Landfills are known to be one of the anthropogenic sources of methane (CH4) and this gas is an important contributor to global warming. Aside the threat posed by methane, if properly managed, it could be harnessed as a source of energy. The efficient management of landfill generated CH4 gas would require the accurate prediction, monitoring and utilization of this useful source. Therefore, this study is focused on the life cycle assessment (LCA) of Olushosun landfill in Lagos metropolis. Environmental benefits between operation of landfills with and without gas recovery systems in Olushosun landfill were determined. LCA analysis showed greenhouse gas (GHG) emissions from the present waste disposal system was 3,029,151tons of carbon dioxide emissions (CO2). The adoption of sanitary landfill with gas recovery system is a preferred management route for solid waste disposal in Lagos metropolis due to CO2 emissions reduction of 1,725,761 tons. The results obtained also corroborate the use of LCA as a decision support tool in waste management system. It is therefore recommended that LCA should be implemented in developing countries to reduce long term environmental effects of waste management activities.

Landfills are one of the major sources of methane (CH4) emissions. Prediction of CH4 emissions from landfills is important in estimating power generation potential and greenhouse gas (GHG) emissions from landfills. The most widely used landfill gas (LFG) models developed based on the first order decay (FOD) reaction do not take into account changing waste composition and landfill site conditions in methane estimations. The aim of this study was therefore to develop a LFG model for estimation of methane emissions from landfills in Lagos metropolis. Field investigations were carried out to determine waste composition, waste disposal rates and site conditions relevant for methane emissions estimation. Waste composition studies were conducted and waste fractions were divided into rapidly, moderately and slowly degrading. The output of the model was verified with the US EPA Landfill Gas Emission model (Land GEM). Results revealed maximum CH4 emissions estimated occurred at the end of landfill's closure. Methane generation potential ( ) and methane generation rate ( ) parameters were dependent on waste composition and site conditions. Model verification also showed methane emissions peaked at the end of landfill's closure for both models and variation in modelling parameters by Land GEM model resulted in significant change in methane emissions.

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Access to clean water and sanitation is a major requirement for all countries in achieving the Sustainable Development Goals (SDG). The main aim of the study was to investigate the state and condition of water and sanitary facilities in selected secondary schools within Oyo State, Ibadan, Nigeria. Data was collected through the use of structured questionnaires and interviews with the students and teachers. Physical observation was also done onsite to supplement data gathering. The results revealed that deep-tube wells and pit latrines were the most widely used water and sanitation facilities in the study area. 70% of the schools surveyed used traditional pit latrines while 73% of schools had deep-tube wells respectively. In addition, there were limited drinking water and hand washing facilities in all the schools investigated. This study therefore recommends that government should increase funding for the provision of water and sanitation facilities in all schools in this state; as these would ensure good and enabling environment for learning as well as reducing outbreak of infectious diseases.Keywords facilities, sanitation, schools, SDG, water.