Electrochemical disinfection of process wash water for the fresh-cut industry

The efficacy of electrochemical treatment for the disinfection of process wash water, using boron-doped diamond electrodes, as well as its suitability for the fresh-cut produce industry, has been evaluated. Process water containing different levels of organic matter (chemical oxygen demand (COD), around 60, 300, 550±50 and 750±50 mg L^-1) obtained from lettuce was inoculated with a five-strain cocktail of Escherichia coli O157:H7 at 10⁵ cfu mL^-1. Changes in levels of E. coli O157:H7, free, combined and total chlorine, pH, oxidation-reduction potential, COD and temperature were monitored during the treatments. The results obtained showed that the equipment exhibited potential for water disinfection and organic matter reduction even without adding NaCl. This technology would be able to reduce the high water consumption of the fresh-cut produce industry, as reuse of process wash water will have a positive economic and environmental impact. The use of electrochemical disinfection is presented as an alternative to chlorine, which is the most widely used sanitizer in the fresh-cut industry. Thus, this technology could be used in the fresh-cut industry to maintain the microbiological and physicochemical quality of wash water, reducing chlorination by-products formation with respect to sodium hypochlorite use.