Department of Civil Engineering
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- ItemOpen AccessStudy of Safe Separation Distances between Rural Wells and Neighbouring Soak-Away Systems(Faculty of Agriculture, University of Ife, 1981) Ogedengbe, O.It is becoming increasingly common for educated Nigerians to build houses in rural and semi-urban areas of the country. The plan of a typical modern house includes construction of a septic tank and soakaway for disposal of wastewaters. Very often, a well is dug on the same plot of land for supply of water in lieu of tap water supply. If the homeowner knew that the soak-away system could contaminate his well-water, he might be able to arrange the structures so as to put a safe distance between his well and his soak-away unit. The study reported in this paper shows that in a silty sand soil, the safe separation distance is about 14 meters.
- ItemOpen AccessNigeria’s Water-Supply Nightmare(Obafemi Awolowo University Press, 1997-08-12) Ogedengbe, M. ONigeria's water-supply situation seems to have become a monstrosity, characteristic of a nightmare. All over the country, virtually everywhere there is insufficient water to satisfy the basic human needs - drinking, cooking," washing and sanitation, let alone the commercial, industrial and agricultural needs. The. quantity of water supplied in all the thirty six states of the federation is less. than 25 litres per-capita-per day (lpcd) on the average. The comparable figure in the developed countries of Europe and America is about 4001pcd: The figure recommended by the World Health Organization (WHO) for countries in Nigeria's level of development is about 180lpcd.
- ItemOpen AccessADSORPTION KINETICS OF Pb , Ni AND Cd ONTO POWDERED EGGSHELLS(Ife Journal of Science, 2014-07-07) Oke, I.A; Fasuyi, Enang; Oloyede, H.OIn this paper, the removal of lead, nickel and cadmium from aqueous solution by adsorption was studied. Chicken's eggshells were collected, washed with distilled water, air dried, pulverized, sieved into different particle sizes and stored for use. Powdered eggshells (PES) were separated, its properties were determined and used as an adsorbent to remove each of these selected metals from aqueous solution individually, multi-componen synthetic wastewater and from natural water in a batch process. Effects of initial concentration of the metals, initial pH of the solution and particle size of PES on the adsorption capacities of these selected metals onto PES were monitored. Estimated cost of producing PES was conducted under two major sources of power supply in Nigeria. The study revealed that PES contained calcium, aluminum, and iron as part of its major components. 2+ 2+ 2+ There were slight reductions in the adsorption of Pb , Ni and Cd onto the larger particle size of PES. Higher adsorption occurred when the initial concentrations and the pH values were increased, but the adsorption capacities were not affected. Cost of PES producing was found to be lower (0.43USD) than the cost of 2+ 2+ producing other adsorbents. It was concluded that PES could be used as an adsorbent to remove Pb , Ni and 2+ Cd from aqueous solutions and raw water
- ItemOpen AccessA Study of the Effect of Fines Content on the Performance of Soil as Sub-Base Material for Road Construction(2015-06-23) Ayodele, Adekemi LorettaThis study established optimum and determined the effect of fines content on the engineering properties of lateritic soil for use as sub-base material for roads. It also developed a regression model relating the fines content to the engineering properties. This was with a view to addressing road pavement failure, a common feature of the tropical environment. Lateritic soil samples were collected from three selected borrow pits (one on Mokuro road and two on Ede road) in Ile-Ife and were termed MR, ER1 and ER2, respectively. The fines contents were separated from the coarse fraction by wet sieving through 75 μm sieve size. The fines and the coarse fractions were reconstituted in varying proportions of fines to coarse ratios, from 0:100 to 100:0 in 10% increments. The samples were subjected to compaction, California Bearing Ratio, and unconfined compression tests. The Optimum Moisture Content (OMC), Maximum Dry Density (MDD), soaked and unsoaked California Bearing Ratio (CBRs and CBRu) and the Unconfined Compressive Strength (UCS) were determined. Statistical models relating fines content to the engineering properties were developed and tested to ascertain the effects of fines on the performance of the soil samples. The results showed that as the fines content increased from 10% to 100% the OMC values for samples MR, ER1 and ER2 varied from 10% to 30.5%, 12% to 31.2% and 10% to 40.5%, respectively. There was about 20%, 35% and 43% decrease in the MDD values as the fines content increased from 10% to 100% for samples MR, ER1 and ER2, respectively. The CBRu decreased to 0% from 85, 30 and 64% as the fines content increased from 10% to 50%; while the CBRs decreased to 0% from 65, 22 and 57% as the fines content increased from 10% to 30% for samples MR, ER1 and ER2, respectively. The UCS, however, increased with increasing fines content to about 60% before it decreased rapidly to zero. The results further showed a linear relationship between fines content and MDD (r = 0.937, p < 0.05); and OMC (r = 0.946, p < 0.05). The CBR and fines content exhibited a polynomial relationship of third order (r = 0.910, p < 0.05), implying that a small increase in fines content will decrease the CBR significantly making the soil much less stable. Based on the engineering properties, fines content of 10% was obtained as the optimum percentage for the investigated soil samples. The study concluded that increase in fines content reduced the strength of lateritic soil for use as sub-base material in road construction.