Simultaneous degradation of two textile dyes Orange G and Basic blue 41

Abstract

Cobalt-doped alumina catalyst was tested in peroxymonosulfate-induced degradation of two textile dyes: anionic-Orange G (OG) and cationic-Basic Blue 41 (BB). Oxone®, mixed salt containing peroxymonosulfate as an active component, was used as an oxidizing agent. Catalytic tests were performed in a thermostated reactor equipped with a mechanical stirrer. Dyes degradation was followed using a UV-Vis spectrophotometer. Characteristic peak maximum in UV-Vis spectrum was identified at λ=478 nm for OG, and at λ=609 nm for BB. Two OG concentrations were applied: 20 mg dm-3 and 50 mg dm-3. BB concentration was 20 mg dm-3 in all experiments. The reaction temperature was 30 ºC. Apart from simultaneous dyes degradation, single-component solution degradation tests were also performed. Both dyes were found to be degradable in single dyes systems, with OG showing a higher degradation rate. When it comes to simultaneous degradation, it was noticed that the degradation of the BB did not occur while OG was present in the system. This phenomenon can probably be attributed to the difference in the molecular structure and charge of the investigated dyes.