Effect of Mixing Time on Anaerobic Co-digestion of Palm Oil Mill Waste and Block Rubber Wastewater

Abstract

This paper aims to study a biogas production of Anaerobic Continuous Stirred Tank Reactor (An-CSTR) using decanter cake from palm oil mill factory with block rubber wastewater as a co-anaerobic digestion. The objective is to study the effect of mixing time for co-digestion on An-CSTR. The best co-digestion mixing ratio from the previous research is used for the continuous An-CSTR processes. Two different values of Hydraulic Retention Times (HRTs) were used in these studies which were 10 and 30 days. Also, two values of mixing time at 12 and 24 hr/day were used. Both parameters were used in the biogas production in this study. The biogas production was observed from all reactors. The results from both reactors of the 10-day-HRT are similar. The results from both reactors of the 30-day- HRT are also similar. Thus, it can be concluded that the 12 and 24 hr/day of mixing time on An-CSTR processes have no significant effect on the biogas production. The biogas production from the 10-day-HRT reactor was higher than that from the 30-day-HRT reactor. The best biogas production performance on An-CSTR process of decanter cake and block rubber wastewater was observed from the reactor with 10-day-HRT and 12 hr/day mixing time. The average methane was 441mL/day.