Applied Chemistry

In this study, physicochemical properties of Gilgel Gibe-I hydroelectric Dam water were investigated. Water samples were collected three times per day, from six sampling sites of the Dam. Physicochemical parameters including pH, dissolved oxygen (DO), electrical conductivity (EC), Temperature and Turbidity were determined in situ, whereas, other parameters such as alkalinity, total dissolved solids (TDS), total hardness (TH), total suspended solid (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), phosphate, nitrate, chloride, fluoride and heavy metals like Fe, Cu, Zn, Co and Cd were analyzed by FAAS in the laboratory. The finding of the study revealed that some physicochemical properties such as pH, EC, turbidity and nitrate of the studied water samples were exceeding WHO permissible limit for surface water and only Fe were investigated in the sample and within permissible limit domestic purposes. But, the remaining studied parameters are below the permissible range prescribed in WHO guideline for the surface water.

This research work is an investigation into how agbono cotyledon extracted from the seed of a specie of the agbono plant (irvingia excelsa) can be processed for long-shelf life. The agbono chaff extracted from agbono cotyledon through solvent extraction using petroleum spirit(60-80)oC was preserved in desiccators and also in black polyethene bags. The findings showed that agbono cotyledon can be processed and preserved to retain the cherished characteristics (sliminess, taste, aroma, etc ) without moulding or fungal growth. The processed agbono was welcomed by the general public. It is recommended that agbono cotyledons be processed by defatting and preserved for food preparations.

Human health risk assessment on intake of fish contaminated with organochlorine contaminants has been investigated in seven fish species from Lake Bosomtwi and Weija Lake in Ghana. The species studied were Tilapia busumana, Hemiscrimis faciatus, Sarotherodon galileu from Lake Bosomtwi and Tilapia zilli, Tilapia nile, Tilapia galilaea and Clarius gariepinus from Weija Lake. Risk assessment was carried out by estimating daily exposure as well as carcinogenic and non-carcinogenic implications on consumption of the studied fishes. Estimated daily exposures to OCs on dietary intake of fish were in the range of 0.002 µg/kg to 0.176 µg/kg and 0.001 µg/kg to 0.0892 µg/kg for children and adults respectively. Consumption of Clarias gariepinus indicated the highest health risk to organochlorine exposure. Children were exposed to more OCs than adults on consumption of the same quantity of contaminated fish. Estimated daily exposures however, fell below USEPA reference doses. Cancer hazard analysis showed that more than one in a million of the consuming population could get cancer on eating Clarias gariepinus due to hexachlorocyclohexanes (HCHs) contamination. However, consumption of the investigated fish from Lake Bosomtwi presents no risk of cancer. Organochlorines were extracted from samples by sonicating on an ultrasonic bath with hexane/acetone solvent system and organochlorine contaminants were determined using capillary gas chromatograph equipped with electron capture detector.

Hydrogen peroxide induce the oxidative stress on the cells. The free oxygen radicle denature the protein by oxidizing the thiole group of protein having cysteine or methionine amino acid that donate proton to free oxygen species thus creating un even di sulphide bonds in protein. Besides H2O2 reduces protein synthesis in various ways with increasing concentration of infusion as well as time. Glutathione which is a natural anti oxidant in cell tries to reduce the oxidative stress in the cell. Glutathione is a tri peptide of glutamate, cysteine and glycine produced by cells. Glutathione prevent oxidation which protect cell and its components from free radicles, reactive oxygen species and peroxides. The ratio of oxidised and reduced glutathione within a cell is indicator of state of oxidative stress on the cell. Thiole group of glutathione donates proton to reduce the oxidative stress on the cell. In an in vitro experiment, liver cell of goat were cultured in M199 media and production of glutathione per milligram of protein with respect to different concentration of hydrogen peroxide as well as different time, glutathione production and protein synthesis was measured by standard method. The production of glutathione per milligram of protein increases with increase in concentration of H2O2 and time.

The inhibition of the corrosion of mild steel in 0.1 M HCl solution by Pyridine from 303 K to 333 K at concentrations of 5 x 10-4 M, 1 x 10-4 M, 5 x 10-5, 2 x 10-5 M and 1 x 10-5 M was studied using gravimetric technique. The maximum inhibition efficiency 70 % at 5 x 10-4 M for 333 K was observed. The compound acted as corrosion inhibitors in 0.1 M HCl solution through adsorption on the mild steel surface. The maximum heat of adsorption (Q) was 1.0297 KJ/mol whereas the average kinetic energy (Ea) was 20.0 KJ/mol. The weight loss data treated kinetically gave a first order type of mechanism. The results elucidated the effects of inhibitor concentration, temperature, d? – P? interaction between the metal surface, the heteroatom of the inhibitor, and the electron charge densities on the heteroatoms of the Pyridine molecule. The adsorption of the inhibitor on the metal surface obeyed Temkin adsorption isotherm. Quantum chemical calculations using Hartree-fock density functional theory by Hamiltonian method was employed with PM3 (NDDO) basic set of minimal valence basis as STO3G Program.

Linear model of cadmium content of soil samples in five commercial motor parks in some cities in South-eastern Nigeria were studied using analysis of variance and least significant difference test. The results showed that the mean values of three out of the five samples investigated and modeled were statistically significant at 95% probability level. Three of these five samples when compared with the cadmium permissible limits of 0.01 mg/kg were statistically significant at 95% probability level using the calculated least significant difference of 0.112 mg/kg. From the results of the analyses of the study, the Cadmium content in these choice locations were greater than the permissible limit of 0.01 mg/kg for Cadmium level in the environment.

The spectroscopic characteristics (IR) and the thermal properties (TGA, DTG and DTA) of the solid complexes obtained by the reaction of 2-hydroxyphenylhydrazoacetoacetanilide (2-HPHAAA) with Uranyl(II), and Thorium (IV) are reported and discussed.

: The equilibrium constants for metal complex formation have been employed from long as an effective measure and parameter of the affinity of a ligand for a metal ion in solution. PHmetry is one of the most convenient and successful technique employed for metal complex equilibrium measurements. pHmetric measurement of hydrogen ion concentration may be employed when the degree of complex formation is sensitive to the hydrogen ion concentration thus the degree of complex formation undergoes increase/ decrease with change in pH. In the present work, we investigate the stability constants of Paracetamol complexes with Co2+, Zn2+ and Cd2+pHmetrically using pH metric technique at three temperatures (25 ±0.1, 30 ±0.1 and 35± 0.10 C) and at an ionic strength of 0.1 mol L-1 (KNO3). The method of Calvin and Bjerrum as adopted by Irving and Rossotti has been employed to determine log K1 values. The thermodynamic parameters ?G, ?H and ?S are calculated. System tend to progress in the direction of increasing entropy as entropy is a measure of a system’s tendency towards spontaneous change. KEYWORDS: pH metry, Stability constant, Thermodynamic parameters, Entropy

In this work we reported the status of one of Ethiopia’s Great Rift Valley Lakes; “The ever expanding Lake known as Beseka” in respect to water quality parameters. A composite sample was prepared by combining equal volumes of water samples taken from five Sampling sites. Five physical parameters (pH, DO, EC, T° and Turbidity) were determined for all samples at the spot of sampling while other physical parameters such as TSS and TDS were determined in the laboratory. AAS was used for the determination of heavy metals Pb, As, Cd, Cr, Fe, and Pb while spectrophotometer was used to determine water hardness, total chlorine, NO3-, PO43-, NH3, SO42 Alkali metals Na and K are determined by Flame Photometer. The findings indicated that the lake was found to be alkaline with pH above nine and brakish with TDS value of 2569.70 mg/L. The measured higher values of EC and turbidity resulted from higher values of TDS and TSS. Also these values are much higher than the acceptable values for surface water such as lakes. Similarly Pb, Cd, As, F- and total Cl are above the permissible values while other Physical and chemical parameter are within the acceptable limit of both WHO and FAO Guidelines for drinking and irrigation water.

Kaolin is a clay material consisting of substantially pure kaolinite. Kaolin is used in many industrial applications such as ceramic, paint and paper industries. This paper aims to study, for the first time, the beneficiation of Libya kaolin ore. Attrition scrubbing and classification were used to separate the free silica. Wet high intensity magnetic separation was applied to remove colored contaminants. The kaolinite mineral content increased from 63.5 % to 85 %. The whiteness and brightness of kaolin concentrates were efficiently improved. A final kaolin products containing 0.79 – 0.85% Fe2O3 and 0.66 – 0.68% TiO2 were obtained with whiteness about 85%.