Parametric Studies of In-house Resin for Hardness Removal

Abstract

Presence of high amount of calcium and/or magnesium makes the water hard as these ions in water react with other chemical agents and constituents of metallic plumbing etc. The process accelerates in the presence of heat. It decreases the efficiency of the unit operation due to the formation of scales. Hence, scaling is the main issue for which hard water is required to be treated or polished. De-mineralized water finds wide application in the fields of steam generation plant, high-pressure boiler feed, power-production plant, process plant, cooling systems, steel mills, refineries, petrochemical complexes, hydrometallurgical, metals finishing etc. The high-purity water from a de-mineralized plant is typically used in computer chip, micro-electronics, semiconductor industries. A highly efficient resin Polyacrylamide Carboxylic acid has been developed in-house in Desalination Division, which is capable of removing calcium to the extent of 98.5% in substantially short span of time of 5 min from feed containing calcium as high as 500 ppm and the resin work excellently for streams having pH 4–7. Also, the loaded metal ions can be recovered and resin can be reused. In this regard, experimental studies by varying different process parameters viz., concentration, time, loading, mesh size, elution etc. have been reported in this paper to highlight the basic parameters for resin selection.