Electrolyzed water is a technique first developed in Japan in the 1990s. The concept involves electrolysis of water containing a small amount of sodium chloride (0.1%) in an electrolysis chamber where anode and cathode are separated by a bipolar membrane imparting unique characteristics to the water collected from the two electrodes. The water from the anode normally has a pH of <2.7 and an oxidation reduction potential (ORP) of >1,100 mV The

water produced from the cathode side has a pH of >11.4 and ORP of <-795 mV The sche­matic diagram depicting the process is included in Figure 3.5. The low pH acidic electrolyzed water (AEW) and the high pH alkaline electrolyzed water have been used recently to pretreat DDGS, and subsequently for fermentation into ABE (Wang et al. 2009a). Scanning electron micrograph (SEM) images of DDGS pretreated with AEW showed the crystalline structure of the DDGS was disrupted by the pretreatments with AEW at pH 2.7 (Wang et al. 2009a). A major advantage of using electrolyzed water is that it is produced using water with no added chemicals other than very dilute sodium chloride.