ANALYSIS OF ELECTRIC DOUBLE LAYER STRUCTURE FORMED DURING CORROSION OF STEEL PIPES CARRYING POTABLE WATER

Abstract

Corrosion of steel pipes carrying drinking water is a universal issue. It affects human health as the corrosion sediments in these pipes can be toxic and unfit for consumption. Further, the amassing of the corrosion products can lead to operational difficulties. Drinking water consists of anions like carbonate, hydroxides and chloride ions which are responsible for the corrosion process. In such types of aqueous corrosion, there is an interfacial region formed between the corroding metal and the bulk of the aqueous environment. This interfacial region is called the Electrical Double Layer. In this article, we direct to study the effects on Double Layer Surface which takes place during the corrosion process. In order to develop an analytical model for simulation to obtain results in our system, we study and obtain certain chemical and physical properties of the chemical components in potable water such as Initial concentrations, Stokes radius, Ionic radii, relative permittivity etc. Results of the effects on the Double Layer Structure are obtained by varying certain parameters like electric potential, metallic flux and temperature. From the results obtained, we notice that CO32- anion is the single dominant factor causing corrosion in steel pipes. Concentration of CO32- ion on the metal surface increases with voltage. At the same time, concentration of water on the surface reduces by increasing the voltage and eventually gets thrown off the metal surface.