Atmospheric corrosion of mild steel in the Niger Delta region of Nigeria. Part 1: Characterization of the Calabar, Cross River State environment

Abstract

The atmospheric corrosion of Calabar, Cross River State environment has been investigated for 12 months using weight loss technique. The extent of pollution of the environment was also determined via measurements of the precipitation and air quality parameters. Apart from the suspended particulate matter (SPM) (113-630 μg/m 3 ) and NO 2 (> 0.06 ppm) values, other measured atmospheric parameters (CO < 9.2 ppm, NH 3 < 4.3 ppm and SO 2 < 0.380 ppm) and precipitation parameters (pH > 5.0, conductivity < 60 µScm -1 , TDS < 41.48 mg/l, TSS < 0.05 mg/l, NO 3 -< 3.00 mg/l, SO 4 2-<1.00 mg/l and NH 4 + <1.00 mg/l) indicate that the environment has received little or no detrimental influence by human activities. The average corrosion rates for all the stations studied were below 35 μm/yr, and are due principally to natural phenomenon (high rainfall, humidity and temperature).