The role of sulphur dioxide and gas flare particulates on the corrosion of galvanized iron roof sheets in south-south region of Nigeria

摘要

The failure of galvanized iron roofs is one of the problems suspected to be associated with environmental pollution in the south- south region of Nigeria often called Niger Delta. In this study, two parameters, sulphur dioxide and particulate matters linked to gas flaring were examined in an outdoor exposure test to determine their relative contributions to the corrosion impact. The experiment involved the exposure of specimen of galvanized iron sheets to the atmosphere for twelve months while readings of the two parameters were taken periodically. The mass loss of each of the specimens was determined at the end of the experiment. The obtained data were subjected to statistical treatment and the examination of the output of the descriptive statistics, multiple regression and Pearson product moment correlation analyses reveal that sulphur dioxide (SO2) did not significantly contribute to the problem while aerosol did. When the pollutants were regressed separately, their results showed that sulphur dioxide had an R2value of 0.389 and significant F change of 0.030 (p&0.05), and aerosol, an R2value of 0.660 and significant F change of 0.001 (p&0.05); however, in combination, the two parameters were shown to be more significant in a combined regression analysis (R2= 0.70) (p&0.05). Thus, their combined influence in the promotion of corrosion is higher than their separate impacts suggesting synergism. The study confirmed that gas flaring contributed significantly to the corrosion of galvanized iron roofs in the region.