The effect of organic loading rate’s natural variation on the biogas yields from swine manure digestion at different hydraulic retention time

ABSTRACT The study of anaerobic digesters at laboratory focuses on the control of certain parameters that are not so easy to control in the field, which makes it difficult to process scale-up. One example is the Organic Loading Rate. To swine manure, this parameter can change daily due to weather conditions, management practices, feeding and others. In order to verify the impact of this fluctuation on biogas yield, the behavior of a CSTR reactor was analyzed in two different Hydraulic Retention Times (20 and 30 days) for a total period of 180 days. The result demonstrated that the increase of OLR result in a decrease of treatment efficiency as well as biogas yields. The study with HRT of 20 days had a better response to changes in organic load.