Corrosion Failure of the External Surface of Chlorinator’s Copper Pipes in a Water Disinfection Station

Abstract

This work investigates the corrosion failure of the chlorinator’s copper pipes in a rural water disinfection station. For this purpose, some corroded samples were provided from the failed pipes and investigated using the X-ray diffraction (XRD) and the scanning electron microscope (SEM) equipped with the energy-dispersive X-ray spectroscopy (EDS). Also, an experimental setup was designed to study the role of the electrolyte formation on the copper pipes. This experimental setup demonstrated that the main factor of pipe failure was the formation of a corrosive electrolyte layer with varying chlorine (presented due to gas leakage) concentration during a day. The electrochemical impedance spectroscopy (EIS) confirmed that variations in the chlorine concentration had an unexpected effect on the corrosion rate. Furthermore, it was found that the main phase in the corrosion products was cupric chloride hydroxide (Cu2(OH)3Cl) with many porosities and cracks. These defects provide suitable places for the formation of the corrosive electrolyte and the following corrosion which ultimately led to the failure of the copper pipes.