Effect of municipal liquid waste on corrosion susceptibility of galvanized steel pipe

Abstract

This investigation studied the effect of municipal liquid waste discharged into the environment within Kano municipal area on the corrosion susceptibility of galvanized steel pipe burial underground. Six stagnant and six moving municipal liquid waste samples were used for the investigation. The corrosion rate of the galvanized steel pipe was measured using the gravimetric technique. The results obtained from weight loss measurement shows a serious corrosion effect of municipal liquid waste on the galvanized steel pipe. The overall corrosion rates are much higher in the stagnant and moving liquid waste samples collected within the core city than the liquid waste samples collected outside the city, but become low with the formation of passive films on galvanized steel surface after 2500 hours. Therefore, this investigation revealed that the galvanized steel pipes used to supply the city with pipe borne water are at high risk of supplying contaminated water due to some leaking pipes.

Key words: Liquid waste, galvanized steel, weight loss, ravimetric, corrosion, leaking