Methane Production from Slaughterhouse Waste and Wheat Straw: Influence of Concentration

Abstract

The indiscriminate generation of slaughterhouse waste and agricultural waste can present pollution problems in the environment. An alternative to counteract these problems is the anaerobic digestion of waste through the production of biogas and methane as clean and renewable energy. In this sense, this study aimed to optimize methane production from anaerobic codigestion of slaughterhouse waste from cattle and wheat straw. The treatments were evaluated using anaerobic sludge as inoculum from the wastewater treatment plant of the city of Ibarra. The tests were carried out under mesophilic conditions (38°C) in digesters with a useful volume of 186 ml. The influence of the substrate concentration was evaluated by anaerobically digesting 45 samples at different concentrations (5, 10 and 15 g VS/l) with a substrate/inoculum ratio of 1:2. The highest accumulated methane yield occurred in the digesters composed of 15 g VS/l. The maximum methane production was 320.48 Nml/g VS. The kinetics of the tests were adjusted with the cone model, where there were correlations greater than 99%.


Keywords: biogas, methane, codigestion, synergy, inoculum, kinetics.


Resumen


La generación indiscriminada de residuos de matadero y desechos agrícolas pueden presentar problemas de contaminación en el medio ambiente. Una alternativa para contrarrestar estos problemas es la digestión anaeróbica de los desechos mediante la produción de biogás y metano como energía limpia y renovable. En este sentido el objetivo de este estudio es la optimización de la producción de metano a partir de la codigestión anaeróbica de residuos de matadero de ganado vacuno y paja de trigo. Los tratamientos se evaluaron empleando como inóculo lodo anaerobio de la planta de tratamiento de aguas residuales de la ciudad de Ibarra. Los ensayos se realizaron en condiciones mesofílicas (38°C) en digestores de 186 ml de volumen útil. La influencia de la concentración del sustrato se evaluó digiriendo anaeróbicamente 45 muestras a diferentes concentraciones (5, 10 y 15 g SV/l) con una relación sustrato/inóculo de 1:2. El mayor rendimiento acumulado de metano se produjo en los digestores compuestos por 15 g SV/l. La producción máxima de metano fue de 320,48 Nml/g SV. La cinética de los ensayos se ajustó con el modelo del cono, donde se tuvo correlaciones superiores al 99%.


Palabras Clave: biogás, metano, codigestión, sinergia, inóculo, cinética.

References
[1] Sangodoyin AY, Agbawhe OM. Environmental study on surface and groundwater pollutants from abattoir effluents. Bioresour Technol. 1992;41(3):193–200.

[2] Aguilera ER. Generación de biogás mediante el proceso de digestión anaerobia, a partir del aprovechamiento de sustratos orgánicos. Rev Científica FAREM-Estelí. 2018;24:60-81.

[3] Cabbai V, Ballico M, Aneggi E, Goi D. BMP tests of source selected OFMSW to evaluate anaerobic codigestion with sewage sludge. Waste Manag. 2013;33(7):1626–32.

[4] Banks CJ, Wang Z. Development of a two-phase anaerobic digester for the treatment of mixed abattoir wastes. Water Sci Technol. 1999;40(1):69–76.

[5] Broughton MJ, Thiele JH, Birch EJ, Cohen A. Anaerobic batch digestion of sheep tallow. Water Res. 1998;32(5):1423–8.

[6] Pagés-Díaz J, Pereda-Reyes I, Taherzadeh MJ, Sárvári-Horváth I, Lundin M. Anaerobic co-digestion of solid slaughterhouse wastes with agro-residues: Synergistic and antagonistic interactions determined in batch digestion assays. Chem Eng J. 2014;245:89–98.

[7] Bauer A, Bösch P, Friedl A, Amon T. Analysis of methane potentials of steam-exploded wheat straw and estimation of energy yields of combined ethanol and methane production. J Biotechnol. 2009;142(1):50– 5.

