Spatial variation in acid and some heavy metal composition of rainwater harvesting in the oil-producing region of Nigeria

The study adopted the experimental research design and field survey of the oil-producing region of Nigeria for the past 10 years. A total of 100 sterilized rain gauges were randomly distributed on the basis of 50 each to the eastern and western division of the oil company operating in the region. The rainwater samples harvested through this process were transferred into sterilized plastic containers and kept in coolers and taken immediately to the laboratory for analysis soon after every rain event. The rainwater samples were analysed in the laboratory with the most appropriate techniques. The physicochemical characteristics of rainwater harvested were subjected to paired t test and 3-year moving average statistical analysis. The following are the results: There is widespread acid rain in the region, this is evident from pH values that span 4.98-5.15 and 5.06 mean values. The result also revealed that acid rain (pH) varied significantly (P > 0.05), and it decreases with increasing distance from gas flare sites throughout the period of study. Other physicochemical characteristics of rainwater resources conform to safe limit with the exception of turbidity, TSS, Pb and NO3, which is also significant at P > 0.05 with increasing distance from the gas flare sites, as such they decreases with increasing distance. This certainly has serious environmental effects on the human and other species, soil, water and vegetation resources and calls for the extinction of gas flaring, in this region. Sources of water that are acidified should be periodically limed to reduce the acid concentration in such water.