1.1 Background of the Study
Emissions from open burning, on a mass pollutant per mass fuel (emission factor) basis, are greater than those from well-controlled combustion sources. Some types of open burning (e.g. biomass) are large sources on a global scale in comparison to other broad classes of sources (e.g. mobile and industrial sources). A detailed literature search was performed to collect and collate available data reporting emissions of organic air toxics from open burning sources, (Kim, Y.J., 2008). The sources that were included in this paper are: Accidental Fires, Agricultural Burning of Crop Residue, Agricultural Plastic Film, Animal Carcasses, Automobile Shredder Fluff Fires, Camp Fires, Car–Boat–Train (the vehicle not cargo) Fires, Construction Debris Fires, Copper Wire Reclamation, Crude Oil and Oil Spill Fires, Electronics Waste, Fiberglass, Fireworks, Grain Silo Fires, Household Waste, Land Clearing Debris (biomass), Landfills/Dumps, Prescribed Burning and Savanna/Forest Fires, Structural Fires, Tire Fires, and Yard Waste Fires, (Moon, D.H., 2007). Availability of data varied according to the source and the class of air toxics of interest.
Volatile organic compound (VOC) and polycyclic aromatic hydrocarbon (PAH) data were available for many of the sources. Non-PAH semi-volatile organic compound (SVOC) data were available for several sources. Carbonyl and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran (PCDD/F) data were available for only a few sources. Examples of agricultural wastes that might be burned are crop residues (e.g. cereal crops peas beans, soya, sugar beet, oil seed rape, etc.), wood, prunings, slash, leaves, plastics and others general wastes (Lee, S.H., 2006). Straw and wood are often used as the fuel for the open burning of agricultural wastes. Poultry and animal excreta are difficult to burn except under controlled conditions. The open burning of agricultural waste is likely to be widespread, although it will rarely be a significant source of emissions except on a local scale for short-time periods, (Kim, Y.J., 2008).
There were several known sources for which no emissions data were available at all. It is desirable that emissions from those sources be tested so that the relative degree of hazard they pose can be assessed. Several observations were made including: Biomass open burning sources typically emitted less VOCs than open burning sources with anthropogenic fuels on a mass emitted per mass burned basis, particularly those where polymers were concerned. Biomass open burning sources typically emitted less SVOCs and PAHs than anthropogenic sources on a mass emitted per mass burned basis. Burning pools of crude oil and diesel fuel produced significant amounts of PAHs relative to other types of open burning (Ortiz de Zarate et al, 2005). PAH emissions were highest when combustion of polymers was taking place. Based on very limited data, biomass open burning sources typically produced higher levels of carbonyls than anthropogenic sources on a mass emitted per mass burned basis, probably due to oxygenated structures resulting from thermal decomposition of cellulose.
It must be noted that local burn conditions could significantly change these relative levels. Based on very limited data, PCDD/F and other persistent bioaccumulative toxic (PBT) emissions varied greatly from source to source and exhibited significant variations within source categories. This high degree of variation is likely due to a combination of factors, including fuel composition, fuel heating value, bulk density, oxygen transport, and combustion conditions (Seo, Y.C., 2002). This highlights the importance of having acceptable test data for PCDD/F and PBT emissions from open burning so that contributions of sources to the overall PCDD/F and PBT emissions inventory can be better quantified (Lee, S.H., 2006).
1.2 Statement of Problem
Open burning of solid wastes, a potential nonpoint emission source, has recently become a topic of interest particularly in the metropolitan area of Ogbomoso, Oyo State. To estimate the effects of irregular open burning on local air quality, we must evaluate the emission levels of harmful substances from test combustion of individual types of domestic municipal solid waste (MSW), including carcass, furs, and other combustible parts of cattle.
1.4 AIMS AND OBJECTIVE
To characterize the anionic component of an abbatoir environment in Ogbomoso metropolis
- To quantify the particulate matter in an abbatoir
- To analyse the anionic component in the fine and coarse particulate
iii. To compare the values in (ii) with other environment in Nigeria.