Preparation of hydrated lime quality for water treatment: to reduce silica concentration from hydrated lime up to standard specification

This research paper examines the effort of preparation of hydrated lime for water treatment matching the required quality. In order to avoid scale formation, hydrated lime quality needs the removal of silica from the lime water. Laboratory tests were conducted on lime samples and then checked for conformity with the AAWSA and AWWA standards. In this research, lime water was prepared from a 1.49% silica concentration of limestone, so much preferable. One of the most practical strategies for reducing silica content in hydrated lime was ion exchange. 2 M NaOH and 0.1 M HCl were dosed in limewater with different dosing amounts. The optical absorption value of silica in final solutions of limewater was recorded by UV-Visible spectrophotometer, and the results found 0.042, 0.132, 0.121, 0.05, 0.688 and 0.21. All these absorbance values are equivalents to less than 0.5% silica concentration lime water, which is adequate for water treatment, hence matching the standards. Among dosages amounts, the optimum dose of sodium hydroxide was 10 mL of 2 M NaOH.