semi-continuous anaerobic co-digestion of poultry manure and wheat straw:effect of loading

We studied the effect of loading on anaerobic co-digestion of poultry manure with straw. The mixture of poultry manure and straw has been experimentally evaluated in a complete-mix, lab-scale digester with working volume of 70 l and the effect of loading on the process wasinvestigated at 34°C and HRT of 15 days. Anaerobic co-digestion appeared feasible with a loading rate of 3.0 kgVS/m3.d. At this state, the specific methane yield was calculated about 0.12 m3/kgVS with a methane content in the biogas of 53-70.2% and the VS removal amounted 72%. At a higher or lower loading in the range from 1.0 to 4.0 kgVS/m3.d, the process appeared inhibited and/or overloaded, as resulted by the accumulation of volatile fatty acids with decreasing in pH and decline in the methane yield. The nitrogen in the feed, ca 5.6% of total solids (TS).

کلیدواژه ها:

anaerobic degestion ، biogas ، poultry manure ، straw