IMPROVEMENT OF METHANOGENESIS FROM COW DUNG AND POULTRY LITTER WASTE DIGESTERS BY ADDITION OF IRON

When 50 mM FeSO4 was added to cow dung and poultry litter waste which had been processed in daily-fed batch digesters, digesters subsequentl y unfed showed a faster conversion of substrate and overloaded digeste rs stabilized within 48 h. Early stabilization of digesters was achiev ed by adding 20 or 50 mM FeSO4 though the latter concentration was fas ter. When 20 mm FeSO4 was added to the daily-fed cow dung and poultry litter waste digesters, it increased methanogenesis by 40% and 42%, re spectively, and increased the turnover rate of total solids, volatile solids and volatile fatty acids and the number of methanogens.