Single and multichamber fixed film anaerobic reactors for biomethanation of acidic petrochemical wastewater-systems performance

Single and multichamber laboratory scale fixed film anaerobic systems were studied using acidic petrochemical industrial wastewater. A single-phase sy stem column reactor was used and for the biphasic system a special multicha mber reactor was constructed. The effect of operational parameters such as hydraulic retention time (HRT), organic loading rate (OLR) and pH was inves tigated on single and multichamber systems. Using acidic wastewater the mul tichamber system had no advantage over the single-phase system but it was p ossible to have temporal separation of two phases efficiently up to a 4-day HRT, OLR of 20.4 kg COD per m(3) per day and pH of 2.5 using petrochemical wastewater. Significant degradation of aromatic compounds was observed in the acidogenic phase, the pH of which was maintained between 5 and 5.5. Max imum COD reduction of 95 +/- 1.0% and methane yield of 0.37 m(3)/m(3) per d ay at an OLR of 20.4 kg COD per m(3) per day was obtained with the multicha mber reactor by separating the two phases. In the single phase system 95 +/ - 1.0% COD reduction with 0.45 m(3)/m(3) per day methane yield at feed pH o f 2.5, OLR of 21.7 kg COD per m(3) per day and HRT of 2.5 days was obtained . (C) 2001 Elsevier Science Ltd. All rights reserved.