Journal of Environmental Science and Health Part A Environmental Science and Engineering and Toxicology · 1996 · 35 citations · 23 references
EngineeringChemical EngineeringEnvironmental EngineeringResource RecoveryWaste ManagementWastewater TreatmentAnaerobic DigestionBiogas ProductionOrganic Waste ManagementOrganic Waste RecoveryResource Recovery From WastewaterWaste TreatmentAnaerobic DigestersBiogas GenerationHydraulic Retention TimeMethaneMethane YieldOrganic Loading RateRemoval EfficiencyWastewater Anaerobic Treatment
Abstract A high‐strength palm oil mill effluent was treated using a hybrid anaerobic digester, in which the bottom two‐thirds were occupied by a sludge blanket and the upper one‐third by submerged PVC rings, under mesophilic conditions. The influent COD concentration varied considerably (11.6–65.0 g/1). The digester was subjected to quantitative increases in organic loading rate (OLR) from 3.3 to 18.6 kg COD/m3 day at a set hydraulic retention time (HRT) of 3.5 days. The data showed that the anaerobic digestion process is feasible for the treatment of, and methane generation from, palm oil mill effluent without pretreatment. A COD removal efficiency and methane yield of 92.3% and 0.335 m3/kg CODremoved, respectively, could be achieved at an OLR of 16.2 kg COD/m3 day. The data also showed that the hybrid digester could be maintained at a HRT of 3.5 days with an OLR of 18.6 kg COD/m3 day. This rate is significantly faster than the rates achieved in previously reported studies. Decreasing digester efficiency was basically characterized by accumulation of propionic acid.
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