Influence of Fermented Cereal and Lactic Acid Bacteria Concentrate on Sewage Sludge Digestion

Abstract

The influence of additives - fermented cereal (6 % and 9 % vol.) and a concentrate of lactic acid bacteria isolated from the fermented cereal (6, 9 and 12 %) - on anaerobic digestion process and methanogenesis is described. In the case of the addition of fermented cereal, biogas production significantly increased (up to 116 %). The addition of a lactic acid bacteria concentrate increased the biogas production up to 67 %. However, the application of additives did not improve the sludge volatile solids removal and the daily amount of waste sludge was the same or slightly higher compared to the control reactor (up to 14 % in the case of a fermented cereal and up to 9 % in the case of a lactic acid bacteria concentrate).

Keywords:

• Additives
• anaerobic digestion
• biogas production
• methanogenesis
• sludge removal