Christopher N AKUJIEZE
University of Benin

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Standardization of the Electricity and Economic Potentials of Landfill gas (LFG) in Lagos, Nigeria. Christopher N AKUJIEZE; Imoukhuede Moses IDEHAI
International Journal of Science and Engineering Vol 7, No 1 (2014)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1281.817 KB) | DOI: 10.12777/ijse.7.1.1-9

Abstract

Globally, various practical data and scholarly estimations of the electricity potentials of landfill gas (LFG) have been forwarded and these can be juxtaposed for estimations in the megacity called Lagos. The calculated values were between 63.22- 700MW of  derivable electricity. However, in order to limit observable disparities and ambiguities in these derivations and thus allow for more accurate projections, these estimations can be gauged using as template; -stoichiometry, establishing 50% of landfill gas as methane, assuming 50% of this volume as recoverable, and using a proposed engine efficiency of 30%. This standardization projects a theoretical mean achievable electrical power of 121.69 MW for the Lagos area from a population of about 21 million with a generation per capita (GPC) of 0.63kg with biodegradable content of about 60%. The yearly electrical energy was placed at 1,066,004.4 MWh with tariff revenue in excess of US$ 106.6 million /yr. An accruing carbon credit of about US$75.59 million /yr is expected from certified emission reduction (CER). The projected derivations can be used as models for evaluation of the landfill gas and electricity potentials in many parts of the world.
PHYSIOCHEMICAL ASSESSMENT OF LANDFILL GENERATED LEACHATES IN LAGOS, NIGERIA Christopher N Akujieze; Imoukhuede Moses IDEHAI
International Journal of Science and Engineering Vol 7, No 2 (2014)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (12.979 KB) | DOI: 10.12777/ijse.7.2.113-123

Abstract

About 3.5 million tonnes of comingled municipal solid wastes (MSW) are dumped annually into the landfill areas of Lagos in Nigeria with a human population of about 21 million. Upon geo-bio-chemical processes, leachates are produced which are improperly collected and may be introduced to the environment with possible insidious effects on human health. Eight (8) composite leachates samples were collected from four (4) landfills in the megacity and tested for their physiochemical parameters in order to determine their suitability for discharge into agricultural soils and groundwater systems. Geological  site investigation reveal that the landfills except Epe have significant attenuative clayey soil protection above groundwater, and can adsorb and/ or precipitate contaminants/ pollutants within its mass. Using ANOVA, juxtapositions of the Fcalculated with the  Fcritical values revealed a metal sequence of : Hg  > Zn >As >Mn >Ni >K >Pb >Cr>Cd>Fe. Also, total alkalinity> total hardness> total acidity. All the measured  anions had Fcalculated above Fcritical values and were in  the hierarchy : Chloride> sulphate> phosphate>nitrate.. Mean concentrations were in the order  : Fe>Cd>Cr>Pb>K>Ni=Mn>As>Zn>Hg. Fe also posted the highest value for standard deviation. Results of the ratios of the standard deviation to the means were in the sequence: Fe> Zn>K> Ni > Mn>Pb> Cr> Cd> Hg> As. The presence of arsenic above prescribed limits in the Epe leachate is a  major concern because the lithology is sandy, and has a reported depth of about 3m to the unconfined aquifer that adjoins the Epe Lagoon. This  expansive landfill is recommended for closure.