Thermophilic anaerobic digestion of livestock waste: the effect of ammonia

摘要: Ammonia concentrations of 4 g N/l or more inhibited thermophilic digestion cattle manure. A stable manure could be maintained with ammonia up to 6 after months operation. However, the methane yield was reduced and concentration volatile fatty acids increased from 1 3 g/l as acetate, compared controls an 2.5 N/l. The temporary strong inhibition following one-step increase in by applying a gradual increase. specific methanogenic activity ammonia-inhibited reactors (6 N/l) acetate hydrogen substrate 73 52%, respectively. Tests toxicity on acetate- hydrogen-utilizing populations showed higher sensitivity aceticlastic hydrogenotrophic methanogens; growth rate for methanogens halved at 3.5 N/l, 7 methanogens.