Comparative performance of a UASB reactor and an anaerobic packed-bed reactor when treating potato waste leachate
Department of Biotechnology, Lund University, Center for Chemistry and Chemical Engineering, P.O. Box 124, SE-221 00 Lund, Sweden; Department of Biochemistry, University of Zimbabwe, P.O. Box MP 167, Mt Pleasant, Harare, Zimbabwe
The results presented in this paper are from studies on a laboratory-scale upflow anaerobic sludge blanket (UASB) reactor and an anaerobic packed-bed (APB) reactor treating potato leachate at increasing organic loading rates from 1.5 to 7.0 g COD/1/day. The hydraulic retention times ranged from 13.2 to 2.8 days for both reactors during the 100 days of the experiment. The maximum organic loading rates possible in the laboratory-scale UASB and APB reactors for stable operation were approximately 6.1 and 4.7 g COD/l day, respectively. The COD removal efficiencies of both reactors were greater than 90% based on the total COD of the effluent. The methane yield increased with increasing organic loading rate up to 0.23 l CH4/g CODdegraded in the UASB reactor and 0.161 CH4/g CODdegraded in the APB reactor. The UASB could be run at a higher organic loading rate than the APB reactor and achieved a higher methane yield. Signs of reactor instability were decreasing partial alkalinity and pH and increasing amounts of volatile fatty acids. The study demonstrated the suitability of the UASB and a packed-bed reactor for treating leachate from potato waste. © 2005 Elsevier Ltd. All rights reserved.
Alkalinity; Anaerobic digestion; Biogas; Effluent treatment; Hydraulics; Leachate treatment; Methane; Packed beds; pH effects; Anaerobic packed-bed; Methane yield; Potato waste; UASB; Chemical reactors; biogas; waste treatment; Alkalinity; Biogas; Chemical Reactors; Effluent Treatment; Hydraulics; Leaching; Methane; Solanum tuberosum