Volume 16, No. 4 (2015)

A GREEN APPROACH FOR THE SELECTIVE REDUCTION OF AROMATIC CARBONYL COMPOUNDS USING RANEY Ni-Al ALLOY

MIRELA SUCEVEANU(1*), ADRIANA FÎNARU(1), MATEI RAICOPOL(2), SORIN I. ROŞCA(2)

Given the significant environmental risk associated with the use of organic solvents and catalysts in the classic reduction reaction catalysts, we are interested in adapting the reaction medium and in developing an eco-friendly methodology for the synthesis of corresponding alcohols in reasonably yields. In this study, the reduction of some aromatic carbonyl compounds with Ni-Al alloy in aqueous alkaline medium was carried out in two versions: with 20 wt% aq NaOH and with 1 wt% aq NaOH without organic solvent. The structures of the reaction products are rigorously proven by gas chromatography-mass spectrometry (GC-MS). There was observed an increase of the reduction reaction rate when we used 1 wt% aq NaOH without addition of organic solvent. For a good part of the studied substrates high conversion and selectivity were achieved by employing mild reaction conditions, minimal environmental pollution and simple work up procedure, foreshadowing yields above 90 % and representing candidates for convenient preparative applications.

NEW ADDUCTS BETWEEN N-[FERROCENYLMETHYL] DIMETHYLAMMONIUM AND HALOMETALLATES: SYNTHESIS AND INFRARED STUDY

MAMADOU NDIAYE(1), ABDOULAYE SAMB(1), LIBASSE DIOP(2*)

Eight new adducts between N-[ferrocenylmethyl]dimethylammonium and halometallates were obtained in ethanolic media. From an infrared study, the suggested structures are monomeric or dimeric for tin compounds which contain [SnCl4(OH)2]2-, [(SnCl5)]- and [(SnI5)]-, [SnCl3(OH)2]- and [(SnI6)]2- complex anions, interacting through hydrogen bonds with the cation, the environments around tin (IV) centers being trigonal bipyramidal or octahedral. For hydrated Cu(II) and Cd(II) adducts, we proposed dimeric structures with hydrogen bridges between cation and water H2O, the environments around Cu(II) being trigonal and trigonal bipyramidal, respective octahedral around Cd(II). One of the compounds may contain the hydrogeno bis [N-ferrocenylmethyldimethylamine] captive cation with a hydrogen bond (N-H….N), the cation interacting electrostatically with [ZnBr4]2-. The crucial role of the cation in all the compounds is outlined. The molecules of cyclopentadiene obtained in situ are lattice.

REMOVAL OF PHENOL AND SURFACTANT FROM LANDFILL LEACHATE BY COAGULATION-FLOCCULATION PROCESS

H. BAKRAOUY(1), S. SOUABI(1*), K. DIGUA(1), A. PALA(2)

Following the action of rainfall and natural fermentation, the stored waste produces a liquid fraction called leachate. This leachate is rich in organic matter (biodegradable but also refractory) and trace elements. There are many techniques of treating the leachate, in particular, biological, physicochemical, membrane processes. The choice of a technique instead of another depends on several parameters including: the age of the leachate, composition... In this work we applied a coagulation-flocculation process to treat intermediate landfill leachate of Rabat city with a combined ferric chloride coagulant and a polymer flocculant. We were inspired by full factorial design, including twenty five experiments, to determine optimal dosages of coagulant and flocculant. We operate at pH 8.4, the best removal efficiencies obtained were 88 % for Turbidity, 98 % for Phenol and 82 % for surfactant. The optimum dosages values determined by this study were 13.2 g∙L-1 of coagulant, 62 mL∙L-1 of flocculant.

THE PREPARATION OF FIXED CARBON DERIVED FROM WASTE TYRE USING PYROLYSIS

NOVE K. ERLIYANTI(1*), HANNY F. SANGIAN(2), SUSIANTO SUSIANTO(3), ALI ALTWAY(3)

This work was aimed at investigating the influence of heating rate, particle size, pyrolysis time and temperature against the content of fixed carbon and characterizing the carbon black using Analysis of Variance (ANOVA). Pyrolysis technique conducted, employed an unstirred semi-batch reactor with capacity 1.150 L, which was equipped by a condenser and operated at 1 atmosphere as well as flowed by nitrogen gas at 1 L∙min-1. The tyre waste used as raw material was 30 g. The research variables used in this study were as follows: heating rate was 10-20 °C∙min-1 particle sizes were -10/+16 mesh, -16/+20 mesh, and -20/+30 mesh; pyrolysis time and temperature were 30-90 min, 400-600 °C, respectively. It was found that heating rate, particle size, pyrolysis time and temperature significantly affected with respect to the content of fixed carbon and carbon black characterization. The biggest content of fixed carbon was 61.8984 %, which was produced at heating rate of 20 °C; particle size was -20/+30 mesh conducted at 600 °C for 90 min. After performing an ANOVA analysis, the best carbon black obtained (iodine number 315.27 mg∙g-1, ash content 3.0983 %) was prepared at heating rate of 10 °C∙min-1, particle size -10/+16 mesh. Meanwhile, the highest moisture was obtained at heating rate of 20 °C∙min-1, particle size -20/+30 mesh with similar pyrolysis time and temperature.

