ABSTRACT

The microbiological and physicochemical characteristics of soil contaminated with lairage. effluent were i:ivestiguted. A total of 20 samples were analyzed for total 20 samples were analyzed for total heterotrophic bacteria count,fungi count, vibrio cholera count. The culture media used were nutrient agar, potato dextrose agar, eosin methylene blue agar, Salmonella-Shigella agar, MacConkey agar, thiosuiphate citrate bile-salt sucrose agar. The pour plate technique was used for the inoculation of samples. The total heterotrophic bacterial count for the contaminated soil ranged from 4.5 x I 0⁵cfu/mg to 8.8 x 10⁵cfu/g while lairage effluent was 2.5 x 10⁶cfu/mL. Fungal count was I .2x10³cfu/g to 4.4 x 10³cfu/g for contaminated soil and 1.9 x 10³cfu/mL for lairage effluent. Salmonella-Shigelia count ranged from 0.2 x 10³cfulg to 0.3 x l03cfulg for contaminated soil and 0.3 x l03cfu1rnL for lairage effluent. Vibrio cholerae count for contaminated soil was between 0.4 x10³cfu/g and 2.0 x 10³cfu/g while lairage effluent was 1.7 x 10³cfu/mL. Total Escherichia coli count for contaminated soil was from 1.0 x 10³cfu/g to 2.4 x 10³cfulg and 2.0 x 10³cfu/mL for lairage effluent. The total coliform count for contaminated soil ranged from 3.4 x 104cfu/g to 4.6 x 104cfu/g and 5.5 x 104cfuJmL for lairage effluent. Results of the physico-chemical analysis showed that the temperatures recorded for contaminated soil and lairage effluents are 29°Cand 30°C respectively, the mean values for pH were 5.8and 7.8. The mean values for conductivity, oil and grease, total organic carbon, phosphate, nitrate, sulphate, calcium, magnesium, potassium in contaminated soil were 55.7l.IS/cm, 2.0mg/kg,l .66%, 1,95mg/kg, 0.66mg/kg, 22.5mg/kg, 303, 92mg/kg, 5.0mg/kg respectively. The mean values for conductivity, turbidity, chloride, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total suspended solids, total dissolved solids, nitrate, sulphate, phosphate, ammonia in lairage effluent were 40.8tS/cm, 72.0NTU, 8.omg/L, I .2mg/L, 36.omg/L, 82.0mg/L, 63.Omg/L, 24.Orng/L, 0.85 mg/L, 10mg/L, 2.2mg/L, 0.83mg/L respectively. The lairage effluent from this result is responsible for the contamination of soil.