Chemical Industry Digest. Nov-Dec 2002 CORROSION INHIBITORS CORROSION INHIBITORS AUTHORS Dr. S M A Shibli is with the Dept of Chemistry, University of Kerala, Thiruvananthapuram. He obtained his PhD in industrial electrochemistry based on his work on fuel cells at the Central Electrochemical Research Institute, Karaikudi, TN. He is engaged in the field of corrosion control methods, especially based on the principles of inhibitors, sacrificial anode, galvanic coating and nanotechnology. Introduction T he objective of cooling water treatment is prevention of corrosion, scaling and fouling of coolers. A successful water treatment would appropriately suit the system metallurgy, operating conditions and the water used. In addition, the programme must be consistently applied and monitored. Corrosion and other related problems cannot be totally eliminated however they can be effectively minimised by adoption of appropriate design and selection of suitable materials. The developments in cooling water additives possesses paramount importance. Selection & Practice of right treatment An effective water treatment method should be selected based on valuable inputs from various sources like laboratory screening of treatment chemicals, pilot plant trials, short-term field studies and from similar plant his- tories. After choosing the right treatment procedures, the next step is to ensure proper application of chemicals and timely response to abnormal events. It is essential to check periodically the concentration of the additives and the optimum values required for desired results. Advanced techniques should be adopted for fast assessment of additive concentration. For example chemiluminescence of the circulated water can be V S Saji has obtained MSc and M Phil degrees in Chemistry from the University of Kerala, Thiruvananthapuram, where he is working on corrosion inhibitors for cooling water systems. The total polymer level may be used to determine the volume of treatment chemicals added to the system, while the free polymer to total polymer ratio indicates the dosage required to maintain system performance. cooling water treatment. This includes proper selection and effective utilization of antiscaling, biocidal and inhibitor additives. This article also discusses on future scopes and alternative measures. A review of worldwide current preferences of cooling water additives are also given, with special reference to open systems. Corrosion Inhibitors in Cooling Towers S M A Shibli, V S Saji SYNOPSIS Selection of a suitable additive is one of the energy saving measures. It is also a material saving measure in cooling water systems. This paper discusses the mechanism, practice and control measures for effective 74