Physicochemical and Mineral Compositions of Wastewater and Soils from Two Selected Abattoirs in Warri, Delta State, Nigeria

This study was carried out to evaluate the physicochemical and mineral compositions of abattoir wastewater and contaminated soils from two selected abattoirs in Warri, Delta State and therefore to assess the impact of abattoir activities on the surrounding soil environment. The pH values of the abattoir wastewater (8.2 ± 0.04 and 8.0 ± 0.14) and contaminated soil (7.28 ± 0.31 and 7.75 ± 0.21) were higher than the control at 6.4 ± 0.01 and 6.6 ± 0.01 (control water) and 5.4 ± 0.02 and 4.2 ± 0.01 (uncontaminated soil). The BOD and COD values for abattoir A wastewater (110 ± 2.82 mg/L and 2.64 ± 2.82 mg/L) and abattoir B (398.5 ± 2.10mg/L and 351 ± 1.41 mg/L) were higher than the WHO standard. All the minerals were below the WHO standard except iron with mean concentration of 0.73 ± 0.17 mg/L and 1.35 ± 0.61 mg/L for abattoir wastewater A and B respectively. The abattoir waste contaminated soils A and B had higher values compared with the controlled soils. The soils A and B had higher values compared with the control soils. The soils A and B have values for organic carbon (16381.25 ± 1.78 mg/L and 12863.1 ± 0.88 mg/L), sulphate (2166.8 ± 1.72 mg/L and 3700.5 ± 0.70 mg/L), chloride ( 4501 ± 1.41 mgL and 2101.5 ± 2.12 mg/L), iron (855.9 ± 0.34 mg/L and 1287.5 ± 2.12 mg/L), lead (27.94 ± 0.42 mg/L and 16.87 ± 0.50 mg/L), manganese (66.32 ± 2.22 mg/L and 44.17 ± 1.12 mg/L) and phosphorus (75.13 ± 1.24 mg/L and 79.01 ± 1.40 mg/L). The continuous discharge of the abattoir wastewater into the surrounding soils led to the pollution of the soil. Adequate treatment of the wastewater before discharge and proper waste disposal systems are necessary.