EVALUATION OF TOTAL PETROLEUM HYDROCARBON POLLUTION LOAD IN OGBOMOSO WASTEWATER AND THE ADJOINING STREAM

Abattoir wastewater contains numerous hazardous pollutants that may have severe effects on human health. Total petroleum hydrocarbons (TPH) is a term used to describe petroleum-based hydrocarbons found in crude oil that can be measured in environmental media, they are often found in wastewaters especially in situation where petroleum products are used such as abattoir. Discharge of wastewater containing pollutant such as petroleum hydrocarbon will affect receiving water body and render it unfit for specific use, this research is therefore aimed to assess level of petroleum hydro carbon contamination in Ogbomoso Central Abattoir and its adjoining rivers. Wastewater samples were collected from the abattoir waste discharge path in amber Winchester glass bottles, other samples were collected at the discharge point and measured distance before (upstream) and after discharge (downstream). Collected samples were prepared and analyzed for physicochemical parameters including TDS, DO, BOD, total hardness, and electrical conductivity following standard procedures. Raw water samples were extracted in triplicate using Liquid-Liquid extraction with Dichloro-methane as the extracting solvent, the extract was cleaned up and total petroleum hydrocarbon was analyzed using Gas chromatography Mass spectroscopy (GC-MS). Physicochemical parameters of wastewater gave mean values of 6.6, 0.01 ms/cm, 129mg L, 143 mg/L, 1.63 mg/L, 440 mg/L and 2100 mg/L for pH, EC, BOD, total hardness, DO, Alkalinity and TDS respectively. The surface water had range of 6.5-7.3, 0.0- 0.02, 1 06-119, 101-122, 1.84-8.7, 1.9-20 and 1800-1950 for pH, EC, BOD, total hardness, DO, Alkalinity and TDS respectively, this values indicate poor character of the wastewater and its influence on adjoining streams. Total petroleum hydrocarbon was present in all water samples, wastewater contained highest TPH with mean values of 140 mg/L. followed by the discharge point and the closer downstream with total values of 19.96 and 16.509 respectively. Least TPH was found in the upstream with mean values of 4.39 and 4.7599 respecctively. EC13- C20 was lower than C23 -C30 at the discharge point (4.12 and 32.28 respectively) and wastewater (68.0 and 396.7 respectively), downstream as well followed same trend. Sources were indicated to be from petrogenic products and use of heavy oils. This indicate the wastewater is polluted with petroleum products. The research concluded that the new Ogbomoso Abattoir wastewater is polluted with petroleum products and it has effects on the adjoining river as the wastewater and adjoining river had overall poor quality, it is hence recommended that alternatives be sought in meat processing and wastewater should be treated before discharge