Fe(III)-catalyzed degradation of persistent textile dyes by chlorine at slightly acidic conditions: the crucial role of Cl(2)(BLACK CIRCLE-)radical in the degradation process and impacts of mineral and organic competitors

Abstract

In this work, we have explored for the first time the potential application of trace-Fe(III)/chlorine system as an innovative oxidation technology for the degradation of persistent textile dyes. Fe(III)/chlorine combination improved the dye removal by ~40% within 30 s, as compared with chlorination alone, mainly through a radical pathway induced by the catalytic activation of chlorine in the presence of Fe(III). A chemical probe method was used for identifying the main reactive species. Cl2●− was found to be the key species responsible of huge abatement of dyes in the Fe(III)/chlorine system, whereas ●OH and Cl● can participate with only ~5% in the overall removal efficiency. At pH 3, 77% of..