Evaluation of the hydrolytic-acidogenic step of a two-stage mesophilic anaerobic digestion process of sunflower oil cake.

The influence of the hydraulic retention time (HRT) and organic loading rate (OLR) on the performance of the hydrolytic-acidogenic step of a two-stage anaerobic digestion process of sunflower oil cake (SuOC) were assessed. The experiments were performed in laboratory-scale completely stirred tank reactors at mesophilic (35 degrees C) temperature. Six OLR (ranging from 4 to 9 g VS L(-1) d(-1)) for four HRTs (8, 10, 12 and 15 days) were tested to check the effect of each operational variable. Based on the results obtained, it can be concluded that the hydrolysis yields obtained for all HRTs and OLRs assayed were in the range of 20.5-30.1%. In addition, the acidification degree of the substrate was mainly influenced by the OLR but not by the HRTs, the highest value (83.8%) being achieved for an HRT of 10 days and an OLR of 6 g VS L(-1) d(-1).

[1]  P. Weiland.  One- and Two-Step Anaerobic Digestion of Solid Agroindustrial Residues , 1993 .

[2]  R. Borja,et al.  Effect of the organic loading rate on the performance of anaerobic acidogenic fermentation of two-phase olive mill solid residue. , 2008, Waste management.

[3]  M. Henze,et al.  Biological hydrolysis and acidification of sludge under anaerobic conditions: the effect of sludge type and origin on the production and composition of volatile fatty acids. , 2008, Water research.

[4]  G. Vidal,et al.  Molecular weight distribution of Pinus radiata kraft mill wastewater treated by anaerobic digestion. , 2001, Bioresource technology.

[5]  P. Elefsiniotis,et al.  Influence of pH on the acid‐phase anaerobic digestion of primary sludge , 1994 .

[6]  F. Cecchi,et al.  Two-phase anaerobic digestion of a mixture of fruit and vegetable wastes , 1989 .

[7]  P. Pavan,et al.  Acidogenic fermentation of source separated mixtures of vegetables and fruits wasted from supermarkets , 2004, Biodegradation.

[8]  R. Dinsdale,et al.  Hydrogen production from sewage sludge using mixed microflora inoculum: effect of pH and enzymatic pretreatment. , 2008, Bioresource technology.

[9]  Göksel N. Demirer,et al.  Two-phase anaerobic digestion of unscreened dairy manure , 2005 .

[10]  F. Cecchi,et al.  Two-phase continuous anaerobic digestion of fruit and vegetable wastes , 1995 .

[11]  Orhan Ince,et al.  Performance of a two-phase anaerobic digestion system when treating dairy wastewater , 1998 .

[12]  J C Huang,et al.  Ethanol-type fermentation from carbohydrate in high rate acidogenic reactor. , 1997, Biotechnology and bioengineering.

[13]  Diego Sales,et al.  The evolution of biomass in a two-phase anaerobic treatment process during start-up , 2002 .

[14]  S. K. Ghosh,et al.  Developments in anaerobic stabilization of organic wastes--the two-phase concept. , 1971, Environmental letters.

[15]  D. Verrier,et al.  Two-phase methanization of solid vegetable wastes , 1987 .

[16]  H. H. Fang,et al.  Acidification of lactose in wastewater , 2001 .

[17]  M. Martín,et al.  Influence of inoculum–substrate ratio on the anaerobic digestion of sunflower oil cake in batch mode: Process stability and kinetic evaluation , 2009 .

[18]  Moktar Hamdi,et al.  Two-phases anaerobic digestion of fruit and vegetable wastes: bioreactors performance , 2004 .

[19]  B. Pietrangeli,et al.  The Acidogenic Digestion of the Organic Fraction of Municipal Solid Waste for the Production of Liquid Fuels , 1993 .

[20]  Karl-Heinz Robra,et al.  Two-stage anaerobic fermentation of organic waste in CSTR and UFAF-reactors. , 2002, Bioresource technology.

[21]  Göksel N. Demirer,et al.  Effect of retention time and organic loading rate on anaerobic acidification and biogasification of dairy manure , 2004 .

[22]  Alastair J Ward,et al.  Optimisation of the anaerobic digestion of agricultural resources. , 2008, Bioresource technology.

[23]  Xavier Font,et al.  Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55 degrees C) of sewage sludge: influence of pH and solid content. , 2008, Water research.

[24]  S. Pavlostathis,et al.  Kinetics of anaerobic treatment: A critical review , 1991 .

[25]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[26]  R. Borja,et al.  Assessment of a modified and optimised method for determining chemical oxygen demand of solid substrates and solutions with high suspended solid content. , 2008, Talanta.

[27]  I. Koster.  Liquefaction and acidogenesis of tomatoes in an anaerobic two-phase solid-waste treatment system , 1984 .

[28]  Masayoshi Kobayashi,et al.  Dynamic behavior in response to pH shift during anaerobic acidogenesis with a chemostat culture , 1999 .

[29]  O. Yenigün,et al.  Anaerobic acidogenesis of dairy wastewater: the effects of variations in hydraulic retention time with no pH control , 2004 .

[30]  Vipin Chandra Kalia,et al.  Biomethanation of plant materials , 1992 .