Treatment of Effluent from the Agate Dyeing Industry Using Photodegradation and Electrodialysis Processes

Abstract

The industrial dyeing of agates employs considerable quantities of synthetic dyes (organic and metallic ions). The aim of the present study was to investigate the potential value of coupling photodegradation with electrodialysis in the degradation of organic dyes and in the removal of contaminant ions present in raw effluent obtained from the agate dyeing industry. Photodegradation was carried out on a pilot-scale in a flow cell reactor fitted with a 400 W lamp. Electrodialysis was performed in a cell comprising three compartments separated by ion-selective membranes and fitted with a 70TiO₂/30RuO₂ DSA® anode and a titanium plate as cathode. The treatment produced a 62% reduction in the TOC present in the raw effluent, and around 20.5% of total nitrogen was extracted. Thus it was concluded that coupling photochemical degradation with electrodialysis represents an efficient method for treating effluents.

Keywords:

• electrodialysis
• photochemical treatment
• dyes
• toxicity