Open Access Original Research Article

The Solid Phase Extraction of Some Heavy Metal Ions Using Dodecylamine Pillared Mg-Al Layered Double Hydroxides

Rasheed M. A. Q. Jamhour

Chemical Science International Journal, Page 1-10
DOI: 10.9734/ACSJ/2016/25977

Rasheed M. A. Q. Jamhour1*

Pillared host-guest material or layered double hydroxides (LDHs) of the type Mg-Al-CO3 with dodecylamine (DA) has been synthesized. The sorption capacities have been investigated for the removal of some heavy metal ions Ni(II), Cd(II), Co(II), Cu(II), Pb(II) and Cr(III) from natural water samples. The new LDHs compound Mg-Al-DA was characterized by fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction (PXRD) and scanning electron microscope (SEM). The analytical parameters such as pH, volume, the amount of sample and adsorption capacity for the quantitative recoveries of the ions using Mg-Al-DA was investigated. The effect of some common Interfering cations and anions that might be present in the water with the analyte on recovery was also examined. The recovery values of metal ions in natural water with relatively large sample volume of 100-1000 ml were greater than 95%. The determination of the heavy metal ions was carried out using atomic absorption spectroscopy.

Open Access Original Research Article

Source and Distribution of Mercury in Sediments of the Brazilian Amazon Continental Shelf with Influence from Fluvial Discharges

Gilmar W. Siqueira, Fabio Aprile, Georg Irion, Bruce G. Marshall, Elisabete S. Braga

Chemical Science International Journal, Page 1-15
DOI: 10.9734/ACSJ/2016/26625

Place and Aims: Total concentrations of Hg and geochemical analysis of sediments from the Amazon Continental Shelf (47º52'W-4º19'N, 51º04'W-2º16'S) were determined in 25 sampling sites, during the months of lowest flow of the Amazon River. The aim of this study was to determine the influence of fluvial discharge on mercury distribution and deposition in the environment.

Duration of Study: Between 1999 and 2011.

Analyzes: The marine sediments were used to identify heavy minerals, and determine grain size, organic content (organic matter and organic carbon), SiO2, Fe2O3, Al2O3 and MnO, and Hg levels using standard methods.

Results and Conclusion: The Hg concentrations varied from 14 to 160 ng g-1. The highest Hg concentrations occurred in the inner shelf. Both analysis of major oxides and identification of mineral composition in the sediments confirmed the influence of river discharge on Hg deposition in the inner shelf. The geochemical results suggested that the main Hg source in the study area was from natural origins due to erosion and subsequent leaching of tropical lateritic soils, although mining in the Madeira and Tapajos river basins is also a contributing factor.

Open Access Original Research Article

Spectroscopic Elucidation of the Biodeterioration Potentials of Aspergillus niger on Lagenaria siceraria Seed Oil

Peter Michael Dass, Dimas Kubmarawa, Ayodele Akinterinwa, Buba Mohammed

Chemical Science International Journal, Page 1-11
DOI: 10.9734/ACSJ/2016/25510

Vegetable oil was extracted from Lagenaria siceraria seeds and some physico-chemical analysis determined. The refractive index of 1.47, saponification value of 465.9 mgKOH/g, iodine value of 15.86 I2 /100 g, Acid value mgKOH/g of 2.52 and density of 0.93 were obtained. GC-MS of both the un-inoculated and inoculated oil was measured before and after four weeks of incubation with Aspergillus niger. The disappearance and or appearance of some absorption peaks which correspond to hydroxyl, carbonyl, methyl, and carboxylic acid functional groups were identified. MS provided the mass fragments of the possible components formed during the degradation of the oil to include 12-methyl-methyl ester, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, oleic acid, 2, 6, 10-Dodecatrien-1-ol, 3, 7, 11-trimethyl (E.E) and pentadecanoic acid as biodegradation by-products. Despite, low acid value obtained which may have suggested stability of the oil to oxidation, its high iodine value indicated a rather high level of unsaturation i.e. presence of double bonds. The position of double bonds was viewed as possible sites for the initial attack by the microorganisms.

