Low-strength wastewater treatment using an anaerobic baffled reactor.
A 14.7-L, three-chamber anaerobic baffled reactor (ABR) was used to evaluate the treatment of low-strength synthetic wastewater (chemical oxygen demand [COD] of 300 to 400 mg/L) and assess process reactivation after a prolonged period of inactivity. The reactor was inoculated with anaerobic seed and start-up was immediate. At 26 degrees C and hydraulic retention times (HRTs) of 24 and 12 hours, COD removal averaged 87.2 and 91.0%, respectively, and biogas yield for methane (CH4) was 0.184 and 0.102 m3 CH4/kg COD removed, respectively. The ABR was reactivated after two years without feeding. Response was prompt and removal averaged 85.3% even during the initial 10-day period. Lowering temperature to 16 degrees C did not impair removal efficiency at HRTs of 24 and 12 hours. However, biogas release decreased by 30% and apparent COD conversion to methane dropped by 24 and 31%, respectively. At the end of the study, biomass was mostly in the bottom of the reactor and had moved from the first to the second chamber, while organic stabilization was occurring essentially in the first two chambers (56.1 and 22.4%, respectively, in terms of COD).
Manariotis
loannis D
lD
Department of Civil Engineering, University of Patras, Greece.
Grigoropoulos
Sotirios G
SG
D001421:Bacteria, Anaerobic / Q000502:physiology; D018533:Biomass; D019149:Bioreactors; D005740:Gases; D008697:Methane / Q000032:analysis; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D005740:Gases; D008697:Methane; D010100:Oxygen