Biogas production yield of anaerobic baffledreactor in low pH and HRT

The purpose of this research is to examine the performance of anaerobic baffled reactor (ABR) in two different operational conditions with focus on biogas production. For this purpose, a pilot with 6 compartments, having overall net volume of 60 liters, was used and inoculated continuously with dairy wastewater. After start-up, the average COD removal efficiency of instantaneously. The experimental results show that the COD removal efficiency and biogas production yield were reduced dramatically about 46 and 82%, respectively. As a consequence, theM:C ratio was dramatically decreased to 0.14. It can be concludedthat ABR with 6 compartments is rather a robust technology for dairywastewater treatment and biogas production in low HRTs. However,it seems more susceptible to pH reductions. Therefore, for a wellenergy recovery, it obviously requires an equalization or pretreatmentunit as neutralization82% was achieved for 36 hours hydraulic retention time (HRT). Infirst step, by decreasing HRT to 18 hours, the overall COD removalefficiency and total biogas production yield were reduced 5 and 24%,respectively. Here, the ratio of methane to carbon dioxide content ofbiogas was reduced from 1.6 to about 1.14. In the second step, inHRT of 18 hours, the influent pH was reduced below 6

Keywords:

Anaerobic baffled reactor (ABR) , Biogas , DairyWastewater , hydraulic retention time , pH , Operation