The management of MSW is a major concern in several cities of developing countries due to its public health and environmental sustainability implications. This paper thus presents an overview of the current solid waste management practices and problems in some selected states in Nigeria. In addition to the comprehensive review of MSW generation, its characterization, collection, and treatment options in the considered states, an attempt was made to evaluate the major waste–to–energy indicators such as calorific values and energy (electricity) recovery potential. The legislations in place at the federal level to maintain healthy environment is also lucidly presented. An estimated electricity recovery potential in the range of 48.31 to 933.69 MW with a total of about 2600MW from six states was established. Evidences from literature suggested that the existing solid waste management system is inefficient due to uncoordinated and properly planned waste management system. This paper concludes that the thermochemical conversion of waste-to-energy into electricity is a feasible option in Nigeria, although this might require the input of additional quantity of fuel to initiate combustion since the lower heating values of the considered MSW fall below the optimum stipulated by World bank.

An effective method of managing solid wastes from agricultural processing is through thermochemical conversion to energy-dense and carbon-neutral energy products; which relieves the issue of depleting global resources, solves the problem of over-reliance on fossil fuel, reduces the impact on the environment, and brings economic benefits. In this study, the suitability of agricultural solid wastes as potential feedstock for electricity generation in Nigeria via a combined pyrolysis–steam power plant technology was assessed. Technique for order of preference by similarity to ideal solution was used to identify the most appropriate raw material for electricity generation among the considered alternatives–rice husk, corncob, and palm kernel shell. These wastes showed high electricity generation potential (232–2077GWh per annum), high profitability index, and high carbon reduction benefit (about1428kg CO2 eq. /m3of bio-oil).

These A dewatering filter was designed and constructed to dewater sludge collected from Eleyele waterworks using slow sand filtration. Washed sand passing through sieve mesh size of 1.18 mm was used as the filter media. The flow rate of the filtrate was monitored for six (6) days and readings were taken at 30-minute intervals for 6 hours after each sludge loading of 15 L. The dewatered and dried sludge was investigated for use as brick material. The sludge and laterite samples were characterized using Atomic Absorption Spectroscopy. The major chemical components of  the sludge and laterite samples were silicon, aluminium and iron oxides. The laterite soil sample consisted of 60.47% SiO2, 17.77% Al2O3 and 8.18% Fe2O3 while the sludge sample consisted of 52.98% SiO2, 29.46% Al2O3 and 3.63% Fe2O3. Batching method by weight was used in mixing the materials in the ratios of sludge at 0%, 15% and 30% to produce laboratory scale bricks with dimensions of 70 mm by 70 mm by 70 mm and the properties of the bricks were investigated. The average compressive strength of the laterite bricks with dried sludge content of 0%, 15% and 30% were 3.15 N/mm2, 3.08 N/mm2 and 2.64 N/mm2, respectively. The results of this research demonstrated that a locally constructed sludge dewatering filter can be used to thicken waterworks sludge and laterite-sludge can be made from dewatered water works sludge.Keywords—Compressive strength, bricks, filter, media slow sand filtration, waterworks sludge