Survey of heavy metals in sediments of Kolo creek in the Niger Delta, Nigeria

Concentrations of Fe, Pb, Cr, Ni and V were measured in sediments taken from eight (8) sampling stations along a section of Kolo creek which traverses an oil flow station and a point in Epie creek which receive effluent discharges from human and industrial activities. The study was conducted in four seasons (Dry, Late Dry, Rainy and Late Rainy Seasons). Vanadium was less than 0.001 mg/Kg in all the samples analysed. Fe, Pd, Cr and Ni had annual means of 5109.85, 1.60, 14.22 and 10.18 mg/Kg respectively. One way ANOVA at 95% confidence limit showed no significant difference in the nine (9) sampling stations. However, there was significant difference in the four (4) seasons that the study was conducted. Cluster analysis of the data further classified the four seasons into two groups. Geoaccumulation indices showed that the Creek is not polluted by Pb, Cr and Ni, however, it is highly polluted with Fe. The highest positive correlation was between Pb and Cr while the highest negative correlation was between Fe and Ni. Compared to DPR intervention values, Kolo creek is free from pollution by Pb, Cr and Ni.Key words: Heavy metals, sediment, Kolo creek, cluster analysis, geoaccumulation index

Synthesis and characterization of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acid Schiff base and evaluation as corrosion inhibitor of steel in 2.0 M H2SO4

The synthesis of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acidSchiff base, SBDAB was carried out inorder to determine its inhibitory efficiency at higher temperature using weight loss and gasometric  techniques. The results showed that the inhibition efficiency of the studied Schiff base increased with increase in temperature for the corrosion of mild steel which suggests chemisorption reaction mechanism. The negative freeenergy of adsorption obtained confirms a spontaneous adsorption of the Schiff base on the metal surface. The positive values of the heat of adsorption suggest an endothermic reaction. The positive values of the entropy of adsorption suggest a disordered system. The Langmuir adsorption Isotherm result showed a deviation from an ideal Langmuir adsorption isotherm equation, this is due to the interaction of the inhibitor molecules with one another. The inhibition efficiency of 35.20% and 35.31% was obtained for the weight loss and gasometric techniques  respectively. The plots of log(wi - Äw) against time gave linear graph whichconfirms a first order reaction mechanism.©JASE

Synthesis and characterization of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acid Schiff base and evaluation as corrosion inhibitor of steel in 2.0 M H2SO4.

The synthesis of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acid Schiff base, SBDAB was carried out inorder to determine its inhibitory efficiency at higher temperature using weight loss and gasometric techniques. The results showed that the inhibition efficiency of the studied Schiff base increased with increase in temperature for the corrosion of mild steel which suggests chemisorption reaction mechanism. The negative free energy of adsorption obtained confirms a spontaneous adsorption of the Schiff base on the metal surface. The positive values of the heat of adsorption suggest an endothermic reaction. The positive values of the entropy of adsorption suggest a disordered system. The Langmuir adsorption Isotherm result showed a deviation from an ideal Langmuir adsorption isotherm equation, this is due to the interaction of the inhibitor molecules with one another. The inhibition efficiency of 35.20% and 35.31% was obtained for the weight loss and gasometric techniques respectively. The plots of log(wi - & #916;w) against time gave linear graph which confirms a first order reaction mechanism