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING, PHENOL- AND CATECHOL-DEGRADING PSEUDOMONAS PUTIDA STRAIN AMR-12 IN SOILS FROM EGYPT

M. ABD. ABDEL-MONGY(1), M.S. SHUKOR(2), S. HUSSEIN(3), A.P.K. LING(4*), N.A. SHAMAAN(5), M.Y. SHUKOR(2,6)

Sites contaminated with both heavy metals and organic xenobiotic pollutants warrants the effective use of either a multitude of bacterial degraders or bacteria having the capacity to detoxify numerous toxicants simultaneously. A molybdenum-reducing bacterium with the capacity to degrade phenolics is reported. Molybdenum (sodium molybdate) reduction was optimum between pH 6.0 and 7.0 and between 20 and 30 °C. The most suitable electron donor was glucose. A narrow range of phosphate concentrations between 5.0 and 7.5 mM was required for optimal reduction, while molybdate between 20 and 30 mM were needed for optimal reduction. The scanning absorption spectrum of the molybdenum blue produced indicated that Mo-blue is a reduced phosphomolybdate. Molybdenum reduction was inhibited by the heavy metals mercury, silver and chromium. Biochemical analysis identified the bacterium as Pseudomonas putida strain Amr-12. Phenol and phenolics cannot support molybdenum reduction. However, the bacterium was able to grow on the phenolic compounds (phenol and catechol) with observable lag periods. Maximum growth on phenol and catechol occurred around the concentrations of 600 mg∙L-1. The ability of this bacterium to detoxify molybdenum and grown on toxic phenolic makes this bacterium an important tool for bioremediation.

PREPARATION OF POZZOLAN WITH A RAW CLAY MATERIAL FROM BURKINA FASO </br> PREPARATION D’UNE POUZZOLANE A BASE D’UNE MATIERE PREMIERE ARGILEUSE DU BURKINA FASO

FRANÇOIS GANON(1), ADAMA YAMEOGO(2), BRAHIMA SORGHO(1), LAMINE ZERBO(1), MOHAMED SEYNOU(1*), YOUNOUSSA MILLOGO(1,3), RAGUILNABA OUEDRAOGO(1)

A raw clay material from Burkina Faso has been characterized for pozzolan elaboration. The analysis showed that SiO2 (45.91 wt. %), Al2O3 (28.29 wt. %) and Fe2O3 (9.75 wt. %) are the main oxides and kaolinite (71 wt. %) is the principle mineral. The sample has been activated at 680 °C during 2 or 5 hours. The pozzolanic activity has been accessed by coupling several methods. The chemical methods showed the good lime fixing ability by the activated sample. At the first 24 hours, more than 50 wt. % of the lime is fixed and at 28 days around 90 wt. % of lime are fixed. Mineralogical analyses showed the disappearing of portlandite (CH) and the formation of new C-S-H hydrates. The pozzolanic index (81 %) calculated from mechanical strength of mortars made with 25 wt. % substitution of cement by the pozzolan confirm it suitability for portland cement replacement in the field of building materials.

MOLYBDATO ORGANOTIN (IV) ADDUCTS AND COMPLEXES: SYNTHESIS AND INFRARED STUDY

MOUHAMADOU BIRAME DIOP(*), LIBASSE DIOP

Nine new molybdato adducts and complexes have been synthesized and studied by infrared spectroscopy. The suggested structures are discrete or infinite chain, the molybdate behaving as a bidentate, mono-, bi- or tetrachelating ligand, the environment around the tin (IV) centre being octahedral or trigonal bipyramidal. In water containing compounds, when extra intermolecular O-H…O or O-H…Cl hydrogen bonds are considered, supramolecular architectures may be obtained.

A BIODEGRADABLE FILM FROM JACKFRUIT (ARTOCARPUS HETEROPHYLLUS) AND DURIAN (DURIO ZIBETHINUS) SEED FLOURS

DIAH S. RETNOWATI(*), RATNAWATI RATNAWATI, APRILINA PURBASARI

The jackfruit (Artocarpus heterophyllus) and durian (Durio zibethinus) seeds contain high portion of amylose, which makes them potential materials for biodegradable films. The objective of this study is to develop biodegradable films composed of jackfruit and durian seed flours and glycerol as plasticizer. The films were prepared by dispersing flours in water, adding glycerol, heating the mixture, casting the solution on an acrylic plate, and drying the films at 50 ºC for 20 hours. Glycerol contributes to the flexibility of the film, while reduces the strength of the film. The Young’s modulus, tensile strength, and elongation at break increase as the ratio of jackfruit to durian seed flour increases. The films made from jackfruit and durian seed flours in this work are stronger than the film made from rice flour obtained by other researcher. Therefore, jackfruit and durian seed flours are potential raw material for biodegradable films.