Journal of Applied Electrochemistry, Vol.33, No.10, 901-908, 2003
Electrochemical reduction of indigo in fixed and fluidized beds of graphite granules
Reducing agents required in the dyeing process for vat and sulfur dyes cannot be recycled and lead to problematic waste products. The electrochemical reduction of indigo on a fixed bed cathode consisting of graphite granules has been investigated by spectrophotometric experiments in laboratory cells. Experiments yield information about the kinetics and show the possibility of this process for production of water soluble leuco indigo, which offers environmental benefits. The influence of noble metals deposited on the granules and of different pretreatment methods of the graphite is demonstrated. In addition, the immobilization of quinoid molecules on the graphite surface has been investigated.
Keywords:anthraquinone;electrochemical reduction;fixed bed;graphite;indigo;modified electrode;quinone;vat dyes