Influence of chlorine-water equilibria on the electrochemical destruction of thiocarbamate herbicides in NaCl solutions

The electrolytic destruction of thiocarbamates in NaCl solutions takes place mainly through indirect electrolysis with Cl-2, HOCl, ClO- and other oxidising species. The electrochemical destruction of thiocarbamates EPTC and Vernolate was studied in different Cl-2, HOCl, ClO- domains in chlorine-water equilibrium. Differences were found in both destruction rate and in intermediate and end products. Complete mineralisation can be achieved in ClO- domain, where both total organic carbon (TOC) content and chemical oxygen demand (COD) are continuously decreasing and biodegradability is increasing during electrolysis. UV irradiation considerably accelerates the destruction process, i.e. the electrochemical destruction of thiocarbamate Vernolate.