DEGRADATION OF SYNTHETIC ORGANIC DYES IN SOLUTION BY FERRATE – HYPOCHLORITE OR CALCIUM HYPOCHLORITE

Abstract

This study investigated the use of ferrate – hypochlorite solution or solid Ca(OCl)2 as treatment options to remove color and COD from solutions of the synthetic organic dyes: Reactive blue 19, Allura red and Reactive black 5. It was found that doses around 1000 ppm Ca(OCl)2 had color removal efficiencies around 90 % for all the dyes after 15 minutes reaction time; this treatment had a COD removal efficiency of 97 % for azo dye Allura red. The ferrate – hypochlorite (0.06 mM - <400 ppm) treatment resulted in a 50% color removal for Reactive blue 19 dye after 1 hour reaction time. The COD removal of Reactive blue 19 dye was improved from 40% to 84% when the ferrate – hypochlorite solution was used.