This study is aimed at developing an adsorbent from sawdust for optimum removal of dye from textile wastewater. The adsorbent was developed, characterised and, the adsorptive capability for the removal of dye was determined by optimizing the process parameters (adsorbent dosage, contact time and agitation speed) using Response Surface Methodology. The physical and chemical characterization of the effluent was carried out before and after the adsorption studies. From the results, a maximum adsorption capacity of 98.5 % was obtained at the optimized conditions of 1.5 g, 90 min and 275 rpm for adsorbent dose, contact time and agitation speed respectively. The ANOVA of the regression model showed that the model is highly significant with R 2 of 0.98. Further analysis carried out revealed that, in addition to dye removal, trace metals were also adsorbed in the process. This fact was established when the concentration of copper in the wastewater was found to decrease from 0.09 ppm to 0.03 ppm corresponding to 66.7 % removal at the end of the process.

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An assessment of potential biomass resources in Nigeria for the production of methane and power generation is presented in this paper. Nigeria, as an underdeveloped and populous country, needs an uninterrupted source of energy. The country's energy problems have crippled large sectors of the economy. The percentage of people connected to the national grid is 40%. These 40% experience electricity supply failure on average 10–12 hours daily. Energy generation from municipal solid waste (MSW) is an effective MSW management strategy. Yearly waste generation has increased from 6,471 gigagrams (Gg) in 1959 to 26,600 Gg in 2015. This amount is projected to reach 36,250 Gg per year by 2030. Methane emission for 2015 was 491 Gg, and it is projected to reach 669 Gg in 2030. These values translate to 3.48 × 109 kilowatt hours (kWh) of electricity for 2015, with a projected 4.74 × 109 kWh by 2030. The revenue to be derived from the electricity that is generated could have been US$365.04 × 106 for 2015, and it is estimated that it will reach US$473.82 × 106 by 2030. It was found that methane emissions from MSW increased with time, and capturing this gas for energy production will lead to a sustainable waste management.

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