ABSTRACT

The microbiological and physicochemical characteristics of soil receiving palm oil effluent in umuahia were investigated. A total of 10 samples were analyzed for total heterotrophic bacterial count, fungal, hydrocarbon-utilizing bacterial, hydrocarbon utilizing fungi and nitrifying bacterial. The culture media used were nutrient agar, Saboüraud dextrose agar, mineral salt agar, mineral salt agar antibiotics (streptomycin), and nitrogen-free mineral salt agar. The pour plate technique was used for the inoculation of samples. The total heterotrophic bacteria count ranged from LOU x 106 to 1.56 >< 106 CFU/g for soil, while effluent was 6.3 x 10 CPU/mi. fungi count was 3,4 x to 1.7 x iü CFU/g for soil and 4.9 x lO CFU/rni for effluent. The count for hydrocarbon-utilizing bacteria ranged from 1.0 x 102 to 9.1 x CPU! g for soil and 5.9 x 1O CFUImI for effluent. 1-lydrocarbon-utilizing fungi count for soil was from 0.8 x 1O3to 9 x CFU/g for soil and 8 x 1 0 CFU/ml for effuent. The total count for nitrifying bacteria ranged from 0.8 x lO to 2.6 x CFU/g for soil and '2.4 x CFU/ml for effluent. Results of the physicochemical analysis showed that the pH recorded for contaminated soil and control was 6.1 and 5.5 respectively and 7.2 for the effluent. The mean values for conductivity, oil and grease, phosphate, nitrate, sulphate, calcium, sodium, potassium, magnesium', in contaminated soil were 63.8is/cm, 8.1 mg/kg, 3.84%, 1.50mg/kg,0.59mg/kg, 27mg/kg, 219mg/kg, 116mg/kg, 6.0mg/kg, 0.85mg/kg respectively. The mean values for conductivity, oil and grease, phosphate, nitrate, sulphate, calcium, sodium, potassium, magnesium, for the control soil were 46.7ts/cm, 1 .0mg/kg, 0.93%, 0.62mg/kg, 0.3 3mg/kg, 13.0mg/kg, 156mg/kg, 83mg/kg, 3mg/kg, 0.52mg/kg. The mean values for the conductivity, turbidity, chloride, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total suspended solids, total dissolved solids, ammonia, 1liosplmtc, nitrate and sulphate in raw effluent were 26.5 J.ts/cm, 55:ONTU, lomg/L, 1.8rng/L, 25mg/L, 60mg/L,32mg/L, O.35mg/L, 0.40mg/L, 0.21mg/kg,' 0.55mg/kg, 2.0mg/kg respectively. The raw effluent is responsible for the contamination of the soil.