Effect of Abattoir Waste Water on Physico-chemical Characteristics of Soil and Sediment in Southern Nigeria

Aim: The study was carried out to evaluate the biophysical properties of samples contaminated by abattoir wastes. The study aims to determine the physico-chemical properties of samples contaminated by abattoir wastes in order to create public awareness about the state and health implications of abattoir activities on the environment.
Study Design: Abattoirs close to Rivers and creeks that discharge wastes into water bodies were selected in comparison with those not close to such water bodies.
Place and Duration of Study: The study was carried out in abattoirs Located at Ogbe in Ahiazu-Mbaise Local Government Area, Egbu in Owerri North Local Government Area both in Imo State, Nigeria; Trans-Amadi in Port Harcourt City Council and Ahoada in Ahoada East Local Government Area both in Rivers State, Nigeria. The study covered two seasons, rainy and dry seasons between 2010 and 2011.
Methodology: A total of thirty six sampling points were considered for the study. Soil and waste water samples were collected from four abattoirs located at Egbu and Ogbe in Imo state, Trans-Amadi and Ahoada in Rivers State. Sediment samples from Otamiri River and Oginigba Creek around Egbu and Trans-Amadi abattoirs respectively were collected using standard methods recommended by the American Public Health Association (APHA) and other international methods were adopted for the determination of physiochemical characteristics of the samples.
Results: The range of results obtained were 6.71 – 9.37 for pH, 20.0 – 30.4oC for temperature, 165 – 6,080 mg/l for total suspended solids (TSS), 155 – 1,560 mg/l for total dissolved solids (TDS), 75 – 12,000 mg/l(water) and mg/kg(soil) for biochemical oxygen demand (BOD), 100 – 22,500 mg/l(water) and mg/kg(soil) for chemical oxygen demand (COD), 150.2 – 9,265 mg/l(water) and mg/kg(soil) for SO42-, 0.45 – 90.75 mg/l(water) and mg/kg(soil) for PO43-, 0.35 - 308.89 mg/l(water) and mg/kg(soil) for NO¬3-, 4.12 – 45.7 mg/l(water) and mg/kg(soil) for Na, 0.26 – 106 mg/l(water) and mg/kg(soil) for K and 0.00 – 2.551 mg/l(water) and mg/kg(soil) for Polycyclic Aromatic Hydrocarbon (PAH). The results generally showed significant differences, at 0.05 confidence limits, between test and control samples of soil and waste water, while the reverse was the case between rainy and dry seasons.
Conclusion: The study indicated negative impact of abattoir activities on the soil that receive wastes from abattoirs which is probably because effective waste disposal system is not practiced by abattoir operators. The study showed that abattoir wastes have high pollution strength and thus should be treated before being discharged into the environment.