Anaerobic Digestion of Food Industry Wastes: Effect of Codigestion on Methane Yield

Anaerobic treatability of two different wastes that represent the main refuse streams generated by a frozen food factory (fresh vegetable waste and precooked food waste) was assessed. Moreover, the sludge coming from agro-industrial wastewater treatment was codigested with the previously mentioned wastes. Batch tests were performed at different solids content both on the single wastes and on appropriate mixtures of them (also in order to simulate the seasonality of factory production). Both fresh vegetable and precooked food wastes strongly inhibited methanogenesis from unacclimated inoculum at 10% solids content (undiluted waste) and 5% solids content (eight- to nine-fold diluted waste), respectively. This was due to their high contents of potassium and lipids, respectively. The aerobic sludge from the wastewater treatment plant did not exert inhibitory effect up to 10% solids content (undiluted waste). Codigestion of the fresh vegetable waste and sludge (60 and 40% on wet basis) was more effective both in terms of rate and yield of methane production with respect to the single wastes (due to dilution and synergic effects). On the other hand, methanogenesis remained strongly inhibited from mixtures containing pre-cooked food waste (at 25 and 45%, on wet basis). Methanogenesis inhibition could be overcome by a long acclimation period. The results showed that fill-and-draw digestion in a 0.5 L lab-scale reactor of the fresh vegetable waste and sludge mixture after start up with acclimated inoculum allowed higher methane yields (37% at high organic load and 57% at low organic load). Better results were obtained in a 1.7 L micropilot fill-and-draw reactor (yield of 67%) fed at higher frequency.

[1]  A Tilche,et al.  New perspectives in anaerobic digestion. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.

[2]  Gumersindo Feijoo,et al.  Sodium inhibition in the anaerobic digestion process: Antagonism and adaptation phenomena , 1995 .

[3]  M. E. Clark,et al.  Living with water stress: evolution of osmolyte systems. , 1982, Science.

[4]  S Shioya,et al.  Effects of lactate concentration on hybridoma culture in lactate‐controlled fed‐batch operation , 1992, Biotechnology and bioengineering.

[5]  N Deveci,et al.  A mathematical model for the anaerobic treatment of Baker's yeast effluents. , 2001, Waste management.

[6]  M. Roberts,et al.  Osmoadaptation in Archaea , 1999, Applied and Environmental Microbiology.

[7]  Mustafa Öztürk.  Degradation of acetate, propionate, and butyrate under shock temperature , 1993 .

[8]  August Bonmatí,et al.  Air stripping of ammonia from pig slurry: characterisation and feasibility as a pre- or post-treatment to mesophilic anaerobic digestion. , 2003, Waste Management.

[9]  Brunello Ceccanti,et al.  Anaerobic Digestion of Olive Oil Mill Effluents: Evaluation of Wastewater Organic Load and Phytotoxicity Reduction , 2003 .

[10]  K. Jarrell,et al.  The effects of ionophores and metabolic inhibitors on methanogenesis and energy-related properties of Methanobacterium bryantii. , 1983, Archives of biochemistry and biophysics.

[11]  G. Demirer,et al.  Anaerobic biotransformation and methane generation potential of cheese whey in batch and UASB reactors. , 2001, Waste management.

[12]  M. Majone,et al.  Role of Lipids and Phenolic Compounds in the Anaerobic Treatment of Olive Oil Mill Effluents , 1999 .

[13]  Keisuke Hanaki,et al.  Evaluation of Effectiveness of Two-Phase Anaerobic Digestion Process Degrading Complex Substrate , 1987 .

[14]  S. Sung,et al.  Sodium inhibition of thermophilic methanogens , 2003 .

[15]  I. Dunn,et al.  Modeling dynamic experiments on the anaerobic degradation of molasses wastewater , 1988, Biotechnology and bioengineering.

[16]  H. W. Yu,et al.  Energy recovery from grass using two-phase anaerobic digestion. , 2002, Waste management.

[17]  I. J. Kugelman,et al.  Toxicity, Synergism, and Antagonism in Anaerobic Waste Treatment Processes , 1971 .

[18]  C. Forster,et al.  The anaerobic digestion of a simulated coffee waste using thermophilic and mesophilic upflow filters , 1994 .

[19]  L. Bere,et al.  Anaerobic digestion of solid waste: state-of-the-art , 2000 .

[20]  I. Koster,et al.  Inhibition of Methanogenesis from Acetate in Granular Sludge by Long-Chain Fatty Acids , 1987, Applied and environmental microbiology.

[21]  S. Pavlostathis,et al.  Kinetics of Anaerobic Treatment , 1991 .

[22]  Joan Mata-Álvarez,et al.  Anaerobic digestion of organic solid wastes. An overview of research achievements and perspectives , 2000 .

[23]  E. ten Brummeler,et al.  Full scale experience with the BIOCEL process. , 2000 .

[24]  P. Goodrich,et al.  CARBON-TO-NITROGEN RATIO AND HYDRAULIC RETENTION TIME EFFECT ON THE ANAEROBIC DIGESTION OF CHEESE WHEY. , 1988 .

[25]  F. Smith,et al.  COLORIMETRIC METHOD FOR DETER-MINATION OF SUGAR AND RELATED SUBSTANCE , 1956 .

[26]  B. Ahring,et al.  Effects of free long-chain fatty acids on thermophilic anaerobic digestion , 1992, Applied Microbiology and Biotechnology.

[27]  Keisuke Hanaki,et al.  Prevention of Lipid Inhibition in Anaerobic Processes by Introducing a Two-Phase System , 1991 .

[28]  L. A. Roth,et al.  Effect of sodium chloride on growth and methane production of methanogens. , 1977, Canadian journal of microbiology.