Ozonation of azo dye acid black 1 under the suppression effect by chloride ion

• Autor(a) principal: Paprocki,Alexandre
• Data de Publicação: 2010
• Outros Autores: Santos,Heldiane S. dos, Hammerschitt,Marta E., Pires,Marçal, Azevedo,Carla M. N.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532010000300009
• topic: azo dye; ozonation; salt additives; chloride ion; suppression effect

The aim of this study is to determine the kinetics of the Acid Black 1 dye by oxidizing action of ozone and to evaluate the influence of chloride ion contamination on the dye degradation. Pseudo-first order kinetics was observed for both decolorization (620 nm) and aromatic structure (321 nm) degradations. A complete color removal was verified in 25 min ([dye]0 = 1.8 × 10-5 mol L-1), while aromatic structures degraded at slower rates. The presence of chloride ion, the principal impurity of the solid dye reagents, influences significantly the ozonation rate (-42%), even at low chloride concentration (5.6 × 10-4 mol L-1). The most probable mechanism for the chloride suppression effect involves a direct reaction between O3 and Cl- generating HOCl, among other by-products. In despite of that, ozonation could be a competitive degradation process for this dye.