Low-Temperature (10°C) Anaerobic Digestion of Dilute Dairy Wastewater in an EGSB Bioreactor: Microbial Community Structure, Population Dynamics, and Kinetics of Methanogenic Populations
The feasibility of anaerobic digestion of dairy wastewater at 10°C was investigated in a high height？:？diameter ratio EGSB reactor. Stable performance was observed at an applied organic loading rate (OLR) of 0.5–2？kg？COD？m？3？d？1 with chemical oxygen demand (COD) removal efficiencies above 85%. When applied OLR increased to values above 2？kg？COD？m？3？d？1, biotreatment efficiency deteriorated, with methanogenesis being the rate-limiting step. The bioreactor recovered quickly (3 days) after reduction of the OLR. qPCR results showed a reduction in the abundance of hydrogenotrophic methanogenic Methanomicrobiales and Methanobacteriales throughout the steady state period followed by a sharp increase in their numbers (111-fold) after the load shock. Specific methanogenic activity and maximum substrate utilising rate ( ) of the biomass at the end of trial indicated increased activity and preference towards hydrogenotrophic methanogenesis, which correlated well with the increased abundance of hydrogenotrophic methanogens. Acetoclastic Methanosaeta spp. remained at stable levels throughout the trial. However, increased apparent half-saturation constant ( ) at the end of the trial indicated a decrease in the specific substrate affinity for acetate of the sludge, suggesting that Methanosaeta spp., which have high substrate affinity, started to be outcompeted in the reactor. 1. Introduction During the last decades, there has been an increased concern with the environment and the limited energy sources available. In this context, ways to treat wastewaters with energy saving methods need to be developed. Anaerobic digestion (AD) comes forward in this issue because it can treat several types of wastewaters and produce energy in the form of biogas at the same time. In order to improve the energy balance of AD, its application at low temperatures is an interesting option, especially in northern countries, where the temperatures are much lower than the optimum mesophilic temperature range of the process. The application of low-temperature anaerobic digestion (LTAD) at temperatures of 12°C to 15°C has been studied at laboratory- and pilot-scale granular sludge-based bioreactors [1–3]. The possibility of applying the LTAD at 10°C can reduce the operation costs of the plant and improve the energy balance even further. Although LTAD at 10°C has also been studied, to date most studies have examined simple synthetic wastewaters [3]. Up to date there are only few reports describing LTAD of complex (with the presence of particulate compounds) or low-strength recalcitrant
References
[1]
C. M. Bergamo, R. Di Monaco, S. M. Ratusznei, J. A. D. Rodrigues, M. Zaiat, and E. Foresti, “Effects of temperature at different organic loading levels on the performance of a fluidized-bed anaerobic sequencing batch bioreactor,” Chemical Engineering and Processing, vol. 48, no. 3, pp. 789–796, 2009.
[2]
S. McHugh, M. Carton, G. Collins, and V. O'Flaherty, “Reactor performance and microbial community dynamics during anaerobic biological treatment of wastewaters at 16–37°C,” FEMS Microbiology Ecology, vol. 48, no. 3, pp. 369–378, 2004.
[3]
R. M. McKeown, D. Hughes, G. Collins, T. Mahony, and V. O'Flaherty, “Low-temperature anaerobic digestion for wastewater treatment,” Current Opinion in Biotechnology, vol. 23, no. 3, pp. 444–451, 2012.
[4]
M. Takahashi, T. Yamaguchi, Y. Kuramoto et al., “Performance of a pilot-scale sewage treatment: an up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactors combined system by sulfur-redox reaction process under low-temperature conditions,” Bioresource Technology, vol. 102, no. 2, pp. 753–757, 2011.
[5]
A. M. Enright, V. McGrath, D. Gill, G. Collins, and V. O'Flaherty, “Effect of seed sludge and operation conditions on performance and archaeal community structure of low-temperature anaerobic solvent-degrading bioreactors,” Systematic and Applied Microbiology, vol. 32, no. 1, pp. 65–79, 2009.
