Abstract
In an anaerobic digestor which was fed daily with bovine waste, during the early stages after feeding (4 to 7 h) acetate (via the methyl group) accounted for almost 90% of the methane produced. As time after feeding increased, acetate declined as a precursor so that in the 12- to 14-h and 21- to 23-h periods, after feeding the methyl group accounted for 80 and 73% of the methane produced, respectively. Measurements of methane production from CO2 reduction showed that in the 2- to 12-h period after feeding, CO2 accounted for 14% of the methane produced, whereas in the 12- to 24-h period it accounted for 27-5%. These results show that the percentages of methane accounted for by acetate and CO2 vary with time after feeding the digestor.