Assessment of the Physicochemical and Microbiological Quality of Palm Oil Mill Effluent (POME) and Soil in Aluu, Rivers State, Nigeria

Aim: To assess the Physicochemical and microbiological quality of POME and soil in Aluu, Rivers State.

Place and Duration of Study: This study was carried out in Omuahunwo, Aluu near Choba, University of Port Harcourt, Rivers State and Department of Applied and Environmental Biology Farmland, Rivers State University, Port Harcourt in Rivers State.

Materials and Methods: Palm oil mll effluent (POME) samples used in the study were obtained from two local palm oil factories located at Omuahunwo in Aluu near Choba, University of Port Harcourt in Rivers State. Replicate samples were collected bimonthly from the same source. Soil samples were obtained from an uncultivated farmland about 2 km away from the factory and a control soil sample devoid of POME contamination was taken from Department of Applied and Environmental Biology Farmland, Rivers State University, Port Harcourt. Samples were obtained from soil in proximity to the two factories polluted with POME. Samples were analyzed for their physicochemical and microbiological qualities.

Results: Palm oil Mills A and B had the following physicochemical parameters mean values: pH 5.48, 5.36; Conductivity 658μmhos/cm, 756μmhos/cm; total suspended solids 120,200 mg/l,122,000 mg/l;dissolved Oxygen 0mg/l (Palm oil mills A and B) ; BOD 5160 mg/l, 5200 mg/l;COD 432 mg/l, 4370 mg/l; Oil and Grease 165853 mg/l, 165900mg/l ;Phosphate 2.53 mg/l, 2.58 mg/l; Nitrate 68.83 mg/l, 68.90 mg/l; Ammonia 0 mg/l (for Palm Oil Mills A and B). Mean population of 8.25 x 103 cfu/ml, 3.6 x 103 cfu/ml, 3.2 x 102 cfu/ml and 12 MPN Index/100ml were recorded for total heterotrophic bacteria, filamentous Fungi, yeast and total coliforms respectively for the effluent samples from Palm Oil Mill A. Palm Oil Mill B had the following counts for total culturable heterotrophic bacteria, filamentous Fungi, yeast and total coliforms: 6.1 x 103 cfu/ml 2.5 x 103 cfu/ml, 2.2 x 102 cfu/ml and 8 MPN Index/100 ml. The most prevalent bacteria observed in this study were Bacillus spp., Pseudomonas spp., Arthrobacter spp., Enterobacter spp., Staphylococcus aureus and Escherichia coli.The genera isolated are common and many of the individual species are able to grow on petroleum hydrocarbon. The fungal genera identified were Aspergillus spp., Fusarium spp., Penicllium spp., Candida spp. and Saccharomyces spp.

Conclusion: From this study, it was observed that POME could have a positive effect if discharged properly since little application of the effluent can enhance microbial proliferation which increases soil fertility. Most of the physicochemical parameters like BOD, TDS, Oil and grease, etc were above the limits of surface water disposal and land application by FEPA,1991 except sulphate. The organisms isolated in this study that utilized the components of the effluent might not be denitrifiers but are obviously nitrate utilizers.