The impacts of auto-mechanic workshops on soil and groundwater in Ibadan metropolis

Abstract

The extents of groundwater and soil pollution arising from auto-mechanic activities from auto-mechanic workshops at Ibadan metropolis were examined. Groundwater and top soil samples from auto-mechanic villages and control site were collected fortnightly over a period of two months and analysed for both physicochemical parameters and some heavy metals. Results of physicochemical parameters of groundwater ranged from 23 to 29°C for temperature, 0.25 to 8.64 mg/L for DO, 0 to 52.19 mg/L for BOD, 14.7 to 205.86 mg/L for COD, 5.63 to 7.33 for pH, 18 to 133 mg/L for total alkalinity, 23 to 287 mg/L for total hardness, 2 to 32.75 F.T.U for turbidity, 187 to 268 μs/cm for conductivity, 0.7 to 44.6 mg/L for TSS, 135 to 248 mg/L for TDS, 136.3 to 292.6 mg/L for TS, 0.03 to 62.1 mg/L for nitrate, 2.37 to 12.02 mg/L for phosphate, and 0 to 55.6 mg/L for oil and grease. Results of heavy metals analysis for groundwater ranged from 0 to 1.132 mg/L for Cd, 0 to 24.46 mg/L for Pb and 0 to 24.6 mg/L for Fe. Statistical analysis, using Pearson’s correlation coefficient indicated correlations of some parameters at P≤0.01 and 0.05. The mean and standard deviations of the parameters were also calculated. The daily activities of automechanic workshops have negative impacts on both soil and water.

Key words: Ibadan Metropolis, mechanic workshop, pollutants, soil, groundwater.