Comparison study of thermophilic and mesophilic anaerobic degradation of POME wastewater - a start-up operation

Abstract

The start-up or acclimatization process of thermophilic and mesophilic anaerobic degradation for palm oil mill effluent (POME) was carried out in the laboratory anaerobic suspended growth closed bioreactor (ASGCB). The start-up for the thermophilic and mesophilic ASGCB involved step increments of the influent organic loading rates (OLR) from 1.78 kg COD/m³/day to 4.33 kg COD/m³/day which corresponds to hydraulic retention time (HRT) from 35 and 15 days. The start-up strategy was based on monitoring a number of process indicators that supplied complimentary information of the anaerobic degradation process. The indicators used for the start-up of both ASGCB were pH, volatile fatty acid, alkalinity and microbial growth.