These absorption bands disappeared after inoculation and incubation with Aspergillus niger after four weeks with prominent peaks noticed to be of fatty acids as a result of the action of Aspergillus niger on the Lagenaria siceraria oil. The fragmentation of the triglycerides suggested that the unsaturation is not on an even number of carbon atom along the chain length resulting in the propyl – like breakage with molecular weight of 42 (C3H7) whereas, fragmentation on even carbon atom resulting in ethyl-like breakage with molecular weight of 28 (C2H2). The GC-MS showed that acidic metabolites were mostly produced. This is similar to the hydrolysis of vegetable oil by other agents where sterol and fatty acids are usually produced in the ratio 1:3. Therefore, it is recommended that the storage of these oils in the presence of common mold such as Aspergillus niger at temperature above 37°C would lead to its deterioration. However, Lagenaria siceraria seed oil can be used as lubricants, for cooking and paint production.

Open Access Original Research Article

Synthesis and Biological Activity of Novel 5-(Alkylthio)-1,3,4-thiadiazol-2(3H)-thione Derivatives

Elen N. Hambardzumyan, Asya S. Vorskanyan, Ani A. Grigoryan, Aleksandr P. Yengoyan

Chemical Science International Journal, Page 1-9
DOI: 10.9734/ACSJ/2016/26657

Some nonfused biheterocyclic system derivatives containing a combination of 1,3,4-thiadiazole and pharmacophores such as 1,3,4-oxadiazole and/or pyrazoles in the same molecule were obtained based on 2-((5-(alkylthio)-1,3,4-thiadiazol-2-yl)thio)acetohydrazide. The synthesized compounds show pronounced plant growth stimulant properties.

Open Access Original Research Article

Effect of 3 wt% Al Content and Rapid Solidification on the Erosion-corrosion Behavior of 92 wt% Cu and 5 wt% Ni Alloy in Seawater

A. S. Abdulghani, A. M. Badiea, B. G. Mohammed

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/25868

A 92 wt% Cu and 5wt% Ni alloy containing 3 wt% Al is subjected to a rapid solidification processing (RSP) using a rotating copper wheel (7.95 cm φ x 5.95 cm w) at 1420 r.p.m, which produces a thin specimen of 2 mm thickness. The specimens with dimensions of 10.8×15.02 mm2 are then exposed to water flow rate for 28 hours at 30°C and then the corrosion/erosion rates were computed in (g cm-2 h-1) using weight loss measurement method. The corrosion rate of the produced alloy under constant water flow rate tests decreases generally with time (1.5 - 28 h)  and showed only initially some short periods of accelerated oxidation (0.0 - 1.5 h). The obvious weight loss and corrosion rate versus exposure time relationships are rationalized in terms of film formation was hard and its breakdown mechanisms did not occur. The effective of Al2O3 in improving the corrosion/erosion resistance was provided through addition 3% Al to the binary 92% Cu-5% Ni alloy. Thus, a passivity, dense, adherent, and continuous Al2O3 film exists on the surface protecting bare alloy from further oxidation and causing the metal to be little deterioration Moreover, fine inner layer of Cu2O or CuO acts as a super resistance barrier to erosion-corrosion. The metallographic images were photographed using a metallurgical microscope at 1000X magnification to identify the influence of rapid solidification on the structure includes nucleation, grain size, grain growth and particles pushing.

Open Access Original Research Article

Equilibrium and Kinetic Studies of the Adsorption of Pb2+ and Ni2+ Ions from Aqueous Solution by the Use of Activated Locust Bean Husk (LBH)

Nathaniel Oladunni, Idongesit B. Anweting, Elijah I. Agbele

Chemical Science International Journal, Page 1--12
DOI: 10.9734/ACSJ/2016/22724

The removal of Lead and Nickel ions from aqueous solution by adsorption onto activated locust bean husk was investigated in a well stirred batch reactor. Equilibrium and kinetic experiments were performed at various pH, temperature and contact time. The metal removal approached equilibrium within 70 min for lead and nickel. It was observed that removal of Pb2+ and Ni2+ by activated LBH had highest adsorption capacity at pH 6 and that the uptake of the selected heavy metal ions by activated LBH increases with increasing temperature. Kinetic studies carried out showed that the experimental adsorption capacities of Pb2+ and Ni2+ are 4.27 mg/g and 2.9 mg/g respectively. Their calculated adsorption capacities by using pseudo-first order model are 0.05 mg/g and 0.6 mg/g respectively, while that of pseudo- second order model are 4.48 mg/g and 3.57 mg/g respectively. The result obtained showed that the calculated adsorption capacities of all the metals by pseudo- second order model are closer to their respective experimentally determined adsorption capacities than those from pseudo- first order model. Hence, pseudo- second order adsorption model is more suitable to describe the adsorption kinetics of Pb2+ and Ni2+ by activated LBH.