In situ hypochlorous acid generation for the treatment of distillery spentwash

High-strength organic waste like distillery spentwash can be effectively treated by electrolysis in the presence of sodium chloride. Because the graphite anode and stainless steel cathode zones were kept unseparated, chlorine produced during electrolysis forms hypochlorous acid. The hypochlorous acid thus formed oxidizes the organic matter present in the wastewater. The COD removal from the spentwash was found to be 99% for an initial COD concentration of 15 000 mg/L at the end of 240 min of electrolysis. The energy requirements were found to be 36 and 27 W·h/L for treating 20 L of spentwash at 2.5 and 3% sodium chloride concentration, respectively. The observed energy difference is due to improved conductivity of the electrolyte.