données magnétiques entre la température ambiante et la température de l’hélium liquide ont montré un échange de nature ferromagnétique entre les ions métalliques. Les données vibrationnelles ont confirmé les résultats structuraux obtenus., Journal Marocain de Chimie Hétérocyclique, Vol 5, No 1 (2006)

In the last years, concepts have been developed to use etched ion tracks in insulators, such as polymer foils or silicon oxide layers as hosts for nano- and microelectronic structures. Depending on their etching procedure and the thickness of the insulating layer in which they are embedded, such tracks have typical diameters between some 10 nm and a few μm and lengths between some 100 nm and some 10 μm. Due to their extremely high aspect ratios, and due to the possibility to cover very large sample areas, they exceed the potential of nanolithography.In this paper, the strategies of etched ion track manipulation are briefly outlined, that lead to the formation of nanotubules, nanowires, or tubular arrangements of nanoclusters. Examples where nanoelectronic structures are based on single ion tracks, are nanocondensors or sensors for temperature, light, pressure, humidity and/or alcohol vapor. By combination of ion track metallization and conducting track-to-track connections on the foil surface, micromagnets, microtransformers and microcondensors could be formed within polymer foils.Finally, we present our new "TEMPOS" (Tunable Electronic Material with Pores in Oxide on Silicon) concept where nanometric pores, produced by etching of tracks in silicon oxide on silicon wafers, are used as charge extraction (or injection) channels. In comparison with the metal oxide semiconductor field effect transistors (MOS-FETs), the TEMPOS structures have a number of additional parameters (such as the track diameter, density, and shape, and the material embedded therein and its spatial distribution) which makes these novel structures much more complex. This eventually leads to higher compactation of the TEMPOS circuits and to unexpected electronic properties. TEMPOS structures can overtake the function of tunable resistors, condensors, photocells, hygrocells, diodes, sensors, and other elements. As an example, some corresponding current/voltage relations and TEMPOS circuits are presented. In this work we concentrate on TEMPOS structures with fullerene and phthalocyanine. Though not yet verified, TEMPOS structures could, in principle, be scaled down to nanometer sizes.

New solder alloys are being developed for electronic assemblies in replacement for traditional Pb-containing solder materials. New low-melting-point, Sn–In–Ag-based alloys have been investigated. Corrosion resistance and the influence of In and Ag content on the electrochemical behaviour have been studied for some Sn–In–Ag special alloys in 3% NaCl solution. The good resistance of this ternary system has been confirmed, and the increase of corrosion resistance with Ag content of Sn–In–Ag alloys has been established.

L'adsorption de l'octaethylporphyrine de nickel (OEP)Ni par l'hydroxy (HAP) ou la fluorapatite (FAP) phosphocalciques s'est traduite par le transfert de (OEP)Ni de la solution vers le solide apatitique. Ce transfert est justifie tout d'abord par la diminution de la concentration de (OEP)Ni dans la phase liquide. En plus, il est mis en evidence par les donnees UV-visible du solide apatitique - dont la couleur passe du blanc au rose apres adsorption - qui temoignent clairement de l'association (OEP)Ni - apatite. Cette adsorption suit la loi de Langmuir; elle est plus importante pour la FAP que pour la HAP. L'addition des ions calcium ou phosphate au melange apatite-porphyrine inhibe le phenomene d'adsorption, ce qui favorise l'hypothese d'une association de la porphyrine a l'apatite via les sites aussi bien cationiques qu'anioniques.

By differential thermal analysis (DTA) and potentiometry, a part of the Ag–Bi–In ternary system (with 0

This study aims to attempt a treatment strategy based on fungi immobilized on silica-alginate (biocom- posites) for removal of phenolic compounds in olive oil mill wastewater (OMW), OMW supplemented (OMWS) with phenolic compounds and water supplemented (WS) with phenolic compounds, thus decreasing its potential impact in the receiving waters. Active (alive) or inactive (death by sterilization) Pleurotus sajor caju was encapsu- lated in alginate beads. Five beads containing active and inactive fungus were placed in a mold and filled with silica hydrogel (biocomposites). The biocomposites were added to batch reactors containing the OMW, OMWS and WS. The treatment of OMW, OMWS and WS by active and inactive biocomposites was performed throughout 28 days at 25 C. The efficiency of treatment was evaluated by measuring the removal of targeted organic compounds, chemical oxygen demand (COD) and relative absorbance ratio along the time. Active P. sajor caju biocomposites were able to remove 64.6-88.4 % of phenolic compounds from OMW and OMWS and 91.8-97.5 % in water. Fur- thermore, in the case of OMW there was also a removal of 30.0-38.1 % of fatty acids, 68.7 % of the sterol and 35 % of COD. The silica-alginate-fungi biocomposites showed a high removal of phenolic compounds from OMW and water. Furthermore, in the application of biocomposites to the treatment of OMW it was observed also a decrease on the concentration of fatty acids and sterols as well as a reduction on the COD.

Manganese(II), iron(II), cobalt(II), nickel(II) and copper(II) halide complexes with 1,2,4-triazole as a ligand were synthesized and studied. Their structures were discussed on the basis of electronic and magnetic data. The electronic spectra of the compounds prepared (MX2TA:M = Fe, Co, Ni, Cu, X = Cl; M = Co, Ni, Cu, X = Br; MX2TA2: M = Co, Ni, Cu, X = Cl; M = Mn, Co, Ni, X = Br; TA = 1,2,4-triazole) were analysed in the range 5000–50,000 cm−1. The values obtained for Dq and B and the room temperature magnetic moments are consistent with a pseudo-octahedral arrangement for the metal. This implies that the complexes are polynuclear, probably polymeric. Using variable temperature magnetic susceptibility data, the parameters C, g and θ were determined. The iron, cobalt and copper compounds studied exhibit an antiferromagnetic interaction with a particular magnetic behaviour for CuX2TA2 compounds. NiX2TA complexes show a ferromagnetic exchange coupling. Moreover, a sharp maximum is observed in the ηp vs T plots of these two compounds at temperatures below that at which the ferromagnetic intra-chain interactions operate.

Twelve heteroleptic double-decker complexes [M{sup IV}(P)(Pc)]{sup n} (M = Zr, Hf; P = dianionic octaethylporphyrin (OEP) or tetraphenyporphyrin (TPP), Pc = phthalocyanine) were prepared. The complexes were characterized by NMR, UV-vis, IR, and EPR spectroscopies and the electrochemistry of the complexes was evaluated by cyclic voltammetry. Shifts in redox potentials for these compounds and Th(IV) and U(IV) analogs are considered.