[8] Wang B, Strömberg S, Li C et al. Effects of substrate concentration on methane potential and degradation kinetics in batch anaerobic digestion. Bioresour Technol. 2015;194:240–6.

[9] Angelidaki I, Alves M, Bolzonella D, et al. Defining the biomethane potential (BMP) of solid organic wastes and energy crops: a proposed protocol for batch assays. Water Sci Technol. 2009;59(5):9-27.

[10] Lianhua L, Dong L, Yongming S, Longlong M, Zhenhong Y, Xiaoying K. Effect of temperature and solid concentration on anaerobic digestion of rice straw in South China. Int J Hydrogen Energy. 2010;35(13):7261–6.

[11] Elsayed M, Andres Y, Blel W, Gad A, Ahmed A. Effect of VS organic loads and buckwheat husk on methane production by anaerobic co-digestion of primary sludge and wheat straw. Energy Convers Manag. 2016;117:538–47.

[12] Raposo F, Banks CJ, Siegert I, Heaven S, Borja R. Influence of inoculum to substrate ratio on the biochemical methane potential of maize in batch tests. Process Biochem. 2006;41(6):1444–50.

[13] Wang YT, Suidan MT, Pfeffer JT, Najm I. Effects of some alkyl phenols on methanogenic degradation of phenol. Appl Environ Microbiol. 1988;54(5):1277–1279.

[14] Cuetos MJ, Gómez X, Otero M, Morán A. Anaerobic digestion of solid slaughterhouse waste (SHW) at laboratory scale: Influence of co-digestion with the organic fraction of municipal solid waste (OFMSW). Biochem Eng J. 2008;40(1):99–106.

[15] Bayr S, Rantanen M, Kaparaju P, Rintala J. Mesophilic and thermophilic anaerobic co-digestion of rendering plant and slaughterhouse wastes. Bioresour Technol. 2012;104:28–36.

[16] VDI VDI. 4630: Fermentation of organic materials-Characterisation of the substrate, sampling, collection of material data, fermentation tests. Verein Dtsch Ingenieure (VDI), Ed VDI Handb Energietechnik Berlin Beuth Verlag GmbH. 2006;44–59.

[17] Baquerizo CRJ, Díaz J, Pereda RI. El modelo de Buswell. Aplicación y comparación. Principales factores que influyen en su aplicación. Virtual Pro. 2016;168:1900 6241.

[18] Zahan Z, Othman MZ, Muster TH. Anaerobic digestion/co-digestion kinetic potentials of different agroindustrial wastes: A comparative batch study for C/N optimisation. Waste Manag. 2018;71:663–74.

[19] Li K, Liu R, Sun C. Comparison of anaerobic digestion characteristics and kinetics of four livestock manures with different substrate concentrations. Bioresour Technol. 2015;198:133–40.

[20] Alvarez R, Lidén G. Semi-continuous co-digestion of solid slaughterhouse waste, manure, and fruit and vegetable waste. Renew Energy. 2008;33(4):726–34.

[21] García-Gen S, Sousbie P, Rangaraj G et al. Kinetic modelling of anaerobic hydrolysis of solid wastes, including disintegration processes. Waste Manag. 2015;35:96–104.

[22] Jensen PD, Ge H, Batstone DJ. Assessing the role of biochemical methane potential tests in determining anaerobic degradability rate and extent. Water Sci Technol. 2011;64(4):880–6.

[23] Achinas S, Krooneman J, Euverink GJW. Enhanced biogas production from the anaerobic batch treatment of banana peels. Engineering. 2019;5(5):970–8.

[24] Mao C, Wang X, Xi J, Feng Y, Ren G. Linkage of kinetic parameters with process parameters and operational conditions during anaerobic digestion. Energy. 2017;135:352–60.

[25] Raposo F, Fernández-Cegrí V, De la Rubia MA et al. Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlaboratory study. J Chem Technol Biotechnol. 2011;86(8):1088–98.