[6]
B. Demirel, O. Yenigun, and T. T. Onay, “Anaerobic treatment of dairy wastewaters: a review,” Process Biochemistry, vol. 40, no. 8, pp. 2583–2595, 2005.
[7]
J. P. Kushwaha, V. C. Srivastava, and I. D. Mall, “An overview of various technologies for the treatment of dairy wastewaters,” Critical Reviews in Food Science and Nutrition, vol. 51, no. 5, pp. 442–452, 2011.
[8]
C. Lee, J. Kim, K. Hwang, V. O'Flaherty, and S. Hwang, “Quantitative analysis of methanogenic community dynamics in three anaerobic batch digesters treating different wastewaters,” Water Research, vol. 43, no. 1, pp. 157–165, 2009.
[9]
R. M. McKeown, C. Scully, T. Mahony, G. Collins, and V. O'Flaherty, “Long-term (1243 days), low-temperature (4–15°C), anaerobic biotreatment of acidified wastewaters: bioprocess performance and physiological characteristics,” Water Research, vol. 43, no. 6, pp. 1611–1620, 2009.
[10]
K. Bialek, A. Kumar, T. Mahony, P. N. Lens, and V. O'Flaherty, “Microbial community structure and dynamics in anaerobic fluidized-bed and granular sludge-bed reactors: influence of operational temperature and reactor configuration,” Microbial Biotechnology, vol. 5, no. 6, pp. 738–752, 2012.
[11]
K. Bialek, J. Kim, C. Lee, G. Collins, T. Mahony, and V. O'Flaherty, “Quantitative and qualitative analyses of methanogenic community development in high-rate anaerobic bioreactors,” Water Research, vol. 45, no. 3, pp. 1298–1308, 2011.
[12]
D. Cysneiros, C. J. Banks, S. Heaven, and K. A. G. Karatzas, “The role of phase separation and feed cycle length in leach beds coupled to methanogenic reactors for digestion of a solid substrate (Part 2): hydrolysis, acidification and methanogenesis in a two-phase system,” Bioresource Technology, vol. 102, no. 16, pp. 7393–7400, 2011.
[13]
J. D. Coates, M. F. Coughlan, and E. Colleran, “Simple method for the measurement of the hydrogenotrophic methanogenic activity of anaerobic sludges,” Journal of Microbiological Methods, vol. 26, no. 3, pp. 237–246, 1996.
[14]
S. Rebac, S. Gerbens, P. Lens et al., “Kinetics of fatty acid degradation by psychrophilically grown anaerobic granular sludge,” Bioresource Technology, vol. 69, no. 3, pp. 241–248, 1999.
[15]
B. K. Ahring and P. Westermann, “Kinetics of butyrate, acetate, and hydrogen metabolism in a thermophilic, anaerobic, butyrate-degrading triculture,” Applied and Environmental Microbiology, vol. 53, no. 2, pp. 434–439, 1987.
[16]
D. R. Boone, R. W. Castenholz, and G. M. Garrity, Bergey's Manual of Systematic Bacteriology, vol. 1 of The Archaea and the Deeply Branching and Phototrophic Bacteria, 2001.
[17]
D. Cysneiros, A. Thuillier, R. Villemont, A. Littlestone, T. Mahony, and V. O'Flaherty, “Temperature effects on the trophic stages of perennial rye grass anaerobic digestion,” Water Science and Technology, vol. 64, no. 1, pp. 70–76, 2011.
[18]
D. Karakashev, D. J. Batstone, E. Trably, and I. Angelidaki, “Acetate oxidation is the dominant methanogenic pathway from acetate in the absence of Methanosaetaceae,” Applied and Environmental Microbiology, vol. 72, no. 7, pp. 5138–5141, 2006.
[19]
T. Hori, S. Haruta, Y. Ueno, M. Ishii, and Y. Igarashi, “Dynamic transition of a methanogenic population in response to the concentration of volatile fatty acids in a thermophilic anaerobic digester,” Applied and Environmental Microbiology, vol. 72, no. 2, pp. 1623–1630, 2006.
[20]
R. M. McKeown, C. Scully, A. M. Enright et al., “Psychrophilic methanogenic community development during long-term cultivation of anaerobic granular biofilms,” ISME Journal, vol. 3, no. 11, pp. 1231–1242, 2009.
[21]
K. J. Chin, T. Lukow, and R. Conrad, “Effect of temperature on structure and function of the methanogenic archaeal community in an anoxic rice field soil,” Applied and Environmental Microbiology, vol. 65, no. 6, pp. 2341–2349, 1999.
[22]
M. S. M. Jetton, A. J. M. Stams, and A. J. B. Zehnder, “Acetate threshold values and acetate activating enzymes in methanogenic bacteria,” FEMS Microbiology Ecology, vol. 73, no. 4, pp. 339–344, 1990.
[23]
J. B. Van Lier, N. Mahmould, and G. Zeeman, Anaerobic Wastewater Treatment, in Biological Wastewater Treatment, IWA publishing, London, UK, 2008.
[24]
A. Siggins, A. M. Enright, and V. O'Flaherty, “Temperature dependent (37–15°C) anaerobic digestion of a trichloroethylene-contaminated wastewater,” Bioresource Technology, vol. 102, no. 17, pp. 7645–7656, 2011.
[25]
S. Rebac, J. B. Van Lier, P. Lens et al., “Psychrophilic anaerobic treatment of low strength wastewaters,” Water Science and Technology, vol. 39, no. 5, pp. 203–210, 1999.
[26]
S. Rebac, J. Ruskova, S. Gerbens, J. B. Van Lier, A. J. M. Stams, and G. Lettinga, “High-rate anaerobic treatment of wastewater under psychrophilic conditions,” Journal of Fermentation and Bioengineering, vol. 80, no. 5, pp. 499–506, 1995.
[27]
A. Schnürer, G. Zellner, and B. H. Svensson, “Mesophilic syntrophic acetate oxidation during methane formation in biogas reactors,” FEMS Microbiology Ecology, vol. 29, no. 3, pp. 249–261, 1999.
[28]
J. A. Robinson and J. M. Tiedje, “Kinetics of hydrogen consumption by rumen fluid, anaerobic digestor sludge, and sediment,” Applied and Environmental Microbiology, vol. 44, no. 6, pp. 1374–1384, 1982.
[29]
S. D. Allison and J. B. H. Martiny, “Resistance, resilience, and redundancy in microbial communities,” Proceedings of the National Academy of Sciences of the United States of America, vol. 105, no. 1, pp. 11512–11519, 2008.
[30]
J. K. Hardman and T. C. Stadtman, “Metabolism of omega-amino acids. I: fermentation of gamma-aminobutyric acid by Clostridium aminobutyricum n. sp,” Journal of bacteriology, vol. 79, pp. 544–548, 1960.
[31]
J. R. Liu, R. S. Tanner, P. Schumann et al., “Emended description of the genus Trichococcus, description of Trichococcus collinsii sp. nov., and reclassification of Lactosphaera pasteurii as Trichococcus pasteurii comb. nov. and of Ruminococcus palustris as Trichococcus palustris comb. nov. in the low-G+C Gram-positive bacteria,” International Journal of Systematic and Evolutionary Microbiology, vol. 52, no. 4, pp. 1113–1126, 2002.
[32]
H. D. Ariesyady, T. Ito, K. Yoshiguchi, and S. Okabe, “Phylogenetic and functional diversity of propionate-oxidizing bacteria in an anaerobic digester sludge,” Applied Microbiology and Biotechnology, vol. 75, no. 3, pp. 673–683, 2007.
[33]
S. Chen, X. Liu, and X. Dong, “Syntrophobacter sulfatireducens sp. nov., a novel syntrophic, propionate-oxidizing bacterium isolated from UASB reactors,” International Journal of Systematic and Evolutionary Microbiology, vol. 55, no. 3, pp. 1319–1324, 2005.
[34]
E. H. Valdebenito-Rolack, T. C. Araya, L. E. Abarzua et al., “Thiosulphate oxidation by Thiobacillus thioparus and Halothiobacillus neapolitanus strains isolated from the petrochemical industry,” Electronic Journal of Biotechnology, vol. 14, no. 1, 2011.
