ENZYMATIC DEGRADATION OF AZO DYES USING PEROXIDASE IMMOBILIZED ONTO COMMERCIAL CARRIERS WITH EPOXY GROUPS

The treatment of colored wastewater has been paid attention in the recent years because of the high amount of dyes, mostly carcinogenic, discharged into the water. Enzymatic degradation shows several advantages such as: shorter processing time, reduction in sludge volume and ease of controlling the process. In this work, seven different industrial dyes were tested as substrates for horseradish peroxidase. The native enzyme was covalently immobilized onto two types of epoxy-supports, different in spacer length. Among the tested dyes the highest substrate conversions were achieved for Amido Black 10 (AB10). The highest recovered activity was obtained when the epoxy-activated support with longer spacer arm was used. After ten reuse cycles for the degradation of AB10, the covalently bound peroxidase preserved about 80% of the initial activity.