Corrosion is the deterioration of a material caused by its reaction with the environment, leading to serious loss. The corrosion behavior of steel pipes influenced by the paint effluent reveals the following results: The effluent of paint industries contains both organic and inorganic wastes that cause damages through corrosion to Galvanized Iron Pipes (GIPs), which are frequently used in Central Effluent Treatment Plants (CETPs). Most of the structures in a CETP are made of Medium Carbon Steel (MCS). Hence, the samples were prepared using MCS. The pH of the untreated effluents and effluents treated by electrochemical oxidation were 3.75 and 4.73 respectively. Chemical Oxygen Demand (COD) values were found to be decreased after electrochemical oxidation. The weight loss of the MCS coupon was widely varied in treated and untreated effluents with respect to exposure time. Based on the results, it has been concluded that the corrosion rate of MCS in untreated paint effluent was much severer than that of the treated one. Hence, necessary steps must be taken to minimize the corrosion effect on MCS and GIP that are exposed to CETP. It has also been suggested that the effluents must be treated to reduce the COD before releasing them in the environment.

Corrosion is the destruction of metallic materials by electrochemical reaction with the environment. Corrosion signifies the range of reactions between metals and their non-metallic environments. The sources of the paint effluent include disposed unwanted chemicals, plant washings, equipments, and water used for floor washing. It contains both organic and inorganic matters like formaldehyde, trisodium phosphate and creselic acid, and this effluent substantially increases the Chemical Oxygen Demand (COD) when it is discharged. Such paint effluent deteriorates due to ageing or chemical modification, becomes sticky or hard and affects the properties of Galvanized Iron Pipe (GIP) and structures made of Medium Carbon Steel (MCS), which are frequently used in Central Effluent Treatment Plants (CETPs) (Waldmann, 2000).

Corrosion enhances cracks on the external or internal surfaces of pipes, tanks or other industrial assets made of MCS and reduces the integrity of the material, thereby reducing the life of the equipments. These defects may be due to various forms of corrosion, including stress corrosion cracking. Long exposure of these materials, used in bridges, industries, aerospace engineering, pipelines and marine products, brings down their life drastically (Kanters and Ginzel, 2002). In this connection, the present study has been carried out to understand the effect of paint effluent on MCS.

Chemistry Journal, Medium Carbon Steel, Corrosion, Central Effluent Treatment Plants, Galvanized Iron Pipes, Chemical Oxygen Demand, Stress Corrosion Cracking, Marine Products, Aerospace Engineering, Electrochemical Oxidation Method, Organic Compounds.