Effect of sludge treatment on biogas production from Saccharina japonica ethanol fermentation by-products

The brown seaweed contained various carbohydrates, such as alginate, laminaran, and mannitol. However, the production of pure culture that utilized carbohydrates was extremely limited. A mixed culture produces better results for digestion than does a pure culture. The aim of this study was to determine the level of biogas production from by-products of Saccharina japonica using a sludge pretreatment with an optimal pH. A freeze pretreatment was found to produce a better result than heat and ultrasonic irradiation pretreatments, and the optimal initial pH for biogas production was 8.