In distilleries, ethanol production by fermentation results in generation of concentrated wastewater stream, called as spent wash (SW). It contains high total solids (TS), and chemical oxygen demand (COD). Unscientific disposal of SW in aquatic or terrestrial ecosystems poses high risk to the surrounding environment. In India, biomethanation is the preferred treatment option for SW. However, the by-product, i.e., biomethanated SW (BMSW) contains dark brown color, high COD and low biodegradability. The present study reports the performance of electro-Fenton (EF) process for the treatment of SW (COD = 135 g/L) and BMSW (COD = 65.5 g/L) in a laboratory scale reactor (capacity = 250 mL). A COD reduction of upto 60% and 50% could be obtained with diluted SW and BMSW, respectively. However, electrode fouling and foaming were observed during EF runs. Lower voltage, use of AC supply and adequate stirring could reduce the above problems significantly.
Biomethanated spent wash, electro-Fenton oxidation, iron electrode