Applied Chemistry

The metal complexes of Co²⁺ and Ni²⁺ 1,2,3-triazole mixed ligand have been synthesized. The synthesized complexes in different ratios have been characterized by element chemical analysis, molar conductance and Uv-visible and FTIR spectroscopic studies. IR spectra data suggests the involvement of sulphur and nitrogen in coordination to the central metal ions. On the basis of spectral studies and elemental analysis, a tetrahedral geometry was assigned for the nickel complexes while dimerization was suspected for cobalt(II) complexes. The free ligand and metal complexes were tested in vitro against a number of microorganisms (fungi and bacteria) in order to assess their microbial properties. They are found to be proactive against fungi and bacteria upon the metal complexes, nickel complexes performed better than the cobalt complees.

Sulphate-rich acid mine drainage (AMD) generated by some mining industries is a serious issue to water treatment industry operators and the South African government. The aim of carrying this study is to reduce if not completely remove the high concentration of sulphate in the AMD by using reagent grade chemical barium chloride. Precipitation technique was used to synthesize barium sulphate from sulphate-rich acid mine water with the addition of barium chloride solution to form a white precipitate. The precipitate formed was characterized using analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HTREM), Fourier transform infra-red (FTIR) spectroscopy and Brunauer-Emmett-Teller (BET). Synthesized barium sulphate was compared with reagent grade synthesized BaSO4 was characterize with XRD to identify the mineral phase, while SEM and HRTEM revealed similar morphology and the BET surface area for both synthesized and reagent grade barium sulphate crystals were determined to be 7.7 m2/g and 68 m2/g. The results from this study shows that sulphate in the acid mine water can be used to synthesize barium sulphate.

A novel method for analytical detection of H2O2 based on ruthenium nanoparticles (RuNPs) functionalized chemically reduced graphene (CRGR) nanocomposite is developed. The RuNPs/CRGR nanocomposite was characterized employing different techniques, such as transmitted electron microscope (TEM), cyclic voltammetry (CV) and chronoamperometry (CA). The RuNPs/CRGR nanocomposite sensor exhibits higher catalytic effect to H2O2 by greatly enhancing the reduction peak current and completely eliminating the interference of other species as compared with a bare electrode. A fast amperometric response was observed by the RuNPs/CRGR electrode with a linear range from 10 to 170 µM and lower detection limit of 0.16±0.01 µM as compared to some other reports. The high reproducibility, specificity as well as long time stability obtained with the proposed sensor indicated that the present method is an effective for H2O2 determination.

Citrullus lanatus, Cucumeropsis edulis and Lagenaria siceraria are three species of squash widely cultivated and used in food in Benin. The aim of this study is to determinate the physicochemical characteristic and antimicrobial activities of their seeds oil. Oils were obtained by Soxhlet extraction; their quality index were evaluated according to the methods listed in the ‘’AFNOR’’. The oil yield of the seeds of the three cucurbits ranged from 36.23 to 42.28%, the moisture contents of the seeds oils ranged from 0.47 and 0.98%. In terms of quality index, the values are between: 5.04-14.58 mg/g for acid value, 31.70 - 31.86 % for iodine, 1.65 - 8.42 meqO2/Kg-oil for peroxide value, 50.49 - 75.73 mg KOH/g-oil saponification and for ester 40.39 - 70.68%. Their calculated calorific value varies between 44611.05 and 45717.65 Kj /Kg-oil). AAS revealed that these oils had low content of Iron, Manganese and Potassium and do not contain Sodium at all. HPLC showed that the three oils are good sources of fat-soluble vitamins (A, E and K1) with 6.18 mg/100g vitamin E in Citrullus lanatus seeds oil and K1 (0.83 mg / 100g). They were all bacteriostatic and fungistatic on the strains explored but Citrullus lanatus and Cucumeropsis edulis oils had an antibiotic power on Escherichia coli and Staphylococcus aureus.

This work focuses on the management of biomedical waste at the University Hospital Center for Mother and Child - Lagune of Benin wich exhibits deficiencies in compliance with regulations. The study aims to comprehensively assess all stages of solid waste management, including collection, transportation, conditioning, storage, treatment, and final disposal. Weaknesses in waste management are evident, encompassing insufficient trash cans, garbage mixing, incinerator malfunctions, and a lack of training for most hygiene and purification personnel. Furthermore, the study conducted physical and chemical analyses on the wastewater discharged from both the laundry and the wastewater treatment plant (WWTP) into the Cotonou lagoon. Field measurements were taken for physical parameters using a multiparameter measuring device. The suspended solids were determined through filtration, and nitrates and nitrites were quantified using the Nessler and Zambelli methods, respectively. BOD (Biochemical Oxygen Demand) was assessed using a BOD meter, while COD (Chemical Oxygen Demand) was determined through oxidation with potassium dichromate. The analysis results for the laundry's wastewater revealed COD levels of approximately 146 mg/L, BOD5 at 62 mg/L, and suspended solids at 63.74 mg/L. These values, exceeding Benin's standards, raise concerns about the potential impact of discharging these waters into the Cotonou lagoon. It is imperative that these wastewater streams be directed to a treatment station before being released into the lagoon.

Thevetia Nerrifolia and Jathropha Curcas seed oils were extracted from their oil seeds by soxhlet extraction using petroleum ether (40-60 oC) as solvent. The oils were characterized and the oil yield, refractive index acid value, saponification value, iodine value, colour and relative density were found to be 47.77%, 1.464, 4.365 (mg/KOH), 125.62 (mg/KOH), 98.48 (wij), 4+ and 0.926 for Thevetia Nerrifolia seed oil and 46.56%, 1.496, 33.65 (mg/KOH), 175.12 (mg/KOH) 105.43 (Wij), 3 and 0.913 for Jathropha Curcas seed oil respectively. Dimer acids were prepared from these seed oils by heating 200g of each of the oils under nitrogen inert atmosphere in a four necked resin kettle at a temperature of 300oC for 12 hours. The Dimer acids were thenreacted with 1,2- phenylenediamine at 210 ± 10oC in an inert atmosphere for 2 hours to give a fatty polyamide of Thevetia Nerrifolia and Jathropha Curcas respectively. Analysis of the fatty polyamide in term of physicochemical properties shows that their properties compare favourably with those prepared from dimer acids from well known vegetable oils in the fatty polyamidesynthesis.

Coordination compounds derived from N-phthaloylglycine and N-phthaloyltyrosine were synthesized. The ligands were formed by 1:2 molar condensation of phthalic anhydride with tyrosine and glycine respectively. The complexes were formulated as [Zn(PHG)2 (H2O)2] (OAc)2[1], [Ni(PHG)2 (H2O)2] (OAc)2 [2] and [Cu(PHT)2 ] (OAc)2 [3] characterized by melting point, conductivity, AAS , IR, Uv-Visible spectroscopies. Both ligands were found to be bidentate. For complexes [1] and [2] the metal ions coordinate through both oxygen of OH and C=O in the carboxylic group to give octahedral geometry whereas in the [3] the coordination of metal ion occurs through both oxygen of phenoxyl and carbonyl group resulting in tetrahedral geometry. The antimicrobial studies using four test organisms(P.aerugenosa, E.Coli, S. aureus and C. albicans) revealed that the metal complexes exhibit higher activity than their respective ligands.

This study focuses on Sô-Ava’s population well-being regarding to drinking water quality especially in the villages of Ahomey- lokpo and Ahomey-ounmey. Samples of water were taken at three kinds of sites (bollard fountains, river sô and shallows) and analysed for searching their physico-chemical and microbiogical characteristics. The differents parameters values obtained are sometimes higher than standards. Indeed for example the averages are ranged from 0,0264mg/L to 0,5247 mg/L for nitrites and from 0,73mg/L to 2,86 mg/L for total iron. Averages microbiological parameters also range in 0-19600 UFC/100mL for faecal coliforms and 42-560 UFC/100mL for total coliforms and finally 0-190 UFC/100mL for faecal streptococcus.

Alkylation reactions of phenol with dimerization products of devinylated C4-fraction obtained by the pyrolysis of low-octane gasoil were studied in the presence of KU-23 catalyst. Alkylation reaction was carried out on the continuous unit. As a result of alkylation reaction, it was studied the influence of temperature, time, initial components mol ratios and catalyst amount on the yield and selectivity. From the results of the researches it’s evident that alkylation of phenol pyrolysis process with dimerization products of C4-fraction in the presence of KU-23 catalyst are carried out under the following conditions: tempe¬rature 120°C, mole ratio of phenol to the fraction - 1:2, reaction time - 5 hours and catalyst amount - 10%. In this case the yield of the target product on phenol was 80.4%, and selectivity on the target pro¬duct was 95.7%.

Electro polishing is defined as anodic corrosion. The issue of the effects of corrosion on structural integrity of metal surfaces has been a question of concern for some time. The uses of chemical corrosion inhibitors are common in production and processing operations. Nevertheless, the challenge is to develop a new class of corrosion inhibitors to protect the materials, due to the economic importance of copper there are several researches deals with acceleration and inhibition of this process. In this paper the electropolishing process inhibited with different ratio by the addition of some organic alcohols (methanol, ethanol,propanol, and isopropanol) by addition with concentration (2, 5, 10, 15, 20, 25 and 30 %) .The results reveal that these organic alcohols have a strongest inhibitive effect ranging from8. 7 – 53.8 % and the thermodynamic parameters were present.