Blue dye degradation in an aqueous medium by a combined photocatalytic and bacterial biodegradation process

Abstract

This paper aimed at implementing a treatment system for polluted water with textile dyes, starting with aphotocatalytic decomposition process using sunlight as a source of energy and continuing with a bacterial biodegradationprocess, in order to reach degradation percentages higher than those obtained using only one of the processes mentionedabove. When water treatment with the dye in the combined system was over, an acute ecotoxicity test was performedto make sure that toxic metabolites were not produced due to biodegradation. Solophenyl Blue azoic dye, and ErionylBlue and Terasil Blue anthraquinone dye-colored solutions were treated with the Pd/Al 80 Ce 10 Zr 10 catalyst in a solarcollector for the photocatalytic process. On the other hand, the waste dye, which was obtained from photocatalysiswith a bacterial consortium from polluted areas by metals and hydrocarbons in aerobic conditions, was inoculatedfor biodegradation. Biodegradation was obtained for the dyes after both processes as 90.91% for the Solophenyl Blueazoic dye, and 87.80% and 87.94%, respectively, for the Erionyl Blue and Terasil Blue anthraquinone dyes. After thedegradation processes, it was proven, via an ecotoxicity test with Daphnia magna, that toxic metabolites had not been produced.