Research
The Kinetics and Effect of pH on Removal of Manganese, Cadmium and Lead from Aqueous Solution by Maize Cobs
The ability of maize cobs as a biosorbent of Manganese Cadmium and lead in aqueous solution was studied. The effect of contact time, ionic strength, kinetic of sorption mechanism and the adsorbate concentrations on sorption of Mn2+, Cd2+, and Pb2+ heavy metals were examined. The kinetic of the sorption mechanism of Mn2+, Cd2+ and Pb2+ was evaluated using pseudo-first order (Lagergren) rate and the second order (Ho-model) rate. The results indicate that pseudo-second order model provides a more appropriate description of the metals ions sorption in maize cobs. The adsorption capacities per unit gram of the adsorbent at equilibrium time, neutral pH, 200rpm, and 250C temperature are 5.34 to 37.42 mg kg-1for Mn2+, 2.50 to 19.79 mg kg-1 for Cd2+ and 0.32 to 4.75 for Pb2+ under10 to50 mg kg-1 initial metal concentration. Sorption equilibrium isotherm was determined and correlated with Langmuir and Freundlich model. It was found that the Freudlich adsorption model best fitted the isotherm data. It is concluded that maize cobs can be use as an effective adsorbent for removal of heavy metals from aqueous solution
Analytical Assessment of Cadmium, Lead and Iron in Hand Dug Wells of Ilaro, South-Western Nigeria
The levels of selected heavy metals; Cadmium, Lead and Iron in the hand dug wells of Ilaro town was critically assessed at strategic points of the area to determine the level of pollution caused by anthropogenic activity within the town using different physical and chemical processes. The Mean ± S.D of the results obtained are; Cadmium 0.017±0.016 mg/l; Lead 0.229±0.061 mg/l; Iron 1.076±2.393 mg/l. All the parameters were higher than the standards that were specified for drinking water by WHO. Consequently, the well water in the study location is not suit for drinking.
Application of rainfall- potential evapotranspiration model for determining optimum planting date of yam (Dioscorea rotundata) in a tropical wet-and-dry climate
The application of Rainfall–Potential evapotrans- piration (P-PE) model to yam (Dioscorea rotundata) production was carried out in an on-farm yam trial during the 2006-2007 and 2007-2008 cropping seasons in Abeokuta, South-western Nigeria. The experiment was a 3 x 2 factorial arrangement of three varieties of yam (Efuru, Ise-osi and Oniyere), two planting dates (early and late). The resulting 6 treatments were replicated three times with 14 mounds in each plot, in randomized complete block design. The general model for selecting the planting date of each yam cultivar in the two experimental years was 0.1PE <P < 0.5PE. This was partitioned for the purpose of attaining optimal planting date into early and late, respectively as Σ(P-0.1PE) ≤ 0 designated as T1 and Σ(P-0.5PE) ≤ 0 as T2. For the rest of the season defined by P> PE, the physiological parameters and hydrothermal agro-climatic indices measured during the different phenological stages of yam grown were analyzed with respect to the various treatments. The result showed that model T1 defined as Σ(P-0.1PE) ≤ 10mm appeared as the best model that significantly (P < 0.05) influenced emergence rate, phenological growth and tuber yield. The implications of the study for appropriate schedule of farm operations vis-à -vis agronomic practices for yam cultivation have been noted.
Assessment of Effect of Sewage Intrusion from Septic Tanks into the Consumable Hand Dug Wells in Lagos State, Nigeria
Access to a regular supply of safe water is a basic human right but many people are denied. This study investigated the physical, chemical and microbiological properties of well water installed close to septic tank in some location in Lagos metropolis. Samples were collected from five (5) wells from each location (Ikorodu, Mushin, Shomolu, Itire and Ilasamaja) during the rainy season when ground water intrusion is high. The well water were analyzed for pH, temperature, Total Solid, Dissolved Solid, Suspended Solid, Alkalinity, Acidity, Total Hardness, Dissolved Oxygen, Biological Oxygen Demand, Chemical Oxygen Demand, Sulphate, Manganese, Cadmium, Zinc (Zn), Total coliform count and Total Bacteria count. pH, temperature, TS were determined immediately in the sample. Analysis of the heavy metals was done using Flame Atomic Absorption Spectrophotometer. Data obtained were subjected to descriptive statistics. All the physical, chemical and microbial properties investigated except pH, Total Solid, DO, BOD and the coliform and bacteria count in the sampled well water were within the specified limit of WHO and hence, not suitable for domestic purposes for which they are presently used for in some of the residential area in the study area. Contamination from intrusion from septic tanks and runoff from storm water could account for these differences in sampled water and WHO Limits. Where affordable, water must be treated before consumption and Public enlightenment on water quality should be encouraged to foretell the looming danger from water contamination/pollution.
