THE RELATIONSHIP OF BIOFILMS AND PHYSICOCHEMICAL PROPERTIES OF SOIL SAMPLES WITH CORROSION OF WATER PIPELINES IN MINNA, NIGER STATE, NIGERIA

This study investigated the relationship of biofilms and physicochemical properties of soil samples with corrosion of water pipelines in Barkin-Sale, Bosso, Chanchaga, Keteren-Gwari, Maikunkele and Kwangila areas of Minna metropolis. Corroded water pipes and soil samples were analysed for microbiological and physicochemical properties and their influence on corrosion correlated between the months of February and July, 2008. The corrosion products detected in the soil samples were sulphide and phosphide. The mean concentration of sulphide ranged from 1020 to 3033ppm and that of phosphide ranged from 13.50 to 22.58ppm. The mean organic carbon ranged from 0.35 to 0.89%, mean organic matter ranged from 0.62 to 1.57%, mean pH ranged from 6.73 to 7.70 and mean moisture ranged from 4.33 to 16.63%. There was a significant difference (P<0.05) in the level of sulphide, phosphide, organic carbon, organic matter and moisture in the locations but there was no significant difference (P>0.05) in their pH. The mean total aerobic bacterial counts ranged from 3.5x10³cfu/g to 7.2x10⁴cfu/g, mean total aerobic bacterial counts ranged from 3.0x10³cfu/g t0 5.6x10⁵cfu/g. total aerobic bacterial counts (TABC) was positively correlated with phosphide and negatively correlated with organic matter, pH, moisture, total fungal counts (TFC) and total anaerobic bacterial counts (TAnBC). The total anaerobic bacterial counts (TAnBC) was positively correlated with sulphide, phosphide, organic carbon, organic matter and pH while the total fungal counts (TFC) was positively correlated with sulphide, organic carbon, organic matter, pH and moisture and negatively correlated with phosphide total aerobic bacterial counts and total anaerobic bacterial counts