Exploration and prediction of wet season municipal solid waste for power generation in Ilorin metropolis, Nigeria

The wet season municipal solid waste (MSW) was characterized on Lasoju/Eyenkorin dumpsite for May to August 2020. The aggregate of waste generated was estimated to be 135,882 tons, while the aggregate characterized was estimated to be 80,700 tons. There are thirty-two samples of 240 L (bin of MSW) per sample considered in this investigation. There are twenty-one waste components categorized altogether, with packaging box having the highest proportion of 10.04%, followed by food residue of 9.64%, nylon 9.51%, and leather with the least fraction (0.75%) of the weight basis. Experimental investigations were performed on fourteen combustible fractions of the waste to determine the moisture content, elemental contents, and high heating value. The laboratory analysis reveals that the average carbon content available is 55%, 7% hydrogen, 1.35% nitrogen, 0.44% sulphur, and 30% oxygen; the low heating value of the waste was determined to be 23 MJ/kg. About 672 tons of MSW were investigated for energy production to give an energy and power potentials of 4.2 GWh and 53 MW discretely. The estimated electrical power potential for the wet season MSW is capable of meeting about 59% of the power demand for the Ilorin metropolis.

One-year characterization of organic aerosol markers in urban Beijing: Seasonal variation and spatiotemporal comparison

Organic aerosol (OA) is a major component of fine particulate matter (PM); however, only 10%-30% of OA have been identified as individual compounds, and some are used as markers to trace the sources and formation mechanisms of OA. The temporal and spatial coverage of these OA markers nonetheless remain inadequately characterized. This study presents a year-long measurement of 92 organic markers in PM_2.5 samples collected at an urban site in Beijing from 2014 to 2015. Saccharides were the most abundant (340.1 ng m^-3) species detected, followed by phthalic acids (283.4 ng m^-3). In summer, high proportions (8%-24%) of phthalic acids, n-alkanes, fatty acids, and n-alcohols indicate dominant contributions of biogenic emission and atmospheric oxidation to OA in Beijing. In winter, when anthropogenic sources prevail, saccharides, polycyclic aromatic hydrocarbons, and hopanes are more prominent (4%-25%). The spatial distributions of these OA markers in China show higher concentrations in northern cities (mainly from coal combustion and biomass burning) than in southern cities (mainly from vehicular emission). The inter-annual variations of OA markers, except for hopanes, from 2001 to 2015 suggest significant alleviation of the primary OA pollution in Beijing, with an average reduction of 35%-89% compared with those before 2008. The diagnostic ratio analyses between OA markers indicate that contributions from coal combustion and biomass burning decreased, whereas those from vehicular emission increased. Increasingly large vehicle fleets have increased hopane concentrations since 2008, but the levels were 35% lower in 2015 than those in 2010-2011 because of the tightening of emission controls for vehicles. This study provides a long-term and geographical comparison (from Beijing to other locations in China and beyond) of OA markers, demonstrating the temporal and spatial variations in primary OA, and calls for more studies on secondary OA.