The paper reports the findings of a research work carried out to examine the performance and efficiency of a subsurface constructed wetland (SSFCW) for the treatment of domestic sewage in the University of Lagos (Unilag), Nigeria. The removal patterns and efficiencies of the physical, chemical and biological sewage pollutants parameters of domestic waste water generated within Unilag community by the SSFCW were studied. The wastewater was sampled and analysed along the SSFCW from influent (point1) to effluent (point 11). Total Dissolved Solids (TDS) reduced from 471 mg/l to 11.85 mg/l (97.48%), Turbidity reduced from 108.75 HTU to 0.05HTU (99.95%), Manganese reduced from 6.05 mg/l to 0.61 mg/ (89.92%), Nitrate reduced from 27.5 mg/l to 2.0 mg/l (92.73%), Sulphate reduced from 48.5 mg/l to 28 mg/l (42.27%), Iron reduced from 1.13 mg/l to 0.03 mg/l (97.35%), BOD reduced from 73.14 mg/l to 12.8 mg/l (82.5%), and E-coli reduced from 874 MPN/100 ml to 0.15 MPN/100 ml (99.98%). On the other hand, Dissolved Oxygen content increased along the SSFCW from 3.14 mg/l to 7.49 mg/l (138.54%) while the pH improved from slightly acid level of 6.49 to slightly above neutral level of 7.05 (9.3%). All the parameters at effluent point are within the Nigerian Federal Environmental Protection Agency (FEPA) acceptable standard. The study concludes that the SSFCW is a cheap, efficient and appropriate technology for the treatment of domestic sewage under tropical conditions.

Waste to energy (WtE) refers to any treatment process that creates energy in the form of electricity or heat from a waste source. This research reviews the potential uses of municipal solid waste generated at the University of Lagos, Akoka campus as a sustainable energy source for the tertiary institution. Waste characterization study of the residual waste at the University's sorting centre was conducted to determine the amount, composition and physical properties of the waste. A novel compositional trending ratio (CTR) was used to evaluate the possible calorific variation in samples using ASTMD3286-77 method. A validation of the experimental results was carried out using energy estimation model described by Smith and Scott (2005) and World Bank (1999). The major components of the residual waste were mainly polythene materials (24%), inert (30%), organic waste (15%), and paper (15%). The average calorific value of 17.23 MJ/kg and moisture content of 41.3% could potentially generate 34, 787 kWh daily (about 48.32% of the 72,000 kWh energy demand of the University). There was no significant statistical difference between experimental energy estimation of samples and model energy values (p < 0.001) and a Relative Percent Difference (RPD) < 3% (experimental energy 1112.1MJ/Kg, model value 1108.3 MJ/Kg). The major challenge to adopting WtE technology is the gap in daily tonnage of waste generated which can be overcome through collaborative solid waste management program with closed neighborhood and tertiary institution. The findings provide resourceful information on sustainable management of waste generated for a typical tertiary institution.

Marine water is a vital component to the development of Nigerian economy. Human activities at jetties have potential impact on marine water quality in the study area. The present study investigated the Physicochemical characteristics of marine water at nine jetties along Ikorodu-Lagos Island, Lagos state, South-West Nigeria. Water samples were collected and analysed for Temperature, pH, Conductivity, Total Dissolved Solids(TDS), Colour, Dissolved Oxygen(DO), Biochemical Oxygen Demand(BOD), Nitrate, Cyanuric acid, Chromium, Copper, Iron, Manganese, Sulphate and Phosphate. Results showed the range of each of the parameters tested as: Temperature 20.10 to 22.90ºC, pH 6.66 to 7.34, Conductivity 196 to 5646 µhoS/cm, Total Dissolved Solids(TDS) 125 to 699mg/l, Colour 15 to 98PtCo, Dissolved Oxygen(DO) 6.62 to 8.46mg/l, Biochemical Oxygen Demand(BOD) 98 to 214mg/l, Nitrate 0.00 to 5.2mg/l., Cyanuric acid 0.00 to 5.2mg/l, Chromium 0.00 to 0.12mg/l, Copper 0.29 to 1.17mg/l, Iron 0.22 to 1.10mg/l, Manganese 0.01 to0.79mg/l, Sulphate 20.00 to 65.00mg/l and Phosphate 0.08 to 1.86mg/l. The values of most of the parameters studied were within the acceptable limits specified by WHO/FMnev standards. However, BOD values were beyond limits which could be indicative of direct waste disposal into the water at the jetties.

Domestic wastewater treatment using constructed wetlands have been found to be very efficient and cost effective. Primary treatment facilities such as anaerobic digesters have been reported to reduce the organic load of wastewater before entering the constructed wetland systems. It has also been established that biogas is a product of organic matter decomposition under anaerobic condition. In this study, we evaluated quantity of biogas produced from the anaerobic digester of a constructed wetland domestic wastewater treatment plant. After a period of 148 days (15 th September, 2015 to 8 th February, 2016), the mean of the percentages of methane (CH 4), Carbon dioxide (CO 2), Hydrogen Sulphide (H 2 S) and Carbon monoxide (CO) were 60.97±8.38, 33.93±6.31, 1.03±4.45 and 0.25±2.11% respectively. The average rate of production of biogas was found to be 641.83±88.26 m 3 /day. The study concludes that anaerobic digester pre-treatments do not only assist in reducing organic load for the efficient performance of the constructed wetland but can also serve the purpose of biogas production. It is recommended that further works be carried out to determine the potential of energy recoverable from the anaerobic digester.

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