Transformation of natural and synthetic dyes in pulsed electric discharge in the granular steel bed

Humic substances in groundwaters containing dissolved iron form stable colloids. Pulsed spark discharge in a granular steel bed was applied for abatement humic substances and synthetic indicators mimicking the target molecule fragments. A reversible red-ox cationic methylene blue, an anionic eosin Y and irreversible red-ox indicator furacilin were used to disclose the reactions and adsorption on the discharge erosion products. Partial, for about 40%, mineralization of organic molecules was observed for all substances, whereas rapid red-ox reactions also took place between organic molecules and dissolved ferrous iron. Humic substances adsorbed at the spark erosion products with their anionic groups.