Empirical models for the decoloration of dyes in an electrochemical batch cell

Abstract

Among several types of textiles colorants, reactive dyes represent about 30 50% of the total market share, and the most common group used as chromophore is the azo group (70%), followed by anthraquinone. The removal of such dyes from wastewater is a problem in textile mills. Electrochemical treatment has proven to be an interesting technique for removing dyes from wastewater, as it does not require any added chemical reagents. Generally, this technique is applied to obtain partial dye degradation (until color removal). In this work, electrochemical treatment was performed in a batch cell. The influence of conductivity, temperature, pH, dye concentration, and dyeing electrolyte on the decoloration was studied. The time required to reach a fixed level of decoloration and the corresponding electricity consumption were also evaluated. Six reactive dyes with different chromophores and reactive groups were selected. The main statistical study was carried out on CI Reactive Orange 13, a textile dye with the commercial name ProcionOrange PX-2R (OrPX). Subsequently, the behavior of the other dyes was studied in comparison with the OrPX models.