Biosorption of cadmium (ii) ion from aqueous solution by Afzelia africana

The batch adsorption of cadmium (II) ion from aqueous solution using low-cost adsorbent of biological origin, Afzelia africana shell under different experimental conditions was investigated in this study. The influences of initial Cd (II) ion concentration, initial pH, contact times and temperature were reported. Adsorption of Cd (II) was found to be pH dependent and the results indicate that the optimum pH for its removal from aqueous solution was 5. No marginal effect on the biosorption of cadmium was detected for temperatures between 298 and 313K as observed from their Langmuir isotherm constants (qmax) at different temperatures. qmax values obtained at the different temperatures of 298, 303 and 313K were 13.59, 14.04 and 14.27 mg g-1, respectively. The adsorption equilibrium shows that the process followed both Freundlich and Langmuir models with Freundlich giving a better fit for the adsorption data in comparison to the Langmuir model. The fit of the adsorption data into Freundlich model shows that the adsorption process was predominantly a physisorption. The results reveal that cadmium (ll) was considerably adsorbed on the A. africana shell and could serve as an economical method for the removal of cadmium from aqueous solutions.Keywords: Adsorption isotherms, adsorption kinetics, Afzelia africana, biosorbent, biosorption.African Journal of Biotechnology Vol. 12(32), pp. 5060-506

Evaluation of metal contaminants of surface water sources in an active Pb-Zn mine pit and a nearby pond: comparison of levels of contamination

This study evaluated the potential health risks associated with domestic use of surface water from an active Pb-Zn mine pit, compared to a nearby pond. The concentrations of Pb, Zn, Mn, Co, Cu, Ni and Cr were quantitatively determined in water samples collected from Enyigba Pb-Zn mine and a nearby Uruva pond using atomic absorption spectrophotometer. The results showed varying concentrations of these metals in the samples. The mean values of the metals (mg/L) in the samples from the pit mine (in bracket from Uruva pond) are Pb – 0.80 (0.50), Zn – 0.14 (0.08) , Mn – 0.20 (0.16), Co – 0.07 (0.07), Cu – 0.30 (0.12), Ni – 0.31 (0.80) and Cr – 0.19 (0.23). When compared with World Health Organisation (WHO) recommended limits for metals in drinking water, the values of Pb, Mn, Ni and Cr exceeded the limits in both samples while the values of Zn, Cu and Co were below the limits. The levels of significant differences in the sources of concentrations of the metals in both samples were tested at 95% confidence level (α = 0.05) using F- and student’s t-tests. It showed no evidence of differences (texps < tcrits), suggesting that the metal contamination of the water samples originated from common sources, such as the soil geochemistry of the areaKEYWORDS: metal contamination, Pb-Zn mining, surface water, Enyigba mine pit, Uruva pon

Evaluation of metal contaminants of surface water sources in an active Pb-Zn mine pit and a nearby pond: comparison of levels of contamination

This study evaluated the potential health risks associated with domestic use of surface water from an active Pb-Zn mine pit, compared to a nearby pond. The concentrations of Pb, Zn, Mn, Co, Cu, Ni and Cr were quantitatively determined in water samples collected from Enyigba Pb-Zn mine and a nearby Uruva pond using atomic absorption spectrophotometer. The results showed varying concentrations of these metals in the samples. The mean values of the metals (mg/L) in the samples from the pit mine (in bracket from Uruva pond) are Pb – 0.80 (0.50), Zn – 0.14 (0.08) , Mn – 0.20 (0.16), Co – 0.07 (0.07), Cu – 0.30 (0.12), Ni – 0.31 (0.80) and Cr – 0.19 (0.23). When compared with World Health Organisation (WHO) recommended limits for metals in drinking water, the values of Pb, Mn, Ni and Cr exceeded the limits in both samples while the values of Zn, Cu and Co were below the limits. The levels of significant differences in the sources of concentrations of the metals in both samples were tested at 95% confidence level (α = 0.05) using F- and student’s t-tests. It showed no evidence of differences (texps &lt; tcrits), suggesting that the metal contamination of the water samples originated from common sources, such as the soil geochemistry of the areaKEYWORDS: metal contamination, Pb-Zn mining, surface water, Enyigba mine pit, Uruva pond</jats:p

Growth performance and carcass characteristics of finisher broilers fed difference sources of protein

No Abstract.Animal Production Research Advances Vol. 3 (4) 2007: pp. 337-34