Factors Affecting Corrosion in Water and Waste Water Engineering

For any water supply scheme the major investment is in its distribution system. A distribution system may cost anything from 60% to 90% of the total cost of a scheme. Corrosion of water mains reduces its useful life, incre-ases leakeage of water and even leads to bursts of pipes. Leakage detection surveys in some cities in recent years have shown an astounding loss through leakage of over 50% of the total water supplied to the cities. No estimates
of economic losses by way of repairs and replacement costs and cost of water lost by leakage are available for Indian cities. Corrosion in water treatment plants and industrial water usage such as in boilers, cooling towers, conden-sers, etc is quite well-known. In sewage and industrial waste treatment plants, corrosion is the operators, enemy No.1. It is estimated that at any given time in India, half the sewage treatment plants are not functioning owing to corrosion and causes leading to breakdown. Relatively few operators understand the basic concepts or practical methods of reducing corrosion damage.