Evaluation and Modeling of Corrosion Rate of Selected Roofing Sheets Using Tetraoxosulphate (vi) Acid and Trioxonitrate (v) Acid as Simulated Acid Rain

The study focuses on the evaluation of the impact of acid rain on some common roofing sheets, including; Stone Coated, Galvanized, 0.55 m and 0.45 mm Long Span , Aluminum/Zinc sheet using simulated acid rain. The simulated acid rain was from four different molar concentrated H2SO4 and HNO3. The parameter used for the evaluation was a weight loss of the roofing sheet over the study period. Gravimetric analysis technique was adopted for the study. At the end of the study, the result obtained showed that for 1 mole solution H2SO4, 0.45 mm long Span recorded the lowest weight loss of 0.43 g, followed by Cameroon zinc with loss of 0.46 g while 0.55 mm long Span recorded 0.63 g. Stone-coated and galvanized sheet melted up before the end of the experiment. 1 mole solution of HNO3 recorded a similar trend with 0.46 g, 0.36 g, 0.47 g and 3.95 g weight loss for 0.55 mm long Span, Cameroon Zinc, 0.45 mm Long Span and stone Coated sheet respectively while Galvanized sheet melted up before the experiment ends. Stone Coated and Galvanized sheet melted up before the end of the experiment in 0.5 mole H2SO4 while 0.45 mm Long Span, 0.55 mm long span and Cameroon Zinc recorded 0.47 g, 0.5 g and 0.35 g weight loss respectively. Only Galvanized sheet melted up in 0.5 mole of HNO3, 3.5 g, 0.28 g, 0.38 g and 0.3 g weight loss was recorded for stone coated sheet, 0.45 mm long Span, 0.55 mm long Span and Cameroon Zinc respectively. Polynomial model of the fourth order show the best fit for the data. The models obtained for the weight loss and rate of corrosion showed a good fit with R2's ranging from 0.9 and above except for stone coated and galvanized sheets in 1 mole solution of H2SO4 with R2 of 0.782 and 0.8142. It is worthy to note from all the results obtained from the research that high percentage Aluminum base roofing sheet is the best for H2SO4 and HNO3 polluted environment.