Abstract
In order to investigate the effect of ammonia on acidogenic bacterial growth characteristics using carbohydrate and protein in anaerobic digestion, continuous experiment feeding with a synthetic substrate composed of starch and peptone was performed by changing ammonia nitrogen concentration of digester content. The carbohydrate degradation efficiency was decreased to below 20% with increasing the ammonia nitrogen loading rate to 4.21g-TAN/g-VSS. It seemed that acidogenic bacteria with an ability to utilize both of carbohydrate and protein grew by mainly utilizing protein under the toxic ammonia concentration. It also appeared that before the carbohydrate degradation efficiency was dramaticaly decreased, ethanol concentration in metabolite increased with ammonia nitrogen concentration increased.
