Open Access Original Research Article

Metal Contamination of a Fish Species (Mugil curema) of the Beach of Soumbedioune (Dakar/Senegal)

Ibrahima Diagne, Cheikh Tidiane Dione, Momar Ndiaye, Cheikhna Diebakate, Birame Ndiaye, Dame Cisse, Maoudo Hane, Abdoulaye Diop

Chemical Science International Journal, Page 1-6
DOI: 10.9734/CSJI/2018/40583

This present work consists in studying the metal contamination of the beach of Soumbédioune, located at the western frontage of the Dakar area. This site, unloading place of fishery products, includes the channel IV which drains urban rejected waters. We determined the concentrations of the metal elements (Fe, Zn, Cr), in Mugil curema with spectrophotometry UV-visible. Metal elements can be very dangerous for human health when they are present in the environment at high concentrations. Thus the study of the metal contamination in the marine organism, in particular fish, makes it possible to envisage a possible contamination of the man. The results obtained show that the concentrations of the metal elements vary according to the weight and the size of the mullets. T he maximum content in chromium of 133 µg/g was obtained with Mugil curema1, that out of iron was of 85.5 µg/g with Mugil curema8 and that out of zinc obtained with Mugil curema1 was of 150 µg/g. However the found values are definitely higher than the standards established by FAO and the EEC.

Open Access Original Research Article

The Influence of Different Acid Chloride on the General Characterizations, Electrical and Ultrasonic Mechanical of Terpolymers: Comparison Study

Momen S. A. Abdelaty, Abdel Haliem M. Hussien, Kamal I. Ali

Chemical Science International Journal, Page 1-13
DOI: 10.9734/CSJI/2018/40757

Unsaturated terpolyesters have been prepared and investigated by chemical and physical instruments. The effect of acid chloride in the general physical characterizations of terpolyesters was the aim of study. The solubility of terpolyesters has been tested in different solvents. The viscosity average molecular weight was determined according to Mark-Hounwink equation using some standards polymers. The thermal stability and glass transition temperature was recorded by Thermogravimeteric analysis and Differntional thermal analysis respectively. The crystallinity has also been investigated by X-ray diffractogam. Moreover, the morphology and shape of terpolyesters was scanned by scanning electron microscopy. The electrical properties especially dielectrical constant of polymer material have been discussed with some detailed. Our target of study focused on the improvement of physical properties of new unsaturated terpolyesters                   with special interest to the electrical and mechanical properties to be applicable as insulator material.

Open Access Original Research Article

Thiourea Doped Silica Composite for Lead Removal: Isotherm, Kinetic, and Thermodynamic Studies

Oluwatoyin Iyanu Omotunde, Bamikole Walter Osungbemiro

Chemical Science International Journal, Page 1-11
DOI: 10.9734/CSJI/2018/40922

In this study, series of experiments were carried out in batch in order to examine the possibility of thiourea doped silica composite for the removal of lead under different experimental conditions. Adsorption of lead (II) ions was investigated with the difference in the parameters of pH, contact time, and lead (II) ions concentration. The adsorption of lead followed pseudo-second-order rate kinetics. Intra-particle diffusion was established not to be the sole rate-controlling step. Thermodynamic studies tell that the adsorption of lead was endothermic and spontaneous, with a good affinity of the adsorbent. Various isotherm models viz, Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Harkins-Jura isotherms were used to evaluate the equilibrium data. The Freundlich and Temkin models were established to be in actual agreement with the experimental data with high R2, low RMSE, and low χ2 values. The maximum adsorption capacity calculated from Langmuir isotherm was 42.31 mg/g at optimum condition of pH 4 and contact time of 60 min.

Open Access Original Research Article

Study of Competitive Behavior of Cd(II) and Pb(II) Ions Through a Bulk Liquid Membrane

Mersiha Suljkanović, Jasmin Suljagić

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2018/41127

Aims: To investigate the competitive behavior of Cd(II) and Pb(II) ions within their equimolar mixtures, during transportation through a bulk liquid membrane, using macrocyclic carriers.

Study Design:  Study was based on transport experiments, using homemade transport cell.

Place and Duration of Study: Department of Analytical Chemistry, Faculty of Technology, between September 2017 and February 2018.

Methodology: The bulk liquid membrane systems consisted of homemade transport cell constructed for transport of cations. Cell contained three separated phases: two aqueous and non-aqueous membrane phase between them. 1,2-dichloroethane (1,2-DCE) and dichloromethane (DCM) were used as liquid membranes. Macrocyclic ligands: dibenzo-18-crown-6 (DB18C6) and 18-crown-6 (18C6) were used as ligands for cations within the membranes. Both aqueous phases were buffered at pH = 5. Source phase contained an equimolar mixture of investigated metal ions and picrates as counter ions. Receiving phase contained thiosulphate as stripping agent. Duration of transport experiments were 3 hours and concentration of transported cations was measured using flame atomic absorption spectrometry.

Results: Higher ligand selectivity for Pb(II) ions resulted with higher transport rates compared to Cd(II) ions: 63.25% of Pb(II) > 51.80% of Cd(II) using 18C6 in 1,2-DCE; 38.90% of Pb(II) > 30.50% of Cd(II) using DB18C6 in 1,2-DCE; 43.15 % of Pb(II) > 35.40 % of Cd(II) using 18C6 in DCM and 26.75% of Pb(II) > 8.90% of Cd(II) using DB18C6 in DCM. Higher selectivity of 18C6 as ionophore is also evident here. 1,2-DCE showed higher efficiency compared to DCM in competitive experiments (unlike individual experiments). Overall transport of Pb(II) in competitive experiments is lower compared to individual ones in DCM membrane: 40.30%<70.40% (with 18C6) and 26.75%<36.05% (with DB18C6). Overall transport of Cd(II) in competitive experiments is lower compared to individual ones in DCM membrane: 35.40%<48.10% (with 18C6) and 8.90<38.25% (with DB18C6).

Conclusion: The results showed that higher ligand selectivity for Pb(II) ions lead to higher transport rates compared to Cd(II) ions from their equimolar mixtures. 18C6 was more selective for both cations as ionophore compared to DB18C6. 1,2-DCE showed higher efficiency as membrane solvent in competitive experiments compared to DCM, unlike the individual experiments. Competition between cations decreased their overall transport in DCM, but increased in 1,2-DCE membrane.

Open Access Original Research Article

Sequestration of Hexavalent Chromium from Aqueous Medium Using Biochar Prepared from Water Hyacinth Biomass

R. P. Premalatha, E. Parameswari, P. Malarvizhi, S. Avudainayagam, V. Davamani

Chemical Science International Journal, Page 1-15
DOI: 10.9734/CSJI/2018/40547

The global issue associated with the health of environment and human is the quality of water. A serious threat to the aquatic environment through anthropogenic activities is the heavy metal pollution. To protect our environment from the serious threats of contamination and to save many lives, it is essential to remove Cr from wastewater. This paper reports the utilization of the water hyacinth biochar, a carbonaceous material as adsorbent for removal of hexavalent chromium (Cr(VI)) from aqueous solution. The experiment was carried out in the Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore in a completely randomized design with 4 replications. The adsorbent was characterized by FTIR, SEM and EDX. The effect of various process parameters like solution pH, adsorbate concentration, contact time, adsorbent dosage and size has been studied. The optimum conditions for the removal of Cr(VI) were found to be  pH=2.0, adsorbent size= 0.2 mm, adsorbent dosage=2.5 g/100 ml, adsorbate concentration=100 mg/L of Cr(VI) at 25ºC at 250 rpm. The rate of adsorption was rapid and the equilibrium was attained at 36 hrs. Models of Langmuir, Freundlich and Temkin isotherms were used for mathematical description of the equilibrium adsorption data. Adsorption data was well described by the Langmuir isotherm with maximum adsorption capacity of 55.55 mg/g. On comparison with various kinetic models, our results fitted excellently with pseudo second order model (R2=0.999). It can be concluded that, carbonaceous material derived from water hyacinth biomass can be used as a low cost adsorbent for the treatment of Cr(VI) containing